Connect to events.pagerduty.com:443 connect timed out - jenkins

Question

Jenkins 2.82
Jenkins master - From this machine, I don't have access to internet/outside world.
Jenkins slave server, running docker containers (for slave server), do have access to outside world/internet.
I installed PagerDuty Plugin and configured it correctly in a job to send notification per failure and when the status is back to normal.
When I ran the job, I got the following error mesg com.mashape.unirest.http.exceptions.UnirestException: org.apache.http.conn.ConnectTimeoutException: Connect to events.pagerduty.com:443 [events.pagerduty.com/54.244.255.45, events.pagerduty.com/54.241.36.66, events.pagerduty.com/104.45.235.10] failed: connect timed out.
0:49:44
10:49:44 Resolving incident
10:50:14 Error while trying to resolve
10:50:14 com.mashape.unirest.http.exceptions.UnirestException: org.apache.http.conn.ConnectTimeoutException: Connect to events.pagerduty.com:443 [events.pagerduty.com/54.244.255.45, events.pagerduty.com/54.241.36.66, events.pagerduty.com/104.45.235.10] failed: connect timed out
10:50:14 Build step 'PagerDuty Incident Trigger' marked build as failure
10:50:14 Notifying upstream projects of job completion
10:50:14 Finished: FAILURE
I logged onto the slave machine first and tried to ping the IPs next to events.pagerduty.com server (as listed above) and ping worked fine. Doing telnet on port 443 (ssh) also gave valid output.
As the slave servers are actually docker containers, I went inside one of the container slave server and did the same (ping, telnet on 443 for those
events.pagerduty.com IPs, nslookup and nc / ncat etc and output looks good).
Here, Im inside the docker slave container's host i.e. I ran docker exec -it shenazi_ninza bash and I'm now inside the container's host/IP:
root#da5ca3fef1c8:/data# hostname
da5ca3fef1c8
root#da5ca3fef1c8:/data# hostname; hostname -i
da5ca3fef1c8
172.17.137.77
root#da5ca3fef1c8:/data# nslookup events.pagerduty.com
Server: 17.178.6.10
Address: 17.178.6.10#53
Non-authoritative answer:
events.pagerduty.com canonical name = events.gslb.pagerduty.com.
Name: events.gslb.pagerduty.com
Address: 54.241.36.66
Name: events.gslb.pagerduty.com
Address: 54.245.112.46
Name: events.gslb.pagerduty.com
Address: 104.45.235.10
root#da5ca3fef1c8:/data#
root#da5ca3fef1c8:/data# for s in `nslookup events.pagerduty.com|grep "Address: [0-9]"|sed "s/ //g"|cut -d':' -f2`; do echo Server: $s; telnet $s 443; done
Server: 54.245.112.46
Trying 54.245.112.46...
Connected to 54.245.112.46.
Escape character is '^]'.
^]
telnet> quit
Connection closed.
Server: 104.45.235.10
Trying 104.45.235.10...
Connected to 104.45.235.10.
Escape character is '^]'.
^]
telnet> quit
Connection closed.
Server: 54.241.36.66
Trying 54.241.36.66...
Connected to 54.241.36.66.
Escape character is '^]'.
^]
telnet> quit
Connection closed.
root#da5ca3fef1c8:/data# for s in `nslookup events.pagerduty.com|grep "Address: [0-9]"|sed "s/ //g"|cut -d':' -f2`; do echo Server: $s; telnet $s 443; done
Server: 54.245.112.46
Trying 54.245.112.46...
Connected to 54.245.112.46.
Escape character is '^]'.
^]
telnet> quit
Connection closed.
Server: 54.241.36.66
Trying 54.241.36.66...
Connected to 54.241.36.66.
Escape character is '^]'.
^]
telnet> quit
Connection closed.
Server: 54.244.255.45
Trying 54.244.255.45...
Connected to 54.244.255.45.
Escape character is '^]'.
^]
telnet> quit
Connection closed.
root#da5ca3fef1c8:/data# ^C
root#da5ca3fef1c8:/data# nc -v -w 1 events.pagerduty.com 443
Connection to events.pagerduty.com 443 port [tcp/https] succeeded!
root#da5ca3fef1c8:/data#
PagerDuty integration in Jenkins job's configuration is available under POST Built Actions area.
My question is, isn't the whole job running on the slave server (aka container's slave from where I have access to the outside world and Im able to connect to events.pagerduty.com server)?
It seems like Jenkins is running anything under the POST Build Data section, on the master Jenkins instance from where I don't have access to events.pagerduty.com (ping/telnet etc)? As we don't want Jenkins master to have outside world access, how can this issue be resolved so that I can get alerted if a build fails for that job?

Answer 1

So, instead of opening all access, added the route to use a given gateway / route to access only events.pagerduty.com server
/sbin/route add -net 50.0.0.0/8 x.x.x.x dev eth0
/sbin/route add default gw x.y.z.someIP
/sbin/route add -net 50.0.0.0 netmask 255.0.0.0 gw x.y.z.ip
and now from master Jenkins I'm able to see/access just the events.pagerduty.com server / it's IPs.
x.y.z.ip is what you'll have to put.