Let’s talk about the problem of docker container not restarting

Docker is an open source application containerization platform that can easily package applications and all their dependencies, ensuring application consistency across different environments. Using Docker containers, multiple homogeneous applications can be run on the same hardware, improving resource utilization. However, when you encounter the need to update the container, you may encounter a trouble, that is, the Docker container restarts.

On the Docker platform, restarting the container will have a certain impact on the running of the application. First, you need to stop the Docker container and then start a new version of the container, which may cause the application to be unavailable for a period of time. Second, restarting containers may result in data loss or application crashes, affecting business continuity. In order to solve these problems, we need to master some techniques so that the Docker container can be restarted without causing too much impact on the application.

1. Use Dockerfile

You can use Dockerfile to create a custom Docker image, so that you can package all dependencies in your application, and when the application needs to be updated, you only need to use the new The Docker image is sufficient, and there is no need to restart the Docker container. A Dockerfile is a text file that contains instructions to build a Docker image. All dependencies of your application can be easily handled using a Dockerfile, thus avoiding the impact of container restarts.

2. Use external data volumes

Using external data volumes can make the data independent of the Docker container, which can avoid the risk of data loss. If the Docker container needs to be restarted when the application is updated, using an external data volume can preserve data integrity without worrying about data loss. Using external data volumes is a simple and effective way to avoid the risk of data loss when containers are restarted.

3. Use Docker restart strategy

You can use Docker's restart strategy to define how the container should be handled when it exits. Docker has three restart strategies, including "no", "on-failure" and "always". By default, the restart policy is "no", which means that the container will not automatically restart on exit. If you use the "always" policy, Docker will automatically restart the container when it exits, even if the container was stopped by running the "docker stop" command. However, if the container was deleted by running the "docker rm" command, it will not restart automatically.

It is useful to use the "on-failure" policy, which means that the container will only automatically restart if the exit code is non-zero. This will cause the container to automatically restart when an error occurs, but not during normal operation.

4. Use Docker Compose

Use Docker Compose to quickly create and manage multiple Docker containers and combine them into one application. You can use Docker Compose to define the entire architecture of your application, including services, containers, and networks. This makes application updates and restarts much easier, as you only need to update the container and service definitions in the Compose file, rather than manually stopping and starting the containers.

On the Docker platform, container restart is a common problem that affects the continuity and integrity of the application. However, using the tips above, you can easily resolve these issues and ensure that your application will function properly when updated without too much impact on your business.

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