Running Spring Boot project with Gradle using Docker [in progress]

We can start using Docker and creating a container with it.

Required installations

• Docker

Create docker file using example below and save as dockerfile

FROM adoptopenjdk:8-jdk-hotspot

CMD ["gradle"]

ENV GRADLE_HOME /opt/gradle

RUN set -o errexit -o nounset \
    && echo "Adding gradle user and group" \
    && groupadd --system --gid 1000 gradle \
    && useradd --system --gid gradle --uid 1000 --shell /bin/bash --create-home gradle \
    && mkdir /home/gradle/.gradle \
    && chown --recursive gradle:gradle /home/gradle \
    \
    && echo "Symlinking root Gradle cache to gradle Gradle cache" \
    && ln -s /home/gradle/.gradle /root/.gradle

VOLUME /home/gradle/.gradle

WORKDIR /home/gradle

RUN apt-get update \
    && apt-get install --yes --no-install-recommends \
        fontconfig \
        unzip \
        wget \
        \
        bzr \
        git \
        mercurial \
        openssh-client \
        subversion \
    && rm -rf /var/lib/apt/lists/*

ENV GRADLE_VERSION 5.5.1
ARG GRADLE_DOWNLOAD_SHA256=222a03fcf2fcaf3691767ce9549f78ebd4a77e73f9e23a396899fb70b420cd00
RUN set -o errexit -o nounset \
    && echo "Downloading Gradle" \
    && wget --no-verbose --output-document=gradle.zip "https://services.gradle.org/distributions/gradle-${GRADLE_VERSION}-bin.zip" \
    \
    && echo "Checking download hash" \
    && echo "${GRADLE_DOWNLOAD_SHA256} *gradle.zip" | sha256sum --check - \
    \
    && echo "Installing Gradle" \
    && unzip gradle.zip \
    && rm gradle.zip \
    && mv "gradle-${GRADLE_VERSION}" "${GRADLE_HOME}/" \
    && ln --symbolic "${GRADLE_HOME}/bin/gradle" /usr/bin/gradle \
    \
    && echo "Testing Gradle installation" \
    && gradle --version

To build an image from this dockerfile you need to run that command line:

docker build -t gradle-project .

Gradle needs to get all dependencies every time we are going to run that docker image, then we need to create a volume where it is going to save the dependencies after first time we running this image.

docker volume create --name gradle-cache

After that, we can run any gradle commands.

Running a Spring Boot project:

docker run --rm -u gradle -v gradle-cache:/home/gradle/.gradle -v "$PWD":/home/gradle/project -w /home/gradle/project -p 8081:8080 gradle-project /bin/bash -c "gradle clean &&  gradle bootRun"

HEADS UP: You need to be into project folder.

Your project is going to be published at localhost:8081 as parameters above say.