Docker container for Herald application

This is a Docker container that holds a Herald app inside. Herald is a puppet report processor that provides a gateway for consuming puppet reports, a REST API and a simple Web app to display them.

More info about the application and how to use it with Puppet are available on repo page: https://github.com/wavesoftware/gem-puppet-herald

Overview

A docker image to run Herald app on any Docker host: Linux, Mac or Windows. It utilize PostgreSQL as a database containing Puppet reports. While application stats it will try to migrate database to desired state.

Configuration

Configuration can be provided by setting environment variables while running the container. Every env variable is prefixed with HERALD_

ENV	DESCRIPTION	Default value
HERALD_POSTGRES_HOST	IP host for PostgresSQL. If using container link, set it to postgres named container	postgres
HERALD_POSTGRES_PORT	PostgresSQL port	5432
HERALD_POSTGRES_USER	User that will be used to connect to database	pherald
HERALD_POSTGRES_DB_NAME	Database name	pherald
HERALD_POSTGRES_PASSWORD	Password to database. Remeber to set this variable for security!!!	VGh1IEphbiAyMSAxNDo1NzowOSBDRVQgMjAxNgo
HERALD_POSTGRES_CREATE_DATABASE	If set to yes script in the container will try to create database and user with provided env variables	yes

Run with PostgreSQL docker container

If you like to run Herald with private docker container execute commands below:

docker run -d --name=postgres postgres
docker run -d --link postgres -p 11303:11303 --name=herald coigovpl/herald

Run with remote PostgreSQL

If you like to run Herald with external postgres set appropriate configuration options with environment variables HERALD_* similar to:

docker run -d \
  -e HERALD_POSTGRES_HOST=herald-db.localdomain \
  -p 11303:11303 \
  --name=herald coigovpl/herald

Sample system startup scripts that uses this container

file (executable) in /etc/docker-apps/herald/container:

#!/bin/bash -e

action=$1

export THISDIR=$(dirname $(readlink -f $0))
export CONTAINER=herald
HERALD_POSTGRES_PASSWORD=$(cat /etc/herald/passfile)

case $action in
  run)
    exec docker run --rm \
      --name $CONTAINER \
      -p 11303:11303 \
      -e HERALD_POSTGRES_HOST=herald-db.localdomain \
      -e HERALD_POSTGRES_PASSWORD=$HERALD_POSTGRES_PASSWORD \
      coigovpl/herald
    ;;
  kill)
    docker kill --signal 'SIGINT' $CONTAINER || true
    for i in $(seq 1 30); do
      running=$(docker inspect --format="{{ .State.Running }}" $CONTAINER || echo false)
      if [ "$running" == 'true' ]; then
        sleep 1
      else
        docker rm -f $CONTAINER || true
	      break
      fi
    done
  ;;
  *)
    echo './container <run|kill>' 1>&2
    exit 2
  ;;
esac

systemd init file

file in: /etc/systemd/system/herald.service

[Unit]
Description=Herald service
Requires=docker.service
After=docker.service

[Service]
Type=oneshot
RemainAfterExit=yes
WorkingDirectory=/etc/docker-apps/herald
ExecStart=/etc/docker-apps/herald/container run
ExecStop=/etc/docker-apps/herald/container kill

[Install]
WantedBy=local.target

Running tests

rake test

This command will run postgres container and link herald container to it. Later on it will make GET requests with curl to check if service is up and running, and if everything is okey it will remove created containers to finish the test

Contributing

Contributions are welcome!

To contribute, follow the standard git flow of:

1. Fork it
2. Create your feature or bugfix branch (git checkout -b feature/my-new-feature or git checkout -b bugfix/my-bugfix)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to your fork (git push origin feature/my-new-feature)
5. Create new Pull Request

Even if you can't contribute code, if you have an idea for an improvement please open an issue.