# Docker Image for ANTLR4
This Docker image wraps current version of **ANTLR4** inclusive **Java runtime environment** so it can be executed as transparent command line tool even on machines without installed Java.
## Docker Image
The image uses the official [eclipse-temurin:11](https://hub.docker.com/_/eclipse-temurin/tags?page=1&name=11&ordering=-name) image
for building a distribution of ANTLR4 and [eclipse-temurin:11-jre](https://hub.docker.com/_/eclipse-temurin/tags?page=1&name=11-jre&ordering=-name) for runtime.
## Build
You can build docker image from source code locally.
git clone https://github.com/antlr/antlr4.git
cd antlr4/docker
docker build -t antlr/antlr4 --platform linux/amd64 .
## Run
For security reasons is **ANTLR4 Docker image** designed to run in the current folder only, so a container doesn't have any access to any other folders on a host system. Since this is a transparent call of Docker image from command line, where new files are generated, it is also a good idea to execute code inside a Docker as a non root user and match it to the host caller.
Calling a dockerized ANTLR4 image can look like this:
```shell
wget https://raw.githubusercontent.com/antlr/grammars-v4/master/json/JSON.g4
docker run --rm -u $(id -u ${USER}):$(id -g ${USER}) -v `pwd`:/work antlr/antlr4 -Dlanguage=Go JSON.g4
```
## Integration as alias
alias antlr4='docker run -it -u $(id -u ${USER}):$(id -g ${USER}) -v $(pwd):/work antlr/antlr4 $@'