Docker has become an integral part of modern application development and deployment, owing to its capabilities in isolation, scalability, and easy portability. While Docker brings many advantages, administrators and developers may encounter certain issues. One common problem is when a Docker container fails to automatically restart after the host server undergoes a reboot.

Root Causes of the Issue

There are several reasons why a Docker container might not start automatically after the host server restarts. Among the most frequent causes are:

• Misconfigured Docker Service: If the Docker service isn't configured to start automatically upon system boot, containers won't start without manual intervention.
• Missing or Misconfigured Restart Policies: Docker allows defining restart policies for containers, determining how containers should behave when the Docker daemon or system restarts. Without proper configuration, containers won't revive automatically.
• Dependency Problems: Some containers may have dependencies on services or other containers that need to be running before they can start successfully. If these dependencies aren't properly handled, it can lead to startup failures.

Solutions and Best Practices

To prevent issues with Docker containers failing to revive, it's important to implement several best practices and solutions:

• Configure Docker Service for Automatic Startup: Ensure that the Docker service is set up as a service that starts on system boot. This can typically be done using a system service manager like systemd.
• Configure Container Restart Policies: For each container, set up a restart policy using the docker run --restart command. Recommended values include always or unless-stopped to ensure automatic restart.
• Properly Handle Dependencies Between Containers: If containers require specific startup orders due to dependencies, this should be addressed using scripts or container orchestration tools like Docker Compose, which allows defining dependencies between services.

While Docker offers efficient solutions for running applications in containers, it's important to be aware of potential challenges, such as containers not automatically reviving after a host server restart. By configuring properly and adhering to best practices, these issues can be mitigated, ensuring smooth operation of applications.