get postgres container by name, not index (#1504)

Author: FxKu

pkg/cluster/exec.go

@@ -12,7 +12,6 @@ import (
 	"k8s.io/client-go/tools/remotecommand"
 
 	"github.com/zalando/postgres-operator/pkg/spec"
-	"github.com/zalando/postgres-operator/pkg/util/constants"
 )
 
 //ExecCommand executes arbitrary command inside the pod
@@ -32,14 +31,14 @@ func (c *Cluster) ExecCommand(podName *spec.NamespacedName, command ...string) (
 	// iterate through all containers looking for the one running PostgreSQL.
 	targetContainer := -1
 	for i, cr := range pod.Spec.Containers {
-		if cr.Name == constants.PostgresContainerName {
+		if cr.Name == c.containerName() {
 			targetContainer = i
 			break
 		}
 	}
 
 	if targetContainer < 0 {
-		return "", fmt.Errorf("could not find %s container to exec to", constants.PostgresContainerName)
+		return "", fmt.Errorf("could not find %s container to exec to", c.containerName())
 	}
 
 	req := c.KubeClient.RESTClient.Post().

pkg/cluster/k8sres.go

@@ -67,7 +67,7 @@ type spiloConfiguration struct {
 }
 
 func (c *Cluster) containerName() string {
-	return "postgres"
+	return constants.PostgresContainerName
 }
 
 func (c *Cluster) statefulSetName() string {
@@ -1401,14 +1401,18 @@ func addShmVolume(podSpec *v1.PodSpec) {
 		},
 	})
 
-	pgIdx := constants.PostgresContainerIdx
-	mounts := append(podSpec.Containers[pgIdx].VolumeMounts,
-		v1.VolumeMount{
-			Name:      constants.ShmVolumeName,
-			MountPath: constants.ShmVolumePath,
-		})
+	for i, container := range podSpec.Containers {
+		if container.Name == constants.PostgresContainerName {
+			mounts := append(container.VolumeMounts,
+				v1.VolumeMount{
+					Name:      constants.ShmVolumeName,
+					MountPath: constants.ShmVolumePath,
+				})
+
+			podSpec.Containers[i].VolumeMounts = mounts
+		}
+	}
 
-	podSpec.Containers[0].VolumeMounts = mounts
 	podSpec.Volumes = volumes
 }
 
@@ -1439,54 +1443,58 @@ func (c *Cluster) addAdditionalVolumes(podSpec *v1.PodSpec,
 
 	volumes := podSpec.Volumes
 	mountPaths := map[string]acidv1.AdditionalVolume{}
-	for i, v := range additionalVolumes {
-		if previousVolume, exist := mountPaths[v.MountPath]; exist {
+	for i, additionalVolume := range additionalVolumes {
+		if previousVolume, exist := mountPaths[additionalVolume.MountPath]; exist {
 			msg := "Volume %+v cannot be mounted to the same path as %+v"
-			c.logger.Warningf(msg, v, previousVolume)
+			c.logger.Warningf(msg, additionalVolume, previousVolume)
 			continue
 		}
 
-		if v.MountPath == constants.PostgresDataMount {
+		if additionalVolume.MountPath == constants.PostgresDataMount {
 			msg := "Cannot mount volume on postgresql data directory, %+v"
-			c.logger.Warningf(msg, v)
+			c.logger.Warningf(msg, additionalVolume)
 			continue
 		}
 
-		if len(v.TargetContainers) == 0 {
-			spiloContainer := podSpec.Containers[0]
-			additionalVolumes[i].TargetContainers = []string{spiloContainer.Name}
+		// if no target container is defined assign it to postgres container
+		if len(additionalVolume.TargetContainers) == 0 {
+			for j := range podSpec.Containers {
+				if podSpec.Containers[j].Name == c.containerName() {
+					additionalVolumes[i].TargetContainers = []string{c.containerName()}
+				}
+			}
 		}
 
-		for _, target := range v.TargetContainers {
-			if target == "all" && len(v.TargetContainers) != 1 {
+		for _, target := range additionalVolume.TargetContainers {
+			if target == "all" && len(additionalVolume.TargetContainers) != 1 {
 				msg := `Target containers could be either "all" or a list
 						of containers, mixing those is not allowed, %+v`
-				c.logger.Warningf(msg, v)
+				c.logger.Warningf(msg, additionalVolume)
 				continue
 			}
 		}
 
 		volumes = append(volumes,
 			v1.Volume{
-				Name:         v.Name,
-				VolumeSource: v.VolumeSource,
+				Name:         additionalVolume.Name,
+				VolumeSource: additionalVolume.VolumeSource,
 			},
 		)
 
-		mountPaths[v.MountPath] = v
+		mountPaths[additionalVolume.MountPath] = additionalVolume
 	}
 
 	c.logger.Infof("Mount additional volumes: %+v", additionalVolumes)
 
 	for i := range podSpec.Containers {
 		mounts := podSpec.Containers[i].VolumeMounts
-		for _, v := range additionalVolumes {
-			for _, target := range v.TargetContainers {
+		for _, additionalVolume := range additionalVolumes {
+			for _, target := range additionalVolume.TargetContainers {
 				if podSpec.Containers[i].Name == target || target == "all" {
 					mounts = append(mounts, v1.VolumeMount{
-						Name:      v.Name,
-						MountPath: v.MountPath,
-						SubPath:   v.SubPath,
+						Name:      additionalVolume.Name,
+						MountPath: additionalVolume.MountPath,
+						SubPath:   additionalVolume.SubPath,
 					})
 				}
 			}

pkg/cluster/sync.go

@@ -357,8 +357,8 @@ func (c *Cluster) syncStatefulSet() error {
 			// and
 			//  (b) some of the pods were not restarted when the lazy update was still in place
 			for _, pod := range pods {
-				effectivePodImage := pod.Spec.Containers[0].Image
-				stsImage := desiredSts.Spec.Template.Spec.Containers[0].Image
+				effectivePodImage := c.getPostgresContainer(&pod.Spec).Image
+				stsImage := c.getPostgresContainer(&desiredSts.Spec.Template.Spec).Image
 
 				if stsImage != effectivePodImage {
 					if err = c.markRollingUpdateFlagForPod(&pod, "pod not yet restarted due to lazy update"); err != nil {

pkg/cluster/util.go

@@ -227,6 +227,16 @@ func (c *Cluster) logServiceChanges(role PostgresRole, old, new *v1.Service, isU
 	}
 }
 
+func (c *Cluster) getPostgresContainer(podSpec *v1.PodSpec) v1.Container {
+	var pgContainer v1.Container
+	for _, container := range podSpec.Containers {
+		if container.Name == constants.PostgresContainerName {
+			pgContainer = container
+		}
+	}
+	return pgContainer
+}
+
 func (c *Cluster) getTeamMembers(teamID string) ([]string, error) {
 
 	if teamID == "" {

pkg/util/constants/kubernetes.go

@@ -5,7 +5,6 @@ import "time"
 // General kubernetes-related constants
 const (
 	PostgresContainerName = "postgres"
-	PostgresContainerIdx  = 0
 	K8sAPIPath            = "/apis"
 
 	QueueResyncPeriodPod  = 5 * time.Minute