Email - bash-postfix-encrypt-filter-sync-pgp.service (systemd unit)

category: solutionz · date: 2019-12-31 · updated: 2026-10-02 · author: LALA

Email Solution · Config document · referenced from High availability and key synchronization

The systemd unit that starts the synchronization loop for PGP public keys at boot and keeps it in the background.

Item	Value
Path on the server	`/etc/systemd/system/bash-postfix-encrypt-filter-sync-pgp.service`
Shown here	`DC2-A-VCMSX001`
Also on	`DC2-B-VCMSX001`, identical (`diff` is empty)
Starts	`/usr/local/bin/bash-postfix-encrypt-filter-sync-pgp.sh`, as root
Activated with	`systemctl start` and `systemctl enable` of the unit
systemd at the time	the one of RHEL 7

The file

ini

[Unit]
Description = BASH postfix encrypt filter - PGP keys synchronization
After = network.target

[Service]
PIDFile = /run/bash-postfix-encrypt-filter-sync-pgp.pid
User = root
Group = root
WorkingDirectory = /var/spool/postfix/bash-postfix-encrypt-filter/pgp/
ExecStart = /bin/bash /usr/local/bin/bash-postfix-encrypt-filter-sync-pgp.sh
ExecReload = /bin/kill -s HUP $MAINPID
ExecStop = /bin/kill -s TERM $MAINPID
PrivateTmp = true

[Install]
WantedBy = multi-user.target

Reading it today

There is no Restart= line. The design says that systemd restarts the service when it is found not running. This unit does not ask for that: the default is Restart=no, so a loop that dies stays dead until somebody starts it.
PIDFile= has no effect. Without Type= the unit is of type simple, systemd follows the process it started, and nobody writes that file.
ExecReload stops the service. The script has no handler for HUP, so a reload ends the Bash process.
After = network.target orders the unit after the network stack has been brought up; it does not mean that the network is configured, which is what network-online.target is for. The loop does not care: the first rsync happens at the first change of the directory.

Checked against current systemd

As built	Today
`PIDFile =` without `Type=`	Still valid, still without function here. systemd recommends `PIDFile=` only for `Type=forking` and says PID files should be avoided in new units
`After = network.target`	Still valid; `network-online.target` exists for units that need a configured network
`ExecStart`, `ExecReload`, `ExecStop`, `User`, `Group`, `PrivateTmp`, `WantedBy`	All still valid

The unit loads unchanged on a current system, and is as incomplete there as it was.