Allow configuration of patroni's replication mode (#869)

* Add patroni parameters for `synchronous_mode`

* Update complete-postgres-manifest.yaml, removed quotation marks

* Update k8sres_test.go, adjust result for `Patroni configured`

* Update k8sres_test.go, adjust result for `Patroni configured`

* Update complete-postgres-manifest.yaml, set synchronous mode to false in this example

* Update pkg/cluster/k8sres.go

Does the same but is shorter. So we fix that it if you like.

Co-Authored-By: Felix Kunde <felix-kunde@gmx.de>

* Update docs/reference/cluster_manifest.md

Co-Authored-By: Felix Kunde <felix-kunde@gmx.de>

* Add patroni's `synchronous_mode_strict`

* Extend `TestGenerateSpiloConfig` with `SynchronousModeStrict`

Co-authored-by: Felix Kunde <felix-kunde@gmx.de>

charts/postgres-operator/crds/postgresqls.yaml

@@ -218,6 +218,10 @@ spec:
                   type: integer
                 retry_timeout:
                   type: integer
+                synchronous_mode:
+                  type: boolean
+                synchronous_mode_strict:
+                  type: boolean
                 maximum_lag_on_failover:
                   type: integer
             podAnnotations:

docs/reference/cluster_manifest.md

@@ -217,6 +217,12 @@ explanation of `ttl` and `loop_wait` parameters.
   automatically created by Patroni for cluster members and permanent replication
   slots. Optional.
 
+* **synchronous_mode**
+  Patroni `synchronous_mode` parameter value. The default is set to `false`. Optional.
+  
+* **synchronous_mode_strict**
+  Patroni `synchronous_mode_strict` parameter value. Can be used in addition to `synchronous_mode`. The default is set to `false`. Optional.
+  
 ## Postgres container resources
 
 Those parameters define [CPU and memory requests and limits](https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/)

manifests/complete-postgres-manifest.yaml

@@ -67,6 +67,8 @@ spec:
     ttl: 30
     loop_wait: &loop_wait 10
     retry_timeout: 10
+    synchronous_mode: false
+    synchronous_mode_strict: false
     maximum_lag_on_failover: 33554432
 
 # restore a Postgres DB with point-in-time-recovery

manifests/postgresql.crd.yaml

@@ -184,6 +184,10 @@ spec:
                   type: integer
                 maximum_lag_on_failover:
                   type: integer
+                synchronous_mode:
+                  type: boolean
+                synchronous_mode_strict:
+                  type: boolean
             podAnnotations:
               type: object
               additionalProperties:

pkg/apis/acid.zalan.do/v1/crds.go

@@ -358,6 +358,12 @@ var PostgresCRDResourceValidation = apiextv1beta1.CustomResourceValidation{
 							"maximum_lag_on_failover": {
 								Type: "integer",
 							},
+							"synchronous_mode": {
+								Type: "boolean",
+							},
+							"synchronous_mode_strict": {
+								Type: "boolean",
+							},
 						},
 					},
 					"podAnnotations": {

pkg/apis/acid.zalan.do/v1/postgresql_type.go

@@ -125,6 +125,8 @@ type Patroni struct {
 	RetryTimeout          uint32                       `json:"retry_timeout"`
 	MaximumLagOnFailover  float32                      `json:"maximum_lag_on_failover"` // float32 because https://github.com/kubernetes/kubernetes/issues/30213
 	Slots                 map[string]map[string]string `json:"slots"`
+	SynchronousMode       bool                         `json:"synchronous_mode"`
+	SynchronousModeStrict bool                         `json:"synchronous_mode_strict"`
 }
 
 //StandbyCluster

pkg/cluster/k8sres.go

@@ -49,6 +49,8 @@ type patroniDCS struct {
 	LoopWait                 uint32                       `json:"loop_wait,omitempty"`
 	RetryTimeout             uint32                       `json:"retry_timeout,omitempty"`
 	MaximumLagOnFailover     float32                      `json:"maximum_lag_on_failover,omitempty"`
+	SynchronousMode          bool                         `json:"synchronous_mode,omitempty"`
+	SynchronousModeStrict    bool                         `json:"synchronous_mode_strict,omitempty"`
 	PGBootstrapConfiguration map[string]interface{}       `json:"postgresql,omitempty"`
 	Slots                    map[string]map[string]string `json:"slots,omitempty"`
 }
@@ -283,6 +285,12 @@ PatroniInitDBParams:
 	if patroni.Slots != nil {
 		config.Bootstrap.DCS.Slots = patroni.Slots
 	}
+	if patroni.SynchronousMode {
+		config.Bootstrap.DCS.SynchronousMode = patroni.SynchronousMode
+	}
+	if patroni.SynchronousModeStrict != false {
+		config.Bootstrap.DCS.SynchronousModeStrict = patroni.SynchronousModeStrict
+	}
 
 	config.PgLocalConfiguration = make(map[string]interface{})
 	config.PgLocalConfiguration[patroniPGBinariesParameterName] = fmt.Sprintf(pgBinariesLocationTemplate, pg.PgVersion)

pkg/cluster/k8sres_test.go

@@ -70,11 +70,13 @@ func TestGenerateSpiloJSONConfiguration(t *testing.T) {
 				LoopWait:              10,
 				RetryTimeout:          10,
 				MaximumLagOnFailover:  33554432,
+				SynchronousMode:       true,
+				SynchronousModeStrict: true,
 				Slots:                 map[string]map[string]string{"permanent_logical_1": {"type": "logical", "database": "foo", "plugin": "pgoutput"}},
 			},
 			role:     "zalandos",
 			opConfig: config.Config{},
-			result:   `{"postgresql":{"bin_dir":"/usr/lib/postgresql/11/bin","pg_hba":["hostssl all all 0.0.0.0/0 md5","host    all all 0.0.0.0/0 md5"]},"bootstrap":{"initdb":[{"auth-host":"md5"},{"auth-local":"trust"},"data-checksums",{"encoding":"UTF8"},{"locale":"en_US.UTF-8"}],"users":{"zalandos":{"password":"","options":["CREATEDB","NOLOGIN"]}},"dcs":{"ttl":30,"loop_wait":10,"retry_timeout":10,"maximum_lag_on_failover":33554432,"slots":{"permanent_logical_1":{"database":"foo","plugin":"pgoutput","type":"logical"}}}}}`,
+			result:   `{"postgresql":{"bin_dir":"/usr/lib/postgresql/11/bin","pg_hba":["hostssl all all 0.0.0.0/0 md5","host    all all 0.0.0.0/0 md5"]},"bootstrap":{"initdb":[{"auth-host":"md5"},{"auth-local":"trust"},"data-checksums",{"encoding":"UTF8"},{"locale":"en_US.UTF-8"}],"users":{"zalandos":{"password":"","options":["CREATEDB","NOLOGIN"]}},"dcs":{"ttl":30,"loop_wait":10,"retry_timeout":10,"maximum_lag_on_failover":33554432,"synchronous_mode":true,"synchronous_mode_strict":true,"slots":{"permanent_logical_1":{"database":"foo","plugin":"pgoutput","type":"logical"}}}}}`,
 		},
 	}
 	for _, tt := range tests {