chore: re-enable build of preview versions (#296)

Closes #294

Signed-off-by: Niccolò Fei <niccolo.fei@enterprisedb.com>
Signed-off-by: Gabriele Bartolini <gabriele.bartolini@enterprisedb.com>
Co-authored-by: Gabriele Bartolini <gabriele.bartolini@enterprisedb.com>

BUILD.md

@@ -129,6 +129,37 @@ based on their digest through a GitHub workflow, using the
 [`cosign-installer` action](https://github.com/marketplace/actions/cosign-installer), which leverages
 [short-lived tokens issued through OpenID Connect](https://docs.github.com/en/actions/security-for-github-actions/security-hardening-your-deployments/about-security-hardening-with-openid-connect).
 
+## PostgreSQL Preview Versions
+
+PostgreSQL delivers a new major release every year. Before the stable version
+is published, preview builds are made available in the form of beta releases
+(e.g. `beta1`) and one or more release candidates (e.g. `rc1`).
+
+Once the first beta of a new major release is published as a Debian package,
+you can start building preview images by updating the
+`postgreSQLPreviewVersions` array in the `docker-bake.hcl` file. For example:
+
+```yaml
+postgreSQLPreviewVersions = [
+  "19~beta1",
+]
+```
+
+**NOTE:** Always use the Debian package naming convention when specifying
+preview versions (e.g. `19~beta1`, `19~rc1`).
+
+To confirm that version 19 is included in the build process, run:
+
+```bash
+docker buildx bake --print
+```
+
+**IMPORTANT:** Versions listed in `postgreSQLPreviewVersions` are automatically
+excluded if the same version is already available as a stable release in the
+`postgreSQLVersions` array. Although this safeguard prevents duplication, the
+`postgreSQLPreviewVersions` array should be cleared once a preview version is
+promoted to stable (e.g. when `19~rc1` becomes `19.0`).
+
 ## Trademarks
 
 *[Postgres, PostgreSQL and the Slonik Logo](https://www.postgresql.org/about/policies/trademarks/)

README.md

@@ -12,13 +12,23 @@
 
 # CNPG PostgreSQL Container Images
 
-This repository provides maintenance scripts for generating **immutable
-application containers** for all supported PostgreSQL versions (13 to 17),
-as well as for PostgreSQL 18 beta.
+This repository provides maintenance scripts for generating
+**immutable application containers** for all supported
+[PostgreSQL major versions](https://www.postgresql.org/support/versioning/):
 
-These containers are designed to serve as **operands** for the
-[CloudNativePG (CNPG) operator](https://cloudnative-pg.io)
-within Kubernetes environments.
+| Version | Release Date | EOL        |
+|:-------:|:------------:|:----------:|
+|    17   | 2024-09-26   | 2029-11-08 |
+|    16   | 2023-09-14   | 2028-11-09 |
+|    15   | 2022-10-13   | 2027-11-11 |
+|    14   | 2021-09-30   | 2026-11-12 |
+|    13   | 2020-09-24   | 2025-11-13 |
+
+In addition, PostgreSQL 18 RC1 is provided for testing purposes only.
+
+These images are designed to serve as operands of the
+[CloudNativePG (CNPG) operator](https://cloudnative-pg.io) in Kubernetes
+environments, and are not intended for standalone use.
 
 ## Key Features
 

docker-bake.hcl

@@ -29,6 +29,13 @@ postgreSQLVersions = [
   "17.6"
 ]
 
+// PostgreSQL preview versions to build, such as "18~beta1" or "18~rc1"
+// Preview versions are automatically filtered out if present in the stable list
+// MANUALLY EDIT THE CONTENT - AND UPDATE THE README.md FILE TOO
+postgreSQLPreviewVersions = [
+  "18~rc1",
+]
+
 // Barman version to build
 # renovate: datasource=github-releases depName=EnterpriseDB/barman versioning=loose
 barmanVersion = "3.14.0"
@@ -46,7 +53,8 @@ target "default" {
       "standard",
       "system"
     ]
-    pgVersion = postgreSQLVersions
+    // Get the list of PostgreSQL versions, filtering preview versions if already stable
+    pgVersion = getPgVersions(postgreSQLVersions, postgreSQLPreviewVersions)
     base = [
       // renovate: datasource=docker versioning=loose
       "debian:trixie-slim@sha256:c85a2732e97694ea77237c61304b3bb410e0e961dd6ee945997a06c788c545bb",
@@ -132,17 +140,33 @@ function cleanVersion {
     result = replace(version, "~", "")
 }
 
-function isBeta {
+function isPreview {
     params = [ version ]
-    result = length(regexall("[0-9]+~beta.*", version)) > 0
+    result = length(regexall("[0-9]+~(alpha|beta|rc).*", version)) > 0
 }
 
 function getMajor {
     params = [ version ]
-    result = (isBeta(version) == true) ? index(split("~", version),0) : index(split(".", version),0)
+    result = (isPreview(version) == true) ? index(split("~", version),0) : index(split(".", version),0)
 }
 
 function getExtensionsString {
     params = [ version, extensions ]
-    result = (isBeta(version) == true) ? "" : join(" ", formatlist("postgresql-%s-%s", getMajor(version), extensions))
+    result = (isPreview(version) == true) ? "" : join(" ", formatlist("postgresql-%s-%s", getMajor(version), extensions))
+}
+
+function isMajorPresent {
+  params = [major, pgVersions]
+  result = contains([for v in pgVersions : getMajor(v)], major)
+}
+
+function getPgVersions {
+  params = [stableVersions, previewVersions]
+  // Remove any preview version if already present as stable
+  result = concat(stableVersions,
+    [
+      for v in previewVersions : v
+      if !isMajorPresent(getMajor(v), stableVersions)
+    ]
+  )
 }