stevedore is an R package for interacting with docker
from R. With stevedore you can
Almost everything that can be done with the docker command line client (the main exception being that is not possible to send input to a container as if you were on a terminal).
stevedore directly interacts with the docker server over
its HTTP API. This gives a more direct access to docker than going via
the command line.
This vignette quickly walks through the core features of the package.
Because stevedore wraps the docker API directly there are
many more arguments that can be used than are covered here. But this
covers the core use.
The main function in the package is docker_client; this
will construct an object with which we can talk with the docker server.
By default this will look at a number of environment variables and try
to connect to the correct daemon. See ?docker_client for
information on controlling creating the connection.
docker <- stevedore::docker_client()The client object looks a lot like an R6 object (though
it is implemented differently because the interface here is
automatically generated in ways that don’t play nicely with R6). But if
you are at all familiar with R6 objects it should seem quite
familiar.
docker## <docker_client>
## config: Manage docker swarm configs
## container: Work with docker containers
## image: Work with docker images
## network: Work with docker networks
## node: Manage docker swarm nodes
## plugin: Work with docker plugins
## secret: Manage docker swarm secrets
## service: Work with docker services
## swarm: Manage the docker swarm
## task: Work with docker tasks
## volume: Work with docker volumes
## types: Methods for building complex docker types
## api_version()
## connection_info()
## cp(src, dest)
## df()
## events(since = NULL, until = NULL, filters = NULL)
## help(help_type = getOption("help_type"))
## info()
## login(username = NULL, password = NULL, email = NULL,
## serveraddress = NULL)
## ping()
## request(verb, path, query = NULL, body = NULL, headers = NULL,
## stream = NULL)
## version()Each function call (e.g., ping) is callable by accessing
with $, such as
docker$ping()## [1] "OK"
## attr(,"api_version")
## [1] "1.39"
## attr(,"buildkit_version")
## [1] NA
## attr(,"docker_experimental")
## [1] FALSEIn addition there are “collection” objects (e.g.,
container) that are accessed using $, like a
directory structure
docker$container## <docker_container_collection>
## create(image, cmd = NULL, hostname = NULL, domainname = NULL,
## user = NULL, attach_stdin = NULL, attach_stdout = NULL,
## attach_stderr = NULL, ports = NULL, tty = NULL,
## open_stdin = NULL, stdin_once = NULL, env = NULL,
## health_check = NULL, args_escaped = NULL, volumes = NULL,
## working_dir = NULL, entrypoint = NULL, network_disabled = NULL,
## mac_address = NULL, on_build = NULL, labels = NULL,
## stop_signal = NULL, stop_timeout = NULL, shell = NULL,
## host_config = NULL, network = NULL, name = NULL)
## get(id)
## help(help_type = getOption("help_type"))
## list(all = NULL, limit = NULL, size = NULL, filters = NULL)
## prune(filters = NULL)
## remove(id, delete_volumes = NULL, force = NULL, link = NULL)
## run(image, cmd = NULL, ..., detach = FALSE, rm = FALSE,
## stream = stdout(), host_config = NULL)The interface is designed similarly to the command line docker client
(and to the Python docker client), where container commands are within
the container collection and image commands are within the
image collection and so on (the main difference with the
command line client is that the container commands are not at the top
level, so it is docker$container$run(...) not
docker$run(...)).
To run a container, the docker$container$run command
follows the semantics of the command line client and will
res <- docker$container$run("hello-world")## O>
## O> Hello from Docker!
## O> This message shows that your installation appears to be working correctly.
## O>
## O> To generate this message, Docker took the following steps:
## O> 1. The Docker client contacted the Docker daemon.
## O> 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
## O> (amd64)
## O> 3. The Docker daemon created a new container from that image which runs the
## O> executable that produces the output you are currently reading.
## O> 4. The Docker daemon streamed that output to the Docker client, which sent it
## O> to your terminal.
## O>
## O> To try something more ambitious, you can run an Ubuntu container with:
## O> $ docker run -it ubuntu bash
## O>
## O> Share images, automate workflows, and more with a free Docker ID:
## O> https://hub.docker.com/
## O>
## O> For more examples and ideas, visit:
## O> https://docs.docker.com/get-started/
## O>This returns a list with two elements:
names(res)## [1] "container" "logs"The “logs” element is the logs themselves:
res$logs## O>
## O> Hello from Docker!
## O> This message shows that your installation appears to be working correctly.
## O>
## O> To generate this message, Docker took the following steps:
## O> 1. The Docker client contacted the Docker daemon.
## O> 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
## O> (amd64)
## O> 3. The Docker daemon created a new container from that image which runs the
## O> executable that produces the output you are currently reading.
## O> 4. The Docker daemon streamed that output to the Docker client, which sent it
## O> to your terminal.
## O>
## O> To try something more ambitious, you can run an Ubuntu container with:
## O> $ docker run -it ubuntu bash
## O>
## O> Share images, automate workflows, and more with a free Docker ID:
## O> https://hub.docker.com/
## O>
## O> For more examples and ideas, visit:
## O> https://docs.docker.com/get-started/
## O>This is a docker_stream object and codes the output
stream using the stream attribute (it can otherwise be
treated as a character vector).
The “container” element is an object that can be used to interact with a container
res$container## <docker_container>
## commit(repo = NULL, tag = NULL, author = NULL, changes = NULL,
## comment = NULL, pause = NULL, hostname = NULL, domainname = NULL,
## user = NULL, attach_stdin = NULL, attach_stdout = NULL,
## attach_stderr = NULL, exposed_ports = NULL, tty = NULL,
## open_stdin = NULL, stdin_once = NULL, env = NULL, cmd = NULL,
## healthcheck = NULL, args_escaped = NULL, image = NULL,
## volumes = NULL, working_dir = NULL, entrypoint = NULL,
## network_disabled = NULL, mac_address = NULL, on_build = NULL,
## labels = NULL, stop_signal = NULL, stop_timeout = NULL,
## shell = NULL)
## cp_in(src, dest)
## cp_out(src, dest)
## diff()
## exec(cmd, stdin = NULL, stdout = TRUE, stderr = TRUE,
## detach_keys = NULL, tty = NULL, env = NULL, privileged = NULL,
## user = NULL, working_dir = NULL, detach = FALSE,
## stream = stdout())
## exec_create(cmd, stdin = NULL, stdout = TRUE, stderr = TRUE,
## detach_keys = NULL, tty = NULL, env = NULL, privileged = NULL,
## user = NULL, working_dir = NULL)
## export()
## get_archive(path, dest)
## help(help_type = getOption("help_type"))
## id()
## image()
## inspect(reload = TRUE)
## kill(signal = NULL)
## labels(reload = TRUE)
## logs(follow = NULL, stdout = TRUE, stderr = TRUE, since = NULL,
## until = NULL, timestamps = NULL, tail = NULL, stream = stdout())
## name()
## path_stat(path)
## pause()
## ports(reload = TRUE)
## put_archive(src, path, no_overwrite_dir_non_dir = NULL)
## reload()
## remove(delete_volumes = NULL, force = NULL, link = NULL)
## rename(name)
## resize(h = NULL, w = NULL)
## restart(t = NULL)
## start(detach_keys = NULL)
## stats()
## status(reload = TRUE)
## stop(t = NULL)
## top(ps_args = NULL)
## unpause()
## update(cpu_shares = NULL, memory = NULL, cgroup_parent = NULL,
## blkio_weight = NULL, blkio_weight_device = NULL,
## blkio_device_read_bps = NULL, blkio_device_write_bps = NULL,
## blkio_device_read_iops = NULL, blkio_device_write_iops = NULL,
## cpu_period = NULL, cpu_quota = NULL, cpu_realtime_period = NULL,
## cpu_realtime_runtime = NULL, cpuset_cpus = NULL,
## cpuset_mems = NULL, devices = NULL, device_cgroup_rules = NULL,
## disk_quota = NULL, kernel_memory = NULL,
## memory_reservation = NULL, memory_swap = NULL,
## memory_swappiness = NULL, nano_cpus = NULL,
## oom_kill_disable = NULL, init = NULL, pids_limit = NULL,
## ulimits = NULL, cpu_count = NULL, cpu_percent = NULL,
## io_maximum_iops = NULL, io_maximum_bandwidth = NULL,
## restart_policy = NULL)
## wait(condition = NULL)For example the function path_stat gets some information
about paths on the container:
res$container$path_stat("hello")## $name
## [1] "hello"
##
## $size
## [1] 1840
##
## $mode
## [1] 509
##
## $mtime
## [1] "2019-01-01T01:27:56Z"
##
## $linkTarget
## [1] ""The image can also be returned
img <- res$container$image()
img## <docker_image>
## export()
## help(help_type = getOption("help_type"))
## history()
## id()
## inspect(reload = TRUE)
## labels(reload = TRUE)
## name()
## reload()
## remove(force = NULL, noprune = NULL)
## short_id()
## tag(repo, tag = NULL)
## tags(reload = TRUE)
## untag(repo_tag)which is another object with methods that can be invoked to find out about the image, e.g.:
img$history()## id
## 1 sha256:fce289e99eb9bca977dae136fbe2a82b6b7d4c372474c9235adc1741675f587e
## 2 <missing>
## created
## 1 1546306167
## 2 1546306167
## created_by
## 1 /bin/sh -c #(nop) CMD ["/hello"]
## 2 /bin/sh -c #(nop) COPY file:f77490f70ce51da25bd21bfc30cb5e1a24b2b65eb37d4af0c327ddc24f0986a6 in /
## tags size comment
## 1 hello-wo.... 0
## 2 1840The $container object includes methods for interacting
with containers:
docker$container## <docker_container_collection>
## create(image, cmd = NULL, hostname = NULL, domainname = NULL,
## user = NULL, attach_stdin = NULL, attach_stdout = NULL,
## attach_stderr = NULL, ports = NULL, tty = NULL,
## open_stdin = NULL, stdin_once = NULL, env = NULL,
## health_check = NULL, args_escaped = NULL, volumes = NULL,
## working_dir = NULL, entrypoint = NULL, network_disabled = NULL,
## mac_address = NULL, on_build = NULL, labels = NULL,
## stop_signal = NULL, stop_timeout = NULL, shell = NULL,
## host_config = NULL, network = NULL, name = NULL)
## get(id)
## help(help_type = getOption("help_type"))
## list(all = NULL, limit = NULL, size = NULL, filters = NULL)
## prune(filters = NULL)
## remove(id, delete_volumes = NULL, force = NULL, link = NULL)
## run(image, cmd = NULL, ..., detach = FALSE, rm = FALSE,
## stream = stdout(), host_config = NULL)$create creates a new container (similar to
docker container create on the command line) but does not
start it.
x <- docker$container$create("hello-world", name = "hello-stevedore")
x## <docker_container>
## commit(repo = NULL, tag = NULL, author = NULL, changes = NULL,
## comment = NULL, pause = NULL, hostname = NULL, domainname = NULL,
## user = NULL, attach_stdin = NULL, attach_stdout = NULL,
## attach_stderr = NULL, exposed_ports = NULL, tty = NULL,
## open_stdin = NULL, stdin_once = NULL, env = NULL, cmd = NULL,
## healthcheck = NULL, args_escaped = NULL, image = NULL,
## volumes = NULL, working_dir = NULL, entrypoint = NULL,
## network_disabled = NULL, mac_address = NULL, on_build = NULL,
## labels = NULL, stop_signal = NULL, stop_timeout = NULL,
## shell = NULL)
## cp_in(src, dest)
## cp_out(src, dest)
## diff()
## exec(cmd, stdin = NULL, stdout = TRUE, stderr = TRUE,
## detach_keys = NULL, tty = NULL, env = NULL, privileged = NULL,
## user = NULL, working_dir = NULL, detach = FALSE,
## stream = stdout())
## exec_create(cmd, stdin = NULL, stdout = TRUE, stderr = TRUE,
## detach_keys = NULL, tty = NULL, env = NULL, privileged = NULL,
## user = NULL, working_dir = NULL)
## export()
## get_archive(path, dest)
## help(help_type = getOption("help_type"))
## id()
## image()
## inspect(reload = TRUE)
## kill(signal = NULL)
## labels(reload = TRUE)
## logs(follow = NULL, stdout = TRUE, stderr = TRUE, since = NULL,
## until = NULL, timestamps = NULL, tail = NULL, stream = stdout())
## name()
## path_stat(path)
## pause()
## ports(reload = TRUE)
## put_archive(src, path, no_overwrite_dir_non_dir = NULL)
## reload()
## remove(delete_volumes = NULL, force = NULL, link = NULL)
## rename(name)
## resize(h = NULL, w = NULL)
## restart(t = NULL)
## start(detach_keys = NULL)
## stats()
## status(reload = TRUE)
## stop(t = NULL)
## top(ps_args = NULL)
## unpause()
## update(cpu_shares = NULL, memory = NULL, cgroup_parent = NULL,
## blkio_weight = NULL, blkio_weight_device = NULL,
## blkio_device_read_bps = NULL, blkio_device_write_bps = NULL,
## blkio_device_read_iops = NULL, blkio_device_write_iops = NULL,
## cpu_period = NULL, cpu_quota = NULL, cpu_realtime_period = NULL,
## cpu_realtime_runtime = NULL, cpuset_cpus = NULL,
## cpuset_mems = NULL, devices = NULL, device_cgroup_rules = NULL,
## disk_quota = NULL, kernel_memory = NULL,
## memory_reservation = NULL, memory_swap = NULL,
## memory_swappiness = NULL, nano_cpus = NULL,
## oom_kill_disable = NULL, init = NULL, pids_limit = NULL,
## ulimits = NULL, cpu_count = NULL, cpu_percent = NULL,
## io_maximum_iops = NULL, io_maximum_bandwidth = NULL,
## restart_policy = NULL)
## wait(condition = NULL)$get creates a docker_container object from
an container id or name:
y <- docker$container$get("hello-stevedore")
x$id()## [1] "25ba2590b21fac453aec605af5af7f1595d2169e1324254d97f5a08701b59e6c"
y$id()## [1] "25ba2590b21fac453aec605af5af7f1595d2169e1324254d97f5a08701b59e6c"$list() lists containers (like docker list
on the command line) - by default showing only running containers
docker$container$list()## [1] id names image image_id
## [5] command created ports size_rw
## [9] size_root_fs labels state status
## [13] host_config network_settings mounts name
## <0 rows> (or 0-length row.names)
docker$container$list(all = TRUE, limit = 2)## id
## 1 25ba2590b21fac453aec605af5af7f1595d2169e1324254d97f5a08701b59e6c
## 2 e414940048abbea2a66c33fb5191cc881764955ae0b9110ab48ce29cc29ddcce
## names
## 1 hello-st....
## 2 frosty_b....
## image
## 1 hello-world
## 2 sha256:fce289e99eb9bca977dae136fbe2a82b6b7d4c372474c9235adc1741675f587e
## image_id
## 1 sha256:fce289e99eb9bca977dae136fbe2a82b6b7d4c372474c9235adc1741675f587e
## 2 sha256:fce289e99eb9bca977dae136fbe2a82b6b7d4c372474c9235adc1741675f587e
## command created ports size_rw size_root_fs labels state
## 1 /hello 1578823525 characte.... NA NA created
## 2 /hello 1578823523 characte.... NA NA exited
## status host_config network_settings mounts
## 1 Created default list(bri.... characte....
## 2 Exited (0) 1 second ago default list(bri.... characte....
## name
## 1 hello-stevedore
## 2 frosty_banzai$remove() removes a container by name or id:
docker$container$remove("hello-stevedore")## NULL$prune() removes non-running containers (i.e.,
containers that have exited or containers that have been created but not
yet started)
docker$container$prune()## $containers_deleted
## [1] "e414940048abbea2a66c33fb5191cc881764955ae0b9110ab48ce29cc29ddcce"
##
## $space_reclaimed
## [1] 0After creating a container object, there are many more methods to use - all apply to the individual container
x <- docker$container$create("richfitz/iterate", c("1000", "1"))Most are analogues of similarly named docker command
line functions.
First, there are some basic query methods - $id(),
$name() and $labels()
x$id()## [1] "b553018482d2e4119e20c9ccc54fd7a14e6aa7843f630a5266548f31d755211d"
x$name()## [1] "angry_snyder"
x$labels()## stevedore_version
## "0.0.1"More detailed information (much more detailed) can
be retrieved with the $inspect() method
x$inspect()## $id
## [1] "b553018482d2e4119e20c9ccc54fd7a14e6aa7843f630a5266548f31d755211d"
##
## $created
## [1] "2020-01-12T10:05:25.3062459Z"
##
## $path
## [1] "/usr/local/bin/iterate"
##
## $args
## [1] "1000" "1"
##
## $state
## $state$status
## [1] "created"
##
## $state$running
## [1] FALSE
##
## $state$paused
## [1] FALSE
##
## $state$restarting
## [1] FALSE
##
## $state$oom_killed
## [1] FALSE
##
## $state$dead
## [1] FALSE
##
## $state$pid
## [1] 0
##
## $state$exit_code
## [1] 0
##
## $state$error
## [1] ""
##
## $state$started_at
## [1] "0001-01-01T00:00:00Z"
##
## $state$finished_at
## [1] "0001-01-01T00:00:00Z"
##
##
## $image
## [1] "sha256:56b0d98ceb5a402ea61c63ab94a8e7f305cde36e3aa8f080a0b7ab1a8a659e7c"
##
## $resolv_conf_path
## [1] ""
##
## $hostname_path
## [1] ""
##
## $hosts_path
## [1] ""
##
## $log_path
## [1] ""
##
## $node
## NULL
##
## $name
## [1] "/angry_snyder"
##
## $restart_count
## [1] 0
##
## $driver
## [1] "overlay2"
##
## $mount_label
## [1] ""
##
## $process_label
## [1] ""
##
## $app_armor_profile
## [1] ""
##
## $exec_ids
## character(0)
##
## $host_config
## $host_config$cpu_shares
## [1] 0
##
## $host_config$memory
## [1] 0
##
## $host_config$cgroup_parent
## [1] ""
##
## $host_config$blkio_weight
## [1] 0
##
## $host_config$blkio_weight_device
## [1] path weight
## <0 rows> (or 0-length row.names)
##
## $host_config$blkio_device_read_bps
## [1] path rate
## <0 rows> (or 0-length row.names)
##
## $host_config$blkio_device_write_bps
## [1] path rate
## <0 rows> (or 0-length row.names)
##
## $host_config$blkio_device_read_iops
## [1] path rate
## <0 rows> (or 0-length row.names)
##
## $host_config$blkio_device_write_iops
## [1] path rate
## <0 rows> (or 0-length row.names)
##
## $host_config$cpu_period
## [1] 0
##
## $host_config$cpu_quota
## [1] 0
##
## $host_config$cpu_realtime_period
## [1] 0
##
## $host_config$cpu_realtime_runtime
## [1] 0
##
## $host_config$cpuset_cpus
## [1] ""
##
## $host_config$cpuset_mems
## [1] ""
##
## $host_config$devices
## [1] path_on_host path_in_container cgroup_permissions
## <0 rows> (or 0-length row.names)
##
## $host_config$device_cgroup_rules
## character(0)
##
## $host_config$disk_quota
## [1] 0
##
## $host_config$kernel_memory
## [1] 0
##
## $host_config$memory_reservation
## [1] 0
##
## $host_config$memory_swap
## [1] 0
##
## $host_config$memory_swappiness
## [1] NA
##
## $host_config$nano_cpus
## [1] NA
##
## $host_config$oom_kill_disable
## [1] FALSE
##
## $host_config$init
## [1] NA
##
## $host_config$pids_limit
## [1] 0
##
## $host_config$ulimits
## [1] name soft hard
## <0 rows> (or 0-length row.names)
##
## $host_config$cpu_count
## [1] 0
##
## $host_config$cpu_percent
## [1] 0
##
## $host_config$io_maximum_iops
## [1] 0
##
## $host_config$io_maximum_bandwidth
## [1] 0
##
## $host_config$binds
## character(0)
##
## $host_config$container_idfile
## [1] ""
##
## $host_config$log_config
## $host_config$log_config$type
## [1] "json-file"
##
## $host_config$log_config$config
## character(0)
##
##
## $host_config$network_mode
## [1] "default"
##
## $host_config$port_bindings
## NULL
##
## $host_config$restart_policy
## $host_config$restart_policy$name
## [1] ""
##
## $host_config$restart_policy$maximum_retry_count
## [1] 0
##
##
## $host_config$auto_remove
## [1] FALSE
##
## $host_config$volume_driver
## [1] ""
##
## $host_config$volumes_from
## character(0)
##
## $host_config$mounts
## [1] target source type read_only
## [5] consistency bind_options volume_options tmpfs_options
## <0 rows> (or 0-length row.names)
##
## $host_config$cap_add
## character(0)
##
## $host_config$cap_drop
## character(0)
##
## $host_config$dns
## character(0)
##
## $host_config$dns_options
## character(0)
##
## $host_config$dns_search
## character(0)
##
## $host_config$extra_hosts
## character(0)
##
## $host_config$group_add
## character(0)
##
## $host_config$ipc_mode
## [1] "shareable"
##
## $host_config$cgroup
## [1] ""
##
## $host_config$links
## character(0)
##
## $host_config$oom_score_adj
## [1] 0
##
## $host_config$pid_mode
## [1] ""
##
## $host_config$privileged
## [1] FALSE
##
## $host_config$publish_all_ports
## [1] FALSE
##
## $host_config$readonly_rootfs
## [1] FALSE
##
## $host_config$security_opt
## character(0)
##
## $host_config$storage_opt
## NULL
##
## $host_config$tmpfs
## NULL
##
## $host_config$uts_mode
## [1] ""
##
## $host_config$userns_mode
## [1] ""
##
## $host_config$shm_size
## [1] 67108864
##
## $host_config$sysctls
## NULL
##
## $host_config$runtime
## [1] NA
##
## $host_config$console_size
## [1] 0 0
##
## $host_config$isolation
## [1] ""
##
## $host_config$masked_paths
## [1] "/proc/asound" "/proc/acpi" "/proc/kcore"
## [4] "/proc/keys" "/proc/latency_stats" "/proc/timer_list"
## [7] "/proc/timer_stats" "/proc/sched_debug" "/proc/scsi"
## [10] "/sys/firmware"
##
## $host_config$readonly_paths
## [1] "/proc/bus" "/proc/fs" "/proc/irq"
## [4] "/proc/sys" "/proc/sysrq-trigger"
##
##
## $graph_driver
## $graph_driver$name
## [1] "overlay2"
##
## $graph_driver$data
## lower_dir
## "/var/lib/docker/overlay2/2ac2803a954a813a808e9c1d1f63edf0153ef0dbc109d1c12db372dc2c1104d7-init/diff:/var/lib/docker/overlay2/530d1f73dec177ad03a0ee31ad04d0802bf29925cd2eed2b8e5f49258c6824a3/diff:/var/lib/docker/overlay2/e1a21604d525ede2c5e9e6d59ac7dceb33bc7469ad98cc9997477a38c310305c/diff"
## merged_dir
## "/var/lib/docker/overlay2/2ac2803a954a813a808e9c1d1f63edf0153ef0dbc109d1c12db372dc2c1104d7/merged"
## upper_dir
## "/var/lib/docker/overlay2/2ac2803a954a813a808e9c1d1f63edf0153ef0dbc109d1c12db372dc2c1104d7/diff"
## work_dir
## "/var/lib/docker/overlay2/2ac2803a954a813a808e9c1d1f63edf0153ef0dbc109d1c12db372dc2c1104d7/work"
##
##
## $size_rw
## [1] NA
##
## $size_root_fs
## [1] NA
##
## $mounts
## [1] type name source destination driver mode
## [7] rw propagation
## <0 rows> (or 0-length row.names)
##
## $config
## $config$hostname
## [1] "b553018482d2"
##
## $config$domainname
## [1] ""
##
## $config$user
## [1] ""
##
## $config$attach_stdin
## [1] FALSE
##
## $config$attach_stdout
## [1] FALSE
##
## $config$attach_stderr
## [1] FALSE
##
## $config$exposed_ports
## NULL
##
## $config$tty
## [1] FALSE
##
## $config$open_stdin
## [1] FALSE
##
## $config$stdin_once
## [1] FALSE
##
## $config$env
## [1] "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
##
## $config$cmd
## [1] "1000" "1"
##
## $config$healthcheck
## NULL
##
## $config$args_escaped
## [1] NA
##
## $config$image
## [1] "richfitz/iterate"
##
## $config$volumes
## NULL
##
## $config$working_dir
## [1] ""
##
## $config$entrypoint
## [1] "/usr/local/bin/iterate"
##
## $config$network_disabled
## [1] NA
##
## $config$mac_address
## [1] NA
##
## $config$on_build
## character(0)
##
## $config$labels
## stevedore_version
## "0.0.1"
##
## $config$stop_signal
## [1] NA
##
## $config$stop_timeout
## [1] NA
##
## $config$shell
## character(0)
##
##
## $network_settings
## $network_settings$bridge
## [1] ""
##
## $network_settings$sandbox_id
## [1] ""
##
## $network_settings$hairpin_mode
## [1] FALSE
##
## $network_settings$link_local_ipv6_address
## [1] ""
##
## $network_settings$link_local_ipv6_prefix_len
## [1] 0
##
## $network_settings$ports
## list()
##
## $network_settings$sandbox_key
## [1] ""
##
## $network_settings$secondary_ipaddresses
## [1] addr prefix_len
## <0 rows> (or 0-length row.names)
##
## $network_settings$secondary_ipv6_addresses
## [1] addr prefix_len
## <0 rows> (or 0-length row.names)
##
## $network_settings$endpoint_id
## [1] ""
##
## $network_settings$gateway
## [1] ""
##
## $network_settings$global_ipv6_address
## [1] ""
##
## $network_settings$global_ipv6_prefix_len
## [1] 0
##
## $network_settings$ip_address
## [1] ""
##
## $network_settings$ip_prefix_len
## [1] 0
##
## $network_settings$ipv6_gateway
## [1] ""
##
## $network_settings$mac_address
## [1] ""
##
## $network_settings$networks
## $network_settings$networks$bridge
## $network_settings$networks$bridge$ipam_config
## NULL
##
## $network_settings$networks$bridge$links
## character(0)
##
## $network_settings$networks$bridge$aliases
## character(0)
##
## $network_settings$networks$bridge$network_id
## [1] ""
##
## $network_settings$networks$bridge$endpoint_id
## [1] ""
##
## $network_settings$networks$bridge$gateway
## [1] ""
##
## $network_settings$networks$bridge$ip_address
## [1] ""
##
## $network_settings$networks$bridge$ip_prefix_len
## [1] 0
##
## $network_settings$networks$bridge$ipv6_gateway
## [1] ""
##
## $network_settings$networks$bridge$global_ipv6_address
## [1] ""
##
## $network_settings$networks$bridge$global_ipv6_prefix_len
## [1] 0
##
## $network_settings$networks$bridge$mac_address
## [1] ""
##
## $network_settings$networks$bridge$driver_opts
## NULLThe image used by a container can be retrieved with the
$image() method
x$image()## <docker_image>
## export()
## help(help_type = getOption("help_type"))
## history()
## id()
## inspect(reload = TRUE)
## labels(reload = TRUE)
## name()
## reload()
## remove(force = NULL, noprune = NULL)
## short_id()
## tag(repo, tag = NULL)
## tags(reload = TRUE)
## untag(repo_tag)(see below for working with images).
The status of the container (created,
running, exited, paused, etc) can
be read with $status()
x$status()## [1] "created"The container created by by $create is not running - the
$start() method will start it:
x$start()
x$status()## [1] "running"Once the container is running we can query to see what processes are
running in it with $top (standing for Table Of
Processes)
x$top()## PID USER TIME COMMAND
## 1 2918 root 0:00 {iterate} /bin/sh /usr/local/bin/iterate 1000 1
## 2 2953 root 0:00 sleep 1We can also get the logs:
x$logs()## O> Doing 1000 iterations with interval 1
## O> Iteration 1...This returns a special object type docker_stream which
allows control over formatting with format() - the
style argument controls how stderr and stdout are printed.
There is a stream attribute that can be used to separate
out lines too. If a tty was allocated with tty = TRUE the
output will be a plain character vector
format(x$logs(), style = "plain")## [1] "Doing 1000 iterations with interval 1\n"
## [2] "Iteration 1...\n"It can generally be treated as a character vector:
x$logs()[1:2]## [1] "Doing 1000 iterations with interval 1\n"
## [2] "Iteration 1...\n"The $logs() method can be used to do a blocking wait on
a container. Pass follow = TRUE to follow the logs. You
will want to provide a stream argument too, which is where
to stream the log to. This can be stdout() or
stderr(), a file or an R connection.
y <- docker$container$create("richfitz/iterate", c("10", "0.1"))
y$start()
y$logs(stream = stdout(), follow = TRUE)## O> Doing 10 iterations with interval 0.1
## O> Iteration 1...
## O> Iteration 2...
## O> Iteration 3...
## O> Iteration 4...
## O> Iteration 5...
## O> Iteration 6...
## O> Iteration 7...
## O> Iteration 8...
## O> Iteration 9...
## O> Iteration 10...
## O> Done!If running this interactively, the logs will print one line at a time - once control returns to R the container has exited. You can escape this streaming using whatever method you use to interrupt an R calculation (depends on which GUI/IDE you are using) but the container will continue regardless - we are just observing a running container.
y$status()## [1] "exited"The other way of blocking until a container has finished is with
$wait() which blocks until the container exits, then
returns the exit code.
y$start()
y$wait()## $exit_code
## [1] 0Calling $wait() on an exited container is fine, and will
just return immediately:
y$wait()## $exit_code
## [1] 0Containers can be paused with $pause()
x$pause()## NULL
x$status()## [1] "paused"Once paused, they can be restarted with $unpause()
x$unpause()## NULL
x$status()## [1] "running"Additionally, containers can be restarted with
$restart()
x$restart(t = 0)## NULL
x$logs(tail = 5)## O> Iteration 4...
## O> Iteration 5...
## O> Iteration 6...
## O> Doing 1000 iterations with interval 1
## O> Iteration 1...Containers can be stopped with $stop() and removed with
$remove() (calling $remove(force = TRUE) will
kill the container before removing.
x$stop(t = 0)## NULL
x$remove()## NULLOnce a container has been removed most methods will not work properly:
x$status()## Error: No such container: b553018482d2e4119e20c9ccc54fd7a14e6aa7843f630a5266548f31d755211dInformation about ports (for containers that expose them) can be
retrieved with $ports(). The nginx image
creates a web server/proxy that exposes port 80 from the container. We
can map that to a random port by asking docker to expose port 80 but not
saying what to map it to:
nginx <- docker$container$run("nginx", ports = 80,
detach = TRUE, rm = TRUE,
name = "stevedore-nginx")
nginx$ports()## container_port protocol host_ip host_port
## 1 80 tcp 0.0.0.0 32768(alternatively, use ports = TRUE to act like
docker run’s -P and “publish all ports to
random ports).
This shows that the port exposed by the the container (80) is mapped to the port 32768 on the host. We can use this to communicate with the server:
url <- sprintf("http://localhost:%s", nginx$ports()$host_port)
curl::parse_headers(curl::curl_fetch_memory(url)$headers)## [1] "HTTP/1.1 200 OK"
## [2] "Server: nginx/1.17.7"
## [3] "Date: Sun, 12 Jan 2020 10:05:34 GMT"
## [4] "Content-Type: text/html"
## [5] "Content-Length: 612"
## [6] "Last-Modified: Tue, 24 Dec 2019 13:07:53 GMT"
## [7] "Connection: keep-alive"
## [8] "ETag: \"5e020da9-264\""
## [9] "Accept-Ranges: bytes"
nginx$stop(t = 0)## NULLexec
With the command-line tool,
docker exec <container name> <command> lets you
run an arbitrary command within a running container.
stevedore does this with the exec method of a
container object.
Reasons for doing this include debugging (using arbitrary commands to inspect/interact with a container while it does its primary task) but it can also be used in deployment (e.g., sending a “go” signal after copying files into the container).
To demonstrate, we need a long running container:
x <- docker$container$run("richfitz/iterate", c("1000", "10"),
detach = TRUE, rm = TRUE)
x$status()## [1] "running"With the container running we can run additional commands:
res <- x$exec("ls")## O> bin
## O> dev
## O> etc
## O> home
## O> lib
## O> media
## O> mnt
## O> opt
## O> proc
## O> root
## O> run
## O> sbin
## O> srv
## O> sys
## O> tmp
## O> usr
## O> varThis streams the output of the command by default (to the connection
indicated by the stream) argument. Output is also returned
as part of the object:
res## $id
## [1] "62e5e653b88bda606b07b286bd27ca8d0b653e3000e76004463b609974722d0e"
##
## $exit_code
## [1] 0
##
## $details
## $details$can_remove
## [1] FALSE
##
## $details$detach_keys
## [1] ""
##
## $details$id
## [1] "62e5e653b88bda606b07b286bd27ca8d0b653e3000e76004463b609974722d0e"
##
## $details$running
## [1] FALSE
##
## $details$exit_code
## [1] 0
##
## $details$process_config
## $details$process_config$privileged
## [1] FALSE
##
## $details$process_config$user
## [1] NA
##
## $details$process_config$tty
## [1] FALSE
##
## $details$process_config$entrypoint
## [1] "ls"
##
## $details$process_config$arguments
## character(0)
##
##
## $details$open_stdin
## [1] FALSE
##
## $details$open_stderr
## [1] TRUE
##
## $details$open_stdout
## [1] TRUE
##
## $details$container_id
## [1] "9317cd764a3c2648de3d284ea084466afc1512fba48625233498ee1dc9754da2"
##
## $details$pid
## [1] 3673
##
##
## $output
## O> bin
## O> dev
## O> etc
## O> home
## O> lib
## O> media
## O> mnt
## O> opt
## O> proc
## O> root
## O> run
## O> sbin
## O> srv
## O> sys
## O> tmp
## O> usr
## O> varJust like docker cp, stevedore lets you
copy files into and out of containers. The logic mimics the logic in the
docker command line client as closely as possible.
To copy a file into our container x, use
$cp_in
path <- tempfile()
writeLines("hello", path)
x$cp_in(path, "/hello")And the new file is on the container
x$exec(c("cat", "/hello"), stream = FALSE)$output## O> helloThe input can be a single file or a single directory.
To copy out, use $cp_out
dest <- tempfile()
x$cp_out("/usr/local/bin/iterate", dest)Here is the iterate script, from the container:
writeLines(readLines(dest, n = 10))## #!/bin/sh
## set -e
##
## if [ "$#" -ge 1 ]; then
## TIMES=$1
## else
## TIMES=10
## fi
##
## if [ "$#" -ge 2 ]; thenThere is also a convenience method at the root of the docker object
that behaves more like docker cp and requires that one of
the source or destination arguments is given in
<container>:<path> format:
src <- paste0(x$name(), ":/usr/local/bin/iterate")
src## [1] "sad_ptolemy:/usr/local/bin/iterate"as
dest2 <- tempfile()
docker$cp(src, dest2)which achieves the same thing as the $cp_out command
above.
## [1] "87bea4544cfd716dbab5030deb873b62" "87bea4544cfd716dbab5030deb873b62"(don’t forget to remove your detached containers later!)
x$kill()## NULLImages can be directly pulled with docker$image$pull
providing an image name (as either <repo> or
<repo>:<tag>. If the image exists already this
will be quick, and if the network connection is down then this will
fail.
docker$image$pull("bash:latest")## Pulling from library/bash latest
## Already exists 89d9c30c1d48
## Pulling fs layer 1cd014c0f09d
## Pulling fs layer fed606654955
## 1cd014c0f09d: Downloading 31.87 kB/3.17 MB 1%
## fed606654955: Downloading 340 B/340 B 100%
## Verifying Checksum fed606654955
## Download complete fed606654955
## 1cd014c0f09d: Downloading 228.48 kB/3.17 MB 7%
## 1cd014c0f09d: Downloading 588.92 kB/3.17 MB 19%
## 1cd014c0f09d: Downloading 1.08 MB/3.17 MB 34%
## 1cd014c0f09d: Downloading 1.41 MB/3.17 MB 44%
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## 1cd014c0f09d: Downloading 2.08 MB/3.17 MB 65%
## 1cd014c0f09d: Downloading 2.42 MB/3.17 MB 76%
## 1cd014c0f09d: Downloading 2.75 MB/3.17 MB 87%
## 1cd014c0f09d: Downloading 3.07 MB/3.17 MB 97%
## Verifying Checksum 1cd014c0f09d
## Download complete 1cd014c0f09d
## 1cd014c0f09d: Extracting 32.77 kB/3.17 MB 1%
## 1cd014c0f09d: Extracting 262.14 kB/3.17 MB 8%
## 1cd014c0f09d: Extracting 2.16 MB/3.17 MB 68%
## 1cd014c0f09d: Extracting 2.98 MB/3.17 MB 94%
## 1cd014c0f09d: Extracting 3.05 MB/3.17 MB 96%
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## 1cd014c0f09d: Extracting 3.17 MB/3.17 MB 100%
## Pull complete 1cd014c0f09d
## fed606654955: Extracting 340 B/340 B 100%
## fed606654955: Extracting 340 B/340 B 100%
## Pull complete fed606654955
## Digest: sha256:293ac2e5c5be7722d6f4aa620c6451aea359eec1f2f6d5c0faef948b86e449cd
## Status: Downloaded newer image for bash:latest## <docker_image>
## export()
## help(help_type = getOption("help_type"))
## history()
## id()
## inspect(reload = TRUE)
## labels(reload = TRUE)
## name()
## reload()
## remove(force = NULL, noprune = NULL)
## short_id()
## tag(repo, tag = NULL)
## tags(reload = TRUE)
## untag(repo_tag)The other common way of getting images is to build them (the
equivalent of docker build). So if we have a path (here,
iterate) containing a Dockerfile:
dir("iterate")## [1] "Dockerfile" "iterate"The Dockerfile itself contains:
FROM alpine:latest
COPY iterate /usr/local/bin/iterate
CMD chmod +x /usr/local/bin/iterate
LABEL stevedore_version 0.0.1
ENTRYPOINT ["/usr/local/bin/iterate"]and the iterate file is an executable shell script
containing:
#!/bin/sh
set -e
if [ "$#" -ge 1 ]; then
TIMES=$1
else
TIMES=10
fi
if [ "$#" -ge 2 ]; then
INTERVAL=$2
else
INTERVAL=1
fi
echo "Doing $TIMES iterations with interval $INTERVAL"
i=0
while [ $i -lt $TIMES ]; do
let i+=1
echo "Iteration $i..."
sleep $INTERVAL
done
echo "Done!"We can build this image using:
img <- docker$image$build("iterate", tag = "richfitz/iterate", nocache = TRUE)## Step 1/5 : FROM alpine:latest
## ---> cc0abc535e36
## Step 2/5 : COPY iterate /usr/local/bin/iterate
## ---> bfead14674a0
## Step 3/5 : CMD chmod +x /usr/local/bin/iterate
## ---> Running in 3ffd8d1225b8
## Removing intermediate container 3ffd8d1225b8
## ---> d5b6a0eaa685
## Step 4/5 : LABEL stevedore_version 0.0.1
## ---> Running in c150ea2a1f95
## Removing intermediate container c150ea2a1f95
## ---> 346745e9ebc8
## Step 5/5 : ENTRYPOINT ["/usr/local/bin/iterate"]
## ---> Running in a17b554ff885
## Removing intermediate container a17b554ff885
## ---> 244154bfbb99
## Successfully built 244154bfbb99
## Successfully tagged richfitz/iterate:latest
img## <docker_image>
## export()
## help(help_type = getOption("help_type"))
## history()
## id()
## inspect(reload = TRUE)
## labels(reload = TRUE)
## name()
## reload()
## remove(force = NULL, noprune = NULL)
## short_id()
## tag(repo, tag = NULL)
## tags(reload = TRUE)
## untag(repo_tag)The newly created image is returned as an image object and can be
used via $container$run()
## O> Doing 10 iterations with interval 0.1
## O> Iteration 1...
## O> Iteration 2...
## O> Iteration 3...
## O> Iteration 4...
## O> Iteration 5...
## O> Iteration 6...
## O> Iteration 7...
## O> Iteration 8...
## O> Iteration 9...
## O> Iteration 10...
## O> Done!There is a third way of creating an image, which is to import it from
a tar archive. This is not yet documented (TODO) but
can be done via $image$import()
Each image object has a number of methods.
img <- docker$image$get("richfitz/iterate")
img## <docker_image>
## export()
## help(help_type = getOption("help_type"))
## history()
## id()
## inspect(reload = TRUE)
## labels(reload = TRUE)
## name()
## reload()
## remove(force = NULL, noprune = NULL)
## short_id()
## tag(repo, tag = NULL)
## tags(reload = TRUE)
## untag(repo_tag)The $id(), $short_id(),
$labels(), $name() and $tags()
query basic information about an image
img$id()## [1] "sha256:244154bfbb9995fc3c5fede726ec4c2679ba393375f2a8130ffd8537dcce3285"
img$short_id()## [1] "sha256:244154bfbb"
img$labels()## stevedore_version
## "0.0.1"
img$name()## [1] "richfitz/iterate"
img$tags()## [1] "richfitz/iterate:latest"(short_idis always 10 characters long and does not include a leadingsha256:`).
The inspect() method returns detailed information about
the image
img$inspect()## $id
## [1] "sha256:244154bfbb9995fc3c5fede726ec4c2679ba393375f2a8130ffd8537dcce3285"
##
## $repo_tags
## [1] "richfitz/iterate:latest"
##
## $repo_digests
## character(0)
##
## $parent
## [1] "sha256:346745e9ebc8af6b623cdf5729ceddfd215e33d7886a7e72e71beba46d9bceca"
##
## $comment
## [1] ""
##
## $created
## [1] "2020-01-12T10:05:44.4499183Z"
##
## $container
## [1] "a17b554ff885999f2bd26d6716e358fea4d3e01194986dca3c0e6c4b57c095db"
##
## $container_config
## $container_config$hostname
## [1] "a17b554ff885"
##
## $container_config$domainname
## [1] ""
##
## $container_config$user
## [1] ""
##
## $container_config$attach_stdin
## [1] FALSE
##
## $container_config$attach_stdout
## [1] FALSE
##
## $container_config$attach_stderr
## [1] FALSE
##
## $container_config$exposed_ports
## NULL
##
## $container_config$tty
## [1] FALSE
##
## $container_config$open_stdin
## [1] FALSE
##
## $container_config$stdin_once
## [1] FALSE
##
## $container_config$env
## [1] "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
##
## $container_config$cmd
## [1] "/bin/sh"
## [2] "-c"
## [3] "#(nop) "
## [4] "ENTRYPOINT [\"/usr/local/bin/iterate\"]"
##
## $container_config$healthcheck
## NULL
##
## $container_config$args_escaped
## [1] TRUE
##
## $container_config$image
## [1] "sha256:346745e9ebc8af6b623cdf5729ceddfd215e33d7886a7e72e71beba46d9bceca"
##
## $container_config$volumes
## NULL
##
## $container_config$working_dir
## [1] ""
##
## $container_config$entrypoint
## [1] "/usr/local/bin/iterate"
##
## $container_config$network_disabled
## [1] NA
##
## $container_config$mac_address
## [1] NA
##
## $container_config$on_build
## character(0)
##
## $container_config$labels
## stevedore_version
## "0.0.1"
##
## $container_config$stop_signal
## [1] NA
##
## $container_config$stop_timeout
## [1] NA
##
## $container_config$shell
## character(0)
##
##
## $docker_version
## [1] "18.09.2"
##
## $author
## [1] ""
##
## $config
## $config$hostname
## [1] ""
##
## $config$domainname
## [1] ""
##
## $config$user
## [1] ""
##
## $config$attach_stdin
## [1] FALSE
##
## $config$attach_stdout
## [1] FALSE
##
## $config$attach_stderr
## [1] FALSE
##
## $config$exposed_ports
## NULL
##
## $config$tty
## [1] FALSE
##
## $config$open_stdin
## [1] FALSE
##
## $config$stdin_once
## [1] FALSE
##
## $config$env
## [1] "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
##
## $config$cmd
## [1] "/bin/sh" "-c"
## [3] "chmod +x /usr/local/bin/iterate"
##
## $config$healthcheck
## NULL
##
## $config$args_escaped
## [1] TRUE
##
## $config$image
## [1] "sha256:346745e9ebc8af6b623cdf5729ceddfd215e33d7886a7e72e71beba46d9bceca"
##
## $config$volumes
## NULL
##
## $config$working_dir
## [1] ""
##
## $config$entrypoint
## [1] "/usr/local/bin/iterate"
##
## $config$network_disabled
## [1] NA
##
## $config$mac_address
## [1] NA
##
## $config$on_build
## character(0)
##
## $config$labels
## stevedore_version
## "0.0.1"
##
## $config$stop_signal
## [1] NA
##
## $config$stop_timeout
## [1] NA
##
## $config$shell
## character(0)
##
##
## $architecture
## [1] "amd64"
##
## $os
## [1] "linux"
##
## $os_version
## [1] NA
##
## $size
## [1] 5591606
##
## $virtual_size
## [1] 5591606
##
## $graph_driver
## $graph_driver$name
## [1] "overlay2"
##
## $graph_driver$data
## lower_dir
## "/var/lib/docker/overlay2/e1a21604d525ede2c5e9e6d59ac7dceb33bc7469ad98cc9997477a38c310305c/diff"
## merged_dir
## "/var/lib/docker/overlay2/934d66f90f6c661634b1618ea61d7f0b87149631cb4715059b862e18c27eac1f/merged"
## upper_dir
## "/var/lib/docker/overlay2/934d66f90f6c661634b1618ea61d7f0b87149631cb4715059b862e18c27eac1f/diff"
## work_dir
## "/var/lib/docker/overlay2/934d66f90f6c661634b1618ea61d7f0b87149631cb4715059b862e18c27eac1f/work"
##
##
## $root_fs
## $root_fs$type
## [1] "layers"
##
## $root_fs$layers
## [1] "sha256:6b27de954cca6332272e7709b7d8ceccee1489d9452af73391df360a26123580"
## [2] "sha256:14794d0f3100e41f9a96e1d181db26e010ae56489b484f0abcc782dcfc438de5"
##
## $root_fs$base_layer
## [1] NA
##
##
## $metadata
## $metadata$last_tag_time
## [1] "2020-01-12T10:05:44.5147212Z"the exact format varies between docker API versions but should be the same for all images within an API version.
The history() method returns a data.frame of information
about the history of an image (i.e., the layers that it is constructed
from)
img$history()## id
## 1 sha256:244154bfbb9995fc3c5fede726ec4c2679ba393375f2a8130ffd8537dcce3285
## 2 sha256:346745e9ebc8af6b623cdf5729ceddfd215e33d7886a7e72e71beba46d9bceca
## 3 sha256:d5b6a0eaa685450861afb86bc00f05762bba84284ad2b36b252893f4c0972bb4
## 4 sha256:bfead14674a0cf29a4cb48ee5b11d006b7451ddd098086bc3866ded70821cd8d
## 5 sha256:cc0abc535e36a7ede71978ba2bbd8159b8a5420b91f2fbc520cdf5f673640a34
## 6 <missing>
## created
## 1 1578823544
## 2 1578823544
## 3 1578823543
## 4 1578823543
## 5 1577215212
## 6 1577215212
## created_by
## 1 /bin/sh -c #(nop) ENTRYPOINT ["/usr/local/bin/iterate"]
## 2 /bin/sh -c #(nop) LABEL stevedore_version=0.0.1
## 3 /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "chmod +x /usr/local/bin/iterate"]
## 4 /bin/sh -c #(nop) COPY file:8b8ba7864a94787016cc3c519efd97a1c7dde8a1b64fec3d078096872b2ece4c in /usr/local/bin/iterate
## 5 /bin/sh -c #(nop) CMD ["/bin/sh"]
## 6 /bin/sh -c #(nop) ADD file:36fdc8cb08228a87093fb227736f4ce1d4d6c15366326dea541fbbd863976ee5 in /
## tags size comment
## 1 richfitz.... 0
## 2 0
## 3 0
## 4 306
## 5 alpine:l.... 0
## 6 5591300(printing these objects is a real challenge!).
The export() method exports an image as a tar object.
There is some work still required to make this work nicely (currently it
returns a [potentially long] raw vector).
There are several methods that operate to modify or destroy the image:
The $tag() method will tag an image, for example
img$tag("richfitz/iterate", "0.0.1")
img$reload()
img$tags()## [1] "richfitz/iterate:0.0.1" "richfitz/iterate:latest"While the $untag() method will remove a tag
img$untag("richfitz/iterate:0.0.1")The $remove() method will remove an image - this returns
a data.frame indicating what actually happened (images are only actually
deleted if there are no other tags pointing at an image and if
noprune is not TRUE.
img$remove()## untagged
## 1 richfitz/iterate:latest
## 2 <NA>
## 3 <NA>
## 4 <NA>
## 5 <NA>
## 6 <NA>
## deleted
## 1 <NA>
## 2 sha256:244154bfbb9995fc3c5fede726ec4c2679ba393375f2a8130ffd8537dcce3285
## 3 sha256:346745e9ebc8af6b623cdf5729ceddfd215e33d7886a7e72e71beba46d9bceca
## 4 sha256:d5b6a0eaa685450861afb86bc00f05762bba84284ad2b36b252893f4c0972bb4
## 5 sha256:bfead14674a0cf29a4cb48ee5b11d006b7451ddd098086bc3866ded70821cd8d
## 6 sha256:ce1557b8602d2427fb71296d2c6ab9b05103d830cdf2eb5d45cdfe25c3ed11ddDocker volumes provide a useful abstraction for interacting with
(possibly persistent) file volumes across containers. To create a volume
using stevedore (equivalent to
docker volume create) use
$volume$create():
vol <- docker$volume$create("myvolume")Volumes can be listed:
docker$volume$list()## name driver
## 1 myvolume local
## 2 dc5d8f843c0fefd3e0c6a729e7326fe262c94aa50a49065448d7ef664c53a285 local
## mountpoint
## 1 /var/lib/docker/volumes/myvolume/_data
## 2 /var/lib/docker/volumes/dc5d8f843c0fefd3e0c6a729e7326fe262c94aa50a49065448d7ef664c53a285/_data
## created_at status labels scope options usage_data
## 1 2020-01-12T10:05:47Z local NA, NA
## 2 2019-12-23T08:27:51Z local NA, NAThere’s very little that can be done with volume objects:
vol## <docker_volume>
## help(help_type = getOption("help_type"))
## inspect(reload = TRUE)
## map(path, readonly = FALSE)
## name()
## reload()
## remove(force = NULL)We can get the name:
vol$name()## [1] "myvolume"Inspect the metadata
vol$inspect()## $name
## [1] "myvolume"
##
## $driver
## [1] "local"
##
## $mountpoint
## [1] "/var/lib/docker/volumes/myvolume/_data"
##
## $created_at
## [1] "2020-01-12T10:05:47Z"
##
## $status
## NULL
##
## $labels
## NULL
##
## $scope
## [1] "local"
##
## $options
## NULL
##
## $usage_data
## NULLGenerate mount definitions:
vol$map("/comtainer/path")## [1] "myvolume:/comtainer/path"and can remove the volume
vol$remove()## NULLeverything else comes from using volumes with containers.
Containers are mounted the same way as from the docker command line -
with a string in the form <host>:<container>.
Here we can use the volume name on the host side, so saying
<myvolume>:/myvolume mounts our volume at
/myvolume within the container. This can be done easily
with the $map() method.
vol <- docker$volume$create("myvolume")
docker$container$run(
"alpine:latest",
c("sh", "-c", "echo hello world > /myvolume/output"),
volumes = vol$map("/myvolume"),
rm = TRUE)## <docker_run_output>
## $container:
## <docker_container>
## id: 946dbe3f449dd8433847f1517af6106385ff1d31ed755f671ee10a732e31ac65
## name: determined_easley
##
## $logs:
##(We use sh -c here so that the redirect operates within
the container - the third argument is evaluated by the shell within the
container and redirects the value that is echoed to a file.)
We can see the result of this by using a second container to read the file:
docker$container$run(
"alpine:latest",
c("cat", "/myvolume/output"),
volumes = vol$map("/myvolume"),
rm = TRUE)$logs## O> hello world## O> hello worldDocker “networks” make it easy to get containers communicating with each other without exposing ports to the host. To achive this, one creates a docker network, then create containers attached to that network (containers can also be attached to networks after creation).
nw <- docker$network$create("mynetwork")Networks can be listed:
docker$network$list()## name
## 1 host
## 2 mynetwork
## 3 none
## 4 bridge
## id
## 1 d5a076bd27b8f3a0963da06b5c149e6e7ab63ebe5649e124fdf8a22602b215c2
## 2 05492a54216e3b100caa82959b714897dd10dd0292ae82f730328c2d6d29b1bb
## 3 80bf98ad0e7fac320903a891936aa9680462769b37168e38b483c7ff9612bb2c
## 4 8b98e06edb0adb42f306a3d86d2f4f3d62b7a9d15279d7c44d37908c120df1ac
## created scope driver enable_ipv6 ipam
## 1 2019-03-09T11:06:26.652857909Z local host FALSE default,....
## 2 2020-01-12T10:05:50.1991445Z local bridge FALSE default,....
## 3 2019-03-09T11:06:26.606552055Z local null FALSE default,....
## 4 2020-01-10T06:57:36.297181373Z local bridge FALSE default,....
## internal attachable ingress containers options labels
## 1 FALSE FALSE FALSE
## 2 FALSE FALSE FALSE
## 3 FALSE FALSE FALSE
## 4 FALSE FALSE FALSE true, tr....The networks bridge, host and
none always exist - they are special to docker.
Like volume objects, network objects do very little themselves:
nw## <docker_network>
## connect(container = NULL, endpoint_config = NULL)
## containers(reload = TRUE)
## disconnect(container = NULL, force = NULL)
## help(help_type = getOption("help_type"))
## id()
## inspect(reload = TRUE)
## name(reload = TRUE)
## reload()
## remove()The $name() and $id() methods get the name
and id of the network
nw$name()## [1] "mynetwork"
nw$id()## [1] "05492a54216e3b100caa82959b714897dd10dd0292ae82f730328c2d6d29b1bb"$inspect() gets detailed metadata
nw$inspect()## $name
## [1] "mynetwork"
##
## $id
## [1] "05492a54216e3b100caa82959b714897dd10dd0292ae82f730328c2d6d29b1bb"
##
## $created
## [1] "2020-01-12T10:05:50.1991445Z"
##
## $scope
## [1] "local"
##
## $driver
## [1] "bridge"
##
## $enable_ipv6
## [1] FALSE
##
## $ipam
## $ipam$driver
## [1] "default"
##
## $ipam$config
## $ipam$config[[1]]
## subnet gateway
## "172.18.0.0/16" "172.18.0.1"
##
##
## $ipam$options
## list()
##
##
## $internal
## [1] FALSE
##
## $attachable
## [1] FALSE
##
## $ingress
## [1] FALSE
##
## $containers
## list()
##
## $options
## character(0)
##
## $labels
## character(0)$containers() lists containers attached to the network
(currently an empty list - this network has no attached containers)
nw$containers()## list()$remove() removes the network
nw$remove()## NULLGenerally you’ll want to put containers onto a network.
The setup here is to create a network, and then use the
network argument to $container$run() to attach
a container to that network. Once established, containers on the same
network can use another docker container’s name as the hostname and
communicate!
nw <- docker$network$create("mynetwork")
server <- docker$container$run("nginx", network = nw, name = "server",
detach = TRUE, rm = TRUE)
server$status()## [1] "running"Now we can attach other networks to this container and communicate with the server:
docker$container$run("alpine:latest", c("ping", "server", "-c", "3"),
network = nw, stream = stdout(), rm = TRUE)## O> PING server (172.19.0.2): 56 data bytes
## O> 64 bytes from 172.19.0.2: seq=0 ttl=64 time=0.099 ms
## O> 64 bytes from 172.19.0.2: seq=1 ttl=64 time=0.208 ms
## O> 64 bytes from 172.19.0.2: seq=2 ttl=64 time=0.228 ms
## O>
## O> --- server ping statistics ---
## O> 3 packets transmitted, 3 packets received, 0% packet loss
## O> round-trip min/avg/max = 0.099/0.178/0.228 ms## <docker_run_output>
## $container:
## <docker_container>
## id: 36ee5c4501190e86eac95a52284cbfd69a22fe74d95088773f41627e3dc57c93
## name: agitated_pasteur
##
## $logs:
## O> PING server (172.19.0.2): 56 data bytes
## O> 64 bytes from 172.19.0.2: seq=0 ttl=64 time=0.099 ms
## O> 64 bytes from 172.19.0.2: seq=1 ttl=64 time=0.208 ms
## O> 64 bytes from 172.19.0.2: seq=2 ttl=64 time=0.228 ms
## O>
## O> --- server ping statistics ---
## O> 3 packets transmitted, 3 packets received, 0% packet loss
## O> round-trip min/avg/max = 0.099/0.178/0.228 msOmitting the network argument, the second container
can’t find the server:
## E> ping: bad address 'server'## Error: Command 'ping server -c 3' in image 'alpine:latest' returned non-zero exit status 1
## ping: bad address 'server'The server container exposes a webserver on port 80. For containers on the network we can access this port:
res <- docker$container$run("richfitz/curl", c("curl", "-s", "http://server"),
network = nw, rm = TRUE)## O> <!DOCTYPE html>
## O> <html>
## O> <head>
## O> <title>Welcome to nginx!</title>
## O> <style>
## O> body {
## O> width: 35em;
## O> margin: 0 auto;
## O> font-family: Tahoma, Verdana, Arial, sans-serif;
## O> }
## O> </style>
## O> </head>
## O> <body>
## O> <h1>Welcome to nginx!</h1>
## O> <p>If you see this page, the nginx web server is successfully installed and
## O> working. Further configuration is required.</p>
## O>
## O> <p>For online documentation and support please refer to
## O> <a href="http://nginx.org/">nginx.org</a>.<br/>
## O> Commercial support is available at
## O> <a href="http://nginx.com/">nginx.com</a>.</p>
## O>
## O> <p><em>Thank you for using nginx.</em></p>
## O> </body>
## O> </html>
head(res$logs, 10)## [1] "<!DOCTYPE html>\n"
## [2] "<html>\n"
## [3] "<head>\n"
## [4] "<title>Welcome to nginx!</title>\n"
## [5] "<style>\n"
## [6] " body {\n"
## [7] " width: 35em;\n"
## [8] " margin: 0 auto;\n"
## [9] " font-family: Tahoma, Verdana, Arial, sans-serif;\n"
## [10] " }\n"
server$stop()## NULL
nw$remove()## NULLThere are a few functions at the top level of the
docker_client object:
$ping() tests the connection to the server and reports
the API version for the server - this is a (for docker) very fast
function to use to test that things seem to be working.
docker$ping()## [1] "OK"
## attr(,"api_version")
## [1] "1.39"
## attr(,"buildkit_version")
## [1] NA
## attr(,"docker_experimental")
## [1] FALSE$api_version() reports the API version that the
client is using (this can be varied from 1.25 to 1.39)
docker$api_version()## [1] "1.39"$version() reports detailed version information from the
server:
docker$version()## $platform
## $platform$name
## [1] "Docker Engine - Community"
##
##
## $components
## name version details
## 1 Engine 18.09.2 1.39, am....
##
## $version
## [1] "18.09.2"
##
## $api_version
## [1] "1.39"
##
## $min_api_version
## [1] "1.12"
##
## $git_commit
## [1] "6247962"
##
## $go_version
## [1] "go1.10.6"
##
## $os
## [1] "linux"
##
## $arch
## [1] "amd64"
##
## $kernel_version
## [1] "4.9.125-linuxkit"
##
## $experimental
## [1] NA
##
## $build_time
## [1] "2019-02-10T04:13:06.000000000+00:00"$info() reports a bunch of other information about the
state of the server (Docker describes this as “get system information”
in its documentation) - this is equivalent to running
docker info
docker$info()## $id
## [1] "54B2:VUDF:CFVG:KTXY:5ZI6:S7NK:LQNM:7CFA:X6TH:5PRV:SUFC:ZDK4"
##
## $containers
## [1] 0
##
## $containers_running
## [1] 0
##
## $containers_paused
## [1] 0
##
## $containers_stopped
## [1] 0
##
## $images
## [1] 73
##
## $driver
## [1] "overlay2"
##
## $driver_status
## $driver_status[[1]]
## [1] "Backing Filesystem" "extfs"
##
## $driver_status[[2]]
## [1] "Supports d_type" "true"
##
## $driver_status[[3]]
## [1] "Native Overlay Diff" "true"
##
##
## $docker_root_dir
## [1] "/var/lib/docker"
##
## $system_status
## list()
##
## $plugins
## $plugins$volume
## [1] "local"
##
## $plugins$network
## [1] "bridge" "host" "macvlan" "null" "overlay"
##
## $plugins$authorization
## character(0)
##
## $plugins$log
## [1] "awslogs" "fluentd" "gcplogs" "gelf" "journald"
## [6] "json-file" "local" "logentries" "splunk" "syslog"
##
##
## $memory_limit
## [1] TRUE
##
## $swap_limit
## [1] TRUE
##
## $kernel_memory
## [1] TRUE
##
## $cpu_cfs_period
## [1] TRUE
##
## $cpu_cfs_quota
## [1] TRUE
##
## $cpu_shares
## [1] TRUE
##
## $cpu_set
## [1] TRUE
##
## $oom_kill_disable
## [1] TRUE
##
## $ipv4_forwarding
## [1] TRUE
##
## $bridge_nf_iptables
## [1] TRUE
##
## $bridge_nf_ip6tables
## [1] TRUE
##
## $debug
## [1] TRUE
##
## $n_fd
## [1] 26
##
## $n_goroutines
## [1] 53
##
## $system_time
## [1] "2020-01-12T10:06:01.1253405Z"
##
## $logging_driver
## [1] "json-file"
##
## $cgroup_driver
## [1] "cgroupfs"
##
## $n_events_listener
## [1] 2
##
## $kernel_version
## [1] "4.9.125-linuxkit"
##
## $operating_system
## [1] "Docker for Mac"
##
## $os_type
## [1] "linux"
##
## $architecture
## [1] "x86_64"
##
## $n_cpu
## [1] 2
##
## $mem_total
## [1] 2096164864
##
## $index_server_address
## [1] "https://index.docker.io/v1/"
##
## $registry_config
## $registry_config$allow_nondistributable_artifacts_cidrs
## character(0)
##
## $registry_config$allow_nondistributable_artifacts_hostnames
## character(0)
##
## $registry_config$insecure_registry_cidrs
## [1] "127.0.0.0/8"
##
## $registry_config$index_configs
## $registry_config$index_configs$docker.io
## $registry_config$index_configs$docker.io$name
## [1] "docker.io"
##
## $registry_config$index_configs$docker.io$mirrors
## character(0)
##
## $registry_config$index_configs$docker.io$secure
## [1] TRUE
##
## $registry_config$index_configs$docker.io$official
## [1] TRUE
##
##
##
## $registry_config$mirrors
## character(0)
##
##
## $generic_resources
## [1] named_resource_spec discrete_resource_spec
## <0 rows> (or 0-length row.names)
##
## $http_proxy
## [1] "gateway.docker.internal:3128"
##
## $https_proxy
## [1] "gateway.docker.internal:3129"
##
## $no_proxy
## [1] ""
##
## $name
## [1] "linuxkit-025000000001"
##
## $labels
## character(0)
##
## $experimental_build
## [1] FALSE
##
## $server_version
## [1] "18.09.2"
##
## $cluster_store
## [1] ""
##
## $cluster_advertise
## [1] ""
##
## $runtimes
## $runtimes$runc
## $runtimes$runc$path
## [1] "runc"
##
## $runtimes$runc$runtime_args
## character(0)
##
##
##
## $default_runtime
## [1] "runc"
##
## $swarm
## $swarm$node_id
## [1] ""
##
## $swarm$node_addr
## [1] ""
##
## $swarm$local_node_state
## [1] "inactive"
##
## $swarm$control_available
## [1] FALSE
##
## $swarm$error
## [1] ""
##
## $swarm$remote_managers
## [1] node_id addr
## <0 rows> (or 0-length row.names)
##
## $swarm$nodes
## [1] NA
##
## $swarm$managers
## [1] NA
##
## $swarm$cluster
## NULL
##
##
## $live_restore_enabled
## [1] FALSE
##
## $isolation
## [1] ""
##
## $init_binary
## [1] "docker-init"
##
## $containerd_commit
## $containerd_commit$id
## [1] "9754871865f7fe2f4e74d43e2fc7ccd237edcbce"
##
## $containerd_commit$expected
## [1] "9754871865f7fe2f4e74d43e2fc7ccd237edcbce"
##
##
## $runc_commit
## $runc_commit$id
## [1] "09c8266bf2fcf9519a651b04ae54c967b9ab86ec"
##
## $runc_commit$expected
## [1] "09c8266bf2fcf9519a651b04ae54c967b9ab86ec"
##
##
## $init_commit
## $init_commit$id
## [1] "fec3683"
##
## $init_commit$expected
## [1] "fec3683"
##
##
## $security_options
## [1] "name=seccomp,profile=default"
##
## $product_license
## [1] "Community Engine"
##
## $warnings
## character(0)Finally, $df() will return information about resource
and data usage by docker - all containers, networks, volumes, etc.