community.docker.docker_containers inventory – Ansible dynamic inventory plugin for Docker containers.

Note

This inventory plugin is part of the community.docker collection (version 2.7.1).

You might already have this collection installed if you are using the ansible package. It is not included in ansible-core. To check whether it is installed, run ansible-galaxy collection list.

To install it, use: ansible-galaxy collection install community.docker.

To use it in a playbook, specify: community.docker.docker_containers.

New in version 1.1.0: of community.docker

Synopsis

  • Reads inventories from the Docker API.

  • Uses a YAML configuration file that ends with docker.[yml|yaml].

Requirements

The below requirements are needed on the local controller node that executes this inventory.

  • Docker SDK for Python: Please note that the docker-py Python module has been superseded by docker (see here for details). For Python 2.6, docker-py must be used. Otherwise, it is recommended to install the docker Python module. Note that both modules should not be installed at the same time. Also note that when both modules are installed and one of them is uninstalled, the other might no longer function and a reinstall of it is required.

  • Docker SDK for Python >= 1.10.0

Parameters

Parameter

Comments

add_legacy_groups

boolean

Add the same groups as the docker inventory script does. These are the following:

<container id>: contains the container of this ID.

<container name>: contains the container that has this name.

<container short id>: contains the containers that have this short ID (first 13 letters of ID).

image_<image name>: contains the containers that have the image <image name>.

stack_<stack name>: contains the containers that belong to the stack <stack name>.

service_<service name>: contains the containers that belong to the service <service name>

<docker_host>: contains the containers which belong to the Docker daemon docker_host. Useful if you run this plugin against multiple Docker daemons.

running: contains all containers that are running.

stopped: contains all containers that are not running.

If this is not set to true, you should use keyed groups to add the containers to groups. See the examples for how to do that.

Choices:

  • no ← (default)

  • yes

api_version

aliases: docker_api_version

string

The version of the Docker API running on the Docker Host.

Defaults to the latest version of the API supported by Docker SDK for Python and the docker daemon.

If the value is not specified in the task, the value of environment variable DOCKER_API_VERSION will be used instead. If the environment variable is not set, the default value will be used.

Default: “auto”

ca_cert

aliases: tls_ca_cert, cacert_path

path

Use a CA certificate when performing server verification by providing the path to a CA certificate file.

If the value is not specified in the task and the environment variable DOCKER_CERT_PATH is set, the file ca.pem from the directory specified in the environment variable DOCKER_CERT_PATH will be used.

client_cert

aliases: tls_client_cert, cert_path

path

Path to the client’s TLS certificate file.

If the value is not specified in the task and the environment variable DOCKER_CERT_PATH is set, the file cert.pem from the directory specified in the environment variable DOCKER_CERT_PATH will be used.

client_key

aliases: tls_client_key, key_path

path

Path to the client’s TLS key file.

If the value is not specified in the task and the environment variable DOCKER_CERT_PATH is set, the file key.pem from the directory specified in the environment variable DOCKER_CERT_PATH will be used.

compose

dictionary

Create vars from jinja2 expressions.

Default: {}

configure_docker_daemon

boolean

added in 1.8.0 of community.docker

Whether to pass all Docker daemon configuration from the inventory plugin to the connection plugin.

Only used when connection_type=docker-api.

Choices:

  • no

  • yes ← (default)

connection_type

string

Which connection type to use the containers.

One way to connect to containers is to use SSH (ssh). For this, the options default_ip and private_ssh_port are used. This requires that a SSH daemon is running inside the containers.

Alternatively, docker-cli selects the docker connection plugin, and docker-api (default) selects the docker_api connection plugin.

When docker-api is used, all Docker daemon configuration values are passed from the inventory plugin to the connection plugin. This can be controlled with configure_docker_daemon.

Choices:

  • ssh

  • docker-cli

  • docker-api ← (default)

debug

boolean

Debug mode

Choices:

  • no ← (default)

  • yes

default_ip

string

The IP address to assign to ansible_host when the container’s SSH port is mapped to interface ‘0.0.0.0’.

Only used if connection_type is ssh.

Default: “127.0.0.1”

docker_host

aliases: docker_url

string

The URL or Unix socket path used to connect to the Docker API. To connect to a remote host, provide the TCP connection string. For example, tcp://192.0.2.23:2376. If TLS is used to encrypt the connection, the module will automatically replace tcp in the connection URL with https.

If the value is not specified in the task, the value of environment variable DOCKER_HOST will be used instead. If the environment variable is not set, the default value will be used.

Default: “unix://var/run/docker.sock”

groups

dictionary

Add hosts to group based on Jinja2 conditionals.

Default: {}

keyed_groups

list / elements=dictionary

Add hosts to group based on the values of a variable.

Default: []

default_value

string

added in 2.12 of ansible.builtin

The default value when the host variable’s value is an empty string.

This option is mutually exclusive with trailing_separator.

key

string

The key from input dictionary used to generate groups

parent_group

string

parent group for keyed group

prefix

string

A keyed group name will start with this prefix

Default: “”

separator

string

separator used to build the keyed group name

Default: “_”

trailing_separator

boolean

added in 2.12 of ansible.builtin

Set this option to False to omit the separator after the host variable when the value is an empty string.

This option is mutually exclusive with default_value.

Choices:

  • no

  • yes ← (default)

leading_separator

boolean

added in 2.11 of ansible.builtin

Use in conjunction with keyed_groups.

By default, a keyed group that does not have a prefix or a separator provided will have a name that starts with an underscore.

This is because the default prefix is “” and the default separator is “_”.

Set this option to False to omit the leading underscore (or other separator) if no prefix is given.

If the group name is derived from a mapping the separator is still used to concatenate the items.

To not use a separator in the group name at all, set the separator for the keyed group to an empty string instead.

Choices:

  • no

  • yes ← (default)

plugin

string / required

The name of this plugin, it should always be set to community.docker.docker_containers for this plugin to recognize it as it’s own.

Choices:

  • community.docker.docker_containers

private_ssh_port

integer

The port containers use for SSH.

Only used if connection_type is ssh.

Default: 22

ssl_version

string

Provide a valid SSL version number. Default value determined by ssl.py module.

If the value is not specified in the task, the value of environment variable DOCKER_SSL_VERSION will be used instead.

strict

boolean

If yes make invalid entries a fatal error, otherwise skip and continue.

Since it is possible to use facts in the expressions they might not always be available and we ignore those errors by default.

Choices:

  • no ← (default)

  • yes

timeout

integer

The maximum amount of time in seconds to wait on a response from the API.

If the value is not specified in the task, the value of environment variable DOCKER_TIMEOUT will be used instead. If the environment variable is not set, the default value will be used.

Default: 60

tls

boolean

Secure the connection to the API by using TLS without verifying the authenticity of the Docker host server. Note that if validate_certs is set to true as well, it will take precedence.

If the value is not specified in the task, the value of environment variable DOCKER_TLS will be used instead. If the environment variable is not set, the default value will be used.

Choices:

  • no ← (default)

  • yes

tls_hostname

string

When verifying the authenticity of the Docker Host server, provide the expected name of the server.

If the value is not specified in the task, the value of environment variable DOCKER_TLS_HOSTNAME will be used instead. If the environment variable is not set, the default value will be used.

The current default value is localhost. This default is deprecated and will change in community.docker 2.0.0 to be a value computed from docker_host. Explicitly specify localhost to make sure this value will still be used, and to disable the deprecation message which will be shown otherwise.

use_extra_vars

boolean

added in 2.11 of ansible.builtin

Merge extra vars into the available variables for composition (highest precedence).

Choices:

  • no ← (default)

  • yes

Configuration:

  • INI entry:

    [inventory_plugins]
    use_extra_vars = no
    
  • Environment variable: ANSIBLE_INVENTORY_USE_EXTRA_VARS

use_ssh_client

boolean

added in 1.5.0 of community.docker

For SSH transports, use the ssh CLI tool instead of paramiko.

Requires Docker SDK for Python 4.4.0 or newer.

Choices:

  • no ← (default)

  • yes

validate_certs

aliases: tls_verify

boolean

Secure the connection to the API by using TLS and verifying the authenticity of the Docker host server.

If the value is not specified in the task, the value of environment variable DOCKER_TLS_VERIFY will be used instead. If the environment variable is not set, the default value will be used.

Choices:

  • no ← (default)

  • yes

verbose_output

boolean

Toggle to (not) include all available inspection metadata.

Note that all top-level keys will be transformed to the format docker_xxx. For example, HostConfig is converted to docker_hostconfig.

If this is false, these values can only be used during constructed, groups, and keyed_groups.

The docker inventory script always added these variables, so for compatibility set this to true.

Choices:

  • no ← (default)

  • yes

Notes

Note

  • Connect to the Docker daemon by providing parameters with each task or by defining environment variables. You can define DOCKER_HOST, DOCKER_TLS_HOSTNAME, DOCKER_API_VERSION, DOCKER_CERT_PATH, DOCKER_SSL_VERSION, DOCKER_TLS, DOCKER_TLS_VERIFY and DOCKER_TIMEOUT. If you are using docker machine, run the script shipped with the product that sets up the environment. It will set these variables for you. See https://docs.docker.com/machine/reference/env/ for more details.

  • When connecting to Docker daemon with TLS, you might need to install additional Python packages. For the Docker SDK for Python, version 2.4 or newer, this can be done by installing docker[tls] with ansible.builtin.pip.

  • Note that the Docker SDK for Python only allows to specify the path to the Docker configuration for very few functions. In general, it will use $HOME/.docker/config.json if the DOCKER_CONFIG environment variable is not specified, and use $DOCKER_CONFIG/config.json otherwise.

  • This module uses the Docker SDK for Python to communicate with the Docker daemon.

Examples

# Minimal example using local Docker daemon
plugin: community.docker.docker_containers
docker_host: unix://var/run/docker.sock

# Minimal example using remote Docker daemon
plugin: community.docker.docker_containers
docker_host: tcp://my-docker-host:2375

# Example using remote Docker daemon with unverified TLS
plugin: community.docker.docker_containers
docker_host: tcp://my-docker-host:2376
tls: true

# Example using remote Docker daemon with verified TLS and client certificate verification
plugin: community.docker.docker_containers
docker_host: tcp://my-docker-host:2376
validate_certs: true
ca_cert: /somewhere/ca.pem
client_key: /somewhere/key.pem
client_cert: /somewhere/cert.pem

# Example using constructed features to create groups
plugin: community.docker.docker_containers
docker_host: tcp://my-docker-host:2375
strict: false
keyed_groups:
  # Add containers with primary network foo to a network_foo group
  - prefix: network
    key: 'docker_hostconfig.NetworkMode'
  # Add Linux hosts to an os_linux group
  - prefix: os
    key: docker_platform

# Example using SSH connection with an explicit fallback for when port 22 has not been
# exported: use container name as ansible_ssh_host and 22 as ansible_ssh_port
plugin: community.docker.docker_containers
connection_type: ssh
compose:
  ansible_ssh_host: ansible_ssh_host | default(docker_name[1:], true)
  ansible_ssh_port: ansible_ssh_port | default(22, true)

Authors

  • Felix Fontein (@felixfontein)

Hint

Configuration entries for each entry type have a low to high priority order. For example, a variable that is lower in the list will override a variable that is higher up.