Repository: envoyproxy/gateway

Issue:
EnvoyProxy accesslog default not working as expected
https://envoyproxy.slack.com/archives/C03E6NHLESV/p1751364508406689

Following configuration is ignored instead of setting default JSON format.

```yaml
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyProxy
metadata:
  name: proxy-config-public
  namespace: envoy-gateway-system
spec:
  telemetry:
    accessLog:
      settings:
        - sinks:
            - type: File
              file:
                path: /dev/stdout
```

Hints from issue comments:
@zirain: related to https://github.com/envoyproxy/gateway/commit/8f48f5199cf1bbb9a8ac0695c5171bfef6c9198a

Solution patch:
diff --git a/internal/gatewayapi/listener.go b/internal/gatewayapi/listener.go
index a48cbcf6e..4d6fe2668 100644
--- a/internal/gatewayapi/listener.go
+++ b/internal/gatewayapi/listener.go
@@ -590,11 +590,6 @@ func (t *Translator) processAccessLog(envoyproxy *egv1a1.EnvoyProxy, resources *
 					}
 					irAccessLog.Text = append(irAccessLog.Text, al)
 				case egv1a1.ProxyAccessLogFormatTypeJSON:
-					if len(format.JSON) == 0 {
-						// TODO: use a default JSON format if not specified?
-						continue
-					}
-
 					al := &ir.JSONAccessLog{
 						JSON:       format.JSON,
 						Path:       sink.File.Path,
diff --git a/release-notes/current.yaml b/release-notes/current.yaml
index 3974f8243..370871b3c 100644
--- a/release-notes/current.yaml
+++ b/release-notes/current.yaml
@@ -42,6 +42,7 @@ bug fixes: |
   Fixed issue where EnvoyExtensionPolicy ExtProc body processing mode is set to FullDuplexStreamed, but trailers were not sent.
   Fixed validation issue where EnvoyExtensionPolicy ExtProc failOpen is true, and body processing mode FullDuplexStreamed is not rejected.
   Add ConfigMap indexers for EnvoyExtensionPolicies to reconcile Lua changes
+  Fixed issue that default accesslog format not working.
 
 
 # Enhancements that improve performance.



Test patch:
diff --git a/internal/gatewayapi/testdata/envoyproxy-accesslog-file-json-no-format.out.yaml b/internal/gatewayapi/testdata/envoyproxy-accesslog-file-json-no-format.out.yaml
index 32bbeab06..54d161e1b 100644
--- a/internal/gatewayapi/testdata/envoyproxy-accesslog-file-json-no-format.out.yaml
+++ b/internal/gatewayapi/testdata/envoyproxy-accesslog-file-json-no-format.out.yaml
@@ -128,7 +128,9 @@ infraIR:
       namespace: envoy-gateway-system
 xdsIR:
   envoy-gateway/gateway-1:
-    accessLog: {}
+    accessLog:
+      json:
+      - path: /dev/stdout
     http:
     - address: 0.0.0.0
       hostnames:
diff --git a/internal/gatewayapi/testdata/envoyproxy-accesslog-without-format.out.yaml b/internal/gatewayapi/testdata/envoyproxy-accesslog-without-format.out.yaml
index d8a3d583c..596392106 100644
--- a/internal/gatewayapi/testdata/envoyproxy-accesslog-without-format.out.yaml
+++ b/internal/gatewayapi/testdata/envoyproxy-accesslog-without-format.out.yaml
@@ -203,6 +203,8 @@ xdsIR:
             protocol: GRPC
         name: envoy-gateway-system/test
         type: TCP
+      json:
+      - path: /dev/stdout
       openTelemetry:
       - authority: otel-collector.monitoring.svc.cluster.local
         destination: