Cookbook

Rich FitzJohn

2020-01-12

This vignette contains short snippets of stevedore calls to perform simple tasks, alongside a docker command line equivalent.

Conventions:

• We assume that a stevedore docker client object has been created with docker <- stevedore::docker_client() (to avoid repetition in examples)
• All docker command line examples start with $ to represent the unix/bash prompt

docker <- stevedore::docker_client()

Start a container with ports published to the host

With docker cli:

$ docker run --rm -p 8888:80 gplates/gws

the -p 8888:80 publishes port 80 in the container to port 8888 on the host.

In stevedore, this can be done with:

gws <- docker$container$run("gplates/gws", ports = "8888:80",
                            detach = TRUE, rm = TRUE)
gws$ports()

##   container_port protocol host_ip host_port
## 1             80      tcp 0.0.0.0      8888

To use a random port, omit the host portion (here 8888:) as

$ docker run --rm -p 80 gplates/gws

or, with stevedore

gws <- docker$container$run("gplates/gws", ports = 80,
                            detach = TRUE, rm = TRUE)

To determine the port you can use the ports() method

gws$ports()

##   container_port protocol host_ip host_port
## 1             80      tcp 0.0.0.0     32771

If the container declares its exposed ports using an EXPOSE <port> directive in the Dockerfile then you can automatically publish all declared ports to random host ports with -P as

$ docker run --rm -P gplates/gws

or with stevedore by using ports = TRUE

gws <- docker$container$run("gplates/gws", ports = TRUE, detach = TRUE)
gws$ports()

##   container_port protocol host_ip host_port
## 1             80      tcp 0.0.0.0     32772

As contributed by Brian O’Meara in #44