How to Stop and Start Docker Containers?

Docker containers are small and flexible units that hold applications and what they need to run. They help us run software the same way on different computers. It is important for us to know how to stop and start Docker containers. This helps us manage them well. We can make sure we use resources wisely and run applications only when we need them.

In this article, we will look at how to stop and start Docker containers the right way. We will talk about the important commands we need to manage them. We will also see how to forcefully stop a container if we have to. We will learn how to check the status of our containers. Additionally, we will discuss how to make scripts to manage Docker containers better. By the end of this guide, we will understand Docker container management well.

  • How to Effectively Stop and Start Docker Containers?
  • What Are the Commands to Stop Docker Containers?
  • How to Start Stopped Docker Containers?
  • How to Force Stop a Docker Container?
  • How to Check the Status of Docker Containers?
  • How to Create Scripts for Managing Docker Containers?
  • Frequently Asked Questions

For more information about Docker, we can read related articles like What is Docker and Why Should You Use It? and What is a Docker Container and How Does It Operate?.

What Are the Commands to Stop Docker Containers?

We can stop Docker containers using the docker stop command. Just follow it with the container ID or name. This command sends a SIGTERM signal to the container. It lets the container shut down nicely. Here is the basic way to write it:

docker stop <container_id_or_name>

Example

If we want to stop a container called my_container, we would run:

docker stop my_container

If we want to stop more than one container at the same time, we can list their IDs or names with spaces in between:

docker stop container1 container2 container3

Stopping All Running Containers

To stop all containers that are running, we can use this command which combines some commands:

docker stop $(docker ps -q)

Here, docker ps -q lists all the running container IDs. Then docker stop will stop them.

Additional Options

  • Timeout: Normally, docker stop waits 10 seconds for the container to stop before it forcefully ends it. We can change this wait time with the -t option:
docker stop -t 5 my_container

This command sets a wait time of 5 seconds.

For more info on how to manage Docker containers, we can look at this guide on managing Docker container logs.

How to Start Stopped Docker Containers?

To start a Docker container that we stopped before, we can use the docker start command. We follow it with the container ID or name. This command will restart the container just like it was before we stopped it.

Basic Command

docker start <container_id_or_name>

Example

If we have a container called web_server that we want to start, we run:

docker start web_server

Starting Multiple Containers

We also can start many stopped containers at the same time. We just need to give their IDs or names, separated by spaces:

docker start <container_id_1> <container_id_2>

Check Container Status

To check if the container started well, we can look at the status using the docker ps command:

docker ps -a

This will show us all containers and their status. It will tell us if they are running or exited.

Additional Options

If we want to start a container and connect to it right away, we can use the docker start -ai command:

docker start -ai <container_id_or_name>

For more details about managing Docker containers, we can look at this article.

How to Force Stop a Docker Container?

To force stop a Docker container, we can use the docker kill command. This command stops the container right away. It sends a SIGKILL signal. This signal kills the process inside the container without waiting for it to finish.

Command to Force Stop a Docker Container

docker kill <container_id_or_name>

Example

To force stop a container with the name my_container, we can use this command:

docker kill my_container

If we want to force stop a container using its ID, we can do it like this:

docker kill 123abc456def

Additional Options

We can also specify a signal to send with the -s option. For example, if we want to send a SIGTERM signal instead, we would use:

docker kill -s SIGTERM <container_id_or_name>

Checking Status After Force Stop

After we force stop a container, we can check its status by using:

docker ps -a

This command will show the stopped container in the list with its status. If we need more information about managing Docker containers, we can look at how to list running Docker containers.

How to Check the Status of Docker Containers?

We can check the status of Docker containers by using the docker ps command. This command shows all running containers. If we want to see both running and stopped containers, we can use docker ps -a.

Commands to Check Container Status

  • List Running Containers:

    docker ps

  • List All Containers (Running and Stopped):

    docker ps -a

  • Get Detailed Information about a Specific Container:

    docker inspect <container_id_or_name>

Example Output

When we run docker ps, we may see an output like this:

CONTAINER ID   IMAGE         COMMAND                  CREATED        STATUS         PORTS                    NAMES
a1b2c3d4e5f6   nginx:latest  "/docker-entrypoint.…"  2 hours ago    Up 2 hours     0.0.0.0:80->80/tcp       webserver

Key Properties

  • STATUS: Shows if the container is running or exited.
  • NAMES: This is the name we give to the container.
  • PORTS: This shows how we can access the container through ports.

For more detailed information about the status and setup of Docker containers, we can check the Docker documentation.

How to Create Scripts for Managing Docker Containers?

Creating scripts for managing Docker containers helps us automate tasks. This makes our work easier and more consistent. Here is how we can create simple bash scripts for common container tasks.

Script to Start a Docker Container

We can create a script to start a Docker container like this:

#!/bin/bash

# Start a Docker container
CONTAINER_NAME="my_container"
IMAGE_NAME="my_image"

docker run -d --name $CONTAINER_NAME $IMAGE_NAME

Script to Stop a Docker Container

To stop a specific Docker container, we can use this script:

#!/bin/bash

# Stop a Docker container
CONTAINER_NAME="my_container"

docker stop $CONTAINER_NAME

Script to Check Docker Container Status

We can also check the status of our containers with this script:

#!/bin/bash

# Check the status of a Docker container
CONTAINER_NAME="my_container"

docker ps -a | grep $CONTAINER_NAME

Script to Force Stop a Docker Container

If we need to force stop a container, we can use this script:

#!/bin/bash

# Force stop a Docker container
CONTAINER_NAME="my_container"

docker rm -f $CONTAINER_NAME

Script to List All Containers

To list all running and stopped containers, we create this script:

#!/bin/bash

# List all Docker containers
docker ps -a

Making Scripts Executable

After we create our scripts, we need to make them executable with:

chmod +x script_name.sh

Running the Scripts

We can run our scripts in the terminal like this:

./script_name.sh

Additional Considerations

  • It is good to store our scripts in a special directory for easy access.
  • We can use environment variables to make our scripts more flexible.
  • We should think about logging outputs to keep track of how our scripts run.

For more tips on managing Docker containers, check out how to manage Docker container logs.

Frequently Asked Questions

1. What are the basic commands to stop and start Docker containers?

We can use simple commands to manage Docker containers. To stop a running container, we type docker stop <container_name_or_id>. To start a stopped container, we use the command docker start <container_name_or_id>. These commands help us control the lifecycle of our Docker containers. They are very important for anyone using Docker.

2. How can I force stop a Docker container that is not responding?

If a Docker container is not responding, we can force it to stop. We use the command docker kill <container_name_or_id>. This command sends a SIGKILL signal to the container. It makes sure the container stops right away. We should be careful when using this command. It might cause data loss if the container is doing tasks that need to be closed properly.

3. How do I check the status of my Docker containers?

To check the status of our Docker containers, we can use the command docker ps -a. This command shows all containers. It includes both running and stopped containers. We can see their status. This helps us know which containers are active and which ones need our attention. Some may need to be restarted or removed.

4. Can I create scripts to automate stopping and starting Docker containers?

Yes, we can create scripts to automate managing Docker containers. By writing a shell script with commands like docker stop and docker start, we can make our workflow easier. This is very helpful when we manage many containers. It also helps us fit Docker management into bigger automation tasks.

5. What happens to data in a Docker container when it is stopped?

When we stop a Docker container, the data inside stays safe. But if we remove the container using docker rm, the data will go away unless it was saved in a Docker volume or bind mount. So, we need to manage data carefully. This way, we can make sure we do not lose important information when we stop or remove containers. For more on data management in Docker, check out how to bind mount host files to Docker containers.