* src/pid.c: note the stale-pidfile-cleanup exception to the
documented "Finit does not touch pid:! pidfiles" rule.
* doc/config/services.md: add a user-facing paragraph on the same.
* doc/ChangeLog.md: add Unreleased section covering this PR --
stale pidfile cleanup, restart log with signal name and core
dump flag, and the SIGUNKOWN typo fix.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Conditions in Finit are dependencies: if A is asserted, service B is
allowed to run. When A goes through FLUX (e.g., upstream reloads),
dependents are PAUSED and then simply resumed when the condition is
reasserted -- this is the correct behavior for barrier-style deps
like <pid/syslogd>.
However, some setups have tightly coupled services where dependents
must be reloaded/restarted when an upstream service reloads, not just
resumed. E.g., the FRR routing stack on Infix OS:
netd <pid/mgmtd> ← zebra <!pid/netd> ← {staticd,ripd} <!pid/zebra>
When netd reloads (SIGHUP), zebra and its dependents must be restarted
to pick up the new configuration.
The new '~' condition prefix marks a dependency as flux-sensitive:
service <!~pid/netd> name:zebra ...
When the upstream condition goes FLUX and returns to ON, the dependent
is reloaded (SIGHUP) or restarted (noreload '!') instead of merely
resumed. Transitivity follows naturally through the condition chain.
Closes#416Closes#476
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Implement supplementary group support for services, allowing them to
access resources owned by multiple groups. Uses the @user:group,sup1,sup2
syntax to explicitly specify supplementary groups, in addition to now
reading group membership from /etc/group.
Joachim Wiberg