ci/docker: unify image build logic and run virgin tests across all distros

Refactor Dockerfile into multi-stage virgin/full targets and introduce a single
flag-based image build script. Standardize image naming, remove redundant build
scripts, and update Makefile targets accordingly. CI workflows now build missing
virgin images and run root and user tests consistently across all supported
distributions.

https://chatgpt.com/share/693c29d9-9b28-800f-a549-5661c783d968

scripts/build/build-image-missing.sh

@@ -1,24 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
-source "${SCRIPT_DIR}/resolve-base-image.sh"
-
-IMAGE="package-manager-test-$distro"
-BASE_IMAGE="$(resolve_base_image "$distro")"
-
-if docker image inspect "$IMAGE" >/dev/null 2>&1; then
-    echo "[build-missing] Image already exists: $IMAGE (skipping)"
-    exit 0
-fi
-
-echo
-echo "------------------------------------------------------------"
-echo "[build-missing] Building missing image: $IMAGE"
-echo "BASE_IMAGE = $BASE_IMAGE"
-echo "------------------------------------------------------------"
-
-docker build \
-    --build-arg BASE_IMAGE="$BASE_IMAGE" \
-    -t "$IMAGE" \
-    .

scripts/build/build-image-no-cache.sh

@@ -1,15 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
-source "${SCRIPT_DIR}/resolve-base-image.sh"
-
-base_image="$(resolve_base_image "$distro")"
-
-echo ">>> Building test image for distro '$distro' with NO CACHE (BASE_IMAGE=$base_image)..."
-
-docker build \
-  --no-cache \
-  --build-arg BASE_IMAGE="$base_image" \
-  -t "package-manager-test-$distro" \
-  .

scripts/build/build-image.sh

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
-source "${SCRIPT_DIR}/resolve-base-image.sh"
-
-base_image="$(resolve_base_image "$distro")"
-
-echo ">>> Building test image for distro '$distro' (BASE_IMAGE=$base_image)..."
-
-docker build \
-  --build-arg BASE_IMAGE="$base_image" \
-  -t "package-manager-test-$distro" \
-  .

scripts/build/image.sh

@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Unified docker image builder for all distros.
+#
+# Supports:
+#   --missing     Build only if image does not exist
+#   --no-cache    Disable docker layer cache
+#   --target      Dockerfile target (e.g. virgin|full)
+#   --tag         Override image tag (default: pkgmgr-$distro[-$target])
+#
+# Requires:
+#   - env var: distro (arch|debian|ubuntu|fedora|centos)
+#   - base.sh in same dir
+#
+# Examples:
+#   distro=arch   bash scripts/build/image.sh
+#   distro=arch   bash scripts/build/image.sh --no-cache
+#   distro=arch   bash scripts/build/image.sh --missing
+#   distro=arch   bash scripts/build/image.sh --target virgin
+#   distro=arch   bash scripts/build/image.sh --target virgin --missing
+#   distro=arch   bash scripts/build/image.sh --tag myimg:arch
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck source=/dev/null
+source "${SCRIPT_DIR}/base.sh"
+
+: "${distro:?Environment variable 'distro' must be set (arch|debian|ubuntu|fedora|centos)}"
+
+NO_CACHE=0
+MISSING_ONLY=0
+TARGET=""
+IMAGE_TAG="" # derive later unless --tag is provided
+
+usage() {
+  local default_tag="pkgmgr-${distro}"
+  if [[ -n "${TARGET:-}" ]]; then
+    default_tag="${default_tag}-${TARGET}"
+  fi
+
+  cat <<EOF
+Usage: distro=<distro> $0 [--missing] [--no-cache] [--target <name>] [--tag <image>]
+
+Options:
+  --missing         Build only if the image does not already exist
+  --no-cache        Build with --no-cache
+  --target <name>   Build a specific Dockerfile target (e.g. virgin|full)
+  --tag <image>     Override the output image tag (default: ${default_tag})
+  -h, --help        Show help
+EOF
+}
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --no-cache) NO_CACHE=1; shift ;;
+    --missing)  MISSING_ONLY=1; shift ;;
+    --target)
+      TARGET="${2:-}"
+      if [[ -z "${TARGET}" ]]; then
+        echo "ERROR: --target requires a value (e.g. virgin|full)" >&2
+        exit 2
+      fi
+      shift 2
+      ;;
+    --tag)
+      IMAGE_TAG="${2:-}"
+      if [[ -z "${IMAGE_TAG}" ]]; then
+        echo "ERROR: --tag requires a value" >&2
+        exit 2
+      fi
+      shift 2
+      ;;
+    -h|--help) usage; exit 0 ;;
+    *)
+      echo "ERROR: Unknown argument: $1" >&2
+      usage
+      exit 2
+      ;;
+  esac
+done
+
+# Auto-tag: if --tag not provided, derive from distro (+ target suffix)
+if [[ -z "${IMAGE_TAG}" ]]; then
+  IMAGE_TAG="pkgmgr-${distro}"
+  if [[ -n "${TARGET}" ]]; then
+    IMAGE_TAG="${IMAGE_TAG}-${TARGET}"
+  fi
+fi
+
+BASE_IMAGE="$(resolve_base_image "$distro")"
+
+if [[ "${MISSING_ONLY}" == "1" ]]; then
+  if docker image inspect "${IMAGE_TAG}" >/dev/null 2>&1; then
+    echo "[build] Image already exists: ${IMAGE_TAG} (skipping due to --missing)"
+    exit 0
+  fi
+fi
+
+echo
+echo "------------------------------------------------------------"
+echo "[build] Building image: ${IMAGE_TAG}"
+echo "distro     = ${distro}"
+echo "BASE_IMAGE = ${BASE_IMAGE}"
+if [[ -n "${TARGET}" ]]; then echo "target    = ${TARGET}"; fi
+if [[ "${NO_CACHE}" == "1" ]]; then echo "cache     = disabled"; fi
+echo "------------------------------------------------------------"
+
+build_args=(--build-arg "BASE_IMAGE=${BASE_IMAGE}")
+
+if [[ "${NO_CACHE}" == "1" ]]; then
+  build_args+=(--no-cache)
+fi
+
+if [[ -n "${TARGET}" ]]; then
+  build_args+=(--target "${TARGET}")
+fi
+
+build_args+=(-t "${IMAGE_TAG}" .)
+
+docker build "${build_args[@]}"

scripts/test/test-e2e.sh

@@ -12,7 +12,7 @@ docker run --rm \
   -e REINSTALL_PKGMGR=1 \
   -e TEST_PATTERN="${TEST_PATTERN}" \
   --workdir /src \
-  "package-manager-test-${distro}" \
+  "pkgmgr-${distro}" \
   bash -lc '
     set -euo pipefail
 

scripts/test/test-env-nix.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-IMAGE="package-manager-test-${distro}"
+IMAGE="pkgmgr-${distro}"
 
 echo "============================================================"
 echo ">>> Running Nix flake-only test in ${distro} container"

scripts/test/test-env-virtual.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-IMAGE="package-manager-test-$distro"
+IMAGE="pkgmgr-$distro"
 
 echo
 echo "------------------------------------------------------------"

scripts/test/test-integration.sh

@@ -12,7 +12,7 @@ docker run --rm \
   --workdir /src \
   -e REINSTALL_PKGMGR=1 \
   -e TEST_PATTERN="${TEST_PATTERN}" \
-  "package-manager-test-${distro}" \
+  "pkgmgr-${distro}" \
   bash -lc '
     set -e;
     git config --global --add safe.directory /src || true;

scripts/test/test-unit.sh

@@ -12,7 +12,7 @@ docker run --rm \
   --workdir /src \
   -e REINSTALL_PKGMGR=1 \
   -e TEST_PATTERN="${TEST_PATTERN}" \
-  "package-manager-test-${distro}" \
+  "pkgmgr-${distro}" \
   bash -lc '
     set -e;
     git config --global --add safe.directory /src || true;