implement sidecars for pooler

charts/postgres-operator/crds/postgresqls.yaml

@@ -173,6 +173,12 @@ spec:
                             pattern: '^(\d+(e\d+)?|\d+(\.\d+)?(e\d+)?[EPTGMK]i?)$'
                   schema:
                     type: string
+                  sidecars:
+                    type: array
+                    nullable: true
+                    items:
+                      type: object
+                      x-kubernetes-preserve-unknown-fields: true
                   user:
                     type: string
               databases:

docs/reference/cluster_manifest.md

@@ -511,7 +511,8 @@ properties of the persistent storage that stores Postgres data.
 
 Those parameters are defined under the `sidecars` key. They consist of a list
 of dictionaries, each defining one sidecar (an extra container running
-along the main Postgres container on the same pod). The following keys can be
+along the main Postgres container on the same pod). Same way sidecars can be
+defined for the pooler, using `connectionPooler.sidecars` key. The following keys can be
 defined in the sidecar dictionary:
 
 * **name**
@@ -601,6 +602,9 @@ for both master and replica pooler services (if `enableReplicaConnectionPooler`
 * **resources**
   Resource configuration for connection pooler deployment.
 
+* **sidecars**
+  Extra containers to run alongside with PGBouncer container in the same pod. 
+
 ## Custom TLS certificates
 
 Those parameters are grouped under the `tls` top-level key. Note, you have to

manifests/postgresql.crd.yaml

@@ -171,6 +171,12 @@ spec:
                             pattern: '^(\d+(e\d+)?|\d+(\.\d+)?(e\d+)?[EPTGMK]i?)$'
                   schema:
                     type: string
+                  sidecars:
+                    type: array
+                    nullable: true
+                    items:
+                      type: object
+                      x-kubernetes-preserve-unknown-fields: true
                   user:
                     type: string
               databases:

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

@@ -275,6 +275,16 @@ var PostgresCRDResourceValidation = apiextv1.CustomResourceValidation{
 							"schema": {
 								Type: "string",
 							},
+							"sidecars": {
+								Type:     "array",
+								Nullable: true,
+								Items: &apiextv1.JSONSchemaPropsOrArray{
+									Schema: &apiextv1.JSONSchemaProps{
+										Type:                   "object",
+										XPreserveUnknownFields: util.True(),
+									},
+								},
+							},
 							"user": {
 								Type: "string",
 							},

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

@@ -241,12 +241,13 @@ type PostgresStatus struct {
 // makes sense to expose. E.g. pool size (min/max boundaries), max client
 // connections etc.
 type ConnectionPooler struct {
-	NumberOfInstances *int32 `json:"numberOfInstances,omitempty"`
-	Schema            string `json:"schema,omitempty"`
-	User              string `json:"user,omitempty"`
-	Mode              string `json:"mode,omitempty"`
-	DockerImage       string `json:"dockerImage,omitempty"`
-	MaxDBConnections  *int32 `json:"maxDBConnections,omitempty"`
+	NumberOfInstances *int32    `json:"numberOfInstances,omitempty"`
+	Schema            string    `json:"schema,omitempty"`
+	User              string    `json:"user,omitempty"`
+	Mode              string    `json:"mode,omitempty"`
+	DockerImage       string    `json:"dockerImage,omitempty"`
+	MaxDBConnections  *int32    `json:"maxDBConnections,omitempty"`
+	Sidecars          []Sidecar `json:"sidecars,omitempty"`
 
 	*Resources `json:"resources,omitempty"`
 }

pkg/cluster/connection_pooler.go

@@ -342,6 +342,18 @@ func (c *Cluster) generateConnectionPoolerPodTemplate(role PostgresRole) (
 		},
 	}
 
+	sidecars := []v1.Container{}
+	if connectionPoolerSpec.Sidecars != nil && len(connectionPoolerSpec.Sidecars) > 0 {
+		sidecars, err = c.generateSidecarContainers(
+			connectionPoolerSpec.Sidecars,
+			makeDefaultConnectionPoolerResources(&c.OpConfig),
+			0,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("could not generate pooler sidecar containers: %v", err)
+		}
+	}
+
 	// If the cluster has custom TLS certificates configured, we do the following:
 	//  1. Add environment variables to tell pgBouncer where to find the TLS certificates
 	//  2. Reference the secret in a volume
@@ -403,7 +415,7 @@ func (c *Cluster) generateConnectionPoolerPodTemplate(role PostgresRole) (
 		},
 		Spec: v1.PodSpec{
 			TerminationGracePeriodSeconds: &gracePeriod,
-			Containers:                    []v1.Container{poolerContainer},
+			Containers:                    append([]v1.Container{poolerContainer}, sidecars...),
 			Tolerations:                   tolerationsSpec,
 			Volumes:                       poolerVolumes,
 			SecurityContext:               &securityContext,

pkg/cluster/connection_pooler_test.go

@@ -869,6 +869,65 @@ func TestConnectionPoolerDeploymentSpec(t *testing.T) {
 	}
 }
 
+func TestConnectionPoolerSidecars (t *testing.T) {
+	var cluster = New(
+		Config{
+			OpConfig: config.Config{
+				ProtectedRoles: []string{"admin"},
+				Auth: config.Auth{
+					SuperUsername:       superUserName,
+					ReplicationUsername: replicationUserName,
+				},
+				ConnectionPooler: config.ConnectionPooler{
+					ConnectionPoolerDefaultCPURequest:    "100m",
+					ConnectionPoolerDefaultCPULimit:      "100m",
+					ConnectionPoolerDefaultMemoryRequest: "100Mi",
+					ConnectionPoolerDefaultMemoryLimit:   "100Mi",
+				},
+			},
+		}, k8sutil.KubernetesClient{}, acidv1.Postgresql{}, logger, eventRecorder)
+	cluster.Statefulset = &appsv1.StatefulSet{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test-sts",
+		},
+	}
+	cluster.ConnectionPooler = map[PostgresRole]*ConnectionPoolerObjects{
+		Master: {
+			Deployment:     nil,
+			Service:        nil,
+			LookupFunction: true,
+			Name:           "",
+			Role:           Master,
+		},
+	}
+	cluster.Spec = acidv1.PostgresSpec{
+		ConnectionPooler: &acidv1.ConnectionPooler{
+			Sidecars: []acidv1.Sidecar{
+				acidv1.Sidecar{
+					Name:        "sidecar",
+					DockerImage: "image",
+					Env: []v1.EnvVar{
+						{
+							Name:  "SOME_VAR",
+							Value: "some-value",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	deployment, err := cluster.generateConnectionPoolerDeployment(cluster.ConnectionPooler[Master]) 
+	assert.NoError(t, err)
+
+	containers := deployment.Spec.Template.Spec.Containers
+	assert.Equal(t, 2, len(containers), "wrong number of containers")
+	assert.Equal(t, "sidecar", containers[1].Name, "wrong name of sidecar")
+	assert.Equal(t, "image", containers[1].Image, "wrong image of sidecar")
+	assert.Equal(t, "SOME_VAR", containers[1].Env[0].Name, "wrong name of env var in sidecar")
+	assert.Equal(t, "some-value", containers[1].Env[0].Value, "wrong value of env var in sidecar")
+}
+
 func testServiceAccount(cluster *Cluster, podSpec *v1.PodTemplateSpec, role PostgresRole) error {
 	poolerServiceAccount := podSpec.Spec.ServiceAccountName