Swarm: Get Node Ip and Container IP from service - docker

Question

how could i get nodes ip and container ip (running on manager(s) and workers(s) node(s) ) from a created service?
I'd like to inspect this for studying round robin load balancing of docker swarm engine and develop a new load balancing.

Answer 1

To get the node IP address you can use below command:
docker node inspect self --format '{{ .Status.Addr }}'
To get the service IP address, Just add service-id in the end, like:
docker node inspect self --format '{{ .Status.Addr }}' service-id
To get the container IP address, use:
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container-id

Answer 2

I am assuming you mean getting all this information on your terminal using docker command, for a programming language integration check docker-py
Containers
To get managers and workers info you can use docker node command:
docker node ls
Gives you details on each node, for example:
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS
j74jxqb4wz38l2odl2seiiuzh * db-cluster-1 Ready Active Leader
As you can see it also includes a "manager status" field
Swarm nodes
docker service ps <SERVICE-NAME>
Gives you a list of each service node, its ID and status, for example:
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
ypd65x4i06nn db-cluster.1 severalnines/mariadb:latest db-cluster-1 Running Running 2 hours ago
278rdv7m4015 db-cluster.2 severalnines/mariadb:latest db-cluster-1 Running Running 2 hours ago
z9zr6xgnyuob db-cluster.3 severalnines/mariadb:latest db-cluster-1 Running Running 2 hours ago
then you can use inspect to get more detailed information on any object, for example:
docker inspect ypd65x4i06nn
check NetworksAttachments section to get network details

Answer 3

for getting the node IP address, the value is in different places depending on if the node is a worker or a manager.
docker node inspect node1 --pretty
ID: 0lkd116rve1rwbvfuonrfzdko
Hostname: node1
Joined at: 2022-09-18 16:16:28.6670527 +0000 utc
Status:
State: Ready
Availability: Active
Address: 192.168.64.5
Manager Status:
Address: 192.168.64.5:2377
Raft Status: Reachable
Leader: No
...
here node2 is manager
docker node inspect node2 --pretty
ID: u8tfyh5txt5qecgsi543pnimc
Hostname: node2
Joined at: 2022-09-19 09:05:57.91370814 +0000 utc
Status:
State: Ready
Availability: Active
Address: 0.0.0.0. <--------- CHECK HERE ---
Manager Status:
Address: 192.168.64.6:2377
Raft Status: Reachable
Leader: Yes
...
But you can make use of the go template syntax:
> docker node inspect node2 \
--format 'worker addr:{{ .Status.Addr }} {{printf "\n"}}manager addr: {{ .ManagerStatus.Addr }}'
worker addr:0.0.0.0
manager addr: 192.168.64.6:2377