Support rootless Podman builds

bin/setup

@@ -15,6 +15,7 @@ set -e
 
 BUILD_ROOT=$(realpath "${BASH_SOURCE[0]%/*}/..")
 source "$BUILD_ROOT/helpers/message-helpers.sh"
+source "$BUILD_ROOT/helpers/docker-helpers.sh"
 source "$BUILD_ROOT/helpers/paths.sh"
 
 CHECK_ONLY=false
@@ -62,10 +63,12 @@ if command -v apt-get >/dev/null 2>&1; then
   DISTRO="debian"
   PKG_BSDTAR="libarchive-tools"
   PKG_DOCKER="docker.io"
+  PKG_PODMAN="podman"
 elif command -v pacman >/dev/null 2>&1; then
   DISTRO="arch"
   PKG_BSDTAR="libarchive"
   PKG_DOCKER="docker"
+  PKG_PODMAN="podman"
 else
   print_error "Unsupported distribution — need apt-get or pacman"
   exit 1
@@ -73,18 +76,36 @@ fi
 
 print_info "Distribution: $DISTRO"
 
+# A fresh repository host still defaults to Docker. An explicit Podman choice,
+# or a working Podman selected by the shared helper, is left alone.
+if [[ -z "$CONTAINER_ENGINE" ]]; then
+  CONTAINER_ENGINE=docker
+  export CONTAINER_ENGINE
+fi
+if ! container_engine_supported; then
+  print_error "Unsupported CONTAINER_ENGINE: $CONTAINER_ENGINE (use docker or podman)"
+  exit 1
+fi
+if [[ "$CONTAINER_ENGINE" == "docker" ]]; then
+  PKG_ENGINE="$PKG_DOCKER"
+  ENGINE_NAME="Docker"
+else
+  PKG_ENGINE="$PKG_PODMAN"
+  ENGINE_NAME="Podman"
+fi
+
 if [[ "$CHECK_ONLY" != true && $EUID -ne 0 ]]; then
   print_error "Run as root (installing packages and systemd units)"
   exit 1
 fi
 
-# Docker and the release timers are both systemd units. Say so plainly rather
-# than failing later on a missing command — a container is the usual way to end
-# up here, and it cannot be a repository host.
+# The release timers are systemd units. Say so plainly rather than failing
+# later on a missing command — a container is the usual way to end up here,
+# and it cannot be a repository host.
 if [[ "$CHECK_ONLY" != true ]] && ! command -v systemctl >/dev/null 2>&1; then
   print_error "systemctl not found — the repository host must run systemd"
   echo ""
-  echo "Docker and the release timers are systemd units. This looks like a"
+  echo "The release timers are systemd units. This looks like a"
   echo "container; run setup on the host itself."
   exit 1
 fi
@@ -140,24 +161,27 @@ else
 fi
 echo ""
 
-# --- docker ------------------------------------------------------------------
+# --- container engine --------------------------------------------------------
 
-# Docker is left alone when it already works. A host may well be running a
+# The selected engine is left alone when it already works. A host may be running a
 # version from Docker's own repository rather than the distribution's, and
 # replacing that underneath a working builder would be a poor trade for
 # tidiness.
-print_info "Checking Docker..."
+print_info "Checking $ENGINE_NAME..."
 
-if command -v docker >/dev/null 2>&1; then
-  print_step "docker present: $(docker --version 2>/dev/null | head -1)"
-  if docker info >/dev/null 2>&1; then
-    print_success "Docker is installed and running — leaving it alone"
+if command -v "$CONTAINER_ENGINE" >/dev/null 2>&1; then
+  print_step "$CONTAINER_ENGINE present: $("$CONTAINER_ENGINE" --version 2>/dev/null | head -1)"
+  if "$CONTAINER_ENGINE" info >/dev/null 2>&1; then
+    print_success "$ENGINE_NAME is installed and available — leaving it alone"
   elif [[ "$CHECK_ONLY" == true ]]; then
-    print_warning "Docker is installed but not running; would start it"
+    print_warning "$ENGINE_NAME is installed but unavailable"
+  elif [[ "$CONTAINER_ENGINE" == "podman" ]]; then
+    print_error "Podman is installed but unavailable to the current user"
+    exit 1
   else
     print_info "Docker is installed but not running — starting it"
     systemctl enable --now docker.service
-    if docker info >/dev/null 2>&1; then
+    if "$CONTAINER_ENGINE" info >/dev/null 2>&1; then
       print_success "Docker started"
     else
       print_error "Docker is installed but still not responding"
@@ -166,16 +190,24 @@ if command -v docker >/dev/null 2>&1; then
     fi
   fi
 elif [[ "$CHECK_ONLY" == true ]]; then
-  print_warning "Would install $PKG_DOCKER and enable it"
-else
-  print_info "Installing $PKG_DOCKER..."
-  install_packages "$PKG_DOCKER"
-  systemctl enable --now docker.service
-  if docker info >/dev/null 2>&1; then
-    print_success "Docker installed and running"
+  if [[ "$CONTAINER_ENGINE" == "docker" ]]; then
+    print_warning "Would install $PKG_ENGINE and enable it"
   else
-    print_error "Docker installed but not responding"
-    echo "    Check 'systemctl status docker' — builds cannot run without it."
+    print_warning "Would install $PKG_ENGINE"
+  fi
+else
+  print_info "Installing $PKG_ENGINE..."
+  install_packages "$PKG_ENGINE"
+  if [[ "$CONTAINER_ENGINE" == "docker" ]]; then
+    systemctl enable --now docker.service
+  fi
+  if "$CONTAINER_ENGINE" info >/dev/null 2>&1; then
+    print_success "$ENGINE_NAME installed and available"
+  else
+    print_error "$ENGINE_NAME installed but not responding"
+    if [[ "$CONTAINER_ENGINE" == "docker" ]]; then
+      echo "    Check 'systemctl status docker' — builds cannot run without it."
+    fi
     exit 1
   fi
 fi