something important about docker

docker exec -it app bash (running a virtaul bash)

INSTALL DOCKER

uname -r

curl -sSL https://get.docker.com/ | sh

docker -v
    Docker version 1.11.2 build b9f10c9

systemctl start docker

systemctl enable docker ( start docker after boot )

ps -aux | grep docker

DOWNLOAD IMAGES

docker pull busybox

docker images [ -h ]

DELETE IMAGES

docker rmi app:1.0

PUSH IMAGES

docker login

docker push otfsenter/app

CREATE CONTAINERS

docker run -d -p 5000:5000 --restart=always --name registry -m 128m -v /data/registry:/var/lib/registry registry:2
    ( simple ): docker run -d -p 5000:5000 --name app nginx:1.11.1

CHANGE IMAGES'S TAG

docker tag nginx otfsenter/nginx

PUSH IMAGES

docker daemon    
    MODIFY start parameter "--insecure-registry=0.0.0.0/0"

    vim /usr/lib/systemd/system/docker.service
        ExecStart=/usr/bin/docker
            TO
        ExecStart=/usr/bin/docker daemon -H fd:// --insecure-registry=0.0.0.0/0 

    systemctl daemon-reload
    
    systemctl restart docker

    ps -aux | grep docker
        /usr/bin/docker daemon -H fd:// --insecure-registry=0.0.0.0/0

docker push otfsenter/nginx 

OPERATING CONTAINERS

docker create --name web nginx:1.11.1 ( created, not started )

docker stats app ( percentage used memory and cpu )

docker top app ( how many processes running )

* docker exec -it app bash (running a virtaul bash)

docker inspect/update/cp/export(container->tar file)/import/rm
    update memory of app
        docker update -m 256m app
        docker inspect app | grep -i memory    

RELATIONSHIP BETWEEN CONTAINERS AND IMAGES

docker commit ( commit image from container )
    docker commit -a otfsenter -m "demo commit iamge" web web:2.0

docker save ( save as tar file from image )
    docker save app > app.tar

docker load ( insert to images list from tar file )
    docker load < app.tar

SHARE DATA BETWEEN CONTAINERS

create a data container
                                    ro: readonly
    docker run -d -v /web-data:/tmp:ro --name data-container app

get data from data-container
    docker run -d --volumes-from data-container --name web-container apps
    docker run -d --volumes-from data-container --name web2-container apps

BEST PRACTICE OF VOLUME

Dockerfile:
    FROM centos:7
    RUN yum -y install epel-release && 
        yum -y install nginx && 
        yum clean all
    EXPOSE 80 443
    VOLUME ["/usr/share/nginx/html"] ( container's directory )
    CMD ["nginx", "-g", "daemon -off;"]

docker build -t app . ( build app from Dockerfile )

THE WAY OF SAVE FILES
    centos: /var/lib/docker/devicemapper
    ubuntu: /var/lib/docker/aufs
    coreos: /var/lib/docker/overlayfs ( overlay )


BACK UP DATA FROM VOLUME
    docker run --rm --volumes-from dbdata -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /dbdata
RESUME DATA FROM VOLUME
    docker run --rm --volumes-from dbstore2 -v $(pwd):/backup ubuntu bash -c "cd /dbdata && tar xvf /backup/backup.tar --strip 1"

NETWORK MODULE ( nat, host, container, none, overlay )

    default: NAT ( changed ip when container restart every time )
    HOST: ( fixed ip )
        docker run -d --name app2 --net=host nginx:1.11.1
    CONTAINER: ( ping each other, communicate each other )
        docker run -it --name busybox1 busybox sh
        ip addr
        exit without kill ( Ctrl+P+Q )

        docker run -it --name busybox2 --net=container:busybox1 busybox sh
    NONE:
        docker run -it --name none --net=none busybox sh

    OVERLAY: ( since Docker:1.10 )
            (communicate with different container in different host)
            Container(10.0.9.3)--
    hostA                                -(Gateway)-> eth1(192.168.59.100)-----
            Container(10.0.9.2)--                                                              |
                                                                                                Internet
            Container(10.0.9.5)--                                                              |
    hostB                                -(Gateway)-> eth1(192.168.59.101)-----
            Container(10.0.9.4)--                                     

        CMD:
            ( consul )
            vim /usr/lib/systemd/system/docker/service
            ExecStart=/usr/bin/docker daemon -H tcp://0.0.0.0:2376 -H unix:///var/run/docker.sock --cluster-store=consul://192.168.59.100:8500 --cluster-advertise=eth01:2376 --insecure-registry=0.0.0.0/0
            systemctl daemon-reload
            systemctl restart docker
            docker run -d -p 8400:8400 -p 8500:8500 -p 8600:53/udp -h consul progrium/consul -server(server) -bootstrap -ui-dir /ui (show progress)

PRACTICE OF OVERLAY

CREATE OVERLAY NETWORK
    docker network create -d overlay --subnet=10.0.9.0/24 edu-net
    hostA:
        docker run -d --name app1 --net=edu-net newell.com:5000/nginx:1.11.1
        docker exec -it app1 bash
    hostB:
        docker run -d --name app2 --net=edu-net newell.com:5000/nginx:1.11.1
        docker exec -it app1 bash

DOWNLOAD

http://www.docker.com/products/docker-toolbox
c:userzhouxinzheng.dockermachinecache
    boot2docker.iso

download jpress.war (www.jpress.io)
docker pull hub.c.163.com/library/tomcat
vi Dockerfile
    from hub.c.163.com/library/tomcat
    MAINTAINER newell xxx@163.com
    COPY jpress.war /usr/local/tomcat/webapps
    docker build -t jpress:latest .
docker run -d -p 8888:8080 jpress

docker pull hub.c.163.com/library/mysql
docker run -d -p 3306:3306 -e MYSQL_ROOT_PASSWORD=000000 hub.c.163.com/library/mysql:lastest
docker stop 93056e8a957a(mysql container id)
docker run -d -p 3306:3306 -e MYSQL_ROOT_PASSWORD=000000 -e MYSQL_DATABASE=jpress hub.c.163.com/library/mysql:lastest
docker restart 12fdb93345f2(jpress container)

PYTHON FLASK APP

Dockerfile:

    FROM ubuntu:latest
    MAINTAINER newell xxx@163.com
    RUN apt-get update -y
    RUN apt-get install -y python-pip python-dev build-essential

# Add source files
COPY . /app
ENV HOME=/app
WORKDIR /app

# Install Python web server and dependencies
RUN pip install -r requirements.txt

ENV FLASK_APP=anonpost.py

# Expose port
EXPOSE 5000

ENTRYPOINT ["gunicorn", "-b", "0.0.0.0:5000", "-w", "4", "wsgi:app"]

REQUIREMENTS.TXT
    click == 6.6
    Flask == 0.11.1
    gunicorn == 19.6.0
    itsdangerous == 0.24
    Jinja == 22.8
    MarkupSafe == 0.23
    virtualenv == 15.1.0
    Werkzeug == 0.11.11