How To Clone Private Git Repo With Dockerfile?

Cloning the private git repository in the Dockerfile is often used in situations where you want to build a Docker image of the source code or any assets from the private git repository. Cloning git will reduce the size of the docker image by separating the build environment from the runtime environment using the stage-stage build

What is a Dockerfile?

Dockerfile is the source code of the Docker image. Dockefile consists of several instructions that are required to build the Docker image. Docker is an open-source platform that is used to build and deploy applications in the form of Docker containers. With the help of Docker images, you can run the application in containerization. Dockerfile uses DSL (Domain Specific Language) and contains instructions for generating a Docker image. Dockerfile will define the processes needed to quickly produce an image.

Read: What Is Dockerfile?

What is Git Private Repo?

Public repositories are accessible to everyone, but private repositories are accessible to account owners. The owner can provide access to those who want a private repository. Private repositories are more secure.

Read: Git Repositories

Use cases Of Cloning Git Private Repo In Dockerfile

• Building an Application with Private Source Code: You have a Dockerized application that relies on private source code hosted in a private Git repository.
• Fetching Private Dependencies: Your project uses private Git repositories as dependencies, and you want to include them in your Docker image.
• Using a Personal Access Token (PAT): Instead of using SSH keys, you can use a Personal Access Token for authentication when accessing private repositories.
• Using Multi-stage Builds: Minimize the size of the final Docker image by using multi-stage builds to clone the private repository in one stage and copy only necessary artifacts to the final image.

By Using Two methods, We can Clone the Private Git Repo With Dockerfile

1. SSH Key Method

SSH key method involves in coping of the SSH key to the Dockerfile and also we need to install the git while building the docker image by wrttting the docker instructions to it. SSH key will helps the proceses where to e athuticated to SSH to the git all the instructions and keys will be avalible in the dockerfile.

Note: Using the credentials or the Aceses key or SSH key drectly inthe Dockerfile is not at all recamonded by create the enc varible for those key and use that variables in the Dockerfile.

Step-By-Step Process of Cloning Git Private Repo In Dockerfile (Aceses Key Method)

Step 1: Make sure that the git was installed in the hsot server. Here i was using ubuntu server so i was the following command to check the version of the git installed.

Setp 2: Generate an "GIT_ACCESS_TOKEN" in git hub for that you can refer to the

How to Generate Personal Access Token in GitHub?

Step 3: Create an Dockerfile to build an doicker image as follows

FROM alpine:latest

# Set Git access token as an environment variable
ENV GIT_ACCESS_TOKEN=<Give Your Aceses token>

# Install Git and clone private repository
RUN apk --no-cache add git \
    && git clone https://<You github username>:${GIT_ACCESS_TOKEN}@github.com<Complete github Url>

In the above Dockerfile we are using the alpine image as an base image and by using the env variable we are setting up the git access token and we using that variable in thegit clone command.

Step 4: Build the docker image by the docker build command where the image will be build by using the by using Dockerfile as an source code where the git repo will be also cloned in to the docker image.

docker build -t <image name>:<tag> .

In the above you can see that the private git repository was cloning inside the docker image while building by the git private repository URL, The code which is clone is going to be stored in the /app directory of the container.

Step 5: You can inspect the docker image to see the detailed history of the docker image like what the layers presented in the docker image and what are the action has been happend by using the docker inspect commad.

docker inspect <image:tage>

In the above image you can see the all the details for the image like the date and network of the image and even you can sse the layers of the docker image like git clone and updating the base image etc.

Conclusion

In this we have seen that how to clone the private git epsitory into the Dockerfile and use it while building the docker image.By following these steps, you can effectively clone a private Git repository within a Dockerfile, facilitating the integration of your private code into a Dockerized application.