Add option for services to redirect a base domain to www. for ALB

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.8.9] - 2025-01-10
+
+### Added
+
+- A service can specify that its base domain should redirect to a www. domain by adding the `redirectHostToWWW` key with the base domain as the value. e.g. if your hostnames list includes www.example.com you can specify `redirectHostToWWW: example.com` in order to set the ALB rules to do this. At the moment this is only supported for one hostname per service definition.
+
 ## [1.8.8] - 2025-01-03
 
 ### Added

charts/common/Chart.yaml

@@ -2,6 +2,6 @@ apiVersion: v2
 description: Common service chart
 name: common
 type: library
-version: 1.8.8
+version: 1.8.9
 maintainers:
   - name: DevOps

charts/common/templates/_ingress.yaml.tpl

@@ -88,6 +88,17 @@
   {{- $_ := required (printf "You must specify rootDomain in the ingress or global section") $rootDomain }}
 {{- end }}
 
+{{- $wwwRedirect := "" }}
+{{- if hasKey $v "redirectHostToWWW" }}
+  {{- if ne $v.ingressClass "alb" }}
+    {{- $_ := required (printf "www redirect is only supported for ALB ingresses") }}
+  {{- end }}
+  {{- $wwwRedirect = printf "www.%s" $v.redirectHostToWWW }}
+  {{- if $v.imperva }}
+    {{- $wwwRedirect = printf "origin-%s" $wwwRedirect }}
+  {{- end }}
+{{- end }}
+
 ---
 apiVersion: networking.k8s.io/v1
 kind: Ingress
@@ -104,6 +115,10 @@ metadata:
     {{- if and (hasKey $.root.Values "spec" ) (hasKey $.root.Values.spec "clusterName") }}
     external-dns.alpha.kubernetes.io/set-identifier: {{ $.root.Values.spec.clusterName }}
     {{- end }}
+    {{- if $wwwRedirect }}
+    alb.ingress.kubernetes.io/actions.rule-redirect-www: '{"Type":"redirect","RedirectConfig":{"Host":"www.{{ $v.redirectHostToWWW }}","Port":"443","Protocol":"HTTPS","StatusCode":"HTTP_301"}}'
+    alb.ingress.kubernetes.io/conditions.rule-redirect-www: '[{"Field":"host-header","HostHeaderConfig":{"Values":["{{ $v.redirectHostToWWW }}"]}}]'
+    {{- end }}
   labels:
     {{- include "common.helper.labels" (dict "global" $global.labels "override" $v.labels) | nindent 4 }}
 spec:
@@ -120,6 +135,15 @@ spec:
                 name: {{ $v.service.name }}
                 port:
                   number: {{ $v.service.port }}
+      {{- if and $wwwRedirect (eq $wwwRedirect $entry) }}
+          - path: /
+            pathType: {{ $v.pathType | default "Prefix" }}
+            backend:
+              service:
+                name: rule-redirect-www
+                port:
+                  name: use-annotation
+      {{- end }}
     {{- end }}
 {{- end }}
 {{- end }}

test/fixtures/Chart.lock

@@ -1,6 +1,6 @@
 dependencies:
 - name: common
   repository: file://../../../charts/common
-  version: 1.8.8
-digest: sha256:70b1f2648a660ec5bb3adea1161dd333104cdbf3845f545c4c3d89b4d105680e
-generated: "2025-01-03T13:35:32.223025-06:00"
+  version: 1.8.9
+digest: sha256:1a11fa30499ad830bd5aefc1258d5681fdf662062d3ab69e3ec5d1b5c6c4d5b5
+generated: "2025-01-10T14:56:56.181732-05:00"

test/fixtures/Chart.yaml

@@ -6,4 +6,4 @@ version: 1.0.0
 dependencies:
   - name: common
     repository: file://../../../charts/common
-    version: "1.8.8"
+    version: "1.8.9"

test/fixtures/ingresses/values-redirect-to-www.yaml

@@ -0,0 +1,21 @@
+global:
+  awsAccountId: "123456789"
+  image: docker.io/image:abcd1234
+  annotations:
+    provi.repository: https://github.com/example/repo
+    provi.slack: my-cool-team
+  labels:
+    team: cool-team
+
+ingresses:
+  dummy:
+    service:
+      port: 8080
+      name: web
+    scheme: internet-facing
+    ingressClass: "alb"
+    hostnames:
+      - subdomain.example.com
+      - www.example.com
+    redirectHostToWWW: example.com
+    certificateArn: "arn:aws:acm:us-east-2:123456789:certificate/abcd1234-1a2b-3c4d-5e6f-987654abcd123"

test/test_ingresses.bats

@@ -159,3 +159,41 @@ teardown() {
   run helm template -f test/fixtures/ingresses/values-alb-aliases.yaml test/fixtures/ingresses/
   assert_output --partial "alb.ingress.kubernetes.io/conditions.cool_foo_service: '[{\"Field\":\"host-header\",\"HostHeaderConfig\":{\"Values\":[\"test-ingresses.example.com\",\"alias-subdomain1.example.com\",\"alias-subdomain2.example.com\"]}}]'"
 }
+
+# bats test_tags=tag:www-redirect
+@test "www-redirect: creates annotations to redirect base domain to www" {
+  run helm template -f test/fixtures/ingresses/values-redirect-to-www.yaml test/fixtures/ingresses/
+  assert_output --partial "alb.ingress.kubernetes.io/conditions.rule-redirect-www: '[{\"Field\":\"host-header\",\"HostHeaderConfig\":{\"Values\":[\"example.com\"]}}]'"
+  assert_output --partial "alb.ingress.kubernetes.io/actions.rule-redirect-www: '{\"Type\":\"redirect\",\"RedirectConfig\":{\"Host\":\"www.example.com\",\"Port\":\"443\",\"Protocol\":\"HTTPS\",\"StatusCode\":\"HTTP_301\"}}'"
+
+  # check that subdomain.example.com is unchanged
+  assert_output --partial "
+  rules:
+    - host: \"subdomain.example.com\"
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: web
+                port:
+                  number: 8080
+    - host: \"www.example.com\"
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: web
+                port:
+                  number: 8080
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: rule-redirect-www
+                port:
+                  name: use-annotation"
+}