a6s-railway

    0.2.3 • Public • Published

    a6s-railway

    K8s deployment Orchestration tool.

    Dependencies

    • Node.js - LTS version
    • Kubectl
    • Helm
    • Valid credentials in ~/.kube/config file.
    • Other CLI tools you need to use in your deployment scripts.

    Installation

    npm i -g a6s-railway

    Usage

    Run rw in your terminal to get the help.

    Deployment Descriptor File

    Each deployment should be described via deployment descriptor file. There is only one entry point presented in file called "station".

    Format:

     
    # Deployment version 
    version: 1.0.0
    # Base station to start the deployment from 
    station: 
     name: 'station.name' 

    Station

    # Every station should have a name of handler that processes the deployment 
    name: 'a6s.station'
     
    # Each station also might require some options. 
    # There are 2 ways on how options can be passed: 
    # 1) Inline: 
    options:
      a: true
      # here comes the template magic of deployment descriptors 
      # you can reference environment variables inside options: 
      b: <%- env.TEST %>
      # or context variables produced by resolvers (read below) 
      c: <%- context.test %>
      # alternativelly use `$link:<path>` syntax 
      d: '$link:context.test'
    # 2) Via external YAML file. External files are also handled as templates. 
    options_file: 'external.options.yml'
     
    # Templates are resolved at the time deployment runs into station. 
    # The main limitation of template variables is that they can not contain any async processing. 
    # And resolvers are here to help with that. They are invoked before handler execution. Resolvers place their results into 
    # sharable context. Context is globally accessible, so make sure place unique name to avoid race conditions. 
    resolvers:
      test: 
        name: 'a6s.handler'
        # just like station handler may have its own options and be processed as a template 
        options:
        options_file: 'external.handler.options.yml'

    Each station in your deployment descriptor identified single action. Each station is described by name of the handler and options.

    Flow control

    Due to a nature of deployments they can become really complex and look more like a tree where some branches can be executed in parallel to optimize the deployment execution time.

    Special handlers exist to help with deployment processing.

    Sequential Execution

    This is a most commonly used flow control handler. It allows to run multiple actions (stations) one by one.

    name: 'a6s.sequence'
      options:
        name: 'a6s.handler.1'
          options: 
        name: 'a6s.handler.2'
          options:    

    In the example above a6s.handler.2 will only be executed after a6s.handler.1.

    Parallel Execution

    Sometimes it makes zero sense to wait before one handler finishes to start another one. E.g. You need to make installation of 5 services that have no dependencies among each other.

    To help with that parallel handler exists:

    name: 'a6s.parallel'
    options:
     name: 'a6s.handler.1'
       options: 
     name: 'a6s.handler.2'
       options:    

    In the example above a6s.handler.2 will be executed in parallel with a6s.handler.1.

    Complex Execution Example

    name: 'a6s.sequence'
    options:
     name: 'a6s.parallel'
       options:
        name: 'a6s.handler.1'
          options: 
        name: 'a6s.handler.2'
          options:  
     
     name: 'a6s.handler.3'
       options:    

    In this example a6s.handler.1 and a6s.handler.2 will be executed in parallel and a6s.handler.3 will only be started when a6s.parallel is completed. So 3rd handler will wait for first 2 to be completed.

    External Descriptors

    When working on production grade deployment number of services that needs to be deployed will grow dramatically and managing all of them inside single deployment descriptor file will become a pain.

    Split it! Created isolated deployment descriptors for submodules/services you need to deal with.

    name: 'a6s.external'
    options:
      # provide a relative or absolute path to the descriptor 
      file: 'elasticsearch.station.yml'

    "If" Control

    Run over station only when condition occurs.

    name: 'a6s.if'
    options:
      # test value 
      value: 'test'
      # against   
      equals: 'test2'
      # and run station if passes 
      station:
        name: 'a6s.some.station' 

    In the example above test will not match test2 and station a6s.some.station will not be triggered.

    "Switch" Control

    Run over station that matches value.

    name: 'a6s.switch'
    options:
      # test value 
      value: 'test'
      # against keys   
      equals:     
        test:
          name: 'a6s.some.station1' 
        test2:
          name: 'a6s.some.station2'      

    In the example above a6s.some.station1 will be triggered.

    Install

    npm i a6s-railway

    DownloadsWeekly Downloads

    1

    Version

    0.2.3

    License

    MIT

    Unpacked Size

    436 kB

    Total Files

    167

    Last publish

    Collaborators

    • apigeeks-buildmaster
    • apigeeks-paul
    • vlad-tkachenko