How to persist data in a dockerized postgres database using volumes

📝 How to Persist Data in a Dockerized Postgres Database Using Volumes 📦💾

Are you struggling to persist data in your Dockerized Postgres database? 😩 Don't worry, we're here to help! In this blog post, we'll address a common issue and provide easy solutions to ensure your data is safely stored using volumes. Let's dive in! 💪

The Problem: Missing Data in the Local System Directory 🚫📂

One common issue faced by developers is when the data stored inside the Postgres container is not reflected in the local system directory. Let's take a look at the Docker Compose file to understand why this may happen:

postgres:
  container_name: postgres
  restart: always
  image: postgres:latest
  volumes:
    - ./database:/var/lib/postgresql
  ports:
    - 5432:5432

In this case, we want to mount a volume that corresponds to a local folder called ./database inside the Postgres container as /var/lib/postgres. However, when the containers are started, the local system's ./database folder only contains an empty data subfolder. 😕

Possible Causes and Solutions 🧐💡

1. Conflicting Volumes: Upon inspecting the Docker container using docker inspect, we might find that another volume is automatically created and stealing our data. This can happen if the Postgres image creates its own volume.

   • Solution: Instead of mounting the external volume, we can use the volume created by the Postgres image. Modify the Docker Compose file like this:

     postgres: container_name: postgres restart: always image: postgres:latest volumes: - postgres_data:/var/lib/postgresql ports: - 5432:5432 volumes: postgres_data:

     By defining the postgres_data volume, we can utilize the volume created by the Postgres image.

2. Disabling the Preconfigured Volume: If you prefer to use your own volume instead of the one created by the Postgres image, we can disable the preconfigured volume.

   • Solution: Modify the Docker Compose file to explicitly disable the preconfigured volume by defining the volumes property as an empty list, like this:

     postgres: container_name: postgres restart: always image: postgres:latest volumes: [] ports: - 5432:5432

     By removing the volume configuration, Docker will not create the undesired volume.

📣 Call-to-Action: Engage and Share Your Experience! 💬🚀

We hope this guide helped you persist data in your Dockerized Postgres database using volumes! If you faced any other issues or have additional tips to share, let us know in the comments below. Let's help each other and build a stronger community! 🌟😊

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Happy coding! 💻🔨✨