K8SPG-737: expose /pgdata mountpoint for node_exporter (#1113)

* K8SPG-737: expose `/pgdata` mountpoint for node_exporter

https://perconadev.atlassian.net/browse/K8SPG-737

* fix upgrade tests

* fix unit test

* remove version check from pmm v3 container

---------

Co-authored-by: Viacheslav Sarzhan <slava.sarzhan@percona.com>

Author: pooknull

e2e-tests/tests/monitoring-pmm3/08-check-mountpoint-expose.yaml

@@ -0,0 +1,20 @@
+apiVersion: kuttl.dev/v1beta1
+kind: TestStep
+commands:
+  - script: |-
+      set -o errexit
+      set -o xtrace
+
+      source ../../functions
+
+      series_fetched=$(curl --insecure -G "https://admin:admin@$(get_service_ip monitoring-service)/prometheus/api/v1/query_range" \
+           --data-urlencode "query=node_filesystem_free_bytes{mountpoint=\"/pgdata\"}" \
+           --data-urlencode "start=$(($(date +%s) - 300))" \
+           --data-urlencode "end=$(date +%s)" \
+           --data-urlencode "step=5s" | jq -r '.stats.seriesFetched')
+
+      if [[ $series_fetched == 0 ]]; then 
+        echo "seriesFetched is 0"
+        exit 1
+      fi
+    timeout: 360

e2e-tests/tests/monitoring/08-check-mountpoint-expose.yaml

@@ -0,0 +1,20 @@
+apiVersion: kuttl.dev/v1beta1
+kind: TestStep
+commands:
+  - script: |-
+      set -o errexit
+      set -o xtrace
+
+      source ../../functions
+
+      series_fetched=$(curl --insecure -G "https://admin:admin@$(get_service_ip monitoring-service)/prometheus/api/v1/query_range" \
+           --data-urlencode "query=node_filesystem_free_bytes{mountpoint=\"/pgdata\"}" \
+           --data-urlencode "start=$(($(date +%s) - 300))" \
+           --data-urlencode "end=$(date +%s)" \
+           --data-urlencode "step=5s" | jq -r '.stats.seriesFetched')
+
+      if [[ $series_fetched == 0 ]]; then 
+        echo "seriesFetched is 0"
+        exit 1
+      fi
+    timeout: 360

e2e-tests/tests/monitoring/08-deleted-from-server-inventory.yaml renamed to e2e-tests/tests/monitoring/09-deleted-from-server-inventory.yaml

@@ -1352,6 +1352,9 @@ func generateInstanceStatefulSetIntent(_ context.Context,
 	// containers see each other's processes.
 	// - https://docs.k8s.io/tasks/configure-pod-container/share-process-namespace/
 	sts.Spec.Template.Spec.ShareProcessNamespace = initialize.Bool(true)
+	if cluster.CompareVersion("2.7.0") >= 0 {
+		sts.Spec.Template.Spec.ShareProcessNamespace = initialize.Bool(false) // K8SPG-737: should be false
+	}
 
 	// Patroni calls the Kubernetes API and pgBackRest may interact with a cloud
 	// storage provider. Use the instance ServiceAccount and automatically mount

internal/controller/postgrescluster/instance.go

@@ -7,6 +7,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
 
+	"github.com/percona/percona-postgresql-operator/internal/postgres"
 	v2 "github.com/percona/percona-postgresql-operator/pkg/apis/pgv2.percona.com/v2"
 )
 
@@ -42,6 +43,21 @@ func sidecarContainerV2(pgc *v2.PerconaPGCluster) corev1.Container {
 
 	pmmSpec := pgc.Spec.PMM
 
+	volumeMounts := []corev1.VolumeMount{
+		{
+			Name:      "cert-volume",
+			MountPath: "/pgconf/tls",
+			ReadOnly:  true,
+		},
+	}
+	if pgc.CompareVersion("2.7.0") >= 0 {
+		volumeMounts = append(volumeMounts, corev1.VolumeMount{
+			Name:      postgres.DataVolumeMount().Name,
+			MountPath: postgres.DataVolumeMount().MountPath,
+			ReadOnly:  true,
+		})
+	}
+
 	container := corev1.Container{
 		Name:            "pmm-client",
 		Image:           pmmSpec.Image,
@@ -74,13 +90,7 @@ func sidecarContainerV2(pgc *v2.PerconaPGCluster) corev1.Container {
 				},
 			},
 		},
-		VolumeMounts: []corev1.VolumeMount{
-			{
-				Name:      "cert-volume",
-				MountPath: "/pgconf/tls",
-				ReadOnly:  true,
-			},
-		},
+		VolumeMounts: volumeMounts,
 		Env: []corev1.EnvVar{
 			{
 				Name: "POD_NAME",
@@ -306,7 +316,13 @@ func sidecarContainerV3(pgc *v2.PerconaPGCluster) corev1.Container {
 				MountPath: "/pgconf/tls",
 				ReadOnly:  true,
 			},
+			{
+				Name:      postgres.DataVolumeMount().Name,
+				MountPath: postgres.DataVolumeMount().MountPath,
+				ReadOnly:  true,
+			},
 		},
+
 		Env: []corev1.EnvVar{
 			{
 				Name: "POD_NAME",

percona/pmm/pmm.go

@@ -6,7 +6,6 @@ import (
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
@@ -136,7 +135,6 @@ func TestContainer(t *testing.T) {
 			assert.Contains(t, container.Env, tt.verificationEnvVar())
 		})
 	}
-
 }
 
 func TestSidecarContainerV2(t *testing.T) {
@@ -248,7 +246,7 @@ func TestSidecarContainerV2(t *testing.T) {
 		}
 	}
 
-	assert.Len(t, container.VolumeMounts, 1)
+	assert.Len(t, container.VolumeMounts, 2)
 	assert.Equal(t, "/pgconf/tls", container.VolumeMounts[0].MountPath)
 	assert.True(t, container.VolumeMounts[0].ReadOnly)
 }
@@ -357,7 +355,7 @@ func TestSidecarContainerV3(t *testing.T) {
 		}
 	}
 
-	assert.Len(t, container.VolumeMounts, 1)
+	assert.Len(t, container.VolumeMounts, 2)
 	assert.Equal(t, "/pgconf/tls", container.VolumeMounts[0].MountPath)
 	assert.True(t, container.VolumeMounts[0].ReadOnly)
 }