Review 線上課程
Docker Mastery Section3內容
Udemy- Docker mastery Note
Docker Install and Config
docker version verified cli talk to engine
docker info most config values of image
docker 指令的組成結構(新)
docker
ex: docker container run
Starting a Nginx Web Server
image is the application we want to run
container is an instance of that image running as a process
docker container run --publish 7777:80 nginx
starts a new container from an image
docker container run --publish 7777:80 nginx實際上做了????
- 從docker hub download一個名為
nginx的image - 利用這個image建立並啟動一個新的container
- Host ip 開7777 port
- 指向Container ip 的 80 port
docker container run --publish 7777:80 --detach nginx container running in background
docker container ls list running containers
docker container stop stops the container process but doesn’t remove it
[註]run和start差異
docker container run 每次都會建立啟動一個全新的container
docker container start 啟動一個停止的container
docker container run -publish 80:80 --detach --name webhost nginx
docker container logs show logs for specific container
docker container top webhost
docker cotainer rm <container id> <container id> 刪除被停止的container
docker container rm -f <container id>強制刪除 (running container 也會被刪除)
What Happens When we run a container
拆解docker container run 發生的事情
- 先在本機尋找image cache
- 找不到預設會到Docker hub上找image
- 下載最新或是指定的版本
- 利用下載下來的image建立一個新的container (準備啟動)
- 在Docker engine中的private network給一個虛擬IP
- 啟動本機的Port A，並指向container Port B (–publish A:B)
- 利用image Dockerfile中的指令去啟動container
例如:
docker container run --publish 8080:80 --name webhost -d nginx1.11 nginx -T
Container VS. VM
container just processes
Exit when process stops
docker run --name monfo -d mongo
ps aux show all running processes
ps aux | grep mongo
What’s Goning On in Containers
docker container top process list in one container
docker container inspect details of one container config
show metadata about the container
(startup config, volumes, networking,…..)
docker container stats performance stats for all containers
Getting a Shell Inside Containers
docker container run -it start new container interactively
docker container exec -it run additional command in existing container
-t, –tty: allocate a pseudo-TTY
-i, –interactive: keep session open to receive terminal input
docker container run -it --name proxy nginx bash
docker container run -it ubuntu ubuntu
docker container start start -ai ubuntu
-a, –attach
docker container exec -it mysql bash
Alpine Linux: a small security-focused distribution
docker pull alpine
alpine liniux: 輕量!! 使用apx管理!
docker container run -it alpine sh
Docker Networks: Concepts
Each container connected to a private virtual network “brige”
each virtual network routes through NAT firefall on host IP
All container on a virtual network can talk to each other without
-p
docker container run -p 80:80 --name webhost -d nginx
docker container port webhost
docker container inspect --format '｛｛.NetworkSettings.IPAddress}}' webhost
ifconfig en0
Docker Networks: Management
docker network ls show networks
docker network inspect inspect a network
docker network create --driver create a network
docker network connect attach a network to container
docker network disconnect detach a network from container
docker network create my_app_net
docker container run -d --name new_nginx --network my_app_net nginx
docker network connect dynamically creates a NIC in a container on an existing virtual network
docker network connect my_app_net webhost
Docker Networks: DNS
Docker daemon has a built-in DNS server that containers use by default
docker container run -d --name my_nginx --network my_app_net nginx
docker container exec -it my_nginx ping new_nginx