# Changelog All notable changes to this project will be documented in this file. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/). Each revision is versioned by the date of the revision. ## 2026-10-19 ### Changed - Moved the documentation tooling to the centrally managed `platform-engineering-documentation-files` Copier template and added a scheduled workflow that keeps it in sync. There is no change to the charms. ## 2026-10-14 ### Changed - Migrated the `content-cache` and `content-cache-backends-config` Terraform modules to the CC008 Charm Terraform Module standard: renamed `versions.tf` to `terraform.tf` and added `required_version`, split the combined `endpoints` output into `provides`/`requires` maps, and changed the `application` output to the full `juju_application` object. Breaking default changes: `expose` is now an object (`cidrs`/`endpoints`/`spaces`) defaulting to `{}` (exposed with no restrictions) instead of a `bool` defaulting to `false` (not exposed); `base` and `constraints` now default to `null` (the charm’s and Juju’s own defaults) instead of `ubuntu@24.04` and `arch=amd64` respectively. Added a `terraform_modules_compliance` CI workflow, a `terraform_modules_release` workflow tagging the shared `tf-X.Y.Z` module version, and a `generate_terraform_docs` workflow. Moved the Terraform modules to the standard repository layout: `content-cache/terraform` is now `terraform/charm/content_cache`, `content-cache-backends-config/terraform` is now `terraform/charm/content_cache_backends_config`. Removed the example composition Terraform module from `terraform/`. A content-cache application can attach to any number of content-cache-backends-config applications, so compose the two charm modules directly instead. ## 2026-10-07 ### Added - Each backend’s nginx server block now also listens on the IPv6 wildcard address (`[::]:`), in addition to the existing IPv4 listener, so backends reachable only over IPv6 (e.g. Snap Store, Ubuntu Archive) can be proxied ([#167](https://github.com/canonical/content-cache-operator/issues/167)). ### Fixed - The COS Grafana dashboard’s “site” variable, and the per-backend access/cache/error log files it’s derived from, are now keyed by `-` when a backend hostname is configured (falling back to just the port otherwise), so operators can filter logs/dashboards by the actual website being cached while filenames stay unique even if multiple backends share a hostname. The hostname portion is truncated as needed to stay within filesystem filename limits. (Fixes [#163](https://github.com/canonical/content-cache-operator/issues/163)) ## 2026-09-23 ### Added - Added the `client-ip-hash-salt` configuration option to the content-cache charm. When set to a user-owned Juju secret containing a `salt` key, client IP addresses are replaced with a salted SHA-256 hash in the access and cache logs, helping protect user privacy. See [How to hash client IP addresses in logs](https://canonical.com/juju/docs/content-cache-charms/latest/how-to/hash-client-ip-addresses-in-logs/index.html.md#how-to-hash-client-ip-addresses-in-logs) for setup instructions. ## 2026-09-16 ### Added - Added an advanced tutorial walking through deploying `content-cache` behind `ingress-configurator` and `haproxy`, covering hostname-based routing, TLS termination, and other ingress features. ### Fixed - Removed HTML comment blocks from the charm README that were rendering as literal text on the Charmhub landing page. ### Changed - Updated the how-to guides, reference, and explanation pages to reflect the current `ingress-configurator`-based backend configuration flow, while retaining `content-cache-backends-config` as a supported alternative. Corrected the documented TLS certificate file path (`/etc/nginx/certs/content-cache-charm.pem`) and cache directory path (`/data/nginx/cache//`) to match the current charm implementation. ## 2026-08-21 ### Removed - Ejected the outdated “Deploy content-cache” tutorial from the documentation. The tutorial no longer reflects a possible deployment schema for the charms, and work is planned to replace the tutorial with an accurate setup. ## 2026-08-18 ### Added - The content-cache charm now verifies backend TLS certificates when HTTPS backend URLs are configured. Integrate a CA certificate provider via the new `receive-ca-cert` relation (interface: `certificate_transfer`) to supply the CA bundle. nginx is configured with `proxy_ssl_verify on`, `proxy_ssl_trusted_certificate`, and `proxy_ssl_name` pointing to the backend hostname. If HTTPS backends are configured but no CA certificate has been provided, the charm enters `WaitingStatus` until the relation is established. Multiple providers are supported; all CA certificates are merged into a single bundle at `/etc/nginx/certs/ca-bundle.pem`. ## 2026-07-16 ### Changed - The `backends` configuration option on `content-cache-backends-config` now accepts URLs in the form `://:` instead of bare IP addresses with a separate `protocol` option. The `protocol` option has been removed. ### Added - The content-cache charm now publishes a `cache-backend` field to the `cache-config` relation data after nginx becomes active. The field contains a URL representing the address and port at which this unit is listening, so ingress components can discover it automatically. ## 2026-06-18 - Migrated the RTD documentation URL under the Canonical domain. ## 2025-05-06 ### **Changed** - Updated [CONTRIBUTING.md](http://CONTRIBUTING.md) and the documentation. ## 2025-01-13 ### **Added** - Support for healthcheck-valid-status configuration. - Support for healthcheck-ssl-verify configuration. ## 2024-12-18 ### **Added** - Add grafana dashboard for the displaying metrics from COS integration. ## 2024-12-16 ### **Added** - Support for active health checks using LUA scripts. Configured through healthcheck-interval and healthcheck-path. ## 2024-12-11 ### **Fixed** - A issue where content-cache charm integrated with multiple content-cache-backends-config charms causing some configuration to not work correctly. ## 2024-12-05 ### **Added** - Support for COS integration. Integrating with charms that provides cos-agent will cause the charm to forward logs to COS. ## 2024-11-28 ### **Added** - Support for TLS certificate integration. Integrating with charms that provides tls-certificates will enable HTTPS for the content cache. ## 2024-10-17 ## **Added** - Support for fail-timeout, backends-path, proxy-cache-valid configuration options from integration with Content Cache Backends Config charm. ## 2024-10-07 ## **Added** - Changelog for tracking user-relevant changes. - Basic content cache functionality with nginx. - Support for hostname, path, backends, protocol configuration options from integration with Content Cache Backends Config charm.