docker_container.md

docker_container

The docker_container resource is responsible for managing Docker container actions. It speaks directly to the Docker remote API.

Containers are process oriented and move through an event cycle.

Actions

• :create - Creates the container but does not start it. Useful for Volume containers.
• :start - Starts the container. Useful for containers that run jobs and exit.
• :run - The default action. Both :create and :start the container in one action. Redeploys the container on resource change.
• :run_if_missing - Runs a container only once.
• :stop - Stops the container.
• :restart - Stops and then starts the container.
• :kill - Send a signal to the container process. Defaults to SIGKILL.
• :pause - Pauses the container.
• :unpause - Unpauses the container.
• :delete - Deletes the container.
• :redeploy - Deletes and runs the container.
• :reload - Sends SIGHUP to pid 1 in the container by default. Can be changed with reload_signal.

Properties

Most docker_container properties are the snake_case version of the CamelCase keys found in the Docker Remote Api

Core Properties

• container_name - The name of the container. Defaults to the name of the docker_container resource.
• repo - aka image_name. The first half of a the complete identifier for a Docker Image.
• tag - The second half of a Docker image's identity. Defaults to latest.
• command - The command to run when starting the container.
• working_dir - A string specifying the working directory for commands to run in.
• user - A string value specifying the user inside the container.

Resource Management

• cpus - A float or integer value specifying how much of the available CPU resources a container can use. Available in Docker 1.13 and higher.
• cpu_shares - An integer value containing the CPU Shares for the container.
• memory - Memory limit in bytes.
• memory_swap - Total memory limit (memory + swap); set -1 to disable swap limit (unlimited). Must be used with memory and set larger than memory.
• shm_size - The size of /dev/shm. Format is <number><unit>, where number must be greater than 0. Unit is optional: b (bytes), k (kilobytes), m (megabytes), or g (gigabytes). Default is 64m.

Storage and Volumes

• volumes - An array of volume bindings for this container. Each binding can be:
  • container_path - Creates a new volume for the container
  • host_path:container_path - Bind-mounts a host path into the container
  • host_path:container_path:ro - Makes the bind-mount read-only inside the container
• volumes_from - A list of volumes to inherit from another container. Format: <container name>[:<ro|rw>]
• volume_driver - Driver that this container uses to mount volumes.
• tmpfs - A hash or array of tmpfs mounts to add to the container. Provides temporary filesystem without requiring privileged mode.

Networking

• network_mode - Sets the networking mode for the container. One of:
  • bridge - Default Docker bridge network
  • host - Use the host's network stack inside the container
  • container:<name|id> - Use another container's network stack
  • none - No networking
• network_disabled - Boolean to disable networking. Defaults to false.
• network_aliases - Adds network-scoped alias for the container in form ['alias-1', 'alias-2'].
• hostname - The hostname for the container.
• domain_name - Sets the container's dnsdomainname as returned by the dnsdomainname command.
• dns - An array of DNS servers the container will use for name resolution.
• dns_search - An array of domains the container will search for name resolution.
• mac_address - The mac address for the container to use.
• ip_address - Container IPv4 address (e.g. 172.30.100.104)

Security and Resource Constraints

• privileged - Boolean to start the container in privileged mode. Defaults to false.
• cap_add - An array Linux Capabilities (man 7 capabilities) to add to grant the container beyond what it normally gets.
• cap_drop - An array Linux Capabilities (man 7 capabilities) to revoke that the container normally has.
• security_opt - A list of string values to customize labels for MLS systems, such as SELinux.
• userns_mode - Modify the user namespace mode. Defaults to nil, example option: host
• pid_mode - Set the PID (Process) Namespace mode for the container. host: use the host's PID namespace inside the container.
• ipc_mode - Set the IPC mode for the container. Defaults to nil, example option: host
• uts_mode - Set the UTS namespace mode for the container.
• ro_rootfs - Mount the container's root filesystem as read only. Defaults to false

Logging Properties

• log_driver - The logging driver to use for the container. One of:

  • json-file - Default Docker logging driver that writes JSON messages to file
  • syslog - Syslog logging driver that writes log messages to syslog
  • journald - Journald logging driver that writes log messages to systemd journal
  • gelf - Graylog Extended Log Format (GELF) logging driver
  • fluentd - Fluentd logging driver
  • awslogs - Amazon CloudWatch Logs logging driver
  • splunk - Splunk logging driver
  • etwlogs - ETW logging driver for Windows
  • gcplogs - Google Cloud Logging driver
  • logentries - Logentries logging driver
  • loki-docker - Grafana Loki logging driver
  • none - Disables container logging
  • local - Local file-based logging driver Defaults to json-file.

• log_opts - A hash of key-value pairs to configure the selected log driver. Common options include:

  • For json-file:
    • max-size - Maximum size of the log before it is rolled
    • max-file - Maximum number of log files that can exist
  • For syslog:
    • syslog-address - Address of remote syslog server
    • tag - Tag for syslog messages
  • For other drivers, refer to the Docker logging configuration documentation

GPU Support

• gpus - GPU devices to add to the container. Use 'all' to pass all GPUs.
• gpu_driver - GPU driver to use. Defaults to 'nvidia'.

Examples

Basic Container Creation

docker_container 'hello-world' do
  command '/hello'
  action :create
end

Using tmpfs Mounts

# Using hash format with mount options
docker_container 'tmpfs_test' do
  repo 'nginx'
  tmpfs({
    '/tmpfs1' => '',                           # No options
    '/tmpfs2' => 'size=20M,uid=1000',         # With size and uid options
    '/tmpfs3' => 'rw,noexec,nosuid,size=50M'  # With multiple options
  })
end

# Using array format (all mounts will have default options)
docker_container 'tmpfs_test' do
  repo 'nginx'
  tmpfs ['/tmpfs1', '/tmpfs2']
end

Container with GPU Support

docker_container 'gpu_container' do
  repo 'nvidia/cuda'
  tag 'latest'
  gpus 'all'  # Pass all GPUs to the container
  gpu_driver 'nvidia'  # Use NVIDIA driver
end

Create a container without starting it

docker_container 'hello-world' do
  command '/hello'
  action :create
end

Create a container with tmpfs mounts

# Using hash format with mount options
docker_container 'tmpfs_test' do
  repo 'nginx'
  tmpfs({
    '/tmpfs1' => '',  # No options
    '/tmpfs2' => 'size=100M,uid=1000',  # With size and uid options
    '/tmpfs3' => 'rw,noexec,nosuid,size=200M'  # With multiple options
  })
end

# Using array format (all mounts will have default options)
docker_container 'tmpfs_test' do
  repo 'nginx'
  tmpfs ['/tmpfs1', '/tmpfs2']
end

Run a command on every Chef Infra Client run

This will exit succesfully. It will happen on every chef-client run

docker_container 'busybox_ls' do
  repo 'busybox'
  command 'ls -la /'
  action :run
end

The :run action contains both :create and :start the container in one action. Redeploys the container on resource change. It is the default action

Set environment variables in a container

docker_container 'env' do
  repo 'debian'
  env ['PATH=/usr/bin', 'FOO=bar']
  command 'env'
  action :run
end

docker_container 'env_files' do
  repo 'debian'
  env_file lazy { ['/env_file1', '/env_file2'] }
  command 'env'
  action :run
end

This process remains running between chef-client runs, :run will do nothing on subsequent converges

docker_container 'an_echo_server' do
  repo 'alpine'
  tag '3.1'
  command 'nc -ll -p 7 -e /bin/cat'
  port '7:7'
  action :run
end

Let docker pick the host port

docker_container 'another_echo_server' do
  repo 'alpine'
  tag '3.1'
  command 'nc -ll -p 7 -e /bin/cat'
  port '7'
  action :run
end

Specify the udp protocol

docker_container 'an_udp_echo_server' do
  repo 'alpine'
  tag '3.1'
  command 'nc -ul -p 7 -e /bin/cat'
  port '5007:7/udp'
  action :run
end

Kill a container

docker_container 'bill' do
  action :kill
end

Stop a container

docker_container 'hammer_time' do
  action :stop
end

Force-stop a container after 30 seconds

docker_container 'hammer_time' do
  kill_after 30
  action :stop
end

Pause a container

docker_container 'red_light' do
  action :pause
end

Unpause a container

docker_container 'green_light' do
  action :unpause
end

Restart a container

docker_container 'restarter' do
  action :restart
end

Delete a container

docker_container 'deleteme' do
  remove_volumes true
  action :delete
end

Redeploy a container

docker_container 'redeployer' do
  repo 'alpine'
  tag '3.1'
  command 'nc -ll -p 7777 -e /bin/cat'
  port '7'
  action :run
end

execute 'redeploy redeployer' do
  notifies :redeploy, 'docker_container[redeployer]', :immediately
  action :run
end

Bind mount local directories

docker_container 'bind_mounter' do
  repo 'busybox'
  command 'ls -la /bits /more-bits'
  volumes ['/hostbits:/bits', '/more-hostbits:/more-bits']
  action :run_if_missing
end

Mount volumes from another container

docker_container 'chef_container' do
  command 'true'
  volumes '/opt/chef'
  action :create
end

docker_container 'ohai_debian' do
  command '/opt/chef/embedded/bin/ohai platform'
  repo 'debian'
  volumes_from 'chef_container'
end

Mount a tmpfs at a given directory in the container

docker_container 'tmp_db' do
    command '/bin/run_db.sh'
    tmpfs { '/var/lib/db_data' => 'rw,size=2g' }
    action :run
end

Set a container's entrypoint

docker_container 'ohai_again_debian' do
  repo 'debian'
  volumes_from 'chef_container'
  entrypoint '/opt/chef/embedded/bin/ohai'
  command 'platform'
  action :run_if_missing
end

Automatically remove a container after it exits

docker_container 'sean_was_here' do
  command "touch /opt/chef/sean_was_here-#{Time.new.strftime('%Y%m%d%H%M')}"
  repo 'debian'
  volumes_from 'chef_container'
  autoremove true
  action :run
end

Grant NET_ADMIN rights to a container

docker_container 'cap_add_net_admin' do
  repo 'debian'
  command 'bash -c "ip addr add 10.9.8.7/24 brd + dev eth0 label eth0:0 ; ip addr list"'
  cap_add 'NET_ADMIN'
  action :run_if_missing
end

Revoke MKNOD rights to a container

docker_container 'cap_drop_mknod' do
  repo 'debian'
  command 'bash -c "mknod -m 444 /dev/urandom2 c 1 9 ; ls -la /dev/urandom2"'
  cap_drop 'MKNOD'
  action :run_if_missing
end

Set a container's hostname and domainname

docker_container 'fqdn' do
  repo 'debian'
  command 'hostname -f'
  host_name 'computers'
  domain_name 'biz'
  action :run_if_missing
end

Set a container's DNS resolution

docker_container 'dns' do
  repo 'debian'
  command 'cat /etc/resolv.conf'
  host_name 'computers'
  dns ['4.3.2.1', '1.2.3.4']
  dns_search ['computers.biz', 'chef.io']
  action :run_if_missing
end

Add extra hosts to a container's /etc/hosts

docker_container 'extra_hosts' do
  repo 'debian'
  command 'cat /etc/hosts'
  extra_hosts ['east:4.3.2.1', 'west:1.2.3.4']
  action :run_if_missing
end

Manage container's restart_policy

docker_container 'try_try_again' do
  repo 'alpine'
  tag '3.1'
  command 'grep asdasdasd /etc/passwd'
  restart_policy 'on-failure'
  restart_maximum_retry_count 2
  action :run_if_missing
end

docker_container 'reboot_survivor' do
  repo 'alpine'
  tag '3.1'
  command 'nc -ll -p 123 -e /bin/cat'
  port '123'
  restart_policy 'always'
  action :run_if_missing
end

Manage container links

docker_container 'link_source' do
  repo 'alpine'
  tag '3.1'
  env ['FOO=bar', 'BIZ=baz']
  command 'nc -ll -p 321 -e /bin/cat'
  port '321'
  action :run_if_missing
end

docker_container 'link_target_1' do
  repo 'alpine'
  tag '3.1'
  env ['ASD=asd']
  command 'ping -c 1 hello'
  links ['link_source:hello']
  action :run_if_missing
end

docker_container 'link_target_2' do
  repo 'alpine'
  tag '3.1'
  command 'env'
  links ['link_source:hello']
  action :run_if_missing
end

execute 'redeploy_link_source' do
  command 'touch /marker_container_redeploy_link_source'
  creates '/marker_container_redeploy_link_source'
  notifies :redeploy, 'docker_container[link_source]', :immediately
  notifies :redeploy, 'docker_container[link_target_1]', :immediately
  notifies :redeploy, 'docker_container[link_target_2]', :immediately
  action :run
end

Mutate a container between chef-client runs

docker_tag 'mutator_from_busybox' do
  target_repo 'busybox'
  target_tag 'latest'
  to_repo 'someara/mutator'
  target_tag 'latest'
end

docker_container 'mutator' do
  repo 'someara/mutator'
  tag 'latest'
  command "sh -c 'touch /mutator-`date +\"%Y-%m-%d_%H-%M-%S\"`'"
  outfile '/mutator.tar'
  force true
  action :run_if_missing
end

execute 'commit mutator' do
  command 'true'
  notifies :commit, 'docker_container[mutator]', :immediately
  notifies :export, 'docker_container[mutator]', :immediately
  notifies :redeploy, 'docker_container[mutator]', :immediately
  action :run
end

Specify read/write timeouts

docker_container 'api_timeouts' do
  repo 'alpine'
  read_timeout 60
  write_timeout 60
end

Specify a custom logging driver and its options

docker_container 'syslogger' do
  repo 'alpine'
  tag '3.1'
  command 'nc -ll -p 780 -e /bin/cat'
  log_driver 'syslog'
  log_opts 'tag=container-syslogger'
end

Connect to an external docker daemon and create a container

docker_container 'external_daemon' do
  repo 'alpine'
  host 'tcp://1.2.3.4:2376'
  action :create
end

Run a container with health_check options

docker_container 'health_check' do
  repo 'alpine'
  tag '3.1'
  health_check ({
    "Test" =>
      [
        "string"
      ],
      "Interval" => 0,
      "Timeout" => 0,
      "Retries" => 0,
      "StartPeriod" => 0
  })
  action :run
end

Run a container with a device attached

docker_container 'health_check' do
  repo 'alpine'
  tag '3.1'
  devices [{"PathOnHost" => "/dev/dri", "PathInContainer" => "/dev/dri", "CgroupPermissions" => "rwm"}]
  action :run
end

Run a container with GPU support

# Using default NVIDIA driver
docker_container 'gpu_container' do
  repo 'nvidia/cuda'
  tag 'latest'
  command 'nvidia-smi'
  gpus 'all'
  action :run_if_missing
end

# Using a custom GPU driver
docker_container 'custom_gpu_container' do
  repo 'custom/gpu-image'
  tag 'latest'
  gpus 'all'
  gpu_driver 'custom_driver'
  action :run_if_missing
end

Using json-file driver with size limits

docker_container 'webapp' do
  repo 'nginx'
  log_driver 'json-file'
  log_opts({
    'max-size' => '10m',
    'max-file' => '3'
  })
end

Using syslog driver with remote server

docker_container 'webapp' do
  repo 'nginx'
  log_driver 'syslog'
  log_opts({
    'syslog-address' => 'udp://1.2.3.4:1111',
    'tag' => 'webapp'
  })
end