I have 2 nodes in my swarm cluster, a manager and a worker. I deployed a stack with 5 replicas distributed in those nodes. The yaml file has a network called webnet for the service web. After they are deployed I try to access the service, but when I use the IP address of the manager node it load-balances between 2 replicas, and if I use the IP address of the worker it load-balances among the other 3 replicas. So, using only docker, how can I load-balance among all the 5 replicas?
My nodes:
root@debiancli:~/docker# docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
5y256zrqwalq1hcxmqnnqc177 centostraining Ready Active 18.06.0-ce
mkg6ecl3x28uyyqx7gvzz0ja3 * debiancli Ready Active Leader 18.06.0-ce
Tasks in manager (self) and worker (centostraining):
root@debiancli:~/docker# docker node ps self
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
stbe721sstq7 getstartedlab_web.3 get-started:part2 debiancli Running Running 2 hours ago
6syjojjmyh0y getstartedlab_web.5 get-started:part2 debiancli Running Running 2 hours ago
root@debiancli:~/docker# docker node ps centostraining
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
wpvsd98vfwd1 getstartedlab_web.1 get-started:part2 centostraining Running Running less than a second ago
e3z8xybuv53l getstartedlab_web.2 get-started:part2 centostraining Running Running less than a second ago
sd0oi675c2am getstartedlab_web.4 get-started:part2 centostraining Running Running less than a second ago
The stack and its tasks:
root@debiancli:~/docker# docker stack ls
NAME SERVICES ORCHESTRATOR
getstartedlab 1 Swarm
root@debiancli:~/docker# docker stack ps getstartedlab
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
wpvsd98vfwd1 getstartedlab_web.1 get-started:part2 centostraining Running Running less than a second ago
e3z8xybuv53l getstartedlab_web.2 get-started:part2 centostraining Running Running less than a second ago
stbe721sstq7 getstartedlab_web.3 get-started:part2 debiancli Running Running 2 hours ago
sd0oi675c2am getstartedlab_web.4 get-started:part2 centostraining Running Running less than a second ago
6syjojjmyh0y getstartedlab_web.5 get-started:part2 debiancli Running Running 2 hours ago
The networks (getstartedlab_webnet is used by my tasks)
root@debiancli:~/docker# docker network ls
NETWORK ID NAME DRIVER SCOPE
b95dd9ee2ae6 bridge bridge local
63578897e920 docker_gwbridge bridge local
x47kwsfa23oo getstartedlab_webnet overlay swarm
7f77ad495edd host host local
ip8czm66ofng ingress overlay swarm
f2cc6118fde7 none null local
docker-compose.yml used to deploy the stack:
root@debiancli:~/docker#cat docker-compose.yml
version: "3"
services:
web:
image: get-started:part2
deploy:
replicas: 5
resources:
limits:
cpus: "0.1"
memory: 50M
restart_policy:
condition: on-failure
ports:
- "4000:80"
networks:
- webnet
networks:
webnet:
Accessing the service from a third machine (this curl and grep pulls the container name)
[Ubuntu:~]$ debiancli=192.168.182.129
[Ubuntu:~]$ centostraining=192.168.182.133
[Ubuntu:~]$ curl -s $debiancli:4000 | grep -oP "(?<=</b> )[^<].{11}"
f4c1e3ff53f2
[Ubuntu:~]$ curl -s $debiancli:4000 | grep -oP "(?<=</b> )[^<].{11}"
de2110bee2f7
[Ubuntu:~]$ curl -s $debiancli:4000 | grep -oP "(?<=</b> )[^<].{11}"
f4c1e3ff53f2
[Ubuntu:~]$ curl -s $debiancli:4000 | grep -oP "(?<=</b> )[^<].{11}"
de2110bee2f7
[Ubuntu:~]$ curl -s $debiancli:4000 | grep -oP "(?<=</b> )[^<].{11}"
f4c1e3ff53f2
[Ubuntu:~]$ curl -s $debiancli:4000 | grep -oP "(?<=</b> )[^<].{11}"
de2110bee2f7
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
72b757f92983
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
d2e824865436
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
b53c3fd0cfbb
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
72b757f92983
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
d2e824865436
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
b53c3fd0cfbb
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
72b757f92983
[Ubuntu:~]$ curl -s $centostraining:4000 | grep -oP "(?<=</b> )[^<].{11}"
d2e824865436
Notice that when I probe debiancli (swarm manager) it loops through containers f4c1e3ff53f2 and de2110bee2f7 only, that is, the 2 replicas running on the manager and the same happens for the 3 replicas in centostraining (swarm worker). So, what am I missing?