Question: What is going on with systemctl and docker error "Failed to restart docker.service: Unit docker.service not found."
Docker is a popular containerization platform that allows developers to package applications into lightweight, portable containers. It provides an isolated environment for applications to run in, making it easier to deploy and manage them across different environments. However, sometimes issues can arise when trying to restart the Docker service on a system. In this blog post, we will explore some common reasons why the Docker service may not be found and how to troubleshoot and fix these issues.
One of the most common reasons why the Docker service may not be found is because it was not installed properly or the installation process was interrupted. To check if Docker is installed on your system, you can run the following command in a terminal
bashsudo systemctl --quiet is-active docker.service
If the output of this command is "false", then it means that the Docker service is not active and needs to be started. To start the Docker service, you can run the following command
bashsudo systemctl start docker
If the Docker service still does not start after running this command, there may be an issue with the installation process. In this case, it is recommended to uninstall and reinstall Docker using the official package manager for your operating system. For example, on Ubuntu, you can use the following commands to uninstall and reinstall Docker
bashsudo apt-get remove docker.io
sudo apt-get update
sudo apt-get install docker.io
Another common reason why the Docker service may not be found is because it was stopped manually by a user or administrator. To check if the Docker service is stopped, you can run the following command in a terminal
bashsudo systemctl --quiet is-active docker.service
If the output of this command is "false", then it means that the Docker service is not active and needs to be started. To start the Docker service, you can run the following command
bashsudo systemctl start docker
If the Docker service still does not start after running this command, there may be an issue with the configuration of the Docker service. In this case, it is recommended to check the Docker service logs to see if there are any error messages that can help diagnose the issue. To view the logs for the Docker service, you can run the following command in a terminal
bashsudo journalctl -u docker
This will display the logs for the Docker service in the terminal. Look for any error messages that may indicate the cause of the issue.
If the Docker service is not found and none of the above solutions work, there may be an issue with the system configuration or dependencies required by Docker. In this case, it is recommended to consult the official documentation for your operating system and Docker version to see if there are any known issues or workarounds for this problem.
In conclusion, when trying to restart the Docker service on a system, it is important to first check if the service is active and if not, start it using the appropriate command. If the service still does not start, it may be necessary to uninstall and reinstall Docker or check the configuration and logs for any issues. By following these troubleshooting steps, you can quickly identify and resolve any problems with the Docker service on your system.