From 16b167b76c7bd9af525ce03ce6581433129e6896 Mon Sep 17 00:00:00 2001
From: Felix Kunde <felix-kunde@gmx.de>
Date: Mon, 17 Jun 2019 17:18:42 +0200
Subject: [PATCH] improve docs

---
 docs/administrator.md                 | 14 ++++++++++++++
 docs/reference/operator_parameters.md |  9 +++++----
 pkg/cluster/k8sres.go                 | 20 ++++++++++----------
 3 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/docs/administrator.md b/docs/administrator.md
index 4629d1284..caf82af63 100644
--- a/docs/administrator.md
+++ b/docs/administrator.md
@@ -154,6 +154,20 @@ data:
   pod_antiaffinity_topology_key: "failure-domain.beta.kubernetes.io/zone"
 ```
 
+### Pod Disruption Budget
+
+By default the operator uses a PodDisruptionBudget (PDB) to protect the cluster
+from voluntarily disruptions and hence unwanted DB downtime. The `MinAvailable`
+parameter of the PDB is set to `1` which makes it work for single-node clusters
+or in situations when there is no master (e.g. standby clusters).
+
+The PDB is only relaxed in two scenarios:
+* If a cluster is scaled down to `0` instances (e.g. for draining nodes)
+* If the PDB is disabled in the configuration (`enable_pod_disruption_budget`)
+
+The PDB is still in place having `MinAvailable` set to `0`. If enabled it will
+be automatically set to `1` on scale up.
+
 ### Add cluster-specific labels
 
 In some cases, you might want to add `labels` that are specific to a given
diff --git a/docs/reference/operator_parameters.md b/docs/reference/operator_parameters.md
index 811011f82..e44a0f8cf 100644
--- a/docs/reference/operator_parameters.md
+++ b/docs/reference/operator_parameters.md
@@ -162,10 +162,11 @@ configuration they are grouped under the `kubernetes` key.
   the template.
 
 * **enable_pod_disruption_budget**
-  if disabled `MinAvailable` in the PDB's spec will be set to `0`. That means
-  the PDB will get created anyway. The PDB is also relaxed when scaling down the
-  Postgres cluster to `"numberOfInstances": 0`. By default PDB is enabled which
-  results in `"MinAvailable": 1`.
+  PDB is enabled by default to protect the cluster from voluntarily disruptions
+  and hence unwanted DB downtime. However, on some cloud providers it could be
+  necessary to temporarily disabled it, e.g. for node updates. See
+  [admin docs](../administrator.md#pod-disruption-budget) for more information.
+  Default is true.
 
 * **secret_name_template**
   a template for the name of the database user secrets generated by the
diff --git a/pkg/cluster/k8sres.go b/pkg/cluster/k8sres.go
index cd025a687..81054ac93 100644
--- a/pkg/cluster/k8sres.go
+++ b/pkg/cluster/k8sres.go
@@ -1268,26 +1268,26 @@ func (c *Cluster) generateCloneEnvironment(description *acidv1.CloneDescription)
 		result = append(result, v1.EnvVar{Name: "CLONE_WAL_BUCKET_SCOPE_PREFIX", Value: ""})
 
 		if description.S3Endpoint != "" {
-		   result = append(result, v1.EnvVar{Name: "CLONE_AWS_ENDPOINT", Value: description.S3Endpoint})
-		   result = append(result, v1.EnvVar{Name: "CLONE_WALE_S3_ENDPOINT", Value: description.S3Endpoint})
+			result = append(result, v1.EnvVar{Name: "CLONE_AWS_ENDPOINT", Value: description.S3Endpoint})
+			result = append(result, v1.EnvVar{Name: "CLONE_WALE_S3_ENDPOINT", Value: description.S3Endpoint})
 		}
 
 		if description.S3AccessKeyId != "" {
-		   result = append(result, v1.EnvVar{Name: "CLONE_AWS_ACCESS_KEY_ID", Value: description.S3AccessKeyId})
+			result = append(result, v1.EnvVar{Name: "CLONE_AWS_ACCESS_KEY_ID", Value: description.S3AccessKeyId})
 		}
 
 		if description.S3SecretAccessKey != "" {
-		   result = append(result, v1.EnvVar{Name: "CLONE_AWS_SECRET_ACCESS_KEY", Value: description.S3SecretAccessKey})
+			result = append(result, v1.EnvVar{Name: "CLONE_AWS_SECRET_ACCESS_KEY", Value: description.S3SecretAccessKey})
 		}
 
 		if description.S3ForcePathStyle != nil {
-		   s3ForcePathStyle := "0"
+			s3ForcePathStyle := "0"
 
-		   if *description.S3ForcePathStyle {
-			   s3ForcePathStyle = "1"
-		   }
+			if *description.S3ForcePathStyle {
+				s3ForcePathStyle = "1"
+			}
 
-		   result = append(result, v1.EnvVar{Name: "CLONE_AWS_S3_FORCE_PATH_STYLE", Value: s3ForcePathStyle})
+			result = append(result, v1.EnvVar{Name: "CLONE_AWS_S3_FORCE_PATH_STYLE", Value: s3ForcePathStyle})
 		}
 	}
 
@@ -1298,7 +1298,7 @@ func (c *Cluster) generatePodDisruptionBudget() *policybeta1.PodDisruptionBudget
 	minAvailable := intstr.FromInt(1)
 	pdbEnabled := c.OpConfig.EnablePodDisruptionBudget
 
-	// Is PodDisruptionBudget is disabled or if there is no master, set the budget to 0.
+	// if PodDisruptionBudget is disabled or if there are no DB pods, set the budget to 0.
 	if (pdbEnabled != nil && !*pdbEnabled) || c.Spec.NumberOfInstances <= 0 {
 		minAvailable = intstr.FromInt(0)
 	}