Getting started

Default configuration

With the default configuration, debops.mosquitto role will configure Mosquitto with a TLS listener accepting connections from any host (if the debops.pki environment is detected), and plaintext listener accepting connections only from localhost. Anonymous access to the broker will be allowed.

By default, plaintext connections are not allowed over the network. You can change that by setting the mosquitto__allow variable with a list of IP addresses or CIDR subnets to allow plaintext connections.

WebSocket configuration

WebSocket support will be enabled if a sufficient version of the libwebsockets library is detected; this was tested and works on Debian Stretch; using upstream Mosquitto on older OS releases is not enough, and at the time the role was written upstream Stretch version was not available. The WebSocket listener will be configured for localhost connections only.

The role provides two playbooks, a "plain" and "nginx" version (see below). The "nginx" playbook can be used to configure an nginx reverse proxy for the WebSocket listener. By default any host will be able to access the WebSocket connection, this can be controlled separately from the normal TLS connection using mosquitto__websockets_allow variable.

You can test support for WebSockets in Mosquitto using: http://www.hivemq.com/blog/full-featured-mqtt-client-browser

User accounts, ACL, password creation

For better security, you should configure some user accounts (see mosquitto__auth_users) and ACL entries for the broker. When user accounts are defined, the role will automatically block the anonymous access; this can be controlled using the mosquitto__allow_anonymous variable.

The older Mosquitto releases (pre 1.4+) provide a mosquitto_passwd command which does not support batch password creation, therefore the role will not configure the user accounts if such version is detected. You should either enable upstream release (on older OS releases) or use Debian Stretch+ which supports batch password creation.

Avahi CNAME (alias) support

If the Avahi support managed by the debops.avahi Ansible role is detected, the debops.mosquitto role will automatically create Avahi service entries for the configured listeners. The Avahi configuration is managed by the avahi_* parameters in the listener configuration, see mosquitto__listeners for more details.

Example inventory

The debops.mosquitto role needs to be enabled to be used in the DebOps playbook. To do that, add the hosts that you want to configure Avahi on to the [debops_service_mosquitto] Ansible inventory group:

[debops_service_mosquitto]
hostname

If you want to enable the nginx reverse proxy on a given host for WebSocket support, you can add that host to the [debops_service_mosquitto_nginx] Ansible inventory group:

[debops_service_mosquitto_nginx]
hostname

Example playbook

If you are using this role without DebOps, here's an example Ansible playbook that uses the debops.mosquitto role:

---

- name: Configure Mosquitto service
  hosts: [ 'debops_service_mosquitto' ]
  become: True

  environment: '{{ inventory__environment | d({})
                   | combine(inventory__group_environment | d({}))
                   | combine(inventory__host_environment  | d({})) }}'

  roles:

    - role: debops.etc_services
      tags: [ 'role::etc_services', 'skip::etc_services' ]
      etc_services__dependent_list:
        - '{{ mosquitto__etc_services__dependent_list }}'

    - role: debops.tcpwrappers
      tags: [ 'role::tcpwrappers', 'skip::tcpwrappers' ]
      tcpwrappers__dependent_allow:
        - '{{ mosquitto__tcpwrappers__dependent_allow }}'

    - role: debops.ferm
      tags: [ 'role::ferm', 'skip::ferm' ]
      ferm__dependent_rules:
        - '{{ mosquitto__ferm__dependent_rules }}'

    - role: debops.mosquitto
      tags: [ 'role::mosquitto', 'skip::mosquitto' ]

There is a separate playbook for a Mosquitto instance with nginx used as a reverse proxy for WebSocket connections:

---

- name: Configure Mosquitto service with Nginx
  hosts: [ 'debops_service_mosquitto_nginx' ]
  become: True

  environment: '{{ inventory__environment | d({})
                   | combine(inventory__group_environment | d({}))
                   | combine(inventory__host_environment  | d({})) }}'

  roles:

    - role: debops.apt_preferences
      tags: [ 'role::apt_preferences', 'skip::apt_preferences' ]
      apt_preferences__dependent_list:
        - '{{ nginx__apt_preferences__dependent_list }}'

    - role: debops.etc_services
      tags: [ 'role::etc_services', 'skip::etc_services' ]
      etc_services__dependent_list:
        - '{{ mosquitto__etc_services__dependent_list }}'

    - role: debops.tcpwrappers
      tags: [ 'role::tcpwrappers', 'skip::tcpwrappers' ]
      tcpwrappers__dependent_allow:
        - '{{ mosquitto__tcpwrappers__dependent_allow }}'

    - role: debops.ferm
      tags: [ 'role::ferm', 'skip::ferm' ]
      ferm__dependent_rules:
        - '{{ mosquitto__ferm__dependent_rules }}'
        - '{{ nginx__ferm__dependent_rules }}'

    - role: debops.python
      tags: [ 'role::python', 'skip::python' ]
      python__dependent_packages3:
        - '{{ nginx__python__dependent_packages3 }}'
      python__dependent_packages2:
        - '{{ nginx__python__dependent_packages2 }}'

    - role: debops.nginx
      tags: [ 'role::nginx', 'skip::nginx' ]
      nginx__dependent_servers:
        - '{{ mosquitto__nginx__dependent_servers }}'
      nginx__dependent_upstreams:
        - '{{ mosquitto__nginx__dependent_upstreams }}'

    - role: debops.mosquitto
      tags: [ 'role::mosquitto', 'skip::mosquitto' ]

Ansible tags

You can use Ansible --tags or --skip-tags parameters to limit what tasks are performed during Ansible run. This can be used after host is first configured to speed up playbook execution, when you are sure that most of the configuration has not been changed.

Available role tags:

role::mosquitto
Main role tag, should be used in the playbook to execute all of the role tasks as well as role dependencies.
role::mosquitto:acl
Tasks related to ACL configuration.
role::mosquitto:passwd
Tasks related to user/password management.
role::mosquitto:avahi
Tasks related to Avahi service support.
role::mosquitto:config
Tasks related to global configuration.
role::mosquitto:listeners
Tasks related to mosquitto listener configuration.
role::mosquitto:bridges
Tasks which configure MQTT bridge connections.