Add shm_volume option (#427)

Add possibility to mount a tmpfs volume to /dev/shm to avoid issues like
[this](https://github.com/docker-library/postgres/issues/416). To achieve that
two new options were introduced:

* `enableShmVolume` to PostgreSQL manifest, to specify whether or not mount
this volume per database cluster

* `enable_shm_volume` to operator configuration, to specify whether or not mount
per operator.

The first one, `enableShmVolume` takes precedence to allow us to be more flexible.

pkg/apis/acid.zalan.do/v1/postgresql_type.go

@@ -51,6 +51,7 @@ type PostgresSpec struct {
 	Tolerations          []v1.Toleration      `json:"tolerations,omitempty"`
 	Sidecars             []Sidecar            `json:"sidecars,omitempty"`
 	PodPriorityClassName string               `json:"pod_priority_class_name,omitempty"`
+	ShmVolume            *bool                `json:"enableShmVolume,omitempty"`
 }
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object

pkg/apis/acid.zalan.do/v1/util_test.go

@@ -499,7 +499,7 @@ func TestMarshal(t *testing.T) {
 			t.Errorf("Marshal error: %v", err)
 		}
 		if !bytes.Equal(m, tt.marshal) {
-			t.Errorf("Marshal Postgresql expected: %q, got: %q", string(tt.marshal), string(m))
+			t.Errorf("Marshal Postgresql \nexpected: %q, \ngot:      %q", string(tt.marshal), string(m))
 		}
 	}
 }
@@ -507,11 +507,11 @@ func TestMarshal(t *testing.T) {
 func TestPostgresMeta(t *testing.T) {
 	for _, tt := range unmarshalCluster {
 		if a := tt.out.GetObjectKind(); a != &tt.out.TypeMeta {
-			t.Errorf("GetObjectKindMeta expected: %v, got: %v", tt.out.TypeMeta, a)
+			t.Errorf("GetObjectKindMeta \nexpected: %v, \ngot:       %v", tt.out.TypeMeta, a)
 		}
 
 		if a := tt.out.GetObjectMeta(); reflect.DeepEqual(a, tt.out.ObjectMeta) {
-			t.Errorf("GetObjectMeta expected: %v, got: %v", tt.out.ObjectMeta, a)
+			t.Errorf("GetObjectMeta \nexpected: %v, \ngot:       %v", tt.out.ObjectMeta, a)
 		}
 	}
 }