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>
Similar to systemd's RemainAfterExit=yes. Prevents the task from
re-running on runlevel re-entry and ensures the post: script runs
when explicitly stopped or when leaving valid runlevels.
Useful for tasks that set up persistent state like firewall rules:
task [2345] remain:yes \
post:/usr/sbin/teardown-firewall \
/usr/sbin/setup-firewall -- Firewall setup
Not supported for bootstrap-only tasks (runlevel S only) since these
are deleted immediately after completion.
in an initramfs, then transition to the real root filesystem. Useful
for systems requiring early boot tasks like LUKS unlock, LVM activation,
or network boot before mounting the real root.
Adds INIT_CMD_SWITCH_ROOT API command, `initctl switch-root` subcommand,
and HOOK_SWITCH_ROOT plugin hook point. The implementation gracefully
stops services, moves virtual filesystems (/dev, /proc, /sys, /run) to
the new root, deletes initramfs contents to free memory, then execs the
new init as PID 1.
See GitHub Discussion #292 for background.
Some 'respawn' type services, like gettys, may hog the CPU in error
states if the service immediately exits. E.g., due to missing dev.
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.
Cgroups v2 limits are hierarchical - a process is constrained by the
most restrictive limit in its ancestor chain, not just its immediate
cgroup. This patch updates cg_conf() to walk up the hierarchy and
report effective limits by comparing values at each level.
This fixes incorrect "max" (unlimited) reporting in 'initctl --json
status', 'initctl cgroup', and 'initctl top' when child cgroups have
no explicit limits but parents do.
For memory.max and cpu.max: take minimum (most restrictive)
For memory.min: take maximum (most protection)
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The PTY approach caused isatty() to return true for services using
the log directive, triggering programs like fprintd (using glib) to
emit ANSI escape codes and other TTY-specific formatting in syslog.
Using a standard pipe ensures isatty() correctly returns false, so
programs produce plain text output suitable for logging.
For services that require line-buffered output, users can wrap the
command with `stdbuf -oL` as documented in doc/config/logging.md.
Fixes#455
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Implement Linux capability support for services, allowing them to run
with minimal required privileges instead of running as root. This uses
the modern IAB (Inheritable, Ambient, Bounding) API from libcap.
All run/tasks must complete before Finit moves to runlevel 2. This
critical piece of information has mysteriously been missing from the
documentation since the start.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Joachim Wiberg