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