This document discusses using Docker and Docker Compose to run an OpenNMS Horizon container. It provides instructions for starting services, stopping services, upgrading the container, backing up and restoring the database, initializing a new configuration, merging configuration changes, and using an overlay directory. Troubleshooting tips are also included such as checking logs and running commands in the container. Development topics like building OpenNMS as an OCI image and challenges around Karaf containers are briefly mentioned.

1. Container & OpenNMS

2. Operations

3. Docker & Docker Compose
DockerHub Account

4. http://tiny.cc/dj2019docker

5. http://tiny.cc/dj2019docker
docker-compose up -d
Start database and horizon
services in background

6. http://tiny.cc/dj2019docker
docker-compose stop [service]
Stops all services or a specific one.
The last state is preserved.

7. http://tiny.cc/dj2019docker
docker-compose down -v
Stops all services or a specific one.
Last state is removed.
Deletes also Volumes!

8. Upgrade

9. Backup etc, rrd, reports and database
1. Stop horizon: docker-compose stop horizon
2. Backup database:
docker-compose exec database
pg_dump -W -U horizonuser
-Fc -f /tmp/opennms.pgsql.gz horizondb
3. Get backup file from container:
docker cp postgresql:/tmp/opennms.pgsql.gz .
4. docker inspect horizon | grep data-horizon-rrd
demo_data-horizon-rrd:/opt/opennms/share/rrd:rw",
"Name": "demo_data-horizon-rrd",
"Source": "/var/lib/docker/volumes/demo_data-horizon-rrd/_data",

10. Initialise a new etc and apply changes
1. Delete the content of your ./etc directory
2. Bump the image version
3. Initalise a pristine etc from the new version with
docker-compose run horizon -i
4. Restore your modified config files and start

11. Merge changes from identified configs
1. Backup files you have modified
2. Merge your modified files, it means check XML schema
changes. Use
https://github.com/opennms/opennms-etc-pristine
with your target version for the merge

12. docker-compose exec horizon
diff -rq -EBbw ./etc share/etc-pristine | grep "Only in ./etc[/|:]"
docker-compose exec horizon
diff -rq -EBbw ./etc share/etc-pristine | grep "differ"
docker-compose exec horizon
diff -rq -EBbw ./etc share/etc-pristine | grep "Only in share/etc-pristine[/|:]"
1. Identify changed configuration files

13. docker-compose exec horizon
diff -rq -EBbw ./etc share/etc-pristine | grep "Only in ./etc[/|:]"
docker-compose exec horizon
diff -rq -EBbw ./etc share/etc-pristine | grep "differ"
docker-compose exec horizon
diff -rq -EBbw ./etc share/etc-pristine | grep "Only in share/etc-pristine[/|:]"
1. Identify changed configuration files
NMS-12129

14. volumes:
- ./etc-overlay:/opt/opennms-overlay
Overlay Directory
Everything is copied and overwrites files in the directory
/opt/opennms
Use it for files which are not changed from the Web UI
- opennms.properties.d
- Poller Configuration
- Notification Commands
Changes from the Web UI get overwritten on next restart:
- SNMP Communities
- Users, Groups, Destination Paths,
- Notifications, Thresholds, etc.

15. Troubleshooting

16. 1. docker-compose logs -f horizon
2. docker-compose exec horizon bash
3. docker-compose run horizon -t
4. environment:
- JAVA_OPTS=-XX:+UseG1GC
5. docker cp <container-id>:/path/src /path/dest
6. Start with JPDA debugger:
JAVA_OPTS=-agentlib:jdwp=transport=dt_socket,server=y,address=$*:8001,suspend=n

17. Development

18. • Build OCI with the CI/CD
• Integrate in Test environment
• Docker Images as artefacts
• Test the OCI itself
• target is Horizon 25

28. • horizon-core-web -> horizon
• Simplify overlay directories
• Run with OpenShift as non-root
• POC with confd

29. Challenges

30. Karaf Containers

31. 926MiB
567MiB
232MiB
127MiB
CentOS 7 OpenJDK
Dependencies OpenNMS

32. Runtime configs Start-up configs

33. Double-click to edit
• Double-click to edit