add comments to manifest files for postgres operator

Author: Yannic Nevado Hidalgo

manifests/minimal-postgres-manifest.yaml

@@ -1,44 +1,63 @@
+# custom api from zalando
+# https://github.com/zalando/postgres-operator/tree/master/pkg/apis/acid.zalan.do/v1
 apiVersion: "acid.zalan.do/v1"
+# custom api object postgresql
+# https://github.com/zalando/postgres-operator/blob/master/pkg/apis/acid.zalan.do/v1/postgresql_type.go
 kind: postgresql
 metadata:
+  # name of the pod
+  # podtemplate is statefulset -> every instance has the same name with own ordinalindex
   name: acid-minimal-cluster
+  # namespace in k82 where the pods will be created
   namespace: zalando-postgres
 spec:
+  # required parameter from patroni
   teamId: "ACID"
+  # size and accessmode(=defined in storageclass) for persistent volume claim
   volume:
     size: 1Gi
     storageClass: standard
+  # number of pods
+  # 1 is master, others replicas
   numberOfInstances: 3
+  # define some users with access rights
   users:
     zalando:  # database owner
     - superuser
     - createdb
     foo_user: []  # role for application foo
+  # define some database with its owner
   databases:
     foo: zalando  # dbname: owner
     test: zalando
+  # needed for shared_memory, in docker default=64mb 
   enableShmVolume: true
   postgresql:
     version: "11"
+    # parameters for postgresql.conf
+    # can be edited after kubectl apply for example and restart spilo service
     parameters:
       shared_buffers: "128MB"
       max_connections: "10"
       log_statement: "all"
       log_destination: "stderr"
       log_directory: "/var/log/postgresql"
+  # define the minimum and limit of resources of an postgres database container 
   resources:
     requests:
       cpu: 15m
       memory: 150Mi
     limits:
       cpu: 300m
       memory: 275Mi
+  # parameters for initializing database    
   patroni:
     initdb:
       encoding: "UTF8"
       locale: "en_US.UTF-8"
       data-checksums: "true"
       auth-host: "scram-sha-256"
+    # entries for host-based access file in postgres  
     pg_hba:
     - hostssl all all 0.0.0.0/0 scram-sha-256
     - host    all all 0.0.0.0/0 scram-sha-256

manifests/operator-service-account-rbac.yaml

@@ -1,10 +1,13 @@
+# custom k8s ressource ServiceAccount
 apiVersion: v1
 kind: ServiceAccount
 metadata:
   name: zalando-postgres-operator
   namespace: zalando-postgres
 
 ---
+# define ClusterRole for postgres-operator deployment
+# on which apis and resources can the operator execute which operations
 apiVersion: rbac.authorization.k8s.io/v1beta1
 kind: ClusterRole
 metadata:
@@ -161,14 +164,18 @@ rules:
   - patch
   - update
 ---
+# bin clusterrole and serviceaccount from postgres-operator
+# custom k8s ressource
 apiVersion: rbac.authorization.k8s.io/v1
 kind: ClusterRoleBinding
 metadata:
   name: zalando-postgres-operator
+# reference definied ClusterRole for postgres-operator
 roleRef:
   apiGroup: rbac.authorization.k8s.io
   kind: ClusterRole
   name: zalando-postgres-operator
+# bin ti specified ServiceAccount
 subjects:
 - kind: ServiceAccount
 # note: the cluster role binding needs to be defined

manifests/postgres-operator.yaml

@@ -1,33 +1,42 @@
+# custom k8s ressource Deployment
 apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: postgres-operator
 spec:
+  # number of replicas for postgres-operator
   replicas: 1
+  # specification is for evervy replica with the definied selectors
   selector:
     matchLabels:
       name: postgres-operator
   template:
     metadata:
+      # set labels for every postgres-operator replica
       labels:
         name: postgres-operator
     spec:
+      # bin ServiceAccount with definied ClusterRole to every replica
       serviceAccountName: zalando-postgres-operator
+      # every postgres-operator Deployment Pod contains one container
       containers:
       - name: postgres-operator
         image: registry.opensource.zalan.do/acid/postgres-operator:v1.2.0
         imagePullPolicy: IfNotPresent
+        # set requested and limited resources for the container
         resources:
           requests:
             cpu: 500m
             memory: 250Mi
           limits:
             cpu: 2000m
             memory: 500Mi
+        # define at which user the postgres-operator container will run    
         securityContext:
           runAsUser: 1000
           runAsNonRoot: true
           readOnlyRootFilesystem: true
+        # set some environment variables defined in "before" created ConfigMap with the name postgres-operator  
         env:
         # provided additional ENV vars can overwrite individual config map entries
         - name: CONFIG_MAP_NAME