Varnish Controller 5.1.0 Release

Published February 23, 2023.

Note: All components needs to be upgraded for this release, see versioning.

The release includes bug fixes, new features and improvements.

New Features

  • Support for custom headers in router health checks.
  • Support for CNAME for external routes.
  • External routes location template support (for custom location format).
  • getent used as fallback to get uid/gid for components running as a user/group (to support IDM).
  • Flatbuffer schema for gRPC plugin now includes tags for endpoints and support for rejection decision.
  • Support for reject decision routes in the router.
  • Support for regexp routing decision.
  • X-Routed-For header for routed requests in a shared Varnish instance.
  • DebugHeader for RoutingRules, to only show debug information if a configured header is present.
  • UI: There is now a way to send varnishadm command to varnish servers.
  • UI: Now using Gzip or Brotli for compression.
  • UI: Updated the visual appearance of the graphs.


  • Fixes an issue with varnish_stat_id_seq max ID error in the database.
  • Bug fixes for monitoring of agents during invalidation.
  • Improvements to deployment of VCLGroups.
  • Configuration file for the VCLI now have a stricter permission policy.
  • UTC used for the database to avoid time zone issues.
  • Router now reports correct NS records for private routers.
  • Request logging (to stdout) in the router now logs failed requests as well.
  • Fixes a bug where login via API required content-type application/json.
  • Validation added for two or more VCLGroups with same domain cannot use different RoutingRules.
  • Validation added to verify that healthcheck window-size and threshold must be larger than 0.
  • Various updates to VCLI help outputs.
  • TTL for NS records is now correct for the Request Router.
  • All components build with Go 1.20.
  • UI: Can now handle larger datasets more efficiently in CIDR and ASN routing decisions.
  • UI: Fixed a bug in editor related to comments and includes.
  • UI: Fixed a issue with CSRF token.
  • UI: Various bug fixes and improvements to the dashboard.
  • UI: Fixed an issue where large VCLs could get a timeout during the compilation stage.
  • UI: Improved filter and search in data tables.
  • UI: Improved a11y.

See Varnish Controller Changelog for more details on the changes and the upgrade notes for more details on how to upgrade.

Take a look at the Varnish Controller Deprecation page to prepare for upcoming major changes.

This update is recommended for all users.