1. Mirror (images)
1. What is mirroring?
(1) According to Baidu Encyclopedia's explanation: Mirroring is a file storage form and a type of redundant. If the data on one disk exists in the same copy on another disk, it is a mirror.
(2) Many files can be made into a mirror file, and they can be placed in a disk with GHOST and other programs, and then opened with GHOST and other software, and then restored to many files. RAID 1 and RAID 10 use mirrors.
(3) Common mirror file formats include ISO, BIN, IMG, TAO, DAO, CIF, and FCD.
Are you even more dizzy after reading it?
In fact, simply put, mirror is an app package, which contains program code, basic systems, dependency libraries, and tools.
To put it simply, it is a bit similar to the APP installation package.
2. The composition and use of mirrors
（1）Dockerfile
: It is the recipe for making mirrored files
Just like a secret recipe passed down from ancestors: Yunnan Baiyao: Linzhi, ginseng, deer antler, Panax notoginseng, etc.
（2）scratch
: It is the most basic docker image, equivalent to a foundation—》Blank image, nothing --》 Starting from scratch
Use other mirrors as basic mirrors: Other mirrors can be expanded as basic – like standing on the shoulders of giants.
But we need to make a mirror with a tall building starting from the ground, step by step 👣
(3) A complete operating system requires:
2. System calls
3. Applications and libraries
wait
bootfs --》What is needed when the container is started
rootfs --》Operation system inside the container
docker save
docker export
principle:
When the container is started, the kernel starts bootfs and then loads the basic image directly, and then loads it layer by layer –》From the bottom up
When accessing files after the container is run, access them from top to bottom, from the writable layer, layer by layer.
3. Why do you need to make your own mirror?
In the past, I downloaded mysql in Linux, and the yum command was needed in the Centos system. After learning the doker technology, what software is needed? You only need to pull it on docker to get it. Docker is like a huge resource library, only things you can't think of, nothing that it doesn't have.
Some students said: It is technology that restricts my imagination of docker and shed tears of regret.
Some students just said that since docker is so convenient and there are so many mirror files on it, why do we still need to make it ourselves? What do you need? Isn't it okay?
However, in companies, you often need to make your own mirror files, because things made by others are often uneasy, or some specific needs cannot be met. Just like when you go to buy Moutai, the merchant says this is Moutai for ten years, so do you believe it? Is this the ten-year Maotai? Don't go to the identification? If you are a rich man, just pretend I didn't say it, hahahaha
2. Steps of mirror production (10 steps)
Step 1: Edit Dockerfile
[root@sc-docker-server ~]# mkdir /mydocker/ [root@sc-docker-server ~]# cd /mydocker/ [root@sc-docker-server mydocker]# [root@sc-docker-server mydocker]# vim Dockerfile FROM python:2.7-slim WORKDIR /app ADD . /app RUN pip install --trusted-host -r EXPOSE 80 ENV NAME World ENV AUTHOR cali CMD ["python",""]
Step 2: Edit the file
[root@sc-docker-server mydocker]# vim Flask Redis
Step 3: Edit the file, our program file
[root@sc-docker-server mydocker]# vim
from flask import Flask
from redis import Redis, RedisError
import os
import socket
# Connect to Redis
redis = Redis(host="redis", db=0, socket_connect_timeout=2, socket_timeout=2)
app = Flask(__name__)
@("/")
def hello():
try:
visits = ("counter")
except RedisError:
visits = "<i>cannot connect to Redis, counter disabled</i>"
html = "<h3>Hello {name}!</h3>" \
"<b>Hostname:</b> {hostname}<br/>" \
"<b>Visits:</b> {visits}"
return (name=("NAME", "world"), hostname=(), visits=visits)
if __name__ == "__main__":
(host='0.0.0.0', port=80)
Step 4: Generate the mirror file
[root@sc-docker-server mydocker]#docker build -t sc_friendlyhello_1 . docker build -t sc_friendlyhello_1 . Sending build context to Docker daemon 4.608kB Step 1/9 : FROM python:2.7-slim ---> eeb27ee6b893 Step 2/9 : WORKDIR /app ---> Using cache ---> 81aa71984f63 Step 3/9 : ADD . /app ---> Using cache ---> a5c7c6ed471c Step 4/9 : VOLUME ["/data_flask"] ---> Using cache ---> d4db66a741db Step 5/9 : RUN pip install --trusted-host -r ---> Using cache ---> bcdee009e5f7 Step 6/9 : EXPOSE 80 ---> Using cache ---> 475474ce55ff Step 7/9 : ENV NAME World ---> Using cache ---> 0f03ead6c99b Step 8/9 : ENV AUTHOR cali ---> Using cache ---> f844eb0f1a78 Step 9/9 : CMD ["python",""] ---> Using cache ---> ab30484b56b8 Successfully built ab30484b56b8 Successfully tagged sc_friendlyhello_1:latest [root@sc-docker-server mydocker]#
Step 5: Check if the mirror is successful
[root@sc-docker-server mydocker]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE sc_friendlyhello_1 latest ab30484b56b8 32 minutes ago 159MB
Step 6: Use the mirror to start the container
docker run -d -p 5080:80 --name sc-hello-1 sc_friendlyhello_1
Step 7: Access the container's web service
curlorchromeBrowser access Hostip:5080
Hello World! Hostname: f4aeb5d5305a Visits: cannot connect to Redis, counter disabled
Because the redis database container is not started, the flask web service cannot connect to the redis database
Step 8: Start the redis container
docker run -d -p 6379：6379 --name sc-redis-1 redis
Step 9: Start a container that makes your own image again and link to the redis container
docker run -d --name sc-hello-2 -p 5081:80 --link sc-redis-1:redis sc_friendlyhello_1
Step 10: Access the container's web service
curlorchromeBrowser access Hostip:5081
Hello World! Hostname: aad7da1892b5 Visits: 15
3. Mirror production homework
Operation
1. Upgrade the basic image in the sc_friendlyhello_1 image to python:3.9
My own image is renamed to sc_friendlyhello_2
2. Start container and redis container, test access **
Job steps:
Install uploaded files
root@sc-docker-server ~]# yum install lrzsz -y Install uploaded softwareLast dimensional data expiration check：0:25:32 forward，Execute on 2021Year08moon18day Wednesday 09hour52point02Second。 Software Package lrzsz-0.12.20-43.el8.x86_64 Installed。 Dependency resolution。 No processing is required。 complete！ [root@sc-docker-server ~]#
Step 1: Download the app source code
/docker/getting-started existwindowsDownload in，Then upload tolinuxinside yum install git -y linuxinside： git clone /califeng/
Step 2: Unzip the app source code compression package
[root@sc-docker-server ~]# yum install zip unzip -y
[root@sc-docker-1 ~]# unzip
Step 3: Enter the app directory and create a new Dockerfile
[root@sc-docker-1 getting-started-master]# cd app/
[root@sc-docker-1 app]# vim Dockerfile
FROM node:12-alpine
WORKDIR /app
COPY . .
RUN yarn install --production
CMD ["node", "src/"]
Step 4: Make a mirror
[root@sc-docker-1 app]# docker build -t getting-started . -t getting-started It is the name of the specified image，You can define your own name [root@sc-docker-1 app]# docker images View the created imageREPOSITORY TAG IMAGE ID CREATED SIZE getting-started latest 5b903e857b8c 25 seconds ago 179MB redis latest cc69ae189a1a 2 days ago 105MB nginx 1.19.7 35c43ace9216 7 days ago 133MB nginx latest 35c43ace9216 7 days ago 133MB mysql 5.7.33 5f47254ca581 2 weeks ago 449MB nginx 1.19.6 f6d0b4767a6c 6 weeks ago 133MB node 12-alpine 0206ff8a5f9e 7 weeks ago 88.9MB richarvey/nginx-php-fpm latest 5c3ad1891297 5 months ago 506MB hello-world latest bf756fb1ae65 13 months ago 13.3kB jcdemo/flaskapp latest 4f7a2cc79052 2 years ago 88.7MB [root@sc-docker-1 app]#
Step 5: Start the container of the mirrored image you made
[root@sc-docker-1 app]# docker run -dp 3000:3000 getting-started 8f150a72e7d2d1650685b00a18d237469fa07c8cd56977773dd266b281a3b4ad [root@sc-docker-1 app]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 8f150a72e7d2 getting-started "…" 5 seconds ago Up 3 seconds 0.0.0.0:3000->3000/tcp strange_benz deabb58e01b0 nginx "/docker-entrypoint.…" 26 hours ago Up 2 hours 0.0.0.0:6655->80/tcp chenpeng [root@sc-docker-1 app]#
Step 6: Open the browser to access the website in the container
Website in the container: http://192.168.0.161:3000/
Summarize
1. Mirror production is a necessary skill in docker technology. If you say you know how to docker, others will definitely ask you if mirror production? If you say you do what you do to make that thing, others will smile. When you think in your heart, this person's skills must be very low, and you can't even know this, and you even say you can docker, haha.
2. There are detailed steps for mirror production later. The ten-step mirror production method will teach you how to do it. Take your time and do it step by step.
This is the article about Docker image production, upload, pull and deployment. For more related Docker image production, upload, pull and deployment, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!