feat: add configurable cluster domain support

api/v1beta1/argocd_types.go

@@ -982,6 +982,12 @@ type ArgoCDSpec struct {
 	//+operator-sdk:csv:customresourcedefinitions:type=spec,displayName="Version",xDescriptors={"urn:alm:descriptor:com.tectonic.ui:fieldGroup:ArgoCD","urn:alm:descriptor:com.tectonic.ui:text"}
 	Version string `json:"version,omitempty"`
 
+	// ClusterDomain is the cluster domain suffix used for constructing service FQDNs. Defaults to "cluster.local".
+	// The full FQDN will be: <service>.<namespace>.svc.<clusterDomain>
+	// This is useful for clusters that use a different DNS suffix (e.g., "CLUSTER_ID.cluster.local", "edge.local").
+	//+operator-sdk:csv:customresourcedefinitions:type=spec,displayName="Cluster Domain'",xDescriptors={"urn:alm:descriptor:com.tectonic.ui:text","urn:alm:descriptor:com.tectonic.ui:advanced"}
+	ClusterDomain string `json:"clusterDomain,omitempty"`
+
 	// Banner defines an additional banner to be displayed in Argo CD UI
 	Banner *Banner `json:"banner,omitempty"`
 

bundle/manifests/argocd-operator.clusterserviceversion.yaml

@@ -257,7 +257,7 @@ metadata:
     capabilities: Deep Insights
     categories: Integration & Delivery
     certified: "false"
-    createdAt: "2025-08-28T14:32:44Z"
+    createdAt: "2025-09-15T13:17:46Z"
     description: Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes.
     operators.operatorframework.io/builder: operator-sdk-v1.35.0
     operators.operatorframework.io/project_layout: go.kubebuilder.io/v4
@@ -1070,6 +1070,15 @@ spec:
         - urn:alm:descriptor:com.tectonic.ui:fieldGroup:Prometheus
         - urn:alm:descriptor:com.tectonic.ui:fieldGroup:Server
         - urn:alm:descriptor:com.tectonic.ui:booleanSwitch
+      - description: 'ClusterDomain is the cluster domain suffix used for constructing
+          service FQDNs. Defaults to "cluster.local". The full FQDN will be: <service>.<namespace>.svc.<clusterDomain>
+          This is useful for clusters that use a different DNS suffix (e.g., "CLUSTER_ID.cluster.local",
+          "edge.local").'
+        displayName: Cluster Domain'
+        path: clusterDomain
+        x-descriptors:
+        - urn:alm:descriptor:com.tectonic.ui:text
+        - urn:alm:descriptor:com.tectonic.ui:advanced
       - description: 'Deprecated: ConfigManagementPlugins field is no longer supported.
           Argo CD now requires plugins to be defined as sidecar containers of repo
           server component. See ''.spec.repo.sidecarContainers''. ConfigManagementPlugins

bundle/manifests/argoproj.io_argocds.yaml

@@ -10248,6 +10248,12 @@ spec:
                 required:
                 - content
                 type: object
+              clusterDomain:
+                description: |-
+                  ClusterDomain is the cluster domain suffix used for constructing service FQDNs. Defaults to "cluster.local".
+                  The full FQDN will be: <service>.<namespace>.svc.<clusterDomain>
+                  This is useful for clusters that use a different DNS suffix (e.g., "CLUSTER_ID.cluster.local", "edge.local").
+                type: string
               cmdParams:
                 additionalProperties:
                   type: string

common/defaults.go

@@ -289,6 +289,9 @@ vs-ssh.visualstudio.com ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC7Hr1oTWqNqOlzGJOf
 
 	// ArgoCDAgentPrincipalDefaultImageName is the default image name for the ArgoCD agent principal.
 	ArgoCDAgentPrincipalDefaultImageName = "quay.io/argoprojlabs/argocd-agent:v0.3.2"
+
+	// ArgoCDDefaultClusterDomain is the default cluster domain suffix for service FQDNs.
+	ArgoCDDefaultClusterDomain = "cluster.local"
 )
 
 // DefaultLabels returns the default set of labels for controllers.

config/certmanager/certificate.yaml

@@ -15,10 +15,10 @@ metadata:
   name: serving-cert  # this name should match the one appeared in kustomizeconfig.yaml
   namespace: system
 spec:
-  # $(SERVICE_NAME) and $(SERVICE_NAMESPACE) will be substituted by kustomize
+  # $(SERVICE_NAME), $(SERVICE_NAMESPACE) and $(CLUSTER_DOMAIN) will be substituted by kustomize
   dnsNames:
   - $(SERVICE_NAME).$(SERVICE_NAMESPACE).svc
-  - $(SERVICE_NAME).$(SERVICE_NAMESPACE).svc.cluster.local
+  - $(SERVICE_NAME).$(SERVICE_NAMESPACE).svc.$(CLUSTER_DOMAIN)
   issuerRef:
     kind: Issuer
     name: selfsigned-issuer

config/crd/bases/argoproj.io_argocds.yaml

@@ -10237,6 +10237,12 @@ spec:
                 required:
                 - content
                 type: object
+              clusterDomain:
+                description: |-
+                  ClusterDomain is the cluster domain suffix used for constructing service FQDNs. Defaults to "cluster.local".
+                  The full FQDN will be: <service>.<namespace>.svc.<clusterDomain>
+                  This is useful for clusters that use a different DNS suffix (e.g., "CLUSTER_ID.cluster.local", "edge.local").
+                type: string
               cmdParams:
                 additionalProperties:
                   type: string

config/default/kustomization.yaml

@@ -72,3 +72,5 @@ vars:
 #    kind: Service
 #    version: v1
 #    name: webhook-service
+#- name: CLUSTER_DOMAIN
+#  value: cluster.local

config/manifests/bases/argocd-operator.clusterserviceversion.yaml

@@ -289,6 +289,15 @@ spec:
         - urn:alm:descriptor:com.tectonic.ui:fieldGroup:Prometheus
         - urn:alm:descriptor:com.tectonic.ui:fieldGroup:Server
         - urn:alm:descriptor:com.tectonic.ui:booleanSwitch
+      - description: 'ClusterDomain is the cluster domain suffix used for constructing
+          service FQDNs. Defaults to "cluster.local". The full FQDN will be: <service>.<namespace>.svc.<clusterDomain>
+          This is useful for clusters that use a different DNS suffix (e.g., "CLUSTER_ID.cluster.local",
+          "edge.local").'
+        displayName: Cluster Domain'
+        path: clusterDomain
+        x-descriptors:
+        - urn:alm:descriptor:com.tectonic.ui:text
+        - urn:alm:descriptor:com.tectonic.ui:advanced
       - description: 'Deprecated: ConfigManagementPlugins field is no longer supported.
           Argo CD now requires plugins to be defined as sidecar containers of repo
           server component. See ''.spec.repo.sidecarContainers''. ConfigManagementPlugins

controllers/argocd/secret.go

@@ -123,7 +123,7 @@ func newCertificateSecret(suffix string, caCert *x509.Certificate, caKey *rsa.Pr
 	dnsNames := []string{
 		cr.Name,
 		nameWithSuffix("grpc", cr),
-		fmt.Sprintf("%s.%s.svc.cluster.local", cr.Name, cr.Namespace),
+		fmt.Sprintf("%s.%s.svc.%s", cr.Name, cr.Namespace, getClusterDomain(cr)),
 	}
 
 	//lint:ignore SA1019 known to be deprecated

controllers/argocd/util.go

@@ -558,7 +558,7 @@ func getRedisServerAddress(cr *argoproj.ArgoCD) string {
 
 	// If principal is enabled, then Argo CD server/repo server should be configured to use redis proxy from principal (argo cd agent)
 	if cr.Spec.ArgoCDAgent != nil && cr.Spec.ArgoCDAgent.Principal != nil && cr.Spec.ArgoCDAgent.Principal.IsEnabled() {
-		return argoutil.GenerateAgentPrincipalRedisProxyServiceName(cr.Name) + "." + cr.Namespace + ".svc.cluster.local:6379"
+		return fmt.Sprintf("%s.%s.svc.%s:6379", argoutil.GenerateAgentPrincipalRedisProxyServiceName(cr.Name), cr.Namespace, getClusterDomain(cr))
 	}
 
 	if cr.Spec.HA.Enabled {
@@ -592,10 +592,19 @@ func nameWithSuffix(suffix string, cr *argoproj.ArgoCD) string {
 	return fmt.Sprintf("%s-%s", cr.Name, suffix)
 }
 
+// getClusterDomain returns the cluster domain suffix for the given ArgoCD instance.
+// If not specified in the CR, defaults to the standard cluster domain.
+func getClusterDomain(cr *argoproj.ArgoCD) string {
+	if cr.Spec.ClusterDomain != "" {
+		return cr.Spec.ClusterDomain
+	}
+	return common.ArgoCDDefaultClusterDomain
+}
+
 // fqdnServiceRef will return the FQDN referencing a specific service name, as set up by the operator, with the
 // given port.
 func fqdnServiceRef(service string, port int, cr *argoproj.ArgoCD) string {
-	return fmt.Sprintf("%s.%s.svc.cluster.local:%d", nameWithSuffix(service, cr), cr.Namespace, port)
+	return fmt.Sprintf("%s.%s.svc.%s:%d", nameWithSuffix(service, cr), cr.Namespace, getClusterDomain(cr), port)
 }
 
 // InspectCluster will verify the availability of extra features available to the cluster, such as Prometheus and

controllers/argocd/util_test.go

@@ -1697,3 +1697,195 @@ func TestGetNamespacesToDelete(t *testing.T) {
 		})
 	}
 }
+
+func TestGetClusterDomain(t *testing.T) {
+	tests := []struct {
+		name           string
+		clusterDomain  string
+		expectedDomain string
+	}{
+		{
+			name:           "default cluster domain when not specified",
+			clusterDomain:  "",
+			expectedDomain: "cluster.local",
+		},
+		{
+			name:           "custom cluster domain",
+			clusterDomain:  "CLUSTER_ID.cluster.local",
+			expectedDomain: "CLUSTER_ID.cluster.local",
+		},
+		{
+			name:           "custom domain for different cloud provider",
+			clusterDomain:  "eks.amazonaws.com",
+			expectedDomain: "eks.amazonaws.com",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := makeTestArgoCD()
+			a.Spec.ClusterDomain = tt.clusterDomain
+
+			result := getClusterDomain(a)
+			assert.Equal(t, tt.expectedDomain, result)
+		})
+	}
+}
+
+func TestFqdnServiceRefWithCustomDomain(t *testing.T) {
+	tests := []struct {
+		name          string
+		service       string
+		port          int
+		clusterDomain string
+		expectedFQDN  string
+	}{
+		{
+			name:          "default cluster domain",
+			service:       "redis",
+			port:          6379,
+			clusterDomain: "",
+			expectedFQDN:  "argocd-redis.argocd.svc.cluster.local:6379",
+		},
+		{
+			name:          "custom cluster domain",
+			service:       "redis",
+			port:          6379,
+			clusterDomain: "CLUSTER_ID.cluster.local",
+			expectedFQDN:  "argocd-redis.argocd.svc.CLUSTER_ID.cluster.local:6379",
+		},
+		{
+			name:          "repo server with custom domain",
+			service:       "repo-server",
+			port:          8081,
+			clusterDomain: "eks.amazonaws.com",
+			expectedFQDN:  "argocd-repo-server.argocd.svc.eks.amazonaws.com:8081",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := makeTestArgoCD()
+			a.Spec.ClusterDomain = tt.clusterDomain
+
+			result := fqdnServiceRef(tt.service, tt.port, a)
+			assert.Equal(t, tt.expectedFQDN, result)
+		})
+	}
+}
+
+func TestGetRedisServerAddressWithCustomDomain(t *testing.T) {
+	tests := []struct {
+		name          string
+		clusterDomain string
+		haEnabled     bool
+		remoteRedis   *string
+		expectedAddr  string
+	}{
+		{
+			name:          "default cluster domain - standalone redis",
+			clusterDomain: "",
+			haEnabled:     false,
+			expectedAddr:  "argocd-redis.argocd.svc.cluster.local:6379",
+		},
+		{
+			name:          "custom cluster domain - standalone redis",
+			clusterDomain: "CLUSTER_ID.cluster.local",
+			haEnabled:     false,
+			expectedAddr:  "argocd-redis.argocd.svc.CLUSTER_ID.cluster.local:6379",
+		},
+		{
+			name:          "custom cluster domain - HA redis",
+			clusterDomain: "eks.amazonaws.com",
+			haEnabled:     true,
+			expectedAddr:  "argocd-redis-ha-haproxy.argocd.svc.eks.amazonaws.com:6379",
+		},
+		{
+			name:         "remote redis - custom domain ignored",
+			remoteRedis:  stringPtr("remote-redis:6379"),
+			expectedAddr: "remote-redis:6379",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := makeTestArgoCD()
+			a.Spec.ClusterDomain = tt.clusterDomain
+			a.Spec.HA.Enabled = tt.haEnabled
+			a.Spec.Redis.Remote = tt.remoteRedis
+
+			result := getRedisServerAddress(a)
+			assert.Equal(t, tt.expectedAddr, result)
+		})
+	}
+}
+
+// stringPtr is a helper function to get a pointer to a string
+func stringPtr(s string) *string {
+	return &s
+}
+
+func TestGetDexServerAddressWithCustomDomain(t *testing.T) {
+	tests := []struct {
+		name          string
+		clusterDomain string
+		expectedAddr  string
+	}{
+		{
+			name:          "default cluster domain",
+			clusterDomain: "",
+			expectedAddr:  "https://argocd-dex-server.argocd.svc.cluster.local:5556",
+		},
+		{
+			name:          "custom cluster domain",
+			clusterDomain: "CLUSTER_ID.cluster.local",
+			expectedAddr:  "https://argocd-dex-server.argocd.svc.CLUSTER_ID.cluster.local:5556",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := makeTestArgoCD()
+			a.Spec.ClusterDomain = tt.clusterDomain
+
+			result := getDexServerAddress(a)
+			assert.Equal(t, tt.expectedAddr, result)
+		})
+	}
+}
+
+func TestGetRepoServerAddressWithCustomDomain(t *testing.T) {
+	tests := []struct {
+		name          string
+		clusterDomain string
+		remoteRepo    *string
+		expectedAddr  string
+	}{
+		{
+			name:          "default cluster domain",
+			clusterDomain: "",
+			expectedAddr:  "argocd-repo-server.argocd.svc.cluster.local:8081",
+		},
+		{
+			name:          "custom cluster domain",
+			clusterDomain: "CLUSTER_ID.cluster.local",
+			expectedAddr:  "argocd-repo-server.argocd.svc.CLUSTER_ID.cluster.local:8081",
+		},
+		{
+			name:         "remote repo server - custom domain ignored",
+			remoteRepo:   stringPtr("remote-repo:8081"),
+			expectedAddr: "remote-repo:8081",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := makeTestArgoCD()
+			a.Spec.ClusterDomain = tt.clusterDomain
+			a.Spec.Repo.Remote = tt.remoteRepo
+
+			result := getRepoServerAddress(a)
+			assert.Equal(t, tt.expectedAddr, result)
+		})
+	}
+}

deploy/olm-catalog/argocd-operator/0.17.0/argocd-operator.v0.17.0.clusterserviceversion.yaml

@@ -257,7 +257,7 @@ metadata:
     capabilities: Deep Insights
     categories: Integration & Delivery
     certified: "false"
-    createdAt: "2025-08-28T14:32:44Z"
+    createdAt: "2025-09-15T13:17:46Z"
     description: Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes.
     operators.operatorframework.io/builder: operator-sdk-v1.35.0
     operators.operatorframework.io/project_layout: go.kubebuilder.io/v4
@@ -1070,6 +1070,15 @@ spec:
         - urn:alm:descriptor:com.tectonic.ui:fieldGroup:Prometheus
         - urn:alm:descriptor:com.tectonic.ui:fieldGroup:Server
         - urn:alm:descriptor:com.tectonic.ui:booleanSwitch
+      - description: 'ClusterDomain is the cluster domain suffix used for constructing
+          service FQDNs. Defaults to "cluster.local". The full FQDN will be: <service>.<namespace>.svc.<clusterDomain>
+          This is useful for clusters that use a different DNS suffix (e.g., "CLUSTER_ID.cluster.local",
+          "edge.local").'
+        displayName: Cluster Domain'
+        path: clusterDomain
+        x-descriptors:
+        - urn:alm:descriptor:com.tectonic.ui:text
+        - urn:alm:descriptor:com.tectonic.ui:advanced
       - description: 'Deprecated: ConfigManagementPlugins field is no longer supported.
           Argo CD now requires plugins to be defined as sidecar containers of repo
           server component. See ''.spec.repo.sidecarContainers''. ConfigManagementPlugins

deploy/olm-catalog/argocd-operator/0.17.0/argoproj.io_argocds.yaml

@@ -10248,6 +10248,12 @@ spec:
                 required:
                 - content
                 type: object
+              clusterDomain:
+                description: |-
+                  ClusterDomain is the cluster domain suffix used for constructing service FQDNs. Defaults to "cluster.local".
+                  The full FQDN will be: <service>.<namespace>.svc.<clusterDomain>
+                  This is useful for clusters that use a different DNS suffix (e.g., "CLUSTER_ID.cluster.local", "edge.local").
+                type: string
               cmdParams:
                 additionalProperties:
                   type: string

examples/argocd-custom-cluster-domain.yaml

@@ -0,0 +1,7 @@
+apiVersion: argoproj.io/v1beta1
+kind: ArgoCD
+metadata:
+  name: example-argocd
+  namespace: argocd
+spec:
+  clusterDomain: "abc123.cluster.local"