Docker on Ubuntu 2021
https://cwhu.medium.com/docker-tutorial-101-c3808b899ac6
Manual
cd docker-demo-app
npm install # will read package.json file, install dependencies to node_modules
npm start # will read package.json file, display name@version, run script of "node index.js"
firefox 127.0.0.1:3000
Dockerfile
FROM node:10.15.3-alpine
WORKDIR /app
ADD . /app
RUN npm install
EXPOSE 3000
CMD node index.js
FROM means to load nodejs
WORKDIR creates /app under docker
ADD adds current directory (of Dockerfile)'s files to /app
RUN npm install
EXPOSE 3000 port from docker container to external
CME node index.js starts the http server
remember to add a .dockerignore besides Dockerfile that contains "node_modules" so that when ADD the binaries will not be in the image file, or else the image will be big.
Build docker
sudo docker build . -t docker-demo-app # This builds an image with a tag "docker-demo-app"
sudo docker images # list all images in all repos. the tag "docker-demo-app" appears in REPOSITORY
REPOSITORY TAG IMAGE ID CREATED SIZE
docker-demo-app latest af571dd0e6cb 10 minutes ago 73.4MB
Run, check, stop container from image
sudo docker run -p 3000:3000 -it af571dd0e6cb
listening on port 3000 # this is from index.js console.log("listen on port 3000")
# possible error starting userland proxy: listen tcp4 0.0.0.0:3000: bind: address already in use.
# now CTRL+C will not work
sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
49cf1fee8d4d af571dd0e6cb "/bin/sh -c 'node in…" 4 minutes ago Up 4 minutes 0.0.0.0:3000->3000/tcp, :::3000->3000/tcp eager_northcutt
sudo docker stop 49cf1fee8d4d
docker run
sudo docker run -p 3000:3000 -it <IMAGE ID> # is equivalent to below
sudo docker run -p 3000:3000 -it d18ba1dfd218 echo 123 # 123
sudo docker run -p 3000:3000 -it d18ba1dfd218 ls # Dockerfile node_modules index.js 3 more files
sudo docker run -p 3000:3000 -it d18ba1dfd218 pwd # /app
sudo docker run -p 3000:3000 -it d18ba1dfd218 ps # PID 1 USER root TiIME 0:00 COMMAND ps
More notes here (read only)
# 01 Docker Helle World
install curl, add docker repo
=============================
https://www.runoob.com/docker/ubuntu-docker-install.html
curl -fsSL https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-key fingerprint 0EBFCD88
sudo add-apt-repository \
"deb [arch=amd64] https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu/ \
$(lsb_release -cs) \
stable"
test docker
===========
sudo docker run hello-world
sudo docker run ubuntu:15.10 /bin/echo "Hello world"
sudo docker run ubunty:15.10 /bin/bash # run then exit
sudo docker run -it ubuntu:15.10 /bin/bash
# -i for interactive STDIN
# -t for terminal
/# cat /proc/version # Linux version 5.11.0
# exit or CTRL+D to quit
backend mode
============
sudo docker run -d ubuntu:15.10 /bin/sh -c "while true; do echo hello world; sleep1; done"
d65680c3740dff7cd8ba30fa4e476432bc5a3918a96a98b589ef99e6fc90d47d
# this is a container id 64 bytes
sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
d65680c3740d ubuntu:15.10 "/bin/sh -c 'while t…" About a minute ago Up About a minute frosty_kepler
# STATUS can be 7 of Union[Up,Created,Restarting,Removing,Paused,Exited,Dead]
sudo docker logs d65680c3740dff7
sudo docker logs d65680c3740dff
sudo docker logs d65680c3740df
sudo docker logs d65680c3740d
sudo docker logs d656
sudo docker logs d65
sudo docker logs d6
sudo docker logs frosty_kepler
sudo docker stop frosty_kepler
# 02 Container
commands
========
sudo docker images
sudo docker run -it ubuntu:14.04 /bin/bash
sudo docker pull ubuntu:13.10
sudo docker search httpd
sudo docker pull httpd
sudo docker run httpd
sudo docker rmi httpd
sudo docker images
sudo docker rmi httpd
docker commit
=============
commit a changed docker image as another image
sudo docker run -it ubuntu:15.10 /bin/bash
apt-get --version # apt 1.0.10.2ubuntu1
root@44ee34f316fa
apt-get update
exit
sudo docker container ls -a | grep 44ee34f316fa
44ee34f316fa ubuntu:15.10 "/bin/bash" 5 minutes ago Exited (0) 4 minutes ago vibrant_spence
sudo docker commit -m="has update" -a="runoob" 44ee34f316fa runoob/ubuntu:v2
sudo docker commit -m="has update" -a="runoob" 44ee34f316fa bunbun:v3
sudo docker commit -m="has update" -a="runoob" 44ee34f316fa bun/gun:v3
REPOSITORY TAG IMAGE ID CREATED SIZE
bun/gun v3 fb4c50ff7da4 10 seconds ago 137MB
bunbun v3 184d7f91f982 14 seconds ago 137MB
runoob/ubuntu v2 ab7bc95f9950 18 seconds ago 137MB
sudo docker rmi runoob/ubuntu:v2
sudo docker rmi bunbun:v3
sudo docker rmi bun/gun:v3
# 03 Dockerfile, docker build
Dockerfile
==========
vim Dockerfile
FROM centos:6.7
MAINTAINER Fisher "fisher@sudops.com"
RUN /bin/echo 'root:123456' |chpasswd
RUN useradd runoob
RUN /bin/echo 'runoob:123456' |chpasswd
RUN /bin/echo -e "LANG=\"en_US.UTF-8\"" >/etc/default/local
EXPOSE 22
EXPOSE 80
CMD /usr/sbin/sshd -D
docker build
============
sudo docker build -t runoob/centos:6.7 .
// Tag an image (-t)
// Dockerfile from .
Step 1/9 : FROM centos:6.7
6.7: Pulling from library/centos
cbddbc0189a0: Pull complete
Digest: sha256:4c952fc7d30ed134109c769387313ab864711d1bd8b4660017f9d27243622df1
Status: Downloaded newer image for centos:6.7
---> 9f1de3c6ad53
Step 2/9 : MAINTAINER Fisher "fisher@sudops.com"
---> Running in c3cb2314855a
Removing intermediate container c3cb2314855a
---> 0b636d52aae7
Step 3/9 : RUN /bin/echo 'root:123456' |chpasswd
---> Running in ed30059f2f19
Removing intermediate container ed30059f2f19
---> 974b0c91f900
Step 4/9 : RUN useradd runoob
---> Running in 53590233c07a
Removing intermediate container 53590233c07a
---> d6f24b904317
Step 5/9 : RUN /bin/echo 'runoob:123456' |chpasswd
---> Running in b0fe55fdeea9
Removing intermediate container b0fe55fdeea9
---> 05dd496ca42d
Step 6/9 : RUN /bin/echo -e "LANG=\"en_US.UTF-8\"" >/etc/default/local
---> Running in 7b67eb2a5f8e
Removing intermediate container 7b67eb2a5f8e
---> 803ed0f06699
Step 7/9 : EXPOSE 22
---> Running in 8139bbe1ad71
Removing intermediate container 8139bbe1ad71
---> 8d2db7a61261
Step 8/9 : EXPOSE 80
---> Running in 75b4e8f5d60f
Removing intermediate container 75b4e8f5d60f
---> ed01cf55131e
Step 9/9 : CMD /usr/sbin/sshd -D
---> Running in 933cd65d3946
Removing intermediate container 933cd65d3946
---> 5bdb04f9d136
Successfully built 5bdb04f9d136
Successfully tagged runoob/centos:6.7
docker tag
==========
sudo docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
runoob/centos 6.7 5bdb04f9d136 3 minutes ago 191MB
docker tag 5bdb04f9d136 runoob/centos:dev
docker tag 5bdb04f9d136 runoob/centos:bunbun
REPOSITORY TAG IMAGE ID CREATED SIZE
runoob/centos 6.7 5bdb04f9d136 4 minutes ago 191MB
runoob/centos bunbun 5bdb04f9d136 4 minutes ago 191MB
runoob/centos dev 5bdb04f9d136 4 minutes ago 191MB
# 04 docker port
docker run -d -P training/webapp python app.py
# latest: Pulling from training/webapp
# -d Detached mode
# -P docker run [OPTIONS] --publish-all , -P Publish all exposed ports to random ports
# Docker identifies every port from "Dockerfile EXPOSE" and "--expose 8080"
# port mapped to epehmeral port range usually 32768 to 61000
sudo docker inspect training/webapp | vim - /Exposed
"ExposedPorts": {"5000/tcp": {}}
sudo docker inspect training/webapp | grep tcp
"5000/tcp": {}
"5000/tcp": {}
sudo docker ps
b06e5902f88b 0.0.0.0:49153->5000/tcp, :::49153->5000/tcp
# docker mapped host port 49153 to container port 5000
telnet 127.0.0.1 49153
Connected to 127.0.0.1
telnet 127.0.0.1 5000
Connection refused
firefox 127.0.0.1:49153
Hello world!
sudo docker run -d -p 5000:5000 training/webapp python app.py
sudo docker ps
1a93c1aa7e8d 0.0.0.0:5000->5000/tcp, :::5000->5000/tcp
b06e5902f88b 0.0.0.0:49153->5000/tcp, :::49153->5000/tcp
sudo docker run -d -p 127.0.0.1:5001:5000 training/webapp python app.py
sudo docker ps
decf92a9d49c 127.0.0.1:5001->5000/tcp
1a93c1aa7e8d 0.0.0.0:5000->5000/tcp, :::5000->5000/tcp
b06e5902f88b 0.0.0.0:49153->5000/tcp, :::49153->5000/tcp
sudo docker run -d -p 127.0.0.1:5000:5000/udp training/webapp python app.py
acd7d2f46eb7 5000/tcp, 127.0.0.1:5000->5000/udp
decf92a9d49c 127.0.0.1:5001->5000/tcp
1a93c1aa7e8d 0.0.0.0:5000->5000/tcp, :::5000->5000/tcp
b06e5902f88b 0.0.0.0:49153->5000/tcp, :::49153->5000/tcp
sudo docker port strange_mclaren
sudo docker port b06e5902f88b
sudo docker port b06
5000/tcp -> 0.0.0.0:49153
5000/tcp -> :::49153
docker network
==============
sudo docker run -d -P --name runoob training/webapp python app.py
sudo docker ps -l # latest
sudo docker network create -d bridge test-net
# bridge for bridge, overlay for swarm mode
sudo docker run -itd --name test1 --network test-net ubuntu /bin/bash
sudo docker run -itd --name test2 --network test-net ubuntu /bin/bash
sudo docker exec -it test1 /bin/bash
ping test2
command not found
apt-get update
apt install iputils-ping
ping test2
64 bytes from 87b91bb68862 (172.18.0.2): icmp_seq=1 ttl=64 time=0.031 ms
DNS
===
To be continued
End
