Issue #148 fix WORKDIR in distroless stage, document docker cp fallback for macOS/Colima

Author: simbo1905

jdt2jar/Dockerfile

@@ -10,6 +10,7 @@ RUN ["mkdir", "-p", "/empty-work/tmp", "/empty-app"]
 FROM gcr.io/distroless/base-debian13:nonroot
 COPY --from=build --chown=65532:65532 /empty-work /work
 COPY --from=build --chown=65532:65532 /empty-app /app
+WORKDIR /work
 ENV JAVA_TOOL_OPTIONS="-XX:+UseContainerSupport -XX:MaxRAMPercentage=75.0 -Djava.io.tmpdir=/work/tmp -XX:+ExitOnOutOfMemoryError"
 COPY --from=build /opt/jre /jre
 COPY --from=build /build/jdt2jar/target/jdt2jar.jar /app/jdt2jar.jar

jdt2jar/README.md

@@ -1,14 +1,14 @@
 # jdt2jar
 
-`jdt2jar` compiles a JTD schema into a standalone validator JAR at build time. The generated JAR runs on JDK 21+ with no JDK 24+ runtime dependency.
+`jdt2jar` compiles a JTD schema into a standalone validator JAR at build time. The generated JAR runs on JDK 21+ with no JDK 25+ runtime dependency.
 
 ## Use Case
 
 This tool bridges the gap between the interpreter and codegen paths:
 
 - **Interpreter** ([`json-java21-jtd`](../json-java21-jtd/README.md)): ideal for infrequent config parsing — simple, no build step, runs on JDK 21+.
-- **Codegen** ([`json-java21-jtd-codegen`](../json-java21-jtd-codegen/README.md)): ideal for repeated hot-path validation — ~9x faster, but requires JDK 24+ at runtime.
-- **jdt2jar**: pre-compiles schemas into validator JARs at build time (using JDK 24+), then deploys them to any JDK 21+ runtime. Best for CI/CD pipelines, distroless containers, or environments where you want JIT-optimised validators without shipping a JDK 24+ runtime.
+- **Codegen** ([`json-java21-jtd-codegen`](../json-java21-jtd-codegen/README.md)): ideal for repeated hot-path validation — ~9x faster, but requires JDK 25+ at runtime.
+- **jdt2jar**: pre-compiles schemas into validator JARs at build time (using JDK 25+), then deploys them to any JDK 21+ runtime. Best for CI/CD pipelines, distroless containers, or environments where you want JIT-optimised validators without shipping a JDK 25+ runtime.
 
 > **Future note**: `java.util.json` has entered the JDK incubator (`jdk.incubator.json`). Once the API stabilises in the JDK itself, generated bytecode validators can depend directly on future JDK classes rather than this backport, making them even more efficient with zero library overhead.
 
@@ -39,35 +39,47 @@ A minimal distroless container image is available for offline schema compilation
 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:2026.02.05
+docker pull ghcr.io/simbo1905/java.util.json.java21/jdt2jar:2026.05.20
 ```
 
 ### Build Locally
 
-Requires Docker and JDK 24+ (for the build stage). Build from the repository root:
+Requires Docker and JDK 25+ (for the build stage). Build from the repository root:
 
 ```bash
 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).
+
+#### Option 1: Volume mount (Linux, Docker Desktop with file sharing enabled)
+
 ```bash
-# Show help
-docker run --rm ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest --help
+# 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
 
-# Compile a schema to a validator JAR (using docker cp for file I/O)
-cid=$(docker create --name jdt2jar-build ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest /work/person.jtd.json --output /work/person-validator.jar --main)
-docker cp person.jtd.json jdt2jar-build:/work/person.jtd.json
+# PowerShell
+docker run --rm -v "${PWD}:/work" ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest schema.jtd.json --output schema-validator.jar --main
+
+# 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
+```
+
+#### Option 2: docker cp (works everywhere, including Colima on macOS)
+
+```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/person-validator.jar .
+docker cp jdt2jar-build:/work/schema-validator.jar .
 docker rm jdt2jar-build
 
-# Validate a payload with the generated JAR
-java -jar person-validator.jar --validate payload.json
-# Or validate inside a container
-cid=$(docker create --name jdt2jar-validate --entrypoint /jre/bin/java ghcr.io/simbo1905/java.util.json.java21/jdt2jar:latest -jar /work/person-validator.jar --validate /work/payload.json)
-docker cp person-validator.jar jdt2jar-validate:/work/person-validator.jar
+# Validate a payload
+cid=$(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
@@ -76,7 +88,7 @@ docker rm jdt2jar-validate
 ### Image Properties
 
 - **Base**: `gcr.io/distroless/base-debian13:nonroot`
-- **Runtime**: jlink-minimized JDK 24 (~40 MB)
+- **Runtime**: jlink-minimized JDK 25 LTS (~40 MB)
 - **Total size**: ~111 MB disk / ~31 MB content
 - **User**: `nonroot` (uid 65532)
 - **Shell**: none (distroless)

tmp/invalid.json

@@ -0,0 +1 @@
+{"name":123,"age":-1}

tmp/simple.jar

@@ -0,0 +1 @@
+{"properties":{"name":{"type":"string"},"age":{"type":"uint8"}}}

tmp/simple.jtd.json

@@ -0,0 +1,110 @@
+{
+  "definitions": {
+    "user": {
+      "properties": {
+        "id": { "type": "string" },
+        "email": { "type": "string" },
+        "displayName": { "type": "string" },
+        "role": {
+          "enum": ["admin", "manager", "contributor"]
+        }
+      },
+      "optionalProperties": {
+        "timezone": { "type": "string" }
+      }
+    },
+
+    "comment": {
+      "properties": {
+        "id": { "type": "string" },
+        "authorId": { "type": "string" },
+        "message": { "type": "string" },
+        "createdAt": { "type": "timestamp" }
+      }
+    },
+
+    "taskEvent": {
+      "discriminator": "type",
+      "mapping": {
+        "created": {
+          "properties": {
+            "type": { "enum": ["created"] },
+            "createdBy": { "type": "string" },
+            "createdAt": { "type": "timestamp" }
+          }
+        },
+
+        "statusChanged": {
+          "properties": {
+            "type": { "enum": ["statusChanged"] },
+            "from": {
+              "enum": ["todo", "in_progress", "blocked", "done"]
+            },
+            "to": {
+              "enum": ["todo", "in_progress", "blocked", "done"]
+            },
+            "changedBy": { "type": "string" },
+            "changedAt": { "type": "timestamp" }
+          }
+        },
+
+        "commentAdded": {
+          "properties": {
+            "type": { "enum": ["commentAdded"] },
+            "comment": { "ref": "comment" },
+            "addedAt": { "type": "timestamp" }
+          }
+        }
+      }
+    }
+  },
+
+  "properties": {
+    "projectId": { "type": "string" },
+    "name": { "type": "string" },
+
+    "owner": {
+      "ref": "user"
+    },
+
+    "tasks": {
+      "elements": {
+        "properties": {
+          "id": { "type": "string" },
+          "title": { "type": "string" },
+
+          "status": {
+            "enum": ["todo", "in_progress", "blocked", "done"]
+          },
+
+          "assignee": {
+            "ref": "user"
+          },
+
+          "labels": {
+            "elements": {
+              "type": "string"
+            }
+          },
+
+          "activity": {
+            "elements": {
+              "ref": "taskEvent"
+            }
+          }
+        },
+
+        "optionalProperties": {
+          "description": { "type": "string" },
+          "dueDate": { "type": "timestamp" },
+
+          "metadata": {
+            "values": {
+              "type": "string"
+            }
+          }
+        }
+      }
+    }
+  }
+}

tmp/test.jdt.json

@@ -0,0 +1 @@
+{"name":"Alice","age":30}