Tango with systemd integration

Intended audience: administrators

This recipe shows how to set up Tango environment using systemd, for instance on a developer’s box

At first systemd units must be defined for common Tango device servers (db, tango-accesscontrol, tango-test etc):

# /etc/systemd/system/tango-db.service
[Unit]
Description = Tango DB
Requires=mysql.service
After=mysql.service
StopWhenUnneeded=true

[Service]
User=tango
Environment=TANGO_HOST=localhost:10000
ExecStart=/opt/tango-9.2.2/bin/DataBaseds 2 -ORBendPoint giop:tcp::10000

[Install]
WantedBy=tango.target

# /ect/systemd/system/tango-accesscontrol.timer
[Timer]
OnActiveSec=3

[Install]
WantedBy=tango.target

timer is needed because we have to wait before database is ready to accept requests

# /etc/systemd/system/tango-accesscontrol.service
[Unit]
Description=TangoAccessControl device server
Wants=tango-db
After=tango-db
StopWhenUnneeded=true

[Service]
Environment=TANGO_HOST=localhost:10000
ExecStart=/opt/tango-9.2.2/bin/TangoAccessControl 1

A service unit for Starter device server can also be defined:

# /etc/systemd/system/tango-starter.service
[Unit]
Description=Starter device server
After=tango-accesscontrol.service
Requires=tango-db.service
Requires=tango-accesscontrol.service

[Service]
Restart=always
RestartSec=10
User=tango
Environment=TANGO_HOST=localhost:10000
ExecStart=/usr/local/bin/Starter tangobox

Finally combine everything into a single target:

# /etc/systemd/system/tango.target
[Unit]
Description=Tango development environment target
Requires=tango-db.service
Requires=tango-starter.service
Requires=tango-accesscontrol.timer
Requires=tango-test.timer

[Install]
#WantedBy=multi-user.target

Then these entities must be enabled and started:

$> sudo systemctl enable {each timer and service}
$> sudo systemctl start tango.target

systemd unit files may be generated when the device server is built. For instance as it is done in our tango-maven-archetype

Defining Tango servers as systemd units can be also very useful for production.