Add configuration to support running WAL-E.

- Set WAL_S3_BUCKET to point WAL-E where to fetch/store WAL files
- Set annotations/iam.amazonaws.com/role to set the role to access AWS"

The new env vairables are PGOP_WAL_S3_BUCKET and PGOP_KUBE_IAM_ROLE.

pkg/cluster/k8sres.go

@@ -105,6 +105,9 @@ bootstrap:
   - hostssl   all all all md5`, pgVersion, c.OpConfig.PamRoleName, c.OpConfig.PamRoleName),
 		},
 	}
+	if c.OpConfig.WALES3Bucket != "" {
+		envVars = append(envVars, v1.EnvVar{Name:  "WAL_S3_BUCKET", Value: c.OpConfig.WALES3Bucket})
+	}
 	privilegedMode := bool(true)
 	container := v1.Container{
 		Name:            c.Metadata.Name,
@@ -153,6 +156,9 @@ bootstrap:
 		},
 		Spec: podSpec,
 	}
+	if c.OpConfig.KubeIAMRole != "" {
+		template.Annotations = map[string]string{constants.KubeIAmAnnotation: c.OpConfig.KubeIAMRole}
+	}
 
 	return &template
 }