csw-host-config

This is just a helper to create a host configuration application. A component/subsystem is 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 zip 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("Host-Config-App", args)

}
Java
public class JHostConfigApp {

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

}
Note

It is not necessary to have a name of the application as HostConfigApp/JHostConfigApp, user can choose this name.

Command line parameter options

  • --local is an optional parameter. When supplied, get the host configuration file from local machine located at hostConfigPath, else fetch it from config service
  • <file> is a mandatory parameter. It specifies Host configuration file path
  • -s, --container-script <script-path> specifies the path of generated shell script of 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 project contains HostConfigApp and ContainerCmdApp and it depends on required components. Ex. Hcd’s, Assembly’s etc.
  • Navigate to project/target/universal directory
  • Unzip file created with projects name
  • Navigate to bin directory from unzipped content

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

  • trombone-host-config-app : Responsible for starting multiple containers. It takes hostconfig.conf file as an argument which contains list of container specifications.
  • trombone-container-cmd-app : Responsible for starting single container or component in standalone mode. It takes 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 configuration service which contains multiple container configuration, then invoke trombone-container-cmd-app script per container configuration which spawns container

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

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

Note

In above examples, we are passing argument: -s ./trombone-container-cmd-app to ./trombone-host-config-app. here -s stands for script and following to that is script name, in our case its trombone-container-cmd-app. and if you notice, trombone-container-cmd-app does not take container configuration file. hostconfig.conf passed to trombone-host-config-app contains location of container configuration files. Host config app internally parses hostconfig.conf and passes container configuration file location to trombone-container-cmd-app.

Find more details of ContainerCmd application here.

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

TMT_Deployment_Strategy

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

Note

Before running host-config app, make sure that csw-location-server is running on local machine at localhost:7654. As host config application internally executes container-cmd application which uses local HTTP location client which expect location server running locally.

Systemd configuration

Using systemd, you can configure 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

0.7.0