feat: expose HTTP/2 connection keepalive in BackendConfigPolicy#14367
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davidjumani merged 2 commits intoJul 13, 2026
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Adds connectionKeepalive (timeout, interval, connectionIdleInterval) to http2ProtocolOptions, mapping to Envoy's Http2ProtocolOptions.connection_keepalive (KeepaliveSettings). Enables active half-dead-connection detection for long-lived upstream HTTP/2 and gRPC connections: Envoy sends keepalive PINGs and closes the connection if no response arrives within the timeout, surfacing in the http2.keepalive_timeout stat. Previously requested in kgateway-dev#3740 (closed stale). tcpKeepalive covers the OS/TCP layer but cannot detect peers that are TCP-alive yet HTTP/2-dead (e.g. after NAT/LB state loss or a wedged remote process); HTTP/2 PING keepalive is the protocol-level complement. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]> Signed-off-by: Mark Johnson <[email protected]>
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Pull request overview
This PR extends kgateway’s BackendConfigPolicy HTTP/2 upstream configuration surface by adding spec.http2ProtocolOptions.connectionKeepalive, translating it into Envoy’s Http2ProtocolOptions.connection_keepalive to support HTTP/2 PING-based keepalive (half-dead connection detection) for long-lived upstream connections (e.g., gRPC).
Changes:
- Added
ConnectionKeepaliveAPI type underBackendConfigPolicy.spec.http2ProtocolOptionswith CEL validation (requiredtimeout, optionalintervalandconnectionIdleInterval). - Implemented translation to
envoycorev3.KeepaliveSettingsand applied it to HTTP/2 backends. - Updated generated artifacts (deepcopy + CRD) and added/updated translation + API validation tests.
Reviewed changes
Copilot reviewed 5 out of 6 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
| test/e2e/tests/apivalidation/apivalidation.go | Adds API validation coverage for invalid connectionKeepalive duration inputs. |
| pkg/kgateway/extensions2/plugins/backendconfigpolicy/protocoloptions.go | Translates connectionKeepalive into Envoy KeepaliveSettings in HTTP/2 protocol options. |
| pkg/kgateway/extensions2/plugins/backendconfigpolicy/plugin_test.go | Adds a unit test asserting the Envoy cluster config includes connection_keepalive for HTTP/2 backends. |
| install/helm/kgateway-crds/templates/gateway.kgateway.dev_backendconfigpolicies.yaml | Updates CRD schema to include connectionKeepalive and its validations. |
| api/v1alpha1/kgateway/zz_generated.deepcopy.go | Adds generated deepcopy support for the new ConnectionKeepalive type/field. |
| api/v1alpha1/kgateway/backend_config_policy_types.go | Introduces ConnectionKeepalive type and wires it into Http2ProtocolOptions. |
Files not reviewed (1)
- api/v1alpha1/kgateway/zz_generated.deepcopy.go: Generated file
… interval Matches the retry.perTryTimeout precedent: an unparseable duration fails both the format-regex rule and the duration() comparison rule, and the API server reports both. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]> Signed-off-by: Mark Johnson <[email protected]>
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Author
|
Filed #14381 as the accompanying feature issue for visibility/discussion. |
andy-fong
approved these changes
Jul 13, 2026
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Description
Fixes #14381.
Adds
connectionKeepalivetoBackendConfigPolicy.spec.http2ProtocolOptions, mapping to Envoy'sHttp2ProtocolOptions.connection_keepalive:Motivation
Long-lived upstream HTTP/2 / gRPC connections can go half-dead — TCP-alive but HTTP/2-dead (NAT/LB state loss, wedged remote process).
tcpKeepalivecovers the OS layer but cannot detect this class; HTTP/2 PING keepalive is the protocol-level complement, and failures surface in thehttp2.keepalive_timeoutcluster stat for alerting. This was previously requested in #3740 (closed by stalebot in the gloo era).What's included
ConnectionKeepalivetype (requiredtimeout, optionalinterval/connectionIdleInterval), CEL duration validation consistent withtcpKeepaliveenvoycorev3.KeepaliveSettingsmake go-generate-apis)Merging of
http2ProtocolOptionsis unchanged — the block is already merged as a unit, so the new field participates automatically.Change Type
/kind new_feature
Changelog
🤖 Generated with Claude Code