Container 是一種輕量級的虛擬化技術,不用模擬硬件創建虛擬機。
Docker 是基於 Linux Kernel 的 Namespace、CGroups、UnionFileSystem 等技術封裝成的一種自 定義容器格式,從而提供一套虛擬運行環境。
Namespace:用來做隔離的,比如 pid [進程]、net [網絡]、mnt [掛載點]等。
CGroups: Controller Groups用來做資源限制,比如內存和CPU等。
Union file systems:用來做image和container分層。
安裝依賴
sudo yum install -y yum-utils \
device-mapper-persistent-data \
lvm2
(以下可以使用阿里雲鏡像速度快,參考地址:https://blog.csdn.net/DavidSoCool/article/details/102915527)
設置docker倉庫
sudo yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
安裝docker
sudo yum install -y docker-ce docker-ce-cli containerd.io
設置開機啓動
sudo systemctl enable docker
啓動docker
sudo systemctl start docker
查看版本
運行hello-world鏡像生成容器,會先從本地查找,找不到去遠端拉取在運行(鏡像和容器的關係就像java裏面的class文件和創建出來的對象)
拉取tomcat鏡像,不指定版本默認拉取最新的,指定版本可以去hub.docker.com上面找,鏡像名字不對會報錯
查看本地鏡像
運行鏡像, -d 後臺運行,--name 別名,-p 對外端口 9090 對內 8080,運行對應的一些環境變量參數可以去hub.docker.com看
docker run -d --name my-tomcat -p 9090:8080 tomcat
查看後臺運行container
在多創建幾個tomcat的container
查看運行的container
查看所有包括退出的container
docker命令
Usage: docker [OPTIONS] COMMAND
A self-sufficient runtime for containers
Options:
--config string Location of client config files (default "/root/.docker")
-c, --context string Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set with
"docker context use")
-D, --debug Enable debug mode
-H, --host list Daemon socket(s) to connect to
-l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
--tls Use TLS; implied by --tlsverify
--tlscacert string Trust certs signed only by this CA (default "/root/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/root/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/root/.docker/key.pem")
--tlsverify Use TLS and verify the remote
-v, --version Print version information and quit
Management Commands:
builder Manage builds
config Manage Docker configs
container Manage containers
context Manage contexts
engine Manage the docker engine
image Manage images
network Manage networks
node Manage Swarm nodes
plugin Manage plugins
secret Manage Docker secrets
service Manage services
stack Manage Docker stacks
swarm Manage Swarm
system Manage Docker
trust Manage trust on Docker images
volume Manage volumes
Commands:
attach Attach local standard input, output, and error streams to a running container
build Build an image from a Dockerfile
commit Create a new image from a container's changes
cp Copy files/folders between a container and the local filesystem
create Create a new container
diff Inspect changes to files or directories on a container's filesystem
events Get real time events from the server
exec Run a command in a running container
export Export a container's filesystem as a tar archive
history Show the history of an image
images List images
import Import the contents from a tarball to create a filesystem image
info Display system-wide information
inspect Return low-level information on Docker objects
kill Kill one or more running containers
load Load an image from a tar archive or STDIN
login Log in to a Docker registry
logout Log out from a Docker registry
logs Fetch the logs of a container
pause Pause all processes within one or more containers
port List port mappings or a specific mapping for the container
ps List containers
pull Pull an image or a repository from a registry
push Push an image or a repository to a registry
rename Rename a container
restart Restart one or more containers
rm Remove one or more containers
rmi Remove one or more images
run Run a command in a new container
save Save one or more images to a tar archive (streamed to STDOUT by default)
search Search the Docker Hub for images
start Start one or more stopped containers
stats Display a live stream of container(s) resource usage statistics
stop Stop one or more running containers
tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
top Display the running processes of a container
unpause Unpause all processes within one or more containers
update Update configuration of one or more containers
version Show the Docker version information
wait Block until one or more containers stop, then print their exit codes
Run 'docker COMMAND --help' for more information on a command.