Introduction

The JobScheduler Universal Agent can be operated inside a Docker container.

Running JobScheduler Universal Agent inside a Docker container enables you to

• run multiple services inside a Docker container
  • Usually docker containers are restricted to run a single process.
  • If JobScheduler Universal Agent is run as this single process, it can be used to start additional processes.
• start and stop services inside a Docker container without restarting the docker container
• run any number of shell scripts inside a Docker container
• manage workflows with JobScheduler Master and run distributed job chains with job nodes for different Docker containers

Creating a JobScheduler Universal Agent image

• download the Dockerfile
  

  Dockerfile Expand source

  FROM java:8-jre
  EXPOSE 4445
  WORKDIR /root
  RUN wget https://download.sos-berlin.com/JobScheduler.1.10/jobscheduler_unix_universal_agent.1.10.0.tar.gz && \
  tar xfvz jobscheduler_unix_universal_agent.1.10.0.tar.gz
  CMD ["/root/jobscheduler_agent/bin/jobscheduler_agent.sh", "start_docker"]

• put it into a working directory on a Docker host
• cd into the working directory

• create the image with

  docker build --rm -t jsagent .

The dockerfile is based on the jre8 image of https://registry.hub.docker.com/_/java/. It downloads the most recent release of the JobScheduler Universal Agent and extracts it in the /root directory.

It exposes Port 4445 (the standard port of the JobScheduler Universal Agent).

It starts the JobScheduler Universal Agent with the "start_docker" parameter. See JS-1419 - Getting issue details... STATUS

Stopping the Docker container

If the docker container is stopped with

docker stop jsagent

Docker will send a SIGTERM Signal to the Agent startscript process which will try to end JobScheduler Universal Agent gracefully. This means that the Agent will not start any new jobs but let running jobs finish normally.

However, by default Docker has a timout of 10 seconds for stopping a container. So, 10 seconds after the stop command, Docker will kill all running jobs and other processes inside the container.

This might be too short for some jobs to finish, so using a higher timeout is recommended:

docker stop —-time=120 jsagent

Change Management References