[KARAF-4281] System scripts: provide Systemd templates to manage Karaf child instances

• Type: New Feature
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 4.1.0, 4.0.5
• Component/s: karaf
• Assignee: Freeman Fang
• Reporter: Luca Burgazzoli
• Created: 19/Jan/16 08:19
• Updated: 15/Sep/18 05:24
• Resolved: 21/Jan/16 02:21

Description

Systemd's has as a sort of template-engine for unit files which are defined in the form of template-name@.service, i.e. for karaf I've created one named karaf@.service with content like:

  [Unit]
  Description=Karaf - %i
  After=syslog.target network.target

  [Service]
  EnvironmentFile=-/etc/karaf/karaf.conf
  Environment=JAVA_HOME=/opt/java/1.8.0
  Environment=KARAF_HOME=/opt/apache/karaf-4
  Environment=KARAF_BASE=/opt/apache/karaf-4/instances/%i

  ExecStart=/opt/apache/karaf-4/bin/karaf daemon
  ExecStop=/opt/apache/karaf-4/bin/karaf stop

  LimitNOFILE=102642

  [Install]
  WantedBy=multi-user.target

With such configuration, you do not need to create a systemd unit file for each child instance but you can leverage karaf@.service, i.e:

  systemctl start karaf@instance-1

A service created in such way can also be configured to auto-start at boot like any other Systemd unit:

  [lb@home]# systemctl enable karaf@instance-1
  Created symlink from /etc/systemd/system/multi-user.target.wants /[e-mail] to /etc/systemd/system/karaf@.service.