Add envoy filter override (#148)

* Add envoy filter override

* Update changelog

Co-authored-by: Keegan Carruthers-Smith <[email protected]>

Author: abeatrix

charts/sourcegraph/CHANGELOG.md

@@ -3,15 +3,14 @@ Use `**BREAKING**:` to denote a breaking change
 -->
 
 # Changelog
+
 <!-- START CHANGELOG -->
 
 ## Unreleased
 
-## 3.41.1
-
-Sourcegraph 3.41.1 is now available!
+### Added
 
-- [Changelog](https://sourcegraph.com/github.com/sourcegraph/sourcegraph/-/blob/CHANGELOG.md#3-41-1)
+- Add new example `envoy` to enable HTTP trailers using Envoy Filter [#148](https://github.com/sourcegraph/deploy-sourcegraph-helm/pull/148)
 
 ## 3.41.0
 

charts/sourcegraph/examples/envoy/README.md

@@ -0,0 +1,9 @@
+# Envoy Filter
+
+This override file creates a new resource called `EnvoyFilter` to enable HTTP trailers on envoy for gitserver.
+
+It is an example override file to apply a new envoy filter to resolve the following error message in gitserver caused by service mesh (ex. istio):
+
+```
+"git command [git rev-parse HEAD] failed (stderr: \"\"): strconv.Atoi: parsing \"\"
+```

charts/sourcegraph/examples/envoy/override.yaml

@@ -0,0 +1,36 @@
+extraResources:
+  - apiVersion: networking.istio.io/v1alpha3
+    kind: EnvoyFilter
+    metadata:
+      name: enable-trailers
+      labels:
+        deploy: sourcegraph
+    spec:
+      workloadSelector:
+        labels:
+          app: gitserver
+      configPatches:
+        - applyTo: NETWORK_FILTER
+          match:
+            listener:
+              filterChain:
+                filter:
+                  name: "envoy.filters.network.http_connection_manager"
+          patch:
+            operation: MERGE
+            value:
+              name: "envoy.filters.network.http_connection_manager"
+              typed_config:
+                "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager"
+                http_protocol_options:
+                  enable_trailers: true
+        - applyTo: CLUSTER
+          patch:
+            operation: MERGE
+            value:
+              typed_extension_protocol_options:
+                envoy.extensions.upstreams.http.v3.HttpProtocolOptions:
+                  "@type": type.googleapis.com/envoy.extensions.upstreams.http.v3.HttpProtocolOptions
+                  explicit_http_config:
+                    http_protocol_options:
+                      enable_trailers: true