I’ve been wanting to start working on a binding for quite a while. But since I’m a .Net developer by trait the whole Java environment tends to feel a bit too much, too even get started.
But lately I’ve been doing a lot of cross platform dotnet core development using docker containers, and I ran into this:
Where you can also easily build java applications:
So you can build your OpenHAB addon without the need of even a JDK on your local machine. 
But to use it, you need a .devcontainer folder with a dockerfile which has everything to build OpenHAB addons.
I’ve editted Microsofts example to this:
#-------------------------------------------------------------------------------------------------------------
# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License. See https://go.microsoft.com/fwlink/?linkid=2090316 for license information.
#-------------------------------------------------------------------------------------------------------------
FROM mcr.microsoft.com/java/jdk:8u232-zulu-ubuntu
# Avoid warnings by switching to noninteractive
ENV DEBIAN_FRONTEND=noninteractive
# This Dockerfile adds a non-root user with sudo access. Use the "remoteUser"
# property in devcontainer.json to use it. On Linux, the container user's GID/UIDs
# will be updated to match your local UID/GID (when using the dockerFile property).
# See https://aka.ms/vscode-remote/containers/non-root-user for details.
ARG USERNAME=vscode
ARG USER_UID=1000
ARG USER_GID=$USER_UID
# Maven settings
ARG MAVEN_VERSION=3.6.3
ARG MAVEN_SHA=c35a1803a6e70a126e80b2b3ae33eed961f83ed74d18fcd16909b2d44d7dada3203f1ffe726c17ef8dcca2dcaa9fca676987befeadc9b9f759967a8cb77181c0
ENV MAVEN_HOME=/usr/local/share/maven
COPY maven-settings.xml ${MAVEN_HOME}/ref/
# Configure apt and install packages
RUN apt-get update \
&& apt-get -y install --no-install-recommends apt-utils dialog 2>&1 \
#
# Verify git and needed tools are installed
&& apt-get -y install \
git \
iproute2 \
procps \
curl \
apt-transport-https \
gnupg2 \
lsb-release \
wget \
#
# Create a non-root user to use if preferred - see https://aka.ms/vscode-remote/containers/non-root-user.
&& groupadd --gid $USER_GID $USERNAME \
&& useradd -s /bin/bash --uid ${USER_UID} --gid ${USER_GID} -m $USERNAME \
# [Optional] Add sudo support for the non-root user
&& apt-get install -y sudo \
&& echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME\
&& chmod 0440 /etc/sudoers.d/$USERNAME \
#
# Install Maven
&& mkdir -p ${MAVEN_HOME} ${MAVEN_HOME}/ref \
&& curl -fsSL -o /tmp/apache-maven.tar.gz https://archive.apache.org/dist/maven/maven-3/${MAVEN_VERSION}/binaries/apache-maven-${MAVEN_VERSION}-bin.tar.gz \
&& echo "${MAVEN_SHA} /tmp/apache-maven.tar.gz" | sha512sum -c - \
&& tar -xzf /tmp/apache-maven.tar.gz -C ${MAVEN_HOME} --strip-components=1 \
&& rm -f /tmp/apache-maven.tar.gz \
&& ln -s ${MAVEN_HOME}/bin/mvn /usr/local/bin/mvn \
# Install OpenHAB
&& wget -qO - 'https://bintray.com/user/downloadSubjectPublicKey?username=openhab' | apt-key add - \
&& echo 'deb https://dl.bintray.com/openhab/apt-repo2 stable main' | tee /etc/apt/sources.list.d/openhab2.list \
&& apt-get update \
&& apt-get install -y openhab2 \
#
# Clean up
&& apt-get autoremove -y \
&& apt-get clean -y \
&& rm -rf /var/lib/apt/lists/*
# Switch back to dialog for any ad-hoc use of apt-get
ENV DEBIAN_FRONTEND=dialog
It seems to be working, building a bundle works, although I’m having some issues with git detecting a lot of changes. I think it’s a windows vs unix line ending problem.
After I fix that I’ll write up a complete manual. But I’m sharing this already since it’s a quick way to start working on an OpenHAB addons:
- Install Visual Studio Code
- Install Docker for Desktop
- Add plugins to VSCode
- Clone the openhab-addons repo
- Start working in the development container
And it’s the same if your working on Windows or Linux.