Add OCI metadata to custom images

.gitea/workflows/build-images.yaml

@@ -31,6 +31,12 @@ jobs:
             context: postgres
             base_image: postgres:18
             primary_tag: git.ajpanton.se/ajp_anton/postgres-custom:18
+            oci_labels: |
+              org.opencontainers.image.title=PostgreSQL 18 with extensions
+              org.opencontainers.image.description=PostgreSQL 18 with PostGIS, pgvector, pg_cron, and VectorChord preloaded.
+              org.opencontainers.image.documentation=https://git.ajpanton.se/ajp_anton/docker-images#postgres-custom
+              org.opencontainers.image.source=https://git.ajpanton.se/ajp_anton/docker-images
+              org.opencontainers.image.url=https://git.ajpanton.se/ajp_anton/-/packages/container/postgres-custom
             tags: |
               git.ajpanton.se/ajp_anton/postgres-custom:18
               git.ajpanton.se/ajp_anton/postgres-custom:18-postgis3-vchord0.5.3
@@ -45,6 +51,12 @@ jobs:
             context: php8-pgsql
             base_image: php:8-fpm-alpine
             primary_tag: git.ajpanton.se/ajp_anton/php8-pgsql:8
+            oci_labels: |
+              org.opencontainers.image.title=PHP 8 FPM with PostgreSQL support
+              org.opencontainers.image.description=PHP 8 FPM on Alpine with libpq and the pdo_pgsql extension enabled.
+              org.opencontainers.image.documentation=https://git.ajpanton.se/ajp_anton/docker-images#php8-pgsql
+              org.opencontainers.image.source=https://git.ajpanton.se/ajp_anton/docker-images
+              org.opencontainers.image.url=https://git.ajpanton.se/ajp_anton/-/packages/container/php8-pgsql
             tags: |
               git.ajpanton.se/ajp_anton/php8-pgsql:8
               git.ajpanton.se/ajp_anton/php8-pgsql:8-fpm-alpine
@@ -57,6 +69,12 @@ jobs:
             context: python-tools
             base_image: python:3
             primary_tag: git.ajpanton.se/ajp_anton/python-tools:3
+            oci_labels: |
+              org.opencontainers.image.title=Python 3 tools with ExifTool
+              org.opencontainers.image.description=Python 3 utility image with ExifTool for local helper workflows.
+              org.opencontainers.image.documentation=https://git.ajpanton.se/ajp_anton/docker-images#python-tools
+              org.opencontainers.image.source=https://git.ajpanton.se/ajp_anton/docker-images
+              org.opencontainers.image.url=https://git.ajpanton.se/ajp_anton/-/packages/container/python-tools
             tags: |
               git.ajpanton.se/ajp_anton/python-tools:3
               git.ajpanton.se/ajp_anton/python-tools:latest
@@ -83,6 +101,7 @@ jobs:
           BASE_IMAGE: ${{ matrix.image.base_image }}
           PRIMARY_TAG: ${{ matrix.image.primary_tag }}
           TAGS: ${{ matrix.image.tags }}
+          OCI_LABELS: ${{ matrix.image.oci_labels }}
           BUILD_ARGS: ${{ matrix.image.build_args }}
           FINGERPRINT_COMMAND: ${{ matrix.image.fingerprint_command }}
         run: ./scripts/build-image-if-changed.sh

scripts/build-image-if-changed.sh

@@ -6,6 +6,7 @@ set -euo pipefail
 : "${BASE_IMAGE:?}"
 : "${PRIMARY_TAG:?}"
 : "${TAGS:?}"
+: "${OCI_LABELS:?}"
 : "${BUILD_ARGS:?}"
 : "${FINGERPRINT_COMMAND:?}"
 
@@ -17,10 +18,14 @@ cleanup() {
 trap cleanup EXIT
 
 mapfile -t build_args < <(printf '%s\n' "$BUILD_ARGS" | sed '/^[[:space:]]*$/d')
+mapfile -t oci_labels < <(printf '%s\n' "$OCI_LABELS" | sed '/^[[:space:]]*$/d')
 build_flags=(--pull --no-cache --load --tag "$candidate_tag")
 for build_arg in "${build_args[@]}"; do
     build_flags+=(--build-arg "$build_arg")
 done
+for oci_label in "${oci_labels[@]}"; do
+    build_flags+=(--label "$oci_label")
+done
 
 context_hash="$(
     cd "$BUILD_CONTEXT"
@@ -37,6 +42,7 @@ fingerprint() {
         printf 'base-image-id=%s\n' "$base_image_id"
         printf 'context-hash=%s\n' "$context_hash"
         printf 'build-args=%s\n' "$BUILD_ARGS"
+        printf 'oci-labels=%s\n' "$OCI_LABELS"
         docker run --rm --entrypoint /bin/sh "$1" -c "$FINGERPRINT_COMMAND"
     } | sha256sum | awk '{print $1}'
 }