Issue #148 add helper script for restricted volume mount environments, clean up README

Author: simbo1905

jdt2jar/README.md

@@ -35,10 +35,7 @@ A minimal distroless container image is available for offline schema compilation
 ### Pre-built Image (GitHub Container Registry)
 
 ```bash
-# Pull the latest image
 docker pull ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest
-
-# Pull a specific release version
 docker pull ghcr.io/simbo1905/java.util.json.java21/jdt2jar:2026.05.20
 ```
 
@@ -52,39 +49,34 @@ docker build -t jdt2jar -f jdt2jar/Dockerfile .
 
 ### Usage
 
-The container's working directory is `/work`. Mount your local directory there, or use `docker cp` for environments where volume mounts are restricted (e.g., Colima on macOS).
+The container's working directory is `/work`. Mount your project directory there:
+
+```bash
+docker run --rm -v "$(pwd):/work" jdt2jar:latest schema.jtd.json --output schema-validator.jar --main
+```
 
-#### Option 1: Volume mount (Linux, Docker Desktop with file sharing enabled)
+Validate a payload with the generated JAR:
 
 ```bash
-# bash / zsh
-docker run --rm -v "$(pwd):/work" ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest schema.jtd.json --output schema-validator.jar --main
+java -jar schema-validator.jar --validate payload.json
+```
 
-# PowerShell
-docker run --rm -v "${PWD}:/work" ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest schema.jtd.json --output schema-validator.jar --main
+Or validate inside a container:
 
-# cmd.exe
-docker run --rm -v "%CD%:/work" ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest schema.jtd.json --output schema-validator.jar --main
+```bash
+docker run --rm -v "$(pwd):/work" --entrypoint /jre/bin/java jdt2jar:latest -jar /work/schema-validator.jar --validate /work/payload.json
 ```
 
-#### Option 2: docker cp (works everywhere, including Colima on macOS)
+### Helper Script
+
+For environments where volume mounts are restricted (e.g., Colima on macOS with projects outside `~/`), use the helper script:
 
 ```bash
-# Compile a schema
-cid=$(docker create --name jdt2jar-build ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest /work/schema.jtd.json --output /work/schema-validator.jar --main)
-docker cp schema.jtd.json jdt2jar-build:/work/schema.jtd.json
-docker start -a jdt2jar-build
-docker cp jdt2jar-build:/work/schema-validator.jar .
-docker rm jdt2jar-build
-
-# Validate a payload
-cid=$(docker create --name jdt2jar-validate --entrypoint /jre/bin/java ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest -jar /work/schema-validator.jar --validate /work/payload.json)
-docker cp schema-validator.jar jdt2jar-validate:/work/schema-validator.jar
-docker cp payload.json jdt2jar-validate:/work/payload.json
-docker start -a jdt2jar-validate
-docker rm jdt2jar-validate
+./scripts/jdt2jar.sh schema.jtd.json --output schema-validator.jar --main
 ```
 
+The script syncs source to `~/tmp/jdt2jar-work`, runs the container, and syncs output back.
+
 ### Image Properties
 
 - **Base**: `gcr.io/distroless/base-debian13:nonroot`

scripts/jdt2jar.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# jdt2jar helper script for environments where volume mounts are restricted
+# (e.g., Colima on macOS with projects outside ~/).
+#
+# Usage:
+#   ./scripts/jdt2jar.sh <schema.jtd.json> [options...]
+#
+# Example:
+#   ./scripts/jdt2jar.sh .tmp/test.jtd.json --output .tmp/test.jar --main
+
+set -euo pipefail
+
+WORK_DIR="$HOME/tmp/jdt2jar-work"
+IMAGE="${JDT2JAR_IMAGE:-jdt2jar:latest}"
+
+mkdir -p "$WORK_DIR"
+
+# Sync source (respecting .gitignore)
+rsync -a --filter=':- .gitignore' --exclude='.git/' . "$WORK_DIR/"
+
+# Run jdt2jar in container
+docker run --rm -v "$WORK_DIR:/work" "$IMAGE" "$@"
+
+# Sync output back (any new .jar or .java files in the work dir)
+rsync -a --include='*.jar' --include='*.java' --exclude='*' "$WORK_DIR/" ./