Quick-start local docker registry

In this quick guide, I’ll walk you through setting up your own containerized Docker registry locally, ensuring persistent storage is kept separate for a decoupled system to experiment with Docker registry without data loss.

Design

Pre-requisite

• xcode — command line tools
• Homebrew
• Docker Desktop

Install Home-brew

# install homebrew through commandline
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
brew update

Install Docker Desktop

#install docker desktop through commandline
brew install --cask docker

Storage Container

First, let’s create a storage container for the Docker registry. You can also use a local directory to be mounted.

# filename: Dockerfile

# Use a base image (e.g., Ubuntu) for creating the storage container
FROM ubuntu:latest

# Create a directory to store Jenkins workspace and other files
RUN mkdir -p /var/docker

# Set the directory as a volume to persist data
VOLUME /var/docker

# open access
RUN chmod -R 777 /var/docker

# Create a dummy file and tail it to keep the container running indefinitely
CMD touch /var/docker/keep_running && tail -f /var/docker/keep_running

# filename: run.sh
# Run this file to recreate container

# Note!! you will loose anything created by registry earlier
docker rm -f docker-registry-storage
docker rmi -f docker-registry-storage
docker build -t docker-registry-storage .

#start the storage container
docker run -d --name docker-registry-storage docker-registry-storage

Docker Registry Container

Now, let’s create a separate container for the Docker registry and mount the storage created earlier for usage.

# filename: run.sh

# delete the existing container
docker rm -f registry-configured

#run new container
docker run -d -p 5000:5000 \
    --restart=always \
    --name registry-configured\
    --volumes-from docker-registry-storage
    -v docker-registry-storage:/var/lib/registry
    registry:latest


# if you want to use your current directory as storage directory instead of storage container
# use this command for running local docker registry instead of above
# docker run -d -p 5000:5000 --restart=always --name registry -v $(pwd)/docker-registry:/var/lib/registry registry:latest

Usage

Target project

Create your own project or use a sample Node.js project for testing the registry setup.

mkdir web-service
cd web-service

#create initial project
#for project with default values. keep tapping enter till the command ends
npm init

# create a sample project with express
npx express-generator --no-view src

cd src
npm install
npm audit fix --force

# run the below command goto localhost:3000 to test successful run
DEBUG=src:* npm start

create a docker file

# under web-service

# filename: Dockerfile

FROM node:18.16.0-alpine3.17
WORKDIR /app
COPY src/ .
RUN npm install
EXPOSE 3000
CMD [ "npm", "start"]

Create and Push a New Build

#command format
#docker build -t <registry address>/<appname>:<version> .

docker build -t localhost:5000/web-service:1.0.0 .

#command format
#docker push <registry address>/<appname>:<version>

docker push localhost:5000/web-service:1.0.0

Test Successful Push

for testing we will delete the build locally and pull it from the registry

docker rmi localhost:5000/web-service:1.0.0

check docker desktop, the image would be deleted.

Pull fresh image from your registry.

docker pull localhost:5000/web-service:1.0.0

Now you have successfully created your own containerised docker registry.

Run Your Service

docker run -d -p 3000:3000 --name web-service localhost:5000/web-service:1.0.0

Now, visit http://localhost:3000 on your browser to see your containerized app running. This guide provides a practical way to get started with your own containerized Docker registry. Happy learning!