[docker-restapi]: use service dependency in supervisord to start services

dockers/docker-sonic-restapi/start.sh

@@ -2,8 +2,3 @@
 
 mkdir -p /var/sonic
 echo "# Config files managed by sonic-config-engine" > /var/sonic/config_status
-
-rm -f /var/run/rsyslogd.pid
-
-supervisorctl start rsyslogd
-supervisorctl start restapi

dockers/docker-sonic-restapi/supervisord.conf

@@ -3,19 +3,39 @@ logfile_maxbytes=1MB
 logfile_backups=2
 nodaemon=true
 
+[eventlistener:dependent-startup]
+command=python -m supervisord_dependent_startup
+autostart=true
+autorestart=unexpected
+startretries=0
+exitcodes=0,3
+events=PROCESS_STATE
+
 [eventlistener:supervisor-proc-exit-listener]
 command=/usr/bin/supervisor-proc-exit-listener --container-name restapi
 events=PROCESS_STATE_EXITED
 autostart=true
 autorestart=false
 
-[program:start.sh]
-command=/usr/bin/start.sh
+[program:rsyslogd]
+command=/usr/sbin/rsyslogd -n -iNONE
 priority=1
-autostart=true
-autorestart=false
+autostart=false
+autorestart=true
 stdout_logfile=syslog
 stderr_logfile=syslog
+dependent_startup=true
+
+[program:start]
+command=/usr/bin/start.sh
+priority=2
+autostart=false
+autorestart=false
+startsecs=0
+stdout_logfile=syslog
+stderr_logfile=syslog
+dependent_startup=true
+dependent_startup_wait_for=rsyslogd:running
 
 [program:restapi]
 command=/usr/bin/restapi.sh
@@ -24,11 +44,7 @@ autostart=false
 autorestart=true
 stdout_logfile=syslog
 stderr_logfile=syslog
+dependent_startup=true
+dependent_startup_wait_for=start:exited
+
 
-[program:rsyslogd]
-command=/usr/sbin/rsyslogd -n
-priority=2
-autostart=false
-autorestart=true
-stdout_logfile=syslog
-stderr_logfile=syslog