[docker installation and basic commands]

1, docker: container based Virtualization (hosting applications to application containers) implements an application level resource isolation and quota.

What is a container?
Container: lightweight Virtualization (sharing the same system kernel). The container is run by the container image.
Advantages: high container density, fast startup, no extra overhead; disadvantages: only in linux operating system
What's the difference between virtualization and containers?
Differences: both pay attention to isolation. Virtualization is to install virtual machines on physical machines and then install a variety of operating systems (commonly used vmword, openstack and kvm are virtualization technologies); container is to directly install the container layer on the linux operating system to achieve various plate isolation

1.docker installation

Method 1: use the official installation script to install automatically
In fact, download an installation script, and then perform the installation (not recommended, because the version installation cannot be selected)
curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun
Method 2: install using yum, not recommended
yum install docker
In this way, you can install it directly from the CD or yum warehouse. The version is lower
Method 3: use yum add source to install the specified version, recommended
(1) Add docker CE source information

yum-config-manager --add-repo=https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

(2) Update yum source: to cache the package information locally in advance, so as to improve the speed of installing search software

yum makecache fast

(3) Install docker CE

yum -y install docker-ce  #The latest version is downloaded by default

① Check which docker versions are available
yum list docker-ce.x86_64 --showduplicates | sort -r
② Download the specified version, the stable version downloaded here
yum -y install docker-ce-17.03.2.ce

Test: docker version / docker -v

[root@manager yum.repos.d]# docker version
Client: Docker Engine - Community
 Version:           19.03.12
 API version:       1.40
 Go version:        go1.13.10
 Git commit:        48a66213fe
 Built:             Mon Jun 22 15:46:54 2020
 OS/Arch:           linux/amd64
 Experimental:      false
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running? 
 #Description the docker service is not enabled
 [root@manager yum.repos.d]# docker -v
Docker version 1.13.1, build 64e9980/1.13.1s

2. Start service: systemctl enable --now docker

Note 1: possible problems during installation:
The reason is that the old version of docker may have been installed before. When installing, an error is reported as follows
Transaction check error: file /usr/bin/docker from install of docker-ce-cli-1:19.03.12-3.el7.x86_64 conflicts with file from package docker-common-2:1.13.1-161.git64e9980.el7_8.x86_64 file /usr/bin/dockerd from install of docker-ce-3:19.03.12-3.el7.x86_64 conflicts with file from package docker-common-2:1.13.1-161.git64e9980.el7_8.x86_64
Resolution: uninstall the old version of the package
yum remove docker-common-2:1.13.1-161.git64e9980.el7_8.x86_64
Install docker again and it will be installed successfully!

Note 2:[ root@manager ~]#Docker -- help command

2, Three cores of docker: image, container and warehouse

Image: similar to virtual machine image
Container: similar to linux system environment, running and isolating applications. When the container starts from the image, docker will create a writable layer at the top layer of the image. The image itself is read-only and remains unchanged
Warehouse: each warehouse stores a certain type of image. There are two types: docker hub shared warehouse and docker registry private warehouse. (build docker warehouse graphically)

3, docker operation

1. Warehouse related orders

docker search image name	Search image from warehouse
docker pull image name	Pull the image from the warehouse. The latest version is pulled by default
docker push image name	Push image to warehouse[ hub.docker.com You must register an account (docker hub registration account) on the web page to push the image to the warehouse; then use docker login on the command line to log in]

eg1. Search image centos from warehouse

[root@manager ~]# docker search centos  
NAME                               DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
centos                             The official build of CentOS.                   6061                [OK]                
ansible/centos7-ansible            Ansible on Centos7                              130                                     [OK]
consol/centos-xfce-vnc             Centos container with "headless" VNC session...   116                                     [OK]
jdeathe/centos-ssh                 OpenSSH / Supervisor / EPEL/IUS/SCL Repos - ...   114 
...................

eg2: pull image busybox from warehouse

[root@manager ~]# docker pull busybox 
Using default tag: latest
latest: Pulling from library/busybox
76df9210b28c: Pull complete 
Digest: sha256:95cf004f559831017cdf4628aaf1bb30133677be8702a8c5f2994629f637a209
Status: Downloaded newer image for busybox:latest
docker.io/library/busybox:latest

eg3: push the image to the warehouse
hub.docker.com You must register an account (docker hub registration account) on the web page to push the image to the warehouse

docker push Image name
docker login

2. Image related commands

docker search image name	Search image
docker pull image name	Pull out image, the latest version pulled by default
docker image save image name > name.tar.gz	Export image
docker image rm image name	Delete image (to delete a running image plus - f)
docker image load -i filename	Import image
docker image ls	View the current image list
Docker image inspection image name	View image details
docker image tag image name: latest image name: tag name	Mark the image, which is usually used to push the image into the warehouse

eg1: view the current image list, view image details, and view busybox image history

[root@manager ~]# docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              1c35c4412082        3 weeks ago         1.22MB
[root@manager ~]# docker image inspect busybox 
[root@manager ~]# docker image history busybox
IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
1c35c4412082        3 weeks ago         /bin/sh -c #(nop)  CMD ["sh"]                   0B                  
<missing>           3 weeks ago         /bin/sh -c #(nop) ADD file:a84c53d2fe5207d17...   1.22MB

eg2: export image:
Method 1: docker image save image name > path location information( name.tar.gz)

[root@manager ~]# docker image save busybox > busybox1.tar.gz

Method 2: docker image save -o path location information( name.tar.gz )Image name: latest

[root@manager ~]# docker image save -o busybox2.tar.gz busybox:latest

eg3: delete image: docker image rm image name

[root@manager ~]# docker image rm busybox
Untagged: busybox:latest
Untagged: busybox@sha256:95cf004f559831017cdf4628aaf1bb30133677be8702a8c5f2994629f637a209
Deleted: sha256:1c35c441208254cb7c3844ba95a96485388cef9ccc0646d562c7fc026e04c807
Deleted: sha256:1be74353c3d0fd55fb5638a52953e6f1bc441e5b1710921db9ec2aa202725569
[root@manager ~]# docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
centos              7                   b5b4d78bc90c        7 weeks ago         203MB

eg4: import image: docker image load -i path location information

[root@manager ~]# docker image load -i busybox1.tar.gz
1be74353c3d0: Loading layer  1.437MB/1.437MB
Loaded image: busybox:latest
[root@manager ~]# docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              1c35c4412082        3 weeks ago         1.22MB
centos              7                   b5b4d78bc90c        7 weeks ago         203MB

perhaps

[root@manager ~]# docker image import busybox1.tar.gz busybox:v1
sha256:70fe82f93ddc2f501380d3749e743be3e9afd3d9dfc106ae2e22c92d830f91df
[root@manager ~]# docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             v1                  70fe82f93ddc        6 seconds ago       1.44MB
centos              7                   b5b4d78bc90c        7 weeks ago         203MB

eg5: mark the image: tag is generally used to push the image into the warehouse
docker image tag image name: latest image name: tag name

[root@manager ~]# docker image tag busybox:latest busybox:v1.1
[root@manager ~]# docker image tag busybox:latest busybox:v1.2
[root@manager ~]# docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              1c35c4412082        3 weeks ago         1.22MB
busybox             v1.1                1c35c4412082        3 weeks ago         1.22MB
busybox             v1.2                1c35c4412082        3 weeks ago         1.22MB
centos              7                   b5b4d78bc90c        7 weeks ago         203MB
[root@manager ~]# docker image rm busybox:v1.1 busybox:v1.2
Untagged: busybox:v1.1
Untagged: busybox:v1.2
[root@manager ~]# docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              1c35c4412082        3 weeks ago         1.22MB
centos              7                   b5b4d78bc90c        7 weeks ago         203MB

docker image help command

[root@manager ~]# docker image --help

Usage:	docker image COMMAND

Manage images

Commands:
  build       Build an image from a Dockerfile
  history     Show the history of an image
  import      Import the contents from a tarball to create a filesystem image
  inspect     Display detailed information on one or more images
  load        Load an image from a tar archive or STDIN
  ls          List images
  prune       Remove unused images
  pull        Pull an image or a repository from a registry
  push        Push an image or a repository to a registry
  rm          Remove one or more images
  save        Save one or more images to a tar archive (streamed to STDOUT by default)
  tag         Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE

Run 'docker image COMMAND --help' for more information on a command.

3. Container related orders:

docker run image name [- i/-d/-t / – name]	Start container
docker stop container name / container ID	Stop container
docker kill container name / container ID	Kill running containers
docker rm container name / container ID	Delete container (add - f to delete running)
docker start container name / container ID	Activate closed container
docker ps	View information (status) of running containers
docker ps -a	View information (status) for all containers
docker ps -q	View the ID number of the running container
docker ps -aq	View ID numbers for all containers
Docker inspection container name / container ID	View details of a container
Docker exec - shell specified by it container name	Execute the specified command exec on the running container

eg1: start container
Method 1 (not recommended):
First create a container: docker create image name
Restart container: docker start container name

[root@manager ~]# docker create busybox:latest 
47f2de8f995999651498e6f0b58764214817e182ad8eff32b2b0b231f5fd3628
[root@manager ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
47f2de8f9959        busybox:latest      "sh"                16 seconds ago      Created                                 recursing_galileo
[root@manager ~]# docker start recursing_galileo
recursing_galileo
[root@manager ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
[root@manager ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
47f2de8f9959        busybox:latest      "sh"                58 seconds ago      Exited (0) 9 seconds ago                       recursing_galileo

Method 2: docker run image name [- d/-i/-t / – name], the status will be Exited if you enter and exit when you start

[root@manager ~]# docker run -it busybox:latest 
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # exit
[root@manager ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
[root@manager ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
1fcc320d6f11        busybox:latest      "sh"                23 seconds ago      Exited (0) 10 seconds ago                       gracious_hopper
47f2de8f9959        busybox:latest      "sh"                3 minutes ago       Exited (0) 2 minutes ago                        recursing_galileo

The docker run image name [- d/-i/-t / – name], press CTRL+p, CTRL+Q, and the status is UP

[root@manager ~]# docker run -it busybox:latest 
/ # [root@manager ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
328a8dbff50f        busybox:latest      "sh"                9 seconds ago       Up 8 seconds                            vigorous_easley

Or execute in the background (- d) to make the status UP [recommended]

[root@manager ~]# docker run -idt --name c1 busybox:latest 
baafbd0b1a3dfe19692929cac68e29096652c277140ccdc48f2ec8bd331631ac
[root@manager ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
baafbd0b1a3d        busybox:latest      "sh"                10 seconds ago      Up 9 seconds                            c1

eg2: container stopped:

[root@manager ~]# docker stop vigorous_easley
vigorous_easley
[root@manager ~]# docker stop baafbd0b1a3d
baafbd0b1a3d
[root@manager ~]# docker ps 
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

eg3: kill the running container

[root@manager ~]# docker kill competent_robinson
competent_robinson

eg4: activate closed container:

[root@manager ~]# docker start competent_robinson
competent_robinson

eg5: View container details:

[root@manager ~]# docker inspect 9f91c7213a7d
[
    {
        "Id": "9f91c7213a7dda367f8fe152403eb2b6612c2849bb9a06299e360378db3c9f8e",
        "Created": "2020-06-25T09:34:09.421984223Z",
        "Path": "/bin/sh",
        "Args": [],
        "State": {
            "Status": "exited",
            "Running": false,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 0,
            "ExitCode": 0,

View the ID number of the running container

[root@manager ~]# docker ps -q 
f658dc1f9c9f

View ID numbers of all containers

[root@manager ~]# docker ps -aq 
f658dc1f9c9f
328a8dbff50f
baafbd0b1a3d
1fcc320d6f11
47f2de8f9959

eg6: delete container: docker rm container name or container ID
Delete all containers: query all containers IDdocker ps -aq, and add - f to delete the running

[root@manager ~]# docker rm -f `docker ps -aq`
f658dc1f9c9f
328a8dbff50f
baafbd0b1a3d
1fcc320d6f11
47f2de8f9959
[root@manager ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

eg7: execute the specified command exec on the running container:

[root@manager ~]# docker exec -it centos7 /bin/bash
[root@73e57bae16bf /]# cat /etc/redhat-release 
CentOS Linux release 7.8.2003 (Core)
[root@73e57bae16bf /]# exit

Query container internal log:
docker logs

4, External access to the docker container: docker run -p (- p represents port mapping); that is, the application is hosted on the application container

1. Pull Mysql image from the warehouse

[root@manager ~]# docker pull mysql:5.6
5.6: Pulling from library/mysql
7d2977b12acb: Pull complete 
5fb8400e7f07: Pull complete 
234877fbb165: Pull complete 
6fe1021f12f3: Pull complete 
7e36fe6b53f0: Pull complete 
996ec709c11b: Pull complete 
5198b7523387: Pull complete 
cc9bdad4dcc0: Pull complete 
380cd37ad979: Downloading  6.446MB/64.2MB
d64465acf034: Download complete 
d4ee6606b3ab: Download complete 
380cd37ad979: Downloading  18.26MB/64.2MB
380cd37ad979: Downloading  29.01MB/64.2MB
380cd37ad979: Pull complete 
d64465acf034: Pull complete 
d4ee6606b3ab: Pull complete 
Digest: sha256:2bf1a0a05a6ad437dcac6689e48a9c33774ac92c6213fce2c4196343210592f3
Status: Downloaded newer image for mysql:5.6
docker.io/library/mysql:5.6

2. Start the container MySQL (and set the root password), and set the external port mapping

[root@manager ~]# docker run --name mysql -itd -p 3305:3306 -e MYSQL_ROOT_PASSWORD=123456 mysql:5.6 
97be89fd63737771d36882d512f86cf484c5518de9a56848d68ca8ed31edc42c

3. Install mysql5.6 externally and check whether port 3305 listens
yum whatprovides mysql
yum install mariadb -y

[root@manager ~]# netstat -ltunp | grep 3305
tcp6       0      0 :::3305                 :::*                    LISTEN      6379/docker-proxy

4. Access mysql container from outside
Method 1: docker exec - it MySQL - uroot - p123456

[root@manager ~]# docker exec -it mysql mysql -uroot -p123456
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.48 MySQL Community Server (GPL)

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> select version();
+-----------+
| version() |
+-----------+
| 5.6.48    |
+-----------+
1 row in set (0.00 sec)

mysql> exit
Bye

Method 2: mysql-uroot-p-h172.17.0.2

[root@manager ~]# mysql -uroot -p -h172.17.0.2
Enter password: 
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.48 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [(none)]> exit
Bye

Note: external users cannot access mysql directly because they do not have permission

Posted by mark123$ on Thu, 25 Jun 2020 05:08:49 -0700

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