Expand variables from the PodEnvironmentConfigMap

Inject PodEnvironmentConfigMap variables inline into the
statefulset definition in order to be able to figure out
changes to the statefulset when only PodEnvironmentConfigMap
has changed.

pkg/cluster/k8sres.go

@@ -262,7 +262,7 @@ func (c *Cluster) tolerations(tolerationsSpec *[]v1.Toleration) []v1.Toleration
 	}
 
 	podToleration := c.Config.OpConfig.PodToleration
-	if (len(podToleration["key"]) > 0 || len(podToleration["operator"]) > 0 || len(podToleration["value"]) > 0 || len(podToleration["effect"]) > 0) {
+	if len(podToleration["key"]) > 0 || len(podToleration["operator"]) > 0 || len(podToleration["value"]) > 0 || len(podToleration["effect"]) > 0 {
 		return []v1.Toleration{
 			{
 				Key:      podToleration["key"],
@@ -280,7 +280,8 @@ func (c *Cluster) generatePodTemplate(resourceRequirements *v1.ResourceRequireme
 	tolerationsSpec *[]v1.Toleration,
 	pgParameters *spec.PostgresqlParam,
 	patroniParameters *spec.Patroni,
-	cloneDescription *spec.CloneDescription) *v1.PodTemplateSpec {
+	cloneDescription *spec.CloneDescription,
+	extraEnv map[string]string) *v1.PodTemplateSpec {
 	spiloConfiguration := c.generateSpiloJSONConfiguration(pgParameters, patroniParameters)
 
 	envVars := []v1.EnvVar{
@@ -362,10 +363,23 @@ func (c *Cluster) generatePodTemplate(resourceRequirements *v1.ResourceRequireme
 		envVars = append(envVars, c.generateCloneEnvironment(cloneDescription)...)
 	}
 
-	envFromSource := []v1.EnvFromSource{}
-	if c.OpConfig.PodEnvironmentConfigMap != "" {
-		configMapRef := v1.ConfigMapEnvSource{LocalObjectReference: v1.LocalObjectReference{Name: c.OpConfig.PodEnvironmentConfigMap}}
-		envFromSource = append(envFromSource, v1.EnvFromSource{ConfigMapRef: &configMapRef})
+	var names []string
+	// handle environment variables from the PodEnvironmentConfigMap. We don't use envSource here as it is impossible
+	// to track any changes to the object envSource points to. In order to emulate the envSource behavior, however, we
+	// need to make sure that PodConfigMap variables doesn't override those we set explicitely from the configuration
+	// parameters
+	envVarsMap := make(map[string]string)
+	for _, envVar := range envVars {
+		envVarsMap[envVar.Name] = envVar.Value
+	}
+	for name := range extraEnv {
+		if _, ok := envVarsMap[name]; !ok {
+			names = append(names, name)
+		}
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		envVars = append(envVars, v1.EnvVar{Name: name, Value: extraEnv[name]})
 	}
 
 	privilegedMode := true
@@ -395,7 +409,6 @@ func (c *Cluster) generatePodTemplate(resourceRequirements *v1.ResourceRequireme
 			},
 		},
 		Env: envVars,
-		EnvFrom: envFromSource,
 		SecurityContext: &v1.SecurityContext{
 			Privileged: &privilegedMode,
 		},
@@ -429,8 +442,16 @@ func (c *Cluster) generateStatefulSet(spec *spec.PostgresSpec) (*v1beta1.Statefu
 	if err != nil {
 		return nil, fmt.Errorf("could not generate resource requirements: %v", err)
 	}
+	var extraEnv map[string]string
+	if c.OpConfig.PodEnvironmentConfigMap != "" {
+		if cm, err := c.KubeClient.ConfigMaps(c.Namespace).Get(c.OpConfig.PodEnvironmentConfigMap, metav1.GetOptions{}); err != nil {
+			return nil, fmt.Errorf("could not read PodEnvironmentConfigMap: %v", err)
+		} else {
+			extraEnv = cm.Data
+		}
 
-	podTemplate := c.generatePodTemplate(resourceRequirements, &spec.Tolerations, &spec.PostgresqlParam, &spec.Patroni, &spec.Clone)
+	}
+	podTemplate := c.generatePodTemplate(resourceRequirements, &spec.Tolerations, &spec.PostgresqlParam, &spec.Patroni, &spec.Clone, extraEnv)
 	volumeClaimTemplate, err := generatePersistentVolumeClaimTemplate(spec.Volume.Size, spec.Volume.StorageClass)
 	if err != nil {
 		return nil, fmt.Errorf("could not generate volume claim template: %v", err)