Running into the “Error response from daemon: Container is not running” issue in Docker can be frustrating, especially when you’re trying to manage or interact with a container that you assume is active. This error indicates that the Docker container has stopped running, and you need to troubleshoot the cause. In this guide, we will explore what causes this error, how to diagnose it, and the steps to fix it efficiently.
What Does the Error “Container is Not Running” Mean?
🔹 This error message appears when you try to execute a command inside a stopped Docker container.
🔹 The daemon cannot proceed with the request because the container is in an inactive or exited state.
🔹 Common causes include crashes, incorrect startup commands, missing dependencies, or resource limits.
When encountering this error, the first step is to check the status of your container and determine why it stopped.
How to Check the Status of a Docker Container?
Run the following command to list all containers, including those that have stopped:
docker ps -a
This command displays a list of containers along with their status. If the container is not running, its status will be something like Exited (1), indicating that it stopped due to an error.
To see logs and understand why the container stopped, use:
docker logs <container_id>
Replace <container_id> with the actual Container ID from the docker ps -a output.
Common Causes and Solutions
1. The Container Stopped Unexpectedly
If the container has exited due to an issue, you can restart it using:
docker start <container_id>
However, if the container keeps stopping, investigate further by checking logs and error messages.
2. Container Process Crashed
If the application inside the container crashes, the container will stop. Use:
docker inspect <container_id>
Check the Exit Code in the output. If it’s not 0, the application inside the container likely crashed.
3. Missing Dependencies or Incorrect Startup Command
Ensure that the container’s entrypoint or command is correct. If the container is failing due to a bad command, try running it manually:
docker run --rm -it <image_name> /bin/sh
This allows you to enter the container’s shell and test commands interactively.
4. Resource Limitations (Memory or CPU Constraints)
If a container runs out of memory, it will be killed by the system (OOM – Out of Memory). Check system logs using:
dmesg | grep -i 'oom'
To allocate more memory, restart the container with higher limits:
docker run -m 512m --memory-swap 1g <image_name>
This ensures the container gets enough resources.
5. Container Exited Due to a Port Conflict
If your container is using a port that’s already occupied, it will fail to start. Check for conflicts using:
sudo netstat -tulnp | grep :<port_number>
Change the port mapping and restart the container:
docker run -p 8081:80 <image_name>
How to Restart a Stopped Container?
If your container is stopped and you simply need to restart it:
docker start <container_id>
If you want to restart it and attach to its logs interactively:
docker start -ai <container_id>
Alternatively, recreate the container if the issue persists:
docker rm <container_id>
docker run <image_name>
Preventing Future Container Failures
1. Use Auto-Restart Policies
Docker provides restart policies to automatically restart containers if they fail:
docker run --restart=always <image_name>
Options include: 🔹 no – Does not restart the container.
🔹 on-failure – Restarts only if the container exits with a non-zero status.
🔹 always – Ensures the container restarts under any circumstances.
2. Monitor Containers with Docker Logs
Regularly check logs to identify potential problems early:
docker logs <container_id>
Use tools like Prometheus and Grafana for advanced container monitoring.
3. Keep Your Docker Images Updated
Outdated images can have bugs or compatibility issues. Update and rebuild your containers periodically:
docker pull <image_name>
Encountering the “Error response from daemon: Container is not running” message means that your Docker container has stopped due to an issue. By checking logs, inspecting the container’s exit status, and verifying system resources, you can quickly resolve the problem. Setting up restart policies and proactive monitoring ensures your Docker containers run smoothly without unexpected failures.
Start troubleshooting today and keep your Docker environment running efficiently!