commit bd3106373453ff27107f1d93e3628d033696b3d4
parent 250bb97f0dc3136394a64c58c128af6cbc9fd586
Author: Cem Keylan <cem@ckyln.com>
Date: Tue, 7 Jul 2020 14:54:09 +0300
sysmgr: comment cleanup
Diffstat:
| M | sysmgr | | | 101 | +++++++++++++++++++++++++++++++++++-------------------------------------------- |
1 file changed, 45 insertions(+), 56 deletions(-)
diff --git a/sysmgr b/sysmgr
@@ -47,17 +47,16 @@ usage() {
checkprocess() {
- # This function checks if the process is still alive and
- # returns 0 or 1 accordingly. It checks the /proc directory
- # first (which exists in most Linux systems, but not all)
- # and fallbacks to kill if it doesn't. There are three
- # reasons for preferring /proc over kill:
+ # This function checks if the process is still alive and returns 0 or 1
+ # accordingly. It checks the /proc directory first (which exists in most
+ # Linux systems, but not all) and fallbacks to kill if it doesn't. There are
+ # three reasons for preferring /proc over kill:
#
# 1: We don't need to spawn an extra process.
- # 2: We can check processes we don't own, which eliminates
- # the requirement of being root.
- # 3: Checking the existence of a directory is much faster and
- # more efficient than sending a signal to a process.
+ # 2: We can check processes we don't own, which eliminates the requirement
+ # of being root.
+ # 3: Checking the existence of a directory is much faster and more efficient
+ # than sending a signal to a process.
[ -d /proc ] || {
kill -0 "$1" || return 1
return 0
@@ -67,9 +66,8 @@ checkprocess() {
cleanup() {
- # Clean the service run directory so that it can be
- # restarted. Do not remove the run directory if lock
- # file exists.
+ # Clean the service run directory so that it can be restarted. Do not remove
+ # the run directory if lock file exists.
[ -e "${RUNDIR:?}/${service##*/}/lock" ] && return 0
rm -rf "${RUNDIR:?}/${service##*/}"
@@ -78,10 +76,9 @@ cleanup() {
term() {
- # This function is executed when the sysmgr receives an
- # interrupt or a hangup signal. It enters the termination
- # state where it forwards SIGTERM to every other runsyssv
- # process that have their process ids in the RUNDIR
+ # This function is executed when the sysmgr receives an interrupt or a
+ # hangup signal. It enters the termination state where it forwards SIGTERM
+ # to every other runsyssv process that have their process ids in the RUNDIR.
for process in "${RUNDIR:?}"/*/syspid ; do
kill -15 "$(cat "$process")" 2>/dev/null
@@ -90,15 +87,17 @@ term() {
# Wait for the redirections to happen
sleep 1
- # Remove the RUNDIR so we can do a fresh start when we
- # are re-initiating the program.
+ # Remove the RUNDIR so we can do a fresh start when we are re-initiating the
+ # program.
rm -rf "${RUNDIR}"
exit 0
}
getpid() {
+
# This is a function to retrieve the pid from the RUNDIR
+
[ -f "${RUNDIR:?}/$1/${2:-pid}" ] ||
{ error "pid file for $1 could not be found" ; return 1 ;}
read -r pid < "${RUNDIR:?}/$1/${2:-pid}"
@@ -106,10 +105,9 @@ getpid() {
redirectsignal() {
- # We redirect signal that was sent to runsyssv so that
- # those programs are stopped with the exact kill command.
- # Adding a lock file ensures that the directory is not
- # cleaned up.
+ # We redirect signal that was sent to runsyssv so that those programs are
+ # stopped with the exact kill command. Adding a lock file ensures that the
+ # directory is not cleaned up.
sig="$1"
log "${sig:-TERM}" > "${RUNDIR:?}/${service##*/}/lock"
@@ -120,9 +118,9 @@ redirectsignal() {
fn_sysmgr() {
[ "$1" ] && usage
- # Start sanity checks. We first check that we have
- # the "$SYSDIR" variable. We then check whether the
- # given SYSDIR exists, and has service files installed.
+ # Start sanity checks. We first check that we have the "$SYSDIR" variable.
+ # We then check whether the given SYSDIR exists, and has service files
+ # installed.
[ "$SYSDIR" ] || die "Please specify service directory"
[ -d "$SYSDIR" ] || die "$SYSDIR does not exist."
[ "$(ls -1 "$SYSDIR")" ] || error "No service file is found"
@@ -131,21 +129,19 @@ fn_sysmgr() {
# Add pid to $RUNDIR before starting loops
log "$$" > "$RUNDIR/pid"
- # We redirect signals to the 'term' function so that
- # we send kill signals to all sysmgr processes.
+ # We redirect signals to the 'term' function so that we send kill signals to
+ # all sysmgr processes.
trap term INT HUP QUIT ABRT TERM
- # Lots of loops here. The first while loop is to
- # make sure that the sysmgr does not exist. The
- # for loop is to run every single service on the
- # $SYSDIR. We then fork the runsyssv function to
- # the background. This ensures that we don't have
- # to wait until runsyssv has finished, which is a
+ # Lots of loops here. The first while loop is to make sure that the sysmgr
+ # does not exist. The for loop is to run every single service on the
+ # $SYSDIR. We then fork the runsyssv function to the background. This
+ # ensures that we don't have to wait until runsyssv has finished, which is a
# program that is not supposed to exit.
while sleep 1 ; do
[ "$(ls -A "$SYSDIR" )" ] && for service in "$SYSDIR"/* ; do
[ -x "$service" ] || error "$service is not an executable file"
- ! [ -d "$RUNDIR/${service##*/}" ] && runsyssv "$service" &
+ ! [ -d "$RUNDIR/${service##*/}" ] && fn_runsyssv "$service" &
done
done
}
@@ -158,29 +154,25 @@ fn_runsyssv() {
# Record service name in a variable
service="$1"
- # This is the simplest way of checking whether a
- # service is running (or killed by the user with
- # ctl, so that it does not run again).
+ # This is the simplest way of checking whether a service is running (or
+ # killed by the user with ctl, so that it does not run again).
[ -e "$RUNDIR/${service##*/}" ] && exit 1
- # Create the run directory for the service where
- # we will be adding the pid value when we start
- # the process.
+ # Create the run directory for the service where we will be adding the pid
+ # value when we start the process.
mkdir -p "$RUNDIR/${service##*/}"
- # Start the service script. If the service fails
- # exit with failure code 1. If the service exits
- # without a failure (which it probably shouldn't)
- # exit with code 0
+ # Start the service script. If the service fails exit with failure code 1.
+ # If the service exits without a failure (which it probably shouldn't) exit
+ # with code 0.
"$service" &
svpid="$!"
log "$svpid" > "$RUNDIR/${service##*/}/pid"
log "$$" > "$RUNDIR/${service##*/}/syspid"
for sig in INT HUP QUIT ABRT TERM ; do
- # We want to trap every signal with their own
- # value so that we kill the service with the
- # requested signal.
+ # We want to trap every signal with their own value so that we kill the
+ # service with the requested signal.
# shellcheck disable=SC2064
trap "redirectsignal $sig" $sig
done
@@ -188,7 +180,7 @@ fn_runsyssv() {
# Wait until service goes down
wait
- # Do a cleanup when the service is killed
+ # Do a cleanup when the service is killed.
cleanup
}
@@ -196,8 +188,8 @@ fn_svctl() {
# Check if the RUNDIR exists
[ -d "$RUNDIR" ] || die "$RUNDIR could not be found, are you sure sysmgr is running?"
- # Check that there are at least two arguments,
- # get the first argument into a job variable.
+ # Check that there are at least two arguments, get the first argument into a
+ # job variable.
[ "$2" ] || usage; job="$1"; shift
for service; do
# This will retrieve the process id from the service directory.
@@ -205,8 +197,6 @@ fn_svctl() {
case "$job" in
stat|status)
- # Out function will not give an error, so we don't
- # need an if statement here.
# shellcheck disable=2015
checkprocess "$pid" && out "$service: OK" ||
out "$service: DOWN"
@@ -226,8 +216,8 @@ fn_svctl() {
up|start)
rm -rf "${RUNDIR:?}/$service" ;;
once)
- # This will place a lockfile upon start, so sysmgr
- # will not attempt to restart it, if it goes down.
+ # This will place a lockfile upon start, so sysmgr will not
+ # attempt to restart it, if it goes down.
fn_svctl start "$service"
sleep 1
log once > "${RUNDIR:?}/$service/lock"
@@ -238,8 +228,7 @@ fn_svctl() {
}
main() {
- # Call the appropriate function depending on the
- # name of the program.
+ # Call the appropriate function depending on the name of the program.
case "${0##*/}" in
sysmgr) fn_sysmgr "$@" ;;
runsyssv) fn_runsyssv "$@" ;;
