sysmgr

commit e74a213e9c64b65cc76c141cad503f76536dfe1a
parent 5828e0f32dd258ed5584cf7c3a8e2387bf5ce6b7
Author: Cem Keylan <cem@ckyln.com>
Date:   Mon, 23 Mar 2020 23:44:10 +0300

sysmgr-needs: add utility to repository

Diffstat:
A
utils/sysmgr-needs
 | 
29
+++++++++++++++++++++++++++++

1 file changed, 29 insertions(+), 0 deletions(-)
diff --git a/utils/sysmgr-needs b/utils/sysmgr-needs
@@ -0,0 +1,29 @@
+#!/bin/sh
+
+# A simple utility for dependency tracking with sysmgr.
+
+[ "$1" ] || { cat <<EOF
+usage: ${0##*/} [dep1] [dep2] [dep...]
+
+sysmgr utility for service dependency tracking.
+This program waits until all dependencies are
+started with sysmgr.
+EOF
+              exit 1 ;}
+
+checkprocess() {
+    # This is quite similar to the function with the
+    # same name on sysmgr, except it gets the pid itself.
+    read -r pid < "$RUNDIR/$1/pid"
+    [ -d /proc ] || {
+        kill -0 "$pid" || return 1
+        return 0
+    }
+    [ -d "/proc/$pid" ] || return 1
+    return 0
+}
+
+for service in "$@" ; do
+    # We parallelize and wait for all checks to pass.
+    while :; do [ -r "${RUNDIR:=/run/sysmgr}/${service}/pid" ] && checkprocess "$service" && break ; done &
+done; wait