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I setup an OpenShift environment on my Mac with following versions:

Mac OS Sierra, Version:10.12.2 (16C67)
oc v1.5.0-alpha.2+e4b43ee
kubernetes v1.5.2+43a9be4
features: Basic-Auth

I was able to get the developer version running by doing a oc cluster up and gave the developer user administrative rights. Next, I added postgres container by issuing the following command:

oc new-app https://github.com/MojoJojo/authenticated-payments.git --name="postgres-keycloak" -l name="postgres-keycloak" --context-dir=postgres-keycloak

The command worked as expected and created a service with a Cluster Hostname and a Cluster IP address. The 'Cluster Hostname` in the admin console is reflecting as:

~ ❯❯❯ oc describe service/postgres-keycloak
Name:           postgres-keycloak
Namespace:      authenticated-collections
Labels:         app=postgres-keycloak
                name=postgres-keycloak
Selector:       app=postgres-keycloak,deploymentconfig=postgres-keycloak,name=postgres-keycloak
Type:           ClusterIP
IP:             172.30.123.160
Port:           5432-tcp    5432/TCP
Endpoints:
Session Affinity:   None
No events.


~ ❯❯❯ oc describe pods/postgres-keycloak-2-8r9n5                                                                                                                                                                       ⏎
Name:           postgres-keycloak-2-8r9n5
Namespace:      authenticated-collections
Security Policy:    restricted
Node:           192.168.65.2/192.168.65.2
Start Time:     Mon, 23 Jan 2017 03:24:41 +0200
Labels:         app=postgres-keycloak
                deployment=postgres-keycloak-2
                deploymentconfig=postgres-keycloak
                name=postgres-keycloak
Status:         Running

Next, I created another container as below:

oc new-app https://github.com/MojoJojo/authenticated-payments.git --name="jboss-keycloak" -l name="jboss-keycloak" --context-dir=jboss-keycloak

The above Git repository has a Dockerfile that declares the following environment variables:

POSTGRES_PORT_5432_TCP_ADDR=postgres-keycloak.authenticatedcollections.svc.cluster.local 

POSTGRES_PORT_5432_TCP_PORT=5432

I verified and the above environment variables are being set properly in the second container. The problem is that the second service is not able to connect to the 'postgres-keycloak' database in the first container.

Upon further investigation, I found that while I can ping POD, Cluster IP and Cluster hostnames, the psql client is only able to connect if I use the pod's IP address directly. My conclusion so far is that the DNS resolution is working fine - it is just the service configuration that seems a little messed up. It seems that the service proxy is not forwarding the request to the containers. Also, I'm not sure if the Endpoint count (Zero) in the above extract is the cause of the problem? My understand is that Endpoints are only used when services are accessed from outside the cluster.

I've tried installing other services like a web server for testing but it seems like none of the Cluster Hostnames or IP addresses work.

I would really appreciate any tips, hints and pointers to help troubleshoot and fix this issue.

Thank you for your help.

MojoJojo
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1 Answers1

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In your case I see that the namespace is authenticated-collections, but in the env variable you used authenticatedcollections.

I think it should be something like this:

POSTGRES_PORT_5432_TCP_ADDR=postgres-keycloak.authenticated-collections.svc.cluster.local

Is it just a typo in question or misconfiguration? Also, I assume that both pods run in the same project.

Bartosz Bierkowski
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