How to Clone a MongoDB Database Between Docker Containers

How to Clone a MongoDB Database Between Docker Containers

If you're running MongoDB in Docker and want to clone a database from one container to another, you're in the right place. This guide walks you through exporting a MongoDB database from one Docker container and restoring it into another — all using Docker commands and MongoDB’s native tools.

Prerequisites

  • Docker installed on your system
  • Two MongoDB containers:
    • Source container: mongo_source
    • Target container: mongo_target
  • Database to clone: mydb

Step 1: Dump the Database from the Source Container

Use the mongodump command inside the mongo_source container to export the contents of mydb:

docker exec mongo_source mongodump --db=mydb --out=/dump

This command creates a dump in the /dump directory inside the container.

Next, copy that dump to your host machine:

docker cp mongo_source:/dump ./dump

You now have a local copy of your database dump in the ./dump folder on your host.

Step 2: Transfer the Dump to the Target Container

Now that the dump is on your host, copy it into the mongo_target container:

docker cp ./dump mongo_target:/dump

Step 3: Restore the Dump into the Target MongoDB

Run the mongorestore command inside the mongo_target container:

docker exec mongo_target mongorestore --db=mydb /dump/mydb

Want to restore it to a different database name? You can! Just use the --nsFrom and --nsTo flags:

docker exec mongo_target mongorestore --nsFrom='mydb.*' --nsTo='newdb.*' /dump/mydb

Step 4: Clean Up (Optional but Recommended)

Once the database is cloned, you can safely delete the dump files from both the host and the containers:

rm -rf ./dump
docker exec mongo_source rm -rf /dump
docker exec mongo_target rm -rf /dump

Pro Tips

  • Authentication: If your MongoDB uses authentication, add -u, -p, and --authenticationDatabase to your mongodump and mongorestore commands.
  • Custom Ports: If MongoDB is running on a custom port, you can specify it with --port.

Conclusion

You’ve successfully cloned a MongoDB database between two Docker containers. Whether you’re migrating environments or setting up test data, this technique is quick, reliable, and easy to repeat.

Comments

Post a Comment

Popular posts from this blog

Transferring Data Between PostgreSQL Docker Containers

Transferring Data Between PostgreSQL Docker Containers Docker containers provide an efficient way to package, distribute, and run applications, including databases like PostgreSQL. Often, you may need to transfer data from one PostgreSQL container to another, either for backup, migration, or testing purposes. In this guide, we'll walk through the process of transferring data between PostgreSQL Docker containers. Prerequisites Basic understanding of Docker and PostgreSQL. PostgreSQL Docker containers already running. Step 1: Export Data from the Source Container First, we need to export the data from the source PostgreSQL Docker container. We'll use the pg_dump tool for this purpose. docker exec -it <source_container_name> bash pg_dump -U <username> -d <database_name> > /path/to/export/dump.sql exit Replace <source_container_name> , <username> , <database_name> , and /path/...
Read more

Flux vs Argo CD in GitOps

Flux vs Argo CD in GitOps: Which One is Right for You? In the context of GitOps , both Flux and Argo CD are popular tools for continuous deployment (CD) automation. They manage Kubernetes applications using Git as the source of truth. While both are great options, they differ in several aspects, from architecture to feature sets. In this post, we’ll compare Flux and Argo CD to help you decide which is the right tool for your Kubernetes environment. 1. Architecture Flux: Flux is a pull-based system that continuously reconciles the state of the cluster with the state in Git. It watches your Git repositories and automatically updates Kubernetes resources when it detects changes. Flux is lightweight and integrates with the CNCF ecosystem. It also supports Kustomize and Helm natively. Argo CD: Argo CD is also a pull-based tool but provides a declarative user interface for visual feedback on application status, health, and syncing. Ar...
Read more

Install Docker on Debian 12 (Bookworm)

Image
How to Install Docker on Debian Docker is a popular platform for developing, shipping, and running applications inside containers. This guide will show you how to install Docker on a Debian-based system. Step 1: Update the Package Index and Install Necessary Packages sudo apt-get update sudo apt-get install \ ca-certificates \ curl \ gnupg \ lsb-release Step 2: Add Docker’s Official GPG Key sudo mkdir -p /etc/apt/keyrings curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg Step 3: Set Up the Docker Repository echo \ "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/debian \ $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null Step 4: Update the Package Index Again sudo apt-get update Step 5: Install Docker Engine, containerd, an...
Read more

Adding Multiple SSH Keys to Your Raspberry Pi

Adding Multiple SSH Keys to Your Raspberry Pi If you're a Raspberry Pi enthusiast, you know the importance of secure access to your device. Using SSH keys is a secure and convenient way to manage remote access. In this guide, I'll show you how to add multiple SSH keys to your Raspberry Pi, allowing different users or machines to connect securely. Step 1: Generate SSH Keys First, you need to generate SSH keys on each client machine that will access your Raspberry Pi. Open a terminal on your client machine and run the following command: ssh-keygen -t rsa -b 4096 -C "your_email@example.com" Follow the prompts to save the key in the default location ( ~/.ssh/id_rsa ) and optionally add a passphrase for extra security. Step 2: Copy SSH Keys to Raspberry Pi Next, you need to copy the SSH key to your Raspberry Pi. The easiest way to do this is by using the ssh-copy-id command. Replace pi@raspberrypi with your...
Read more

Understanding Swagger and OpenAPI Specifications

Understanding Swagger and OpenAPI Specifications In modern API development, Swagger and OpenAPI have become the go-to tools for designing, documenting, and interacting with RESTful APIs. Let’s break down these essential tools and how they simplify API development. What is OpenAPI? The OpenAPI Specification (OAS) is a standard format to describe REST APIs. Initially known as the Swagger Specification, it was created by Swagger, then donated to the OpenAPI Initiative in 2015. Today, OpenAPI has become the industry standard for describing APIs, making it easier for developers to understand and work with APIs across various platforms. An OpenAPI document provides a structured description of the entire API, including: Endpoints and available operations Input parameters and output formats Authentication methods Error messages and responses Here’s a quick example of an OpenAPI specification snippet in JSON: { ...
Read more