templates: use pg_isready as liveness probe

Resolves: #195

Author: pkubatrh

Diff for: examples/postgresql-ephemeral-template.json

@@ -127,11 +127,11 @@
                   }
                 },
                 "livenessProbe": {
+                  "exec": {
+                    "command": [ "/bin/sh", "-i", "-c", "pg_isready -h 127.0.0.1 -p 5432" ]
+                  },
                   "timeoutSeconds": 1,
-                  "initialDelaySeconds": 30,
-                  "tcpSocket": {
-                    "port": 5432
-                  }
+                  "initialDelaySeconds": 30
                 },
                 "env": [
                   {

Diff for: examples/postgresql-persistent-template.json

@@ -144,11 +144,11 @@
                   }
                 },
                 "livenessProbe": {
+                  "exec": {
+                    "command": [ "/bin/sh", "-i", "-c", "pg_isready -h 127.0.0.1 -p 5432" ]
+                  },
                   "timeoutSeconds": 1,
-                  "initialDelaySeconds": 30,
-                  "tcpSocket": {
-                    "port": 5432
-                  }
+                  "initialDelaySeconds": 30
                 },
                 "env": [
                   {

Diff for: examples/replica/postgresql_replica.json

@@ -211,11 +211,11 @@
                   }
                 },
                 "livenessProbe": {
+                  "exec": {
+                    "command": [ "/bin/sh", "-i", "-c", "pg_isready -h 127.0.0.1 -p 5432" ]
+                  },
                   "timeoutSeconds": 1,
-                  "initialDelaySeconds": 30,
-                  "tcpSocket": {
-                    "port": 5432
-                  }
+                  "initialDelaySeconds": 30
                 },
                 "env": [
                   {
@@ -322,11 +322,11 @@
                   }
                 },
                 "livenessProbe": {
+                  "exec": {
+                    "command": [ "/bin/sh", "-i", "-c", "pg_isready -h 127.0.0.1 -p 5432" ]
+                  },
                   "timeoutSeconds": 1,
-                  "initialDelaySeconds": 30,
-                  "tcpSocket": {
-                    "port": 5432
-                  }
+                  "initialDelaySeconds": 30
                 },
                 "env": [
                   {