Masson

Masson is a configuration management, orchestration and do-anything-you-want tools. It is here to simplify your life installing complex setup and maintaining dozens, hundreds, or even thousands of servers.

At Adaltas, we use it to deploy full featured Hadoop Clusters.

Installation

Run npm install to download the project dependencies.

Usage

The script ./bin/masson is used to pilot the various command. Run it without any arguments to print the help page or as ./bin/big help {command} to obtain help for a particular command.

Features

• SSH: ability to execute remote commands using ssh without having the need for any client to run on the servers.
• Documentation: CoffeeScript Literate provides easy to read and self documented code.
• Code as the single source of thruth
• Work entirely offline
• Easy introspection: source code is easy to navigate and understand

Documentation

Note, this is a proposal for future Masson evolution and doesnt reflect the current implementation.

Option deps

• single Inject a single dependency instead of an array of dependencies. Throw an error if more than one service is present Equals to null if no service is present Used conjointly with local, it will return the local service even if the service is present on more than one node.
• local Load the service on the local node if the service is already activated.
• auto Activate the service. Can be used conjointly with local to ensure a dependency is executed on every node before a given service.
• recommanded Mark the depencency as important, only for information purpose.
• required Ensure a dependency is activated. Cannot be used conjointly with auto, if a service cannot be automatically loaded, then it is pointless to mark it as required.
• min Ensure a dependency isn't activated on less then a minimum values
• max Ensure a dependency isn't activated on more then a maximum values

Usecases:

Considering a service A declared on one node and a service B declared on a second node, we defined service B with a dependency of service A with the following options:

• Use local: true to automatically declare service b on the same node as service A if and only if service B is already defined elsewhere. In the service configuration, the dependency will be set as "null" if service B was not activated elsewhere.
• Use local: true, required: true to automatically declare service B on the same node as service A and ensure service A is activated elsewhere.
• Use local: true, single: true to automatically declare service B on the same node as service A. In the service configuration, the dependency will be set as the service object relative to the current node instead of an array of services for every nodes.
• Use auto: true to automatically activate service B. The service will not be declared on any node. In the service configuration, the dependency will be set as an empty array if the dependency affinity doesnt match any affinity. of services for every nodes.
• Use auto: true, local: true to automatically activate service B and declare service B as a dependency of service a.

Suggestions on api for deps (lucasbak)

local dependencies

• Use local: true for loading the configuration of a module installed locally (on the same node). It enables to reach the configuration in configure directly example, to enrich it or read from it

  `ryba/hadoop/hdfs_nn/index.coffee.md`
  module.exports:
    deps:
      hadoop_core: module: ryba/hadoop/core, local: true

  `ryba/hadoop/hdfs_nn/configure.coffee.md`
  module.exports = (service) ->
    service.deps.hadoop_core.options.nameservice

no-instance dependencies

• Use load: true for loading the configuration of a module which is not installed nor on the same node nor on the cluster. It enables the module which does the require to configure automatically configurations whithout having the module installed. Note: Should we make a special type for this kind of module, ie this kind of module should only contain a configure() function (configure.coffee.md). Using it as a module in configuration declaration (config.coffee) makes no sens

  `ryba/ranger/admin/index.coffee.md`
  module.exports:
    deps:
      db_admin: module: 'ryba/hadoop/core', load: true

  `ryba/ranger/admin/configure.coffee.md`
  module.exports = (service) ->
    service.deps.db_admin.options.engine #defined 

auto dependencies

Suggest-1:

• Use auto: true for installing a module locally (on the same node). as a consequence load: true is implicitly set and the module configuration can be reached.

  `ryba/oozie/server/index.coffee.md`
  module.exports:
    deps:
      mapred_client: module: 'ryba/hadoop/mapred_client', install: true

  `ryba/oozie/server/configure.coffee.md`
  module.exports = (service) ->
    service.deps.mapred_client.options #undefined if no other instanced of mapred_client exist on other nodes 

Suggest-2:

• Use auto: true or an other name install: true for installing a module locally (on the same node). BUT to access local configuration for installed dependency local: true should be set or all instances will be returned. like this the same behaviour is applied for local options

  `ryba/oozie/server/index.coffee.md`
  module.exports:
    deps:
      mapred_client: module: 'ryba/hadoop/mapred_client', install: true, local: true

  `ryba/oozie/server/configure.coffee.md`
  module.exports = (service) ->
    service.deps.mapred_client.options['mapreduce.java.mapred.opts'] #defined 

single dependencies

• User single: true for loading the configuration of only one instance of the module.

  `ryba-env-metal/conf/config.coffee`
  module.exports:
    cluster: 'mycluster': services:
      hdfs_namenode: 
        module: 'ryba/hadoop/hdfs_nn'
        affinity: type: 'nodes', match: 'any', values: ['master01.metal.ryba', 'master02.metal.ryba']

  `ryba/hadoop/hdfs_client/index.coffee.md`
  module.exports:
    deps:
      hdfs_namenode: module: 'ryba/hadoop/hdfs_nn', single: true

  `ryba/hadoop/hdfs_client/configure.coffee.md`
  module.exports = (service) ->
    service.deps.hdfs_nn.options.nameservice #defined 

what about required

• required: true is a good option as it explicty declares the necessary deps. definition of required:true is: a service A required a service B. But it can be on a different node. On both cases an error is raised at configuration time if the layout of services is not good. We can have required: true or required:true and local: true Like this we specifiy if the service should be installed on the same node or not, and load the local config if it is. Note: required:true and local: true is DIFFERENT from auto/install: true as in the first case the service must be declared in the configuration and in the second case the local config is not loaded by default.

options co-habitation

Options auto: true does not imply local: true. To get configuration for auto dependency, local must be set to true. An error must be raised if local: true and single: strue are set. load:true and local:true should be incompatible load:true and auto:true should be incompatible

Contributors

• David Worms: https://github.com/wdavidw