wp-docker-buildx/DOCS.md

Use the Docker plugin to build and push Docker images to a public or even a private registry.

Config

The following parameters are used to configure the plugin:

• registry - authenticates to this registry
• username - authenticates with this username
• password - authenticates with this password
• email - authenticates with this email
• repo - repository name for the image
• tag, tags - repository tags for the image
• dockerfile - dockerfile to be used, defaults to Dockerfile
• context - the context path to use, defaults to root of the git repo
• insecure - enable insecure communication to this registry
• mirror - use a mirror registry instead of pulling images directly from the central Hub
• bip - use for pass bridge ip
• dns - set custom dns servers for the container
• storage_driver - use aufs, devicemapper, btrfs or overlay driver
• storage_path - location of docker daemon storage on disk
• build_args - build arguments to pass to docker build
• mtu - custom mtu settings when starting the docker daemon

The following secret values can be set to configure the plugin.

• DOCKER_REGISTRY - corresponds to registry
• DOCKER_USERNAME - corresponds to username
• DOCKER_PASSWORD - corresponds to password
• DOCKER_EMAIL - corresponds to email

It is highly recommended to put the DOCKER_USERNAME, DOCKER_PASSWORD and DOCKER_EMAIL into secrets so it is not exposed to users. This can be done using the drone-cli.

drone secret add --image=plugins/docker \
    octocat/hello-world DOCKER_USERNAME kevinbacon

drone secret add --image=plugins/docker \
    octocat/hello-world DOCKER_PASSWORD pa55word

drone secret add --image=plugins/docker \
    octocat/hello-world DOCKER_EMAIL kevin.bacon@mail.com

Then sign the YAML file after all secrets are added.

drone sign octocat/hello-world

See secrets for additional information on secrets

Examples

Simple publishing of a docker container:

pipeline:
  docker:
    image: plugins/docker
    username: kevinbacon
    password: pa55word
    email: kevin.bacon@mail.com
    repo: foo/bar
    tag: latest
    dockerfile: Dockerfile
    insecure: false

Publish an image with multiple tags:

pipeline:
  docker:
    image: plugins/docker
    username: kevinbacon
    password: pa55word
    email: kevin.bacon@mail.com
    repo: foo/bar
    tags:
      - latest
      - 1.0.1
      - "1.0"

Build an image with additional arguments:

pipeline:
  docker:
    image: plugins/docker
    username: kevinbacon
    password: pa55word
    email: kevin.bacon@mail.com
    repo: foo/bar
    build_args:
      - HTTP_PROXY=http://yourproxy.com

Using a custom registry

Please note that when using a custom registry (other than DockerHub) you will need to provide the registry URL and you will need to use a fully qualified repository name. For example:

pipeline:
  docker:
    image: plugins/docker
    registry: http://registry.company.com
    repo: registry.company.com/my/image

Caching

The Drone build environment is, by default, ephemeral meaning that you layers are not saved between builds. There are two methods for caching your layers.

Graph directory caching

This is the preferred method when using the overlay or aufs storage drivers. Just use Drone's caching feature to backup and restore the directory /drone/docker, as shown in the following example:

pipeline:
  sftp_cache:
    image: plugins/sftp-cache
    restore: true
    mount: /drone/docker

  docker:
    image: plugins/docker
    storage_path: /drone/docker
    username: kevinbacon
    password: pa55word
    email: kevin.bacon@mail.com
    repo: foo/bar
    tags:
      - latest
      - "1.0.1"

  sftp_cache:
    image: plugins/sftp-cache
    rebuild: true
    mount: /drone/docker

Troubleshooting

For detailed output you can set the DOCKER_LAUNCH_DEBUG environment variable in your plugin configuration. This starts Docker with verbose logging enabled.

pipeline:
  docker:
    environment:
      - DOCKER_LAUNCH_DEBUG=true

Known Issues

There are known issues when attempting to run this plugin on CentOS, RedHat, and Linux installations that do not have a supported storage driver installed. You can check by running docker info | grep 'Storage Driver:' on your host machine. If the storage driver is not aufs or overlay you will need to re-configure your host machine.

This error occurs when trying to use the default aufs storage Driver but aufs is not installed:

level=fatal msg="Error starting daemon: error initializing graphdriver: driver not supported

This error occurs when trying to use the overlay storage Driver but overlay is not installed:

level=error msg="'overlay' not found as a supported filesystem on this host.
Please ensure kernel is new enough and has overlay support loaded."
level=fatal msg="Error starting daemon: error initializing graphdriver: driver not supported"

This error occurs when using CentOS or RedHat which default to the devicemapper storage driver:

level=error msg="There are no more loopback devices available."
level=fatal msg="Error starting daemon: error initializing graphdriver: loopback mounting failed"
Cannot connect to the Docker daemon. Is 'docker -d' running on this host?

The above issue can be resolved by setting storage_driver: vfs in the .drone.yml file. This may work, but will have very poor performance as discussed here.

This error occurs when using Debian wheezy or jessie and cgroups memory features are not configured at the kernel level:

time="2015-12-17T08:06:57Z" level=debug msg="Mounting none /sys/fs/cgroup/blkio cgroup blkio"
time="2015-12-17T08:06:57Z" level=debug msg="Mounting none /sys/fs/cgroup/perf_event cgroup perf_event"
time="2015-12-17T08:06:57Z" level=debug msg="Mounting none /sys/fs/cgroup/cpuset cgroup cpuset"
time="2015-12-17T08:06:57Z" level=debug msg="Mounting none /sys/fs/cgroup/cpu,cpuacct cgroup cpu,cpuacct"
time="2015-12-17T08:06:57Z" level=debug msg="Creating /sys/fs/cgroup/memory"
time="2015-12-17T08:06:57Z" level=debug msg="Mounting none /sys/fs/cgroup/memory cgroup memory"
time="2015-12-17T08:06:57Z" level=fatal msg="no such file or directory"

The above issue can be resolved by editing your grub.cfg and adding cgroup_enable=memory swapaccount=1 to you kernel image. This change should look like that afterwards:

menuentry 'Debian GNU/Linux, avec Linux 3.16.0-0.bpo.4-amd64' --class debian --class gnu-linux --class gnu --class os {
        load_video
        insmod gzio
        insmod raid
        insmod mdraid09
        insmod part_msdos
        insmod part_msdos
        insmod part_msdos
        insmod ext2
        set root='(mduuid/dab6cffad124a3d7a4d2adc226fd5302)'
        search --no-floppy --fs-uuid --set=root a4085974-c507-4993-a9ed-bdc17e375cad
        echo    'Chargement de Linux 3.16.0-0.bpo.4-amd64 ...'
        linux   /boot/vmlinuz-3.16.0-0.bpo.4-amd64 root=/dev/md1 ro  cgroup_enable=memory swapaccount=1 quiet
        echo    'Chargement du disque mémoire initial ...'
        initrd  /boot/initrd.img-3.16.0-0.bpo.4-amd64