Add missing upgrade notes for 5.2 (#295)

* Mentions the removal of `curl` in the apiserver container image in favour of busybox wget.
* Mentions removal of the bundled cloud SQL socket factory.

Signed-off-by: nscuro <nscuro@protonmail.com>

Author: nscuro

docs/guides/administration/configuring-database.md

@@ -28,6 +28,25 @@ The same is not necessarily true for platforms based on heavily modified Postgre
 such as [CockroachDB] or [YugabyteDB]. Such solutions make certain trade-offs to achieve higher levels of scalability,
 which might impact functionality that Dependency-Track relies on.
 
+#### Google Cloud SQL
+
+To connect through the [Cloud SQL socket factory][cloud-sql-jdbc], for example to use IAM database authentication,
+add the socket factory to the API server. The container image doesn't include it.
+
+1. [Build the socket factory JAR with its dependencies][cloud-sql-build].
+2. Mount it into `/opt/owasp/dependency-track/lib-external/`. The API server loads every JAR in that directory.
+3. Set the data source URL to your instance:
+
+```yaml linenums="1" title="docker-compose.yaml"
+services:
+  apiserver:
+    image: dependencytrack/apiserver
+    environment:
+      DT_DATASOURCE_URL: "jdbc:postgresql:///dtrack?cloudSqlInstance=<INSTANCE_CONNECTION_NAME>&socketFactory=com.google.cloud.sql.postgres.SocketFactory"
+    volumes:
+      - "./postgres-socket-factory-jar-with-dependencies.jar:/opt/owasp/dependency-track/lib-external/postgres-socket-factory.jar:ro"
+```
+
 ### Self-hosting
 
 #### Bare Metal / Docker
@@ -247,6 +266,8 @@ services:
 
 [Autovacuum]: https://www.postgresql.org/docs/current/routine-vacuuming.html
 [CockroachDB]: https://www.cockroachlabs.com/
+[cloud-sql-build]: https://github.com/GoogleCloudPlatform/cloud-sql-jdbc-socket-factory#building-the-drivers
+[cloud-sql-jdbc]: https://github.com/GoogleCloudPlatform/cloud-sql-jdbc-socket-factory/blob/main/docs/jdbc.md
 [Neon]: https://neon.tech/
 [PGTune]: https://pgtune.leopard.in.ua/
 [PgBouncer]: https://www.pgbouncer.org/

docs/guides/upgrading/v5.2.0.md

@@ -48,9 +48,23 @@
   and [`dt.vex-upload.max-size-bytes`][max-upload-size-vex]. Both properties default to 100 MiB. Increase them if
   your instances process documents larger than that.
 
+* **The API server container image no longer includes `curl`**. The image's health check now uses `wget`.
+  If you override the health check or run `curl` in an `exec` probe, switch to `wget`:
+
+    ```shell
+    wget -q -Y off -T 3 -O /dev/null http://127.0.0.1:9000/health
+    ```
+
+    In Kubernetes, an `httpGet` probe against port `9000` needs no tool in the image at all.
+
+* **The API server container image no longer includes the Google Cloud SQL socket factory**. If your database URL sets
+  `socketFactory=com.google.cloud.sql.postgres.SocketFactory`, the API server fails to connect after the upgrade.
+  Add the socket factory as described in [Google Cloud SQL][cloud-sql].
+
 [access-control-svc]: ../../concepts/access-control.md#service-accounts
 [allowed-destinations]: ../../reference/configuration/properties.md#dtoutboundallowed-destinations
 [cargo-alt-reg]: https://doc.rust-lang.org/cargo/reference/registries.html#using-an-alternate-registry
 [cargo-idx]: https://doc.rust-lang.org/cargo/reference/registry-index.html#sparse-protocol
+[cloud-sql]: ../administration/configuring-database.md#google-cloud-sql
 [max-upload-size-bom]: ../../reference/configuration/properties.md#dtbom-uploadmax-size-bytes
 [max-upload-size-vex]: ../../reference/configuration/properties.md#dtvex-uploadmax-size-bytes