[docker-fpm-frr]: Start bgpd after zebra was started (#5038)

fixes https://github.com/Azure/sonic-buildimage/issues/5026
Explanation:
In the log from the issue I found:
```
I see following in the log
Jul 22 21:13:06.574831 vlab-01 WARNING bgp#bgpd[49]: [EC 33554499] sendmsg_nexthop: zclient_send_message() failed
```
Analyzing source code I found that the error message could be issues only when `zclient_send_rnh()` return less than 0.
```
	ret = zclient_send_rnh(zclient, command, p, exact_match,
			       bnc->bgp->vrf_id);
	/* TBD: handle the failure */
	if (ret < 0)
		flog_warn(EC_BGP_ZEBRA_SEND,
			  "sendmsg_nexthop: zclient_send_message() failed");
```
I checked [zclient_send_rnh()](88351c8f6d/lib/zclient.c (L654)) and found that this function will return the exit code which the function gets from [zclient_send_message()](88351c8f6d/lib/zclient.c (L266)) But the latter function could return not 0 in two cases:
1.	bgpd didn’t connect to the zclient socket yet [code](88351c8f6d/lib/zclient.c (L269))
2.	The socket was closed. But in this case we would receive the error message in the log. (And I can find the message in the log when we reboot sonic) [code](88351c8f6d/lib/zclient.c (L277))

Also I see from the logs that client connection was set later we had the issue in bgpd.

Bgpd.log
```
Jul 22 21:13:06.574831 vlab-01 WARNING bgp#bgpd[49]: [EC 33554499] sendmsg_nexthop: zclient_send_message() failed
```
Vs
Zebra.log
```
Jul 22 21:13:12.713249 vlab-01 NOTICE bgp#zebra[48]: client 25 says hello and bids fair to announce only static routes vrf=0
Jul 22 21:13:12.820352 vlab-01 NOTICE bgp#zebra[48]: client 30 says hello and bids fair to announce only bgp routes vrf=0
Jul 22 21:13:12.820352 vlab-01 NOTICE bgp#zebra[48]: client 33 says hello and bids fair to announce only vnc routes vrf=0
```
So in our case we should start zebra first. Wait until it is started and then start bgpd and other daemons.

**- How I did it**

I changed a graph to start daemons in the following order:
1. First start zebra
2. Then starts staticd and bgpd
3. Then starts vtysh -b and bgpeoi after bgpd is started.
This commit is contained in:
pavel-shirshov 2020-07-25 03:48:47 -07:00 committed by GitHub
parent 5c67a3c31d
commit 89184038fd
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

View File

@ -47,7 +47,7 @@ startsecs=0
stdout_logfile=syslog
stderr_logfile=syslog
dependent_startup=true
dependent_startup_wait_for=rsyslogd:running
dependent_startup_wait_for=zebra:running
[program:bgpd]
command=/usr/lib/frr/bgpd -A 127.0.0.1 -M snmp
@ -59,7 +59,7 @@ startsecs=0
stdout_logfile=syslog
stderr_logfile=syslog
dependent_startup=true
dependent_startup_wait_for=rsyslogd:running
dependent_startup_wait_for=zebra:running
[program:fpmsyncd]
command=fpmsyncd
@ -93,7 +93,7 @@ startsecs=0
stdout_logfile=syslog
stderr_logfile=syslog
dependent_startup=true
dependent_startup_wait_for=rsyslogd:running
dependent_startup_wait_for=bgpd:running
{% endif %}
{% if WARM_RESTART is defined and WARM_RESTART.bgp is defined and WARM_RESTART.bgp.bgp_eoiu is defined and WARM_RESTART.bgp.bgp_eoiu == "true" %}
@ -107,5 +107,5 @@ startretries=0
stdout_logfile=syslog
stderr_logfile=syslog
dependent_startup=true
dependent_startup_wait_for=rsyslogd:running
dependent_startup_wait_for=bgpd:running
{% endif %}