build: make build-and-push.sh runnable from any directory

- Resolve PROJECT_DIR from the script's own location by default
  (works with absolute, relative and symlinked invocations)
- Allow override via --project-dir flag or PROJECT_DIR env var
- Improve error message for invalid --project-dir paths
- Update usage and README accordingly

README.md

@@ -18,6 +18,10 @@ The script reads `artifactId` and `version` from `pom.xml` for the image name
 and tag, builds for `linux/amd64`, and verifies the image is present on the
 remote after pushing. See `./scripts/build-and-push.sh --help` for all flags.
 
+It can be invoked from any directory: by default it resolves the project root
+from the script's own location. Override with `--project-dir PATH` or the
+`PROJECT_DIR` environment variable when needed.
+
 ## Running the application in dev mode
 
 You can run your application in dev mode that enables live coding using:

scripts/build-and-push.sh

@@ -15,12 +15,14 @@ readonly DEFAULT_PLATFORM="linux/amd64"
 readonly UNREGISTRY_PLUGIN="https://raw.githubusercontent.com/psviderski/unregistry/main/docker-pussh"
 readonly PLUGIN_DIR="${HOME}/.docker/cli-plugins"
 readonly PLUGIN_PATH="${PLUGIN_DIR}/docker-pussh"
+readonly SCRIPT_DIR="$(cd "$(dirname "$(readlink -f "$0")")" && pwd)"
 
 REMOTE=""
 IMAGE_NAME=""
 IMAGE_TAG=""
 SSH_KEY=""
 SSH_CONFIG=""
+PROJECT_DIR="${PROJECT_DIR:-${SCRIPT_DIR}/..}"
 SKIP_BUILD=0
 SKIP_VERIFY=0
 
@@ -63,6 +65,10 @@ Image identity (defaults read from pom.xml):
   --name NAME                Image repository name
   --tag TAG                  Image tag
 
+Working directory (defaults to the parent of the script's directory):
+  --project-dir PATH         Project root containing pom.xml
+                             (override with env PROJECT_DIR)
+
 Build options:
   --skip-build               Skip docker build, only pussh an existing image
   (platform is fixed to ${DEFAULT_PLATFORM})
@@ -81,6 +87,8 @@ Examples:
   $(basename "$0") --remote deploy@prod.example.com
   $(basename "$0") --remote ubuntu@1.2.3.4 --ssh-key ~/.ssh/deploy_ed25519
   $(basename "$0") --remote deploy@prod --skip-build --tag 2.0.0
+  /absolute/path/to/test-quarkus/scripts/$(basename "$0") --remote deploy@prod
+  PROJECT_DIR=/srv/proj $(basename "$0") --remote deploy@prod --skip-build
 EOF
 }
 
@@ -109,6 +117,7 @@ while [[ $# -gt 0 ]]; do
     --tag)          IMAGE_TAG="$2"; shift 2 ;;
     --ssh-key)      SSH_KEY="$2"; shift 2 ;;
     --ssh-config)   SSH_CONFIG="$2"; shift 2 ;;
+    --project-dir)  PROJECT_DIR="$2"; shift 2 ;;
     --skip-build)   SKIP_BUILD=1; shift ;;
     --no-verify)    SKIP_VERIFY=1; shift ;;
     -h|--help)      usage; exit 0 ;;
@@ -116,6 +125,12 @@ while [[ $# -gt 0 ]]; do
   esac
 done
 
+# ---------- resolve project root ----------
+if ! cd "${PROJECT_DIR}" 2>/dev/null; then
+  die "Invalid --project-dir: ${PROJECT_DIR}"
+fi
+PROJECT_DIR="$(pwd)"
+
 # ---------- defaults ----------
 [[ -z "$IMAGE_NAME" ]] && IMAGE_NAME=$(read_pom "/*[local-name()='project']/*[local-name()='artifactId']" "test-quarkus")
 [[ -z "$IMAGE_TAG"  ]] && IMAGE_TAG=$(read_pom  "/*[local-name()='project']/*[local-name()='version']"     "1.0.0-SNAPSHOT")