Fix cloning from GCS (#1176)

* Fix clone from gcs

* pass google credentials env var if using GS bucket

* remove requirement for timezone as GCS returns timestamp in local time to the region it is in

* Revert "remove requirement for timezone as GCS returns timestamp in local time to the region it is in"

This reverts commit ac4eb350d9.

* update GCS documentation

* remove sentence about logical backups

* reword pod environment configmap section

* fix documentation

docs/administrator.md

@@ -686,6 +686,32 @@ aws_or_gcp:
 ...
 ```
 
+### Setup pod environment configmap
+
+To make postgres-operator work with GCS, use following configmap:
+```yml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: pod-env-overrides
+  namespace: postgres-operator-system
+data:
+  # Any env variable used by spilo can be added
+  USE_WALG_BACKUP: "true"
+  USE_WALG_RESTORE: "true"
+  CLONE_USE_WALG_RESTORE: "true"
+```
+This configmap will instruct operator to use WAL-G, instead of WAL-E, for backup and restore.
+
+Then provide this configmap in postgres-operator settings:
+```yml
+...
+# namespaced name of the ConfigMap with environment variables to populate on every pod
+pod_environment_configmap: "postgres-operator-system/pod-env-overrides"
+...
+```
+
+
 ## Sidecars for Postgres clusters
 
 A list of sidecars is added to each cluster created by the operator. The default

pkg/cluster/k8sres.go

@@ -1719,11 +1719,31 @@ func (c *Cluster) generateCloneEnvironment(description *acidv1.CloneDescription)
 			msg := "Figure out which S3 bucket to use from env"
 			c.logger.Info(msg, description.S3WalPath)
 
+			if c.OpConfig.WALES3Bucket != "" {
+				envs := []v1.EnvVar{
+					{
+						Name:  "CLONE_WAL_S3_BUCKET",
+						Value: c.OpConfig.WALES3Bucket,
+					},
+				}
+				result = append(result, envs...)
+			} else if c.OpConfig.WALGSBucket != "" {
+				envs := []v1.EnvVar{
+					{
+						Name:  "CLONE_WAL_GS_BUCKET",
+						Value: c.OpConfig.WALGSBucket,
+					},
+					{
+						Name:  "CLONE_GOOGLE_APPLICATION_CREDENTIALS",
+						Value: c.OpConfig.GCPCredentials,
+					},
+				}
+				result = append(result, envs...)
+			} else {
+				c.logger.Error("Cannot figure out S3 or GS bucket. Both are empty.")
+			}
+
 			envs := []v1.EnvVar{
-				{
-					Name:  "CLONE_WAL_S3_BUCKET",
-					Value: c.OpConfig.WALES3Bucket,
-				},
 				{
 					Name:  "CLONE_WAL_BUCKET_SCOPE_SUFFIX",
 					Value: getBucketScopeSuffix(description.UID),