KyleAnderson/consul

This module manages Consul servers and agents.

• Compatibility
  • What This Module Affects
• Usage
• Web UI
• Service Definition
• Watch Definitions
• Check Definitions
• Removing Service, Check and Watch definitions
• ACL Definitions
  • Policy/Token system
  • Legacy system
• Prepared Queries and Prepared Query Templates
• Key/Value Objects
• Limitations
• Windows Experimental Support
• Telemetry
• Consul Template
• Development

Compatibility

WARNING: Backwards incompatible changes happen in order to more easily support new versions of consul. Pin to the version that works for your setup!

Consul Version	Recommended Puppet Module Version
>= 1.1.0	>= 4.0.0
1.1.0- 0.9.0	<= 3.4.2
0.8.x	<= 3.2.4
0.7.0	<= 2.1.1
0.6.0	<= 2.1.1
0.5.x	1.0.3
0.4.x	0.4.6

What This Module Affects

• Installs the consul daemon (via url or package)
  • If installing from zip, you must ensure the unzip utility is available.
  • If installing from docker, you must ensure puppetlabs-docker_platform module is available.
  • If installing on windows, you must install the puppetlabs/powershell module.
• Optionally installs a user to run it under
  • NOTE: users enabling this and just starting with Consul should consider setting manage_user_home_location to true. It defaults to false for backwards compatibility.
• Installs a configuration file (/etc/consul/config.json)
• Manages the consul service via upstart, sysv, systemd, or nssm.
• Optionally installs the Web UI

Usage

To set up a single consul server, with several agents attached: On the server:

class { 'consul':
  config_hash => {
    'bootstrap_expect' => 1,
    'data_dir'         => '/opt/consul',
    'datacenter'       => 'east-aws',
    'log_level'        => 'INFO',
    'node_name'        => 'server',
    'server'           => true,
  },
}

On the agent(s):

class { 'consul':
  config_hash => {
    'data_dir'   => '/opt/consul',
    'datacenter' => 'east-aws',
    'log_level'  => 'INFO',
    'node_name'  => 'agent',
    'retry_join' => ['172.16.0.1'],
  },
}

Disable install and service components:

class { 'consul':
  install_method => 'none',
  init_style     => false,
  manage_service => false,
  config_hash => {
    'data_dir'   => '/opt/consul',
    'datacenter' => 'east-aws',
    'log_level'  => 'INFO',
    'node_name'  => 'agent',
    'retry_join' => ['172.16.0.1'],
  },
}

Web UI

To install and run the Web UI on the server, include ui => true in the config_hash. You may also want to change the client_addr to 0.0.0.0 from the default 127.0.0.1, for example:

class { 'consul':
  config_hash => {
    'bootstrap_expect' => 1,
    'client_addr'      => '0.0.0.0',
    'data_dir'         => '/opt/consul',
    'datacenter'       => 'east-aws',
    'log_level'        => 'INFO',
    'node_name'        => 'server',
    'server'           => true,
    'ui'               => true,
  },
}

For more security options, consider leaving the client_addr set to 127.0.0.1 and use with a reverse proxy:

$aliases = ['consul', 'consul.example.com']

# Reverse proxy for Web interface
include 'nginx'

$server_names = [$facts['networking']['fqdn'], $aliases]

nginx::resource::vhost { $facts['networking']['fqdn']:
  proxy       => 'http://localhost:8500',
  server_name => $server_names,
}

Service Definition

To declare the availability of a service, you can use the service define. This will register the service through the local consul client agent and optionally configure a health check to monitor its availability.

consul::service { 'redis':
  checks  => [
    {
      script   => '/usr/local/bin/check_redis.py',
      interval => '10s'
    },
  ],
  port    => 6379,
  tags    => ['master'],
  meta    => {
    SLA => '1'
  },
}

See the service.pp docstrings for all available inputs.

You can also use consul::services which accepts a hash of services, and makes it easy to declare in hiera. For example:

consul::services:
  service1:
    address: "%{facts.networking.ip}"
    checks:
      - http: http://localhost:42/status
        interval: 5s
    port: 42
    tags:
      - "foo:%{facts.custom.bar}"
    meta:
      SLA: 1
  service2:
    address: "%{facts.networking.ip}"
    checks:
      - http: http://localhost:43/status
        interval: 5s
    port: 43
    tags:
      - "foo:%{facts.custom.baz}"
    meta:
      SLA: 4

Watch Definitions

consul::watch { 'my_watch':
  handler     => 'handler_path',
  passingonly => true,
  service     => 'serviceName',
  service_tag => 'serviceTagName',
  type        => 'service',
}

See the watch.pp docstrings for all available inputs.

You can also use consul::watches which accepts a hash of watches, and makes it easy to declare in hiera.

Check Definitions

consul::check { 'true_check':
  interval => '30s',
  script   => '/bin/true',
}

See the check.pp docstrings for all available inputs.

You can also use consul::checks which accepts a hash of checks, and makes it easy to declare in hiera.

Removing Service, Check and Watch definitions

Do ensure => absent while removing existing service, check and watch definitions. This ensures consul will be reloaded via SIGHUP. If you have purge_config_dir set to true and simply remove the definition it will cause consul to restart.

ACL Definitions

Policy/Token system

Starting with version 1.4.0, a new ACL system was introduces separating rules (policies) from tokens.

Tokens and policies may be both managed by Puppet:

consul_policy {'test_policy':
  description   => 'test description',
  rules         => [
    {
      'resource'    => 'service_prefix',
      'segment'     => 'test_service',
      'disposition' => 'read'
    },
    {
      'resource'    => 'key',
      'segment'     => 'test_key',
      'disposition' => 'write'
    },
  ],
  acl_api_token => 'e33653a6-0320-4a71-b3af-75f14578e3aa',
}

consul_token {'test_token':
  accessor_id       => '7c4e3f11-786d-44e6-ac1d-b99546a1ccbd',
  policies_by_name  => [
   'test_policy'
  ],
  policies_by_id    => [
    '652f27c9-d08d-412b-8985-9becc9c42fb2'
  ],
}

Here is an example to automatically create a policy and token for each host. For development environments acl_api_token can be the bootstrap token. For production it should be a dedicated token with access to write/read from the acls.

accessor_id must be provided. It is a uuid. It can be generated in several different ways.

1. Statically generated and assigned to the resource. See /usr/bin/uuidgen on unix systems.
2. Dynamically derived from the $facts['dmi']['product']['uuid'] fact in puppet (useful when consul_token has 1:1 mapping to hosts).
3. Dynamically derived from arbitrary string using fqdn_uuid() (useful for giving all instances of a resource unique id).

  # Create ACL policy that allows nodes to update themselves and read others
  consul_policy { $facts['networking']['hostname']:
    description => "${facts['networking']['hostname']}, generated by puppet",
    rules => [
      {
        'resource' => 'node',
        'segment' => "$facts['networking']['hostname']",
        'disposition' => 'write'
      },
      {
        'resource' => 'node',
        'segment' => '',
        'disposition' => 'read'
      }
    ],
    acl_api_token => $acl_api_token,
  }

  consul_token { $facts['networking']['hostname']:
    accessor_id => fqdn_uuid($facts['networking']['hostname']),
    policies_by_name => ["${facts['networking']['hostname']}"],
    acl_api_token => $acl_api_token,
  }

Predefining token secret is supported by setting secret_id property.

Externally created tokens and policies may be used by referencing them by ID (Token: accessor_id property, Policy: ID property, linking: policies_by_id property)

Legacy system

consul_acl { 'ctoken':
  ensure => 'present',
  rules  => {
    'key' => {
      'test' => {
        'policy' => 'read'
      },
    },
  },
  type   => 'client',
}

Do not use duplicate names, and remember that the ACL ID (a read-only property for this type) is used as the token for requests, not the name

Optionally, you may supply an acl_api_token. This will allow you to create ACLs if the anonymous token doesn't permit ACL changes (which is likely). The api token may be the master token, another management token, or any client token with sufficient privileges.

NOTE: This module currently cannot parse ACL tokens generated through means other than this module. Don't mix Puppet and Non-puppet ACLs for best results! (pull requests welcome to allow it to co-exist with ACLs generated with normal HCL)

Prepared Queries and Prepared Query Templates

consul_prepared_query { 'consul':
  ensure               => 'present',
  service_name         => 'consul',
  service_failover_n   => 1,
  service_failover_dcs => [ 'dc1', 'dc2' ],
  service_only_passing => true,
  service_tags         => [ 'tag1', 'tag2' ],
  ttl                  => 10,
}

or a prepared query template:

consul_prepared_query { 'consul':
  ensure               => 'present',
  service_name         => 'consul',
  service_name         => 'consul-${match(1)}' # lint:ignore:single_quote_string_with_variables
  service_failover_n   => 1,
  service_failover_dcs => [ 'dc1', 'dc2' ],
  service_only_passing => true,
  service_tags         => [ '${match(2)}' ], # lint:ignore:single_quote_string_with_variables
  template             => true,
  template_regexp      => '^consul-(.*)-(.*)$',
  template_type        => 'name_prefix_match',
}

Key/Value Objects

Example:

consul_key_value { 'key/path':
  ensure     => 'present',
  value      => 'myvaluestring',
  flags      => 12345,
  datacenter => 'dc1',
}

This provider allows you to manage key/value pairs. It tries to be smart in two ways:

1. It caches the data accessible from the kv store with the specified acl token.
2. It does not update the key if the value & flag are already correct.

These parameters are mandatory when using consul_key_value:

• name Name of the key/value object. Path in key/value store.
• value value of the key.

The optional parameters only need to be specified if you require changes from default behaviour.

• flags {Integer} an opaque unsigned integer that can be attached to each entry. Clients can choose to use this however makes sense for their application. Default is 0.
• acl\_api_token {String} Token for accessing the ACL API. Default is ''.
• datacenter {String} Use the key/value store in specified datacenter. If '' (default) it will use the datacenter of the Consul agent at the HTTP address.
• protocol {String} protocol to use. Either 'http' (default) or 'https'.
• port {Integer} consul port. Defaults to 8500.
• hostname {String} consul hostname. Defaults to 'localhost'.
• api_tries {Integer} number of tries when contacting the Consul REST API. Timeouts are not retried because a timeout already takes long. Defaults to 3.

Limitations

Depends on the JSON gem, or a modern ruby. (Ruby 1.8.7 is not officially supported) Current versions of puppetserver are new enough (2.0.3 & greater are known to work).

Windows Experimental Support

Windows service does no longer need [NSSM] to host the service. Consul will be installed as a native windows service using build-in sc.exe. The following caveats apply:

• By defult eveything will be installed into c:\ProgramData\Consul\ and $consul::config_hash['data_dir'] will default point to that location, so you don't need that in your config_hash
• The service user needs logon as a service permission to run things as a service(not yet supported by this module). therefore will consul::manage_user and consul::manage_group be default false.
• consul::user will default be NT AUTHORITY\NETWORK SERVICE (Has by default logon as a service permission).
• consul::group will default be Administrators

Example:

class { 'consul':
  config_hash => {
    'bootstrap_expect' => 1,
    'datacenter'       => 'dc1',
    'log_level'        => 'INFO',
    'node_name'        => 'server',
    'server'           => true,
  },
}

Telemetry

The Consul agent collects various runtime metrics about the performance of different libraries and subsystems. These metrics are aggregated on a ten second interval and are retained for one minute.

To view this data, you must send a signal to the Consul process: on Unix, this is USR1 while on Windows it is BREAK. Once Consul receives the signal, it will dump the current telemetry information to the agent's stderr.

This telemetry information can be used for debugging or otherwise getting a better view of what Consul is doing.

Example:

class { 'consul':
  config_hash => {
    'bootstrap_expect' => 1,
    'data_dir'         => '/opt/consul',
    'datacenter'       => 'east-aws',
    'log_level'        => 'INFO',
    'node_name'        => 'server',
    'server'           => true,
    'telemetry' => {
      'statsd_address' => 'localhost:9125',
      'prefix_filter' => [
        '+consul.client.rpc',
        '+consul.client.rpc.exceeded',
        '+consul.acl.cache_hit',
        '+consul.acl.cache_miss',
        '+consul.dns.stale_queries',
        '+consul.raft.state.leader',
        '+consul.raft.state.candidate',
        '+consul.raft.apply',
        '+consul.raft.commitTime',
        '+consul.raft.leader.dispatchLog',
        '+consul.raft.replication.appendEntries',
        '+consul.raft.leader.lastContact',
        '+consul.rpc.accept_conn',
        '+consul.catalog.register',
        '+consul.catalog.deregister',
        '+consul.kvs.apply',
        '+consul.leader.barrier',
        '+consul.leader.reconcile',
        '+consul.leader.reconcileMember',
        '+consul.leader.reapTombstones',
        '+consul.rpc.raft_handoff',
        '+consul.rpc.request_error',
        '+consul.rpc.request',
        '+consul.rpc.query',
        '+consul.rpc.consistentRead',
        '+consul.memberlist.msg.suspect',
        '+consul.serf.member.flap',
        '+consul.serf.events',
        '+consul.session_ttl.active',
      ],
    },
  },
}

The metrics for the consul system you can look them in the Official Consul Site with all the description for every metric. Url: https://www.consul.io/docs/agent/telemetry.html

Consul Template

Consul Template is a piece of software to dynamically write out config files using templates that are populated with values from Consul. This module does not configure consul template. See gdhbashton/consul_template for a module that can do that.

Development

Open an issue or fork and open a Pull Request