CODEWITHSUNDEEP
dockerdockerfile
Rpj
Rpj

Reputation: 6100

How to configure docker specific image dependencies which are managed in a different source code repository

How to configure docker specific artifact dependencies which are managed in a different source code repository. My docker image depends on jar files (say project-auth), configuration (say project-theme) which is actually maintained in a different repository than the docker image.

What would be the best way to copy dependencies for a docker image (say project-deploy repo), prior to building the image. i.e in the above case project-deploy needs jar files and configuration which needs to be mounted as a volume from the current folder.

I don't want this to be committed as the dependencies tend to get stale and I want the docker image creation to be part of the build process itself.

Upvotes: 1

Views: 234

Answers (1)

Kapil Khandelwal
Kapil Khandelwal

Reputation: 1176

You can use Docker multi-stage builds for this purpose.

With multi-stage builds, you use multiple FROM statements in your Dockerfile. Each FROM instruction can use a different base, and each of them begins a new stage of the build. You can selectively copy artifacts from one stage to another, leaving behind everything you don’t want in the final image.

For example:

Suppose that the source code for dependencies is present in repo - "https://github.com/demo/demo.git" Using multi stage builds, you can create a stage in which you'll clone the git repo and create the dependency Jar (or anything else that you need) at runtime. At last, you can copy the jar into your final image.

# Use any base image. I took centos here
FROM centos:7 as builder

# Install only those packages which are required.
RUN yum install -y maven git \
&& git clone <YOUR_GIT_REPO_URL>

WORKDIR /myfolder

# Create jar at run time. You can update this step according to your project requirements.
RUN mvn clean package

# From here our normal Dockerfile steps starts.
FROM centos:7

# Add all the necessary steps required to build your image
.
.
.

# This is how you can copy the jar which was created above (Step 4) in your final docker image.
COPY --from=builder SOURCE_PATH DESTINATION_PATH

Please refer this to get a better understanding about multi stage builds in docker.

Upvotes: 1

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