“This is the second day of my participation in the Gwen Challenge in November. See details: The Last Gwen Challenge in 2021”

Common Docker commands

Mirror related commands

Look at mirror

View all local mirrors

docker images
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These images are stored in the /var/lib/docker host directory

Search the mirror

To search for an image on the network, run the following command: Note that you must ensure that your current system is networked

Docker Search Image nameCopy the code

Pull the mirror

Pull image: Download the image from the Docker repository to the local PC. The image name format is name: version number. If the version number is not specified, it is the latest version. If you do not know the version of the image, you can go to the Docker Hub to search for the image.

Docker pull image nameCopy the code

For example, I want to download the Centos7 image

docker pull centos:7
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Remove the mirror

Delete a mirror by its ID

Docker RMI image IDCopy the code

Deleting all Mirrors

Make sure this image is not used by any container before deleting it. If there is a running docker container, it will report “Error: container_delete: Impossible to remove a running container, please stop it fifirst”

Docker images -q # docker images -q #Copy the code

Container-specific commands

Check the container

View the running container

docker ps
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View all containers (view running and stopped)

Docker PS -- a Docker Ps-allCopy the code

View the container that was last run

Docker ps - lCopy the code

View the stopped container

docker ps -f status=exited
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Create and start containers

Create container command:

Docker run parameter Image name: image label /bin/bashCopy the code

Common parameters for creating containers are as follows:

-i runs the container. If this parameter is not added, the container is created through the image and is not started.

-t indicates that the command line is displayed after the container is started. After adding these two parameters, the container creation can be logged in. Assign a dummy terminal (if you only add it, it will automatically enter the container).

-d adds the -d argument to run to create a daemon container to run in the background (so that the container is not automatically logged in after being created).

–name Specifies the name of the created container.

-V indicates directory mapping (the former is a host directory, and the latter is a directory mapped to the host). You can use multiple -v to map multiple directories or files. Note: It is best to do directory mapping, make changes on the host, and then share them on the container.

-p indicates port mapping. The former is a host port, and the latter is a mapped port in the container. You can use multiple -p to do multiple port mappings. For example, you can map port 8080 of the Tomcat container in Docker to a certain port 8080 of the host. Then you only need to visit Tomcat in the future: http://ip address of the host: 8080/

After entering the container, initialize the command to execute: /bin/bash; You can write without writing

Interactive container

Run the container interactively. Run the container directly into the container and exit the container directly into the container

This happens only the first time, and starting the container later is a daemon.

Docker runit --name= container name Image name: tag /bin/bashCopy the code

At this time, we use the ps command to check, and we find that we can see the started container, which is in the started state

Exit the current container

exit
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Guardian container

Docker run-di --name= container name Image name (or image ID): label /bin/bashCopy the code

Log in to the container/go to the container directory

Docker exec-it container name (or container ID) /bin/bashCopy the code

Note: here the script /bin/bash must be written after logging into the container

Stop and start containers

Stop container:

Docker stop container name (container ID)Copy the code

Start container:

Docker start docker startCopy the code

File copy

The cp command can be used if we need to copy the host files to the container

# create an empty file touch xxx. HTML # copy the file to the tomcat webapps directory docker cp xxx. HTML 59 b35c0bbe6d: / usr/local/tomcat/webapps # switch to the tomcat container to check the docker exec - it tomcat container ID/bin/bashCopy the code

You can also copy files out of the container

Docker cp container name: # container need to copy the file or directory to copy to the tomcat container to copy the files back out docker cp 59 b35c0bbe6d: / usr/local/tomcat/webapps/XXX. HTML. /Copy the code

Directory mount

We can create a container by mapping the host directory to the directory in the container, so that we can influence the container by modifying the files in a directory on the host.

Create container add -v host directory: container directory example:

docker run -di -v /usr/local/myhtml:/usr/local/myhtml --name=mycentos3 centos:7
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View the CONTAINER IP address

We can view the various data that the container is running with the following command

Docker inspect Container nameCopy the code

You can also run the following command to output the IP address

Docker inspect - format = '{{. NetworkSettings. IPAddress}}' container name (ID) containerCopy the code

Remove the container

Deletes the specified container. Running containers cannot be deleted

Docker rmI docker rmI docker rmI docker rmI dockerCopy the code

Docker Data Volume

Data Volume Overview

A data volume is a directory or file on the host. After a container directory is bound to a data volume directory, the changes of the container directory are immediately synchronized.

A data volume can be mounted by multiple containers at the same time, and a container can be mounted by multiple data volumes.

Simply put, a data volume is essentially a shared folder, which serves as a bridge for data sharing between the host and the container.

Data Volume function

  • Container data persistence
  • The external machine communicates indirectly with the container
  • Data exchange between containers

Data volume configuration mode

One container is attached to one data volume

When creating a startup container, use the -v parameter to set the data volume

docker run ... -v Host directory (file): directory (file) in the container...Copy the code

Matters needing attention:

  1. The directory must be an absolute path
  2. If the host directory does not exist, it will be created automatically
  3. Multiple data volumes can be mounted

Case study:

Docker run -di --name=c1 -v host_data1:/root/c1_data centos:7 /bin/bashCopy the code

View the data volumes attached to the container

You can run the following command to view the data volumes mounted in the container

Docker inspect Container nameCopy the code

Multiple data volumes are attached to one container

You can run the following command to mount multiple data volumes

docker run -di --name=c1 -v /root/host_data1:/root/c1_data1 -v /root/host_data2:/root/c1_data2 centos:7 /bin/bash
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One data volume is mounted to multiple containers

Multiple containers attach one data volume to implement data sharing

docker run -di --name=c2 -v /root/host_data_common:/root/c2_data centos:7
docker run -di --name=c3 -v /root/host_data_common:/root/c3_data centos:7
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Multiple containers mount 1 container (this container mounts 1 data volume)

## create and start c3 data volume container, Docker run -di --name=c3 -v /root/host_data_common:/root/c3_data centos:7 /bin/bash Run the --volumes-from command to configure the data volume docker run-di --name=c1 --volumes-from C3 centos:7 /bin/bash docker run-di --name=c2 --volumes-from c3 centos:7 /bin/bashCopy the code

Deploy the software in Docker

MySQL deployment

  1. Search for mysql mirror
docker search mysql
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  1. Pull mysql image
Docker pull mysql: 5.7Copy the code
  1. Create containers and set port mapping and directory mapping
docker run -di --name=mysql -p 3307:3306 -v /root/mysql/logs:/logs -v /root/mysql/data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD = 123456 mysql: 5.7Copy the code

Parameter Description:

  • -p 3307:3306: maps port 3306 of a container to port 3307 of a host.
  • -v /root/mysql/logs:/logs: Mounts the logs directory under the host directory (/root/mysql) to /logs in the container. Log directory
  • – v/root/mysql/data: / var/lib/mysql: will host machine directory (/ root/mysql) under the data directory mounted to the container of/var/lib/mysql. The data directory
  • -e MYSQL_ROOT_PASSWORD=123456: Initializes the password of user root.
  1. Enter the container and operate mysql
Docker exec -- it c_mysql /bin/bashCopy the code
  1. Connect to mysql in the container using Navicat

Tomcat deployment

  1. Searching for tomcat Images
docker search tomcat
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  1. Pull the Tomcat image
docker pull tomcat:8-jdk8
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  1. Create containers and set port mapping and directory mapping
docker run -di --name=c_tomcat -p 8080:8080 -v /root/tomcat/webapps:/usr/local/tomcat/webapps tomcat:8-jdk8
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Parameter Description:

  • -p 8080:8080: maps port 8080 of a container to port 8080 of a host
  • – v/root/tomcat/webapps: / usr/local/tomcat/webapps: will host directory (/ root/tomcat/webapps) mounted to the container webapps

  1. Deploy the service to Tomcat using the FinalShell file upload

  2. Use an external machine to access Tomcat to test the deployment service

Nginx deployment

  1. Search for Nginx images
docker search Nginx
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  1. Pull the Nginx image
docker run -di --name=mynginx -p 80:80 nginx
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Redis deployment

  1. Search for redis images
docker search redis
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  1. Pull the Redis image
docker pull redis
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  1. Create a container and set port mapping
docker run -id --name=c_redis -p 6379:6379 redis
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  1. Using an external machine to connect to Redis, test

Migration and Backup

Docker development environment, install a lot of containers in Docker, carry out the corresponding configuration, persist the running containers in Docker into images, and install the corresponding images into the production environment. 1. Persist the corresponding container in the Docker in the development environment into image 2. Save the image as a compressed package and send it to the production server. 3. In the production environment, the compressed package > image > container is required

The container is saved as an image

We can save the container as an image by using the following command

Docker commit {running container name/container ID} {ImageName} :{image Tag} {ImageName} :{Tag} # example docker commit XXX redis:version_xxx_1.0.0Copy the code

If the mirror label is not written, the default value is latest

Image backup

We can save the image as a tar file by using the following command

Docker save -o docker save -o redis. Tar redis:version_xxx_1.0.0 Restored name and tag # -o: output fileCopy the code

Mirror restoration and migration

First we delete the c_tomcat_bak image and then execute this command to restore it

Docker load -i {backup image file} # example docker load -i redis. Tar # -i: specifies the file to importCopy the code

After executing the command, you can view the mirror again and see that the mirror has been restored. You can run the test again

Docker run - di - name = mytomcat -p 8081:8080 - v/root/tomcat/webapps /, / usr/local/tomcat/webapps redis: version_xxx_1. 0.0Copy the code