Three major docker components: container and docker

Three major docker components: container and docker
1. containers are another core concept of Docker.

Simply put, containers are one or more applications that run independently and Their runtime environments. The virtual machine can be understood as a simulation.
A complete set of operating systems (including the running environment and other system environments) and applications running on them.

1.1 start container 1.1.1 and docker run

[root@bfd-v7 ~]# docker run ubuntu:12.04 /bin/echo 'Hello docker'Hello docker

When docker run is used to create a container, the standard operations that Docker runs in the background include:

Check whether a specified image exists locally. If the image does not exist, download the image from the public warehouse and create a container to allocate a file system, the read-only image layer is mounted to the read/write layer to bridge a virtual interface from the bridge interface configured by the host to the container to configure an ip address from the address pool for the container. after the application is executed, the container is terminated 1.1.2, And the docker startdocker ps-a container is started to view all containers including stopped containers. Docker start id

1.2 daemon running

Docker containers run in Daemonized mode in the background. In this case, you can add the-d Parameter
Number.

[root@bfd-v7 ~]# docker run -d ubuntu:12.04 /bin/sh -c "while true; do echo hello world; sleep 1; done"

You can view the docker logs container id as follows:

1.3 docker stop container id

[Root @ bfd-v7 ~] # Docker stop container id

To restart a container in the terminated state, run the docker start command.

1.4 enter the container attach

[Root @ bfd-v7 ~] # Docker run-idt ubuntu: 12.04 [root @ bfd-v7 ~] # Docker attach container id # exit container [root @ bfd-v7 ~] # Exit

1.5 export and Import of containers 1.5.1 and export docker export commands

[root@bfd-v7 container]# docker ps[root@bfd-v7 container]# docker export fb8a9e65bc79 > wyl-nginx.tar

1.5.2 import docker import command

# V1 is a tag sign [root @ bfd-v7 container] # docker import wyl-nginx.tar wyl-nginx: v1 # returns an idsha256: container

Note: You can use docker load to import the image storage file to the local image repository, or use docker import to import a container snapshot to the local image repository. The difference between the two is that the container snapshot file will discard all historical records and metadata (that is, only save the current snapshot status of the container), and the image storage file will save the complete record, the volume is also large. In addition, you can re-specify tag and other metadata information when importing from the container snapshot file.

1.6 Delete the container rm command

You can use docker rm to delete a terminated container. to delete a running container, you can add the-f parameter. Docker sends a SIGKILL signal to the container.

# Delete a stopped container, first view all containers, select the container id to delete [root @ bfd-v7 container] # docker ps-a [root @ bfd-v7 container] # docker rm 7099f90eb56a

# Delete a running container [root @ bfd-v7 container] # docker rm-f fb8a9e65bc79