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

Signed-off-by: Guohan Lu <lguohan@gmail.com>

dockers/docker-sonic-telemetry/start.sh

@@ -2,10 +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 telemetry
-supervisorctl start dialout

dockers/docker-sonic-telemetry/supervisord.conf

@@ -3,27 +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 telemetry
 events=PROCESS_STATE_EXITED
 autostart=true
 autorestart=false
 
-[program:start.sh]
-command=/usr/bin/start.sh
-priority=1
-autostart=true
-autorestart=false
-stdout_logfile=syslog
-stderr_logfile=syslog
-
 [program:rsyslogd]
-command=/usr/sbin/rsyslogd -n
-priority=2
+command=/usr/sbin/rsyslogd -n -iNONE
+priority=1
 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:telemetry]
 command=/usr/bin/telemetry.sh
@@ -32,6 +44,8 @@ autostart=false
 autorestart=false
 stdout_logfile=syslog
 stderr_logfile=syslog
+dependent_startup=true
+dependent_startup_wait_for=start:exited
 
 [program:dialout]
 command=/usr/bin/dialout.sh
@@ -40,3 +54,5 @@ autostart=false
 autorestart=false
 stdout_logfile=syslog
 stderr_logfile=syslog
+dependent_startup=true
+dependent_startup_wait_for=telemetry:running