how to start docker container from gradle? - docker

Question

I am trying to switch from Cmake to gradle. I want to configure gradle to work as follow
$ cd myapp && ls myapp
$ Dockerfile build.gradle src
$ gradle build
Build the docker image from docker file
start container
build the application
The docker image contains complete environment for my app.
FROM debian:stretch
RUN apt-get update -y && apt install -y git \
python3-dev libncurses5-dev libxml2-dev \
libedit-dev swig doxygen graphviz xz-utils ninja-build
RUN echo "deb http://ftp.de.debian.org/debian stretch main" >> /etc/apt/source.list
RUN apt-get update && apt-get install -y openjdk-8-jre openjdk-8-jdk
# Clang 8 as a compiler
RUN apt-get update && apt-get install -y \
xz-utils \
build-essential \
curl \
&& rm -rf /var/lib/apt/lists/* \
&& curl -SL http://releases.llvm.org/8.0.0/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz \
| tar -xJC . && \
mv clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04 clang_8.0.0 && \
echo 'export PATH=/clang_8.0.0/bin:$PATH' >> ~/.bashrc && \
echo 'export LD_LIBRARY_PATH=/clang_8.0.0/lib:LD_LIBRARY_PATH' >> ~/.bashrc
#
RUN apt-get update
#install sdkman
RUN rm /bin/sh && ln -s /bin/bash /bin/sh
RUN apt-get -qq -y install curl wget unzip zip
RUN curl -s "https://get.sdkman.io" | bash
RUN source "$HOME/.sdkman/bin/sdkman-init.sh"
#install gradle
RUN yes | /bin/bash -l -c 'sdk install gradle 6.1'
PS: This is cpp project

Answer 1

You can build a docker image from Gradle tasks by using **com.bmuschko:gradle-docker-plugin:3.1.0 plugin**
buildscript {
repositories {
jcenter()
mavenCentral()
}
dependencies {
classpath 'com.bmuschko:gradle-docker-plugin:3.1.0'
}
}
apply plugin: 'com.bmuschko.docker-remote-api'
import com.bmuschko.gradle.docker.tasks.image.Dockerfile
import com.bmuschko.gradle.docker.tasks.image.DockerBuildImage
import com.bmuschko.gradle.docker.tasks.image.*
task buildImage(type: DockerBuildImage) {
group = ''
inputDir = file('.')
tag = 'image name:'+tag
}
read the documentation for more details https://bmuschko.github.io/gradle-docker-plugin/
Build an image from Gradle task - ./gradlew taskname
To start container and run the command inside it you can use CMD or ENTRYPOINT and specify the command in Dockerfile
CMD ["start.sh"]
in start.sh you can specify your command to be executed after running the container

Answer 2

Let me slightly clean up that Dockerfile first:
FROM debian:stretch
RUN echo "deb http://ftp.de.debian.org/debian stretch main" >> /etc/apt/source.list
RUN apt-get update -y && apt install -qq -y \
python3-dev libncurses5-dev libxml2-dev \
libedit-dev swig doxygen graphviz xz-utils ninja-build \
openjdk-8-jre openjdk-8-jdk \
xz-utils curl git build-essential wget unzip zip
# Clang 8 as a compiler
RUN curl -SL http://releases.llvm.org/8.0.0/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz \
| tar -xJC . && \
mv clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04 clang_8.0.0 && \
echo 'export PATH=/clang_8.0.0/bin:$PATH' >> ~/.bashrc && \
echo 'export LD_LIBRARY_PATH=/clang_8.0.0/lib:LD_LIBRARY_PATH' >> ~/.bashrc
#install sdkman
RUN ln -fs /bin/bash /bin/sh
RUN curl -s "https://get.sdkman.io" | bash
RUN source "$HOME/.sdkman/bin/sdkman-init.sh"
RUN yes | /bin/bash -l -c 'sdk install gradle 6.1'
RUN mkdir /src /work
WORKDIR /src
ENTRYPOINT gradle build -p /src
The important bits are at the bottom: it creates a /src directory and executes gradle build there. All that remains for you is to make that directory available when you build.
Assuming you built the container once with docker build -t my-build-container ., you can run it as follows:
docker run -v $(pwd):/src my-build-container
Depending on your build system, this might pollute your source tree with various build artifacts owned by root. If so, consider switching to out-of-tree builds by changing the default working directory to /work instead. All build results will go to /work, and you can extract them from the container afterwards.

Answer 3

Add docker plugin first
buildscript {
dependencies {
classpath("se.transmode.gradle:gradle-docker:1.2")
}
}
create simple task like this in build.gradle file
task buildDocker(type: Docker, dependsOn: build) {
push = false
project.group = 'testProject'
project.archivesBaseName = jar.baseName
applicationName = jar.baseName
dockerfile = file('src/main/docker/Dockerfile')
doFirst {
copy {
from jar
into stageDir
}
}
}