csw-host-config

This is just a helper to create a host configuration application. A component/subsystem can create their own host configuration application using this helper; to be more precise, every Github repository should have one host configuration application. The reason for having one app per repo is, when you run universal:publish task, it will generate a zip file which will be self contained (will have all the required dependencies) and can be deployed independently on any machine.

This application will start multiple containers on a given host machine and each container will have single/multiple components.

How to create

Scala

object HostConfigApp extends App {

  HostConfig.start("HostConfigApp", CSW, args)

}

Java

public class JHostConfigApp {

    public static void main(String args[]) {
        JHostConfig.start("JHost-Config-App", JSubsystem.CSW, args);
    }

}

Command line parameter options

• --local is an optional parameter. When supplied, get the host configuration file from local machine located at hostConfigPath, otherwise, fetch it from the Config Service
• <file> is a mandatory parameter. It specifies Host configuration file path
• -s, --container-script <script-path> specifies the path of the generated shell script for the container command app from task universal:packageBin (sbt-native-packager task)
• --help prints the help of the application.
• --version prints the version of the application.

Examples

Pre-requisites

• Run sbt project/universal:packageBin command. Here, the project contains HostConfigApp and ContainerCmdApp and it depends on the required components. Ex. Hcd’s, Assembly’s etc.
• Navigate to project/target/universal directory
• Unzip the file created with the project’s name
• Navigate to the bin directory from the unzipped contents

The sbt task: sbt project/universal:packageBin creates the following four scripts in the bin directory:

• trombone-host-config-app : Responsible for starting multiple containers. It takes a hostconfig.conf file as an argument which contains the list of container specifications.
• trombone-container-cmd-app : Responsible for starting a single container or component in standalone mode. It takes a containerConfig.conf file as an argument which contains single container specifications.
• trombone-host-config-app.bat : For Windows machine.
• trombone-container-cmd-app.bat : For Windows machine.

Examples:

1. ./trombone-host-config-app hostconfig.conf -s ./trombone-container-cmd-app
   

   Fetch hostconfig.conf from the Configuration Service which contains a multiple container configuration, then invoke the trombone-container-cmd-app script per the container configuration which spawns the container

2. ./trombone-host-config-app --local hostconfig.conf -s ./trombone-container-cmd-app
   

   Fetch and parse hostconfig.conf from the current directory which contains a multiple container configuration, then invoke the trombone-container-cmd-app script per the container configuration which spawns the container

Where does it fit in overall deployment strategy (may change)

Custom Host Configuration

hostconfig.conf

# This is a host configuration file which contains list of containers to be spawned by host configuration app
containers: [
  {
    # mode can be one of Container or Standalone
    mode: "Container"
    # path of individual container configuration file
    configFilePath: "/Users/salonivithalani/Desktop/tw_tmt/csw/examples/src/main/resources/assemblyContainer.conf"
    # provide 'Remote' if file needs to fetched from config service else
    # provide 'Local' to fetch file from local machine
    configFileLocation: "Local"
  },
  {
    mode: "Standalone"
    configFilePath: "/Users/salonivithalani/Desktop/tw_tmt/csw/examples/src/main/resources/hcdStandalone.conf"
    configFileLocation: "Local"
  }
]

Help

Use the following command to get help on the options available with this app

./bin/trombone-host-config-app --help

Version

Use the following command to get version information for this app

./bin/trombone-host-config-app --version

Systemd configuration

Using systemd, you can configure a host configuration application to spawn containers on a machine to be run automatically on system startup.

For detailed information on systemd configuration, please refer to readme.md