ISSUE-904 - Add support for custom entries in pod /etc/hosts

charts/pega/README.md

@@ -697,6 +697,23 @@ tier:
             name: my-configmap 
 ```
 
+### Custom /etc/hosts entries
+
+You can optionally specify custom entries to add in the /etc/hosts file for your deployment tier by adding `hostAliases`.  For an overview of `hostAliases` and their use, refer to [Adding entries to Pod /etc/hosts with HostAliases](https://kubernetes.io/docs/tasks/network/customize-hosts-file-for-pods/).
+
+Example:
+
+```yaml
+tier:
+  - name: my-tier
+    custom:
+      hostAliases:
+        - ip: "127.0.0.1"
+          hostnames:
+            - "test1.local"
+            - "test2.local"
+```
+
 ### Sidecar Containers
 
 Pega supports adding sidecar containers to manage requirements for your Pega application services that live outside of the primary tomcat container. This may include company policy requirements, utility images, networking containers, or other examples. For an overview of the versatility sidecar containers present, see [How Pods manage multiple containers](https://kubernetes.io/docs/concepts/workloads/pods/#how-pods-manage-multiple-containers).

charts/pega/templates/_pega-deployment.tpl

@@ -76,6 +76,10 @@ spec:
 {{- if .custom.serviceAccountName }}
       serviceAccountName: {{ .custom.serviceAccountName }}
 {{- end }}
+{{- if .custom.hostAliases }}
+      hostAliases:
+{{ toYaml .custom.hostAliases | indent 6 }}
+{{- end }}
 {{- end }}
       volumes:
       # Volume used to mount config files.

terratest/src/test/pega/data/values_hostAliases.yaml

@@ -0,0 +1,10 @@
+---
+global:
+  tier:
+    - name: "web"
+      custom:
+        hostAliases:
+          - ip: "127.0.0.1"
+            hostnames:
+              - "test1.local"
+              - "test2.local"

terratest/src/test/pega/pega-tier-hostAliases_test.go

@@ -0,0 +1,76 @@
+package pega
+
+import (
+	"testing"
+	"bytes"
+
+	"github.com/gruntwork-io/terratest/modules/helm"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"path/filepath"
+	"k8s.io/apimachinery/pkg/util/yaml"
+)
+
+func TestPegaHostAliases(t *testing.T) {
+	var supportedVendors = []string{"k8s", "openshift", "eks", "gke", "aks", "pks"}
+	var supportedOperations = []string{"deploy", "install-deploy"}
+	var deploymentNames = []string{"pega", "myapp-dev"}
+	helmChartPath, err := filepath.Abs(PegaHelmChartPath)
+	require.NoError(t, err, "Failed to resolve Helm chart path")
+
+	for _, vendor := range supportedVendors {
+		for _, operation := range supportedOperations {
+			for _, deploymentName := range deploymentNames {
+				// Set the Helm values to configure the labels
+				options := &helm.Options{
+					ValuesFiles: []string{"data/values_hostAliases.yaml"},
+					SetValues: map[string]string{
+						"global.provider":                        vendor,
+						"global.actions.execute":                 operation,
+						"global.deployment.name":                 deploymentName,
+					},
+				}
+
+				// Render the Kubernetes manifests using Helm
+				output := RenderTemplate(t, options, helmChartPath, []string{"templates/pega-tier-deployment.yaml"})
+
+				// Create a YAML decoder from the output
+				decoder := yaml.NewYAMLOrJSONDecoder(bytes.NewReader([]byte(output)), 4096)
+				for {
+					var resource unstructured.Unstructured
+					err := decoder.Decode(&resource)
+					if err != nil {
+						// Break on EOF
+						break
+					}
+
+                    // Only check Deployment resources
+                    if resource.GetKind() == "Deployment" {
+                        // Extract and validate hostAliases
+                        spec, found, err := unstructured.NestedMap(resource.Object, "spec", "template", "spec")
+                        require.NoError(t, err, "Error extracting spec from resource")
+                        if !found {
+                            t.Errorf("spec.template.spec not found in Deployment %s", resource.GetName())
+                            continue
+                        }
+
+                        hostAliases, found, err := unstructured.NestedSlice(spec, "hostAliases")
+                        require.NoError(t, err, "Error extracting hostAliases from spec")
+                        if !found {
+                            t.Errorf("hostAliases not found in Deployment %s", resource.GetName())
+                            continue
+                        }
+
+                        // Validate the content of hostAliases
+                        assert.Equal(t, 1, len(hostAliases), "Expected exactly 1 hostAliases entry in Deployment %s", resource.GetName())
+                        entry := hostAliases[0].(map[string]interface{})
+                        assert.Equal(t, "127.0.0.1", entry["ip"], "Unexpected IP in hostAliases of Deployment %s", resource.GetName())
+                        assert.Contains(t, entry["hostnames"], "test1.local", "Expected hostname test1.local in hostAliases of Deployment %s", resource.GetName())
+                        assert.Contains(t, entry["hostnames"], "test2.local", "Expected hostname test2.local in hostAliases of Deployment %s", resource.GetName())
+                    }
+				}
+			}
+		}
+	}
+}