docker_swarm_info – Retrieves facts about Docker Swarm cluster

New in version 2.8.

Synopsis

  • Retrieves facts about a Docker Swarm.
  • Returns lists of swarm objects names for the services - nodes, services, tasks.
  • The output differs depending on API version available on docker host.
  • Must be run on Swarm Manager node; otherwise module fails with error message. It does return boolean flags in on both error and success which indicate whether the docker daemon can be communicated with, whether it is in Swarm mode, and whether it is a Swarm Manager node.

Requirements

The below requirements are needed on the host that executes this module.

  • Docker API >= 1.24
  • Docker SDK for Python: Please note that the docker-py Python module has been superseded by docker (see here for details).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 (use docker-py for Python 2.6)

Parameters

Parameter Choices/Defaults Comments
api_version
string
Default:
"auto"
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.

aliases: docker_api_version
ca_cert
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.

aliases: tls_ca_cert, cacert_path
client_cert
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.

aliases: tls_client_cert, cert_path
client_key
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.

aliases: tls_client_key, key_path
debug
boolean
    Choices:
  • no ←
  • yes
Debug mode
docker_host
string
Default:
"unix://var/run/docker.sock"
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.

aliases: docker_url
nodes
boolean
    Choices:
  • no ←
  • yes
Whether to list swarm nodes.
nodes_filters
dictionary
A dictionary of filter values used for selecting nodes to list.
For example, name: mynode.
See the docker documentation for more information on possible filters.
services
boolean
    Choices:
  • no ←
  • yes
Whether to list swarm services.
services_filters
dictionary
A dictionary of filter values used for selecting services to list.
For example, name: myservice.
See the docker documentation for more information on possible filters.
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.
tasks
boolean
    Choices:
  • no ←
  • yes
Whether to list containers.
tasks_filters
dictionary
A dictionary of filter values used for selecting tasks to list.
For example, node: mynode-1.
See the docker documentation for more information on possible filters.
timeout
integer
Default:
60
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.
tls
boolean
    Choices:
  • no ←
  • yes
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 yes 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.
tls_hostname
string
Default:
"localhost"
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.
unlock_key
boolean
    Choices:
  • no ←
  • yes
Whether to retrieve the swarm unlock key.
validate_certs
boolean
    Choices:
  • no ←
  • yes
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.

aliases: tls_verify
verbose_output
boolean
    Choices:
  • no ←
  • yes
When set to yes and nodes, services or tasks is set to yes, then the module output will contain verbose information about objects matching the full output of API method.
For details see the documentation of your version of Docker API at https://docs.docker.com/engine/api/.
The verbose output in this module contains only subset of information returned by _info module for each type of the objects.

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://docker-py.readthedocs.io/en/stable/machine/ 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 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.

Examples

- name: Get info on Docker Swarm
  docker_swarm_info:
  ignore_errors: yes
  register: result

- name: Inform about basic flags
  debug:
    msg: |
      Was able to talk to docker daemon: {{ result.can_talk_to_docker }}
      Docker in Swarm mode: {{ result.docker_swarm_active }}
      This is a Manager node: {{ result.docker_swarm_manager }}

- block:

- name: Get info on Docker Swarm and list of registered nodes
  docker_swarm_info:
    nodes: yes
  register: result

- name: Get info on Docker Swarm and extended list of registered nodes
  docker_swarm_info:
    nodes: yes
    verbose_output: yes
  register: result

- name: Get info on Docker Swarm and filtered list of registered nodes
  docker_swarm_info:
    nodes: yes
    nodes_filter:
      name: mynode
  register: result

- debug:
    var: result.swarm_facts

- name: Get the swarm unlock key
  docker_swarm_info:
    unlock_key: yes
  register: result

- debug:
    var: result.swarm_unlock_key

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key Returned Description
can_talk_to_docker
boolean
both on success and on error
Will be true if the module can talk to the docker daemon.

docker_swarm_active
boolean
both on success and on error
Will be true if the module can talk to the docker daemon, and the docker daemon is in Swarm mode.

docker_swarm_manager
boolean
both on success and on error
Will be true if the module can talk to the docker daemon, the docker daemon is in Swarm mode, and the current node is a manager node.
Only if this one is true, the module will not fail.

nodes
list
When nodes is yes
List of dict objects containing the basic information about each volume. Keys matches the docker node ls output unless verbose_output=yes. See description for verbose_output.

services
list
When services is yes
List of dict objects containing the basic information about each volume. Keys matches the docker service ls output unless verbose_output=yes. See description for verbose_output.

swarm_facts
dictionary
always
Facts representing the basic state of the docker Swarm cluster.
Contains tokens to connect to the Swarm

swarm_unlock_key
string
When unlock_key is true.
Contains the key needed to unlock the swarm.

tasks
list
When tasks is yes
List of dict objects containing the basic information about each volume. Keys matches the docker service ps output unless verbose_output=yes. See description for verbose_output.



Status

Authors

  • Piotr Wojciechowski (@WojciechowskiPiotr)

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