feat: make expressions router default

.github/workflows/main-pr.yaml

@@ -126,8 +126,8 @@ jobs:
     strategy:
       matrix:
         kic-version:
-        - "2.10"
         - "2.11"
+        - "2.12"
         kong-version:
         - "3.3"
         - "3.2"

charts/ingress/CHANGELOG.md

@@ -1,5 +1,22 @@
 # Changelog
 
+## 0.10.0
+
+### Improvements
+
+- Changed the default Gateway's router flavor (`gateway.env.router_flavor` value) to performance-boosting `expressions`.
+  It can make `helm install` fail if you're using this chart with Kong Ingress Controller pinned to a version
+  older than `3.0.0`.
+  To fix it, you have the following options for given controller versions:
+  - < `2.10.0`:
+    1. Bump the controller version to >= `3.0.0`.
+    1. Set `gateway.env.router_flavor` to `traditional` to keep using the old router flavor.
+  - \>= `2.10.0` and < `3.0.0`:
+    1. Bump the controller version to >= `3.0.0`.
+    1. Set `gateway.env.router_flavor` to `traditional` to keep using the old router flavor.
+    1. Set `controller.env.feature_gates=ExpressionRoutes=true` to use the new router flavor.
+  [#939](https://github.com/Kong/charts/pull/939)
+
 ## 0.9.0
 
 ### Improvements

charts/ingress/Chart.yaml

@@ -8,7 +8,7 @@ maintainers:
 name: ingress
 sources:
   - https://github.com/Kong/charts/tree/main/charts/ingress
-version: 0.9.0
+version: 0.10.0
 appVersion: "3.4"
 dependencies:
   - name: kong

charts/ingress/templates/validation.tpl

@@ -0,0 +1,51 @@
+{{- /* Validate 'expressions' router flavor is not used with KIC < 2.10 as it's not supported */}}
+{{- if and .Values.controller.ingressController.enabled
+           (eq .Values.gateway.env.router_flavor "expressions")
+           (semverCompare "< 2.10" (include "kong.effectiveVersion" .Values.controller.ingressController.image))
+-}}
+    {{- fail (printf `
+⚠️ Warning!
+
+"kong/ingress" chart in version 0.10.0 has introduced "gateway.env.router_flavor" value defaulting to "expressions".
+"expressions" router flavor is not supported with Kong Ingress Controller %q that you're using.
+
+✅ How to fix it (alternatives)
+
+1. Upgrade to Kong Ingress Controller 3.0 to use this feature.
+
+2. If you want to keep using your Kong Ingress Controller version, set "gateway.env.router_flavor" to "traditional" to
+backoff to the previous router flavor in your values.yaml:
+
+gateway:
+  env:
+    router_flavor: "traditional"` .Values.controller.ingressController.image.tag  ) -}}
+{{- end -}}
+
+{{- /* Validate that when 'expressions' router flavor is used with KIC < 3.0, feature flag must be set. */ -}}
+{{- if and (.Values.controller.ingressController.enabled)
+           (eq .Values.gateway.env.router_flavor "expressions")
+           (not (contains "ExpressionRoutes=true" (default "" .Values.controller.ingressController.env.feature_gates)))
+           (semverCompare "< 3.0" (include "kong.effectiveVersion" .Values.controller.ingressController.image)) -}}
+    {{- fail (printf `
+⚠️ Warning!
+
+"kong/ingress" chart in version 0.10.0 has introduced "gateway.env.router_flavor" value defaulting to "expressions".
+You're using Kong Ingress Controller version %q which supports this feature only when feature flag "ExpressionRoutes=true" is set.
+
+✅ How to fix it (alternatives)
+
+1. Upgrade to Kong Ingress Controller 3.0 to use this feature.
+
+2. Set "controller.ingressController.env.feature_gates" to "ExpressionRoutes=true" to enable this feature in your values.yaml:
+
+controller:
+  ingressController:
+    env:
+      feature_gates: "ExpressionRoutes=true"
+
+3. Set "gateway.env.router_flavor" to "traditional" to use the previous router flavor in your values.yaml:
+
+gateway:
+  env:
+    router_flavor: "traditional"` .Values.controller.ingressController.image.tag) -}}
+{{- end -}}

charts/ingress/values.yaml

@@ -44,3 +44,4 @@ gateway:
   env:
     role: traditional
     database: "off"
+    router_flavor: "expressions"

scripts/test-run.sh

@@ -86,8 +86,16 @@ then
 fi
 
 # Configure values for all tests
-# Enable Gateway API
+
+# Enable feature gates.
+if [[ -n "${KIC_VERSION-}" ]]; then
+# If testing old version, set ExpressionRoutes.
+ADDITIONAL_FLAGS+=("--set ${CONTROLLER_PREFIX}ingressController.env.feature_gates=ExpressionRoutes=true,GatewayAlpha=true")
+else
+# Otherwise, just GatewayAlpha.
 ADDITIONAL_FLAGS+=("--set ${CONTROLLER_PREFIX}ingressController.env.feature_gates=GatewayAlpha=true")
+fi
+
 # Tests should not show up in reporting
 ADDITIONAL_FLAGS+=("--set ${CONTROLLER_PREFIX}ingressController.env.anonymous_reports=false")