<p>back with another head scratcher. I've got my kube cluster up and running, I've attached a mysql pod, a postgres pod, and associated volume/service mappings. These configurations are nearly identical with exception to the app name, port, and the information in the containers element. I mention this because this is seemingly where my issue is.</p>
<p>I can connect to my mysql instance at 'mysql' with no issues from my local machine using forwarding, and from any pod. But my postgres pod.. none of my other pods can seemingly access it. I can connect to 'postgres' using my DB console locally using forwarding, but the pods get 'Connection Refused' whenever they try to connect.</p>
<p>Here's an example. I loaded up a simple alpine image, installed the postgres client, connected to mysql, and then attempted to connect to my postgres instance.</p>
<pre><code>$ cat utils.yaml
apiVersion: v1
kind: Pod
metadata:
  name: utils
  namespace: default
spec:
  restartPolicy: Always
  serviceAccountName: default
  containers:
  - name: utils
    image: alpine:latest
    command:
      - sleep
      - &quot;14400&quot;
    imagePullPolicy: IfNotPresent
$ kubectl apply -f utils.yaml
kupod/utils created
$ kubectl exec -it utils -- /bin/ash
# apk add mysql-client
fetch https://dl-cdn.alpinelinux.org/alpine/v3.14/main/x86_64/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.14/community/x86_64/APKINDEX.tar.gz
(1/7) Installing mariadb-common (10.5.12-r0)
(2/7) Installing libgcc (10.3.1_git20210424-r2)
(3/7) Installing ncurses-terminfo-base (6.2_p20210612-r0)
(4/7) Installing ncurses-libs (6.2_p20210612-r0)
(5/7) Installing libstdc++ (10.3.1_git20210424-r2)
(6/7) Installing mariadb-client (10.5.12-r0)
(7/7) Installing mysql-client (10.5.12-r0)
Executing busybox-1.33.1-r3.trigger
OK: 39 MiB in 21 packages
# apk add postgresql-client
(1/6) Installing gdbm (1.19-r0)
(2/6) Installing libsasl (2.1.27-r12)
(3/6) Installing libldap (2.4.58-r0)
(4/6) Installing libpq (13.4-r0)
(5/6) Installing readline (8.1.0-r0)
(6/6) Installing postgresql-client (13.4-r0)
Executing busybox-1.33.1-r3.trigger
OK: 42 MiB in 27 packages
# mysql -h mysql -utestuser -p
Enter password:
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 155
Server version: 5.6.51 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [(none)]&gt; Ctrl-C -- exit!
Aborted
# psql -h postgres -U testuser
psql: error: could not connect to server: Connection refused
    Is the server running on host &quot;postgres&quot; (192.168.152.97) and accepting
    TCP/IP connections on port 5432?
</code></pre>
<p>Here are my yamls for postgres:</p>
<pre><code>---
#create secrets and maps using:
#kubectl create configmap postgres --from-file=postgres-config/
#kubectl create secret generic postgres --from-file=postgres-ecrets/
---
apiVersion: v1
kind: Service
metadata:
  name: postgres
  namespace: default
  labels:
    app: postgres
spec:
  ports:
  - name: postgres
    port: 5432
  selector:
    app: postgres
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres
  namespace: default
spec:
  selector:
    matchLabels:
      app: postgres
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: postgres
    spec:
      securityContext:
        runAsUser: 70
        fsGroup: 70
      containers:
      - name: postgres
        image: postgres:alpine
        imagePullPolicy: IfNotPresent
        args:
          - -c
          - hba_file=/etc/postgres-config/pg_hba.conf
          - -c
          - config_file=/etc/postgres-config/postgresql.conf
        env:
          - name: PGDATA
            value: /var/lib/postgres-data
          - name: POSTGRES_PASSWORD_FILE
            value: /etc/postgres-secrets/postgres-pwd.txt
        ports:
        - name: postgres
          containerPort: 5432
          hostPort: 5432
          protocol: TCP
        volumeMounts:
        - name: postgres-config
          mountPath: /etc/postgres-config
        - name: postgres-storage
          mountPath: /var/lib/postgres-data
          subPath: postgres
        - name: postgres-secrets
          mountPath: /etc/postgres-secrets
      volumes:
      - name: postgres-config
        configMap:
          name: postgres      
      - name: postgres-storage
        persistentVolumeClaim:
          claimName: postgres-claim
      - name: postgres-secrets
        secret:
          secretName: postgres
          defaultMode: 384

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: postgres-gluster-pv
  namespace: default
spec:
  capacity:
    storage: 10Gi
  accessModes:
  - ReadWriteMany
  glusterfs:
    endpoints: gluster-cluster
    path: /gv0
    readOnly: false
  persistentVolumeReclaimPolicy: Retain
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: postgres-claim
  namespace: default
spec:
  accessModes:
  - ReadWriteMany
  resources:
     requests:
       storage: 10Gi
</code></pre>
<p>And finally, my postgress.conf and pg_hba.conf:</p>
<pre><code>$ cat postgres.conf
ssl = on
ssl_ca_file = '/etc/postgres-secrets/root.crt'
ssl_cert_file = '/etc/postgres-secrets/server.crt'
ssl_key_file = '/etc/postgres-secrets/server.key'
$ cat pg_hba.conf
# Trust local connection - no password required.
local    all             all                                     trust
hostssl  all             all             all         md5
</code></pre>

The Kaese
<p>Once again...figured it out. @Sami's comment led me down the right path. I had listen-address set to &quot;localhost&quot;, it needs to be set to &quot;*&quot;</p>
