Usage: docker [OPTIONS] COMMAND [arg...]
docker [ --help | -v | --version ]
A self-sufficient runtime for containers.
Options:
--config=~/.docker Location of client config files
-D, --debug Enable debug mode
-H, --host=[] Daemon socket(s) to connect to
-h, --help Print usage
-l, --log-level=info Set the logging level
--tls Use TLS; implied by --tlsverify
--tlscacert=~/.docker/ca.pem Trust certs signed only by this CA
--tlscert=~/.docker/cert.pem Path to TLS certificate file
--tlskey=~/.docker/key.pem Path to TLS key file
--tlsverify Use TLS and verify the remote
-v, --version Print version information and quit
Commands:
attach Attach 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 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 a container, image or task
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
network Manage Docker networks
node Manage Docker Swarm nodes
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 a container
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
service Manage Docker services
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
swarm Manage Docker Swarm
tag Tag an image into a repository
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
volume Manage Docker volumes
wait Block until a container stops, then print its exit code
Pull the image, run the image!
docker pull docker/whalesay:latest
docker images
### lists the images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest 4efb2fcdb1ab 3 months ago 183.4 MB
hello-world latest c54a2cc56cbb 4 months ago 1.848 kB
mendlik/docker-whalesay latest 552104437e78 8 months ago 172.3 MB
docker/whalesay latest 6b362a9f73eb 18 months ago 247 MB
docker run docker/whalesay cowsay ayyyyyy mate
___________
< ayyy mate >
-----------
\
\
\
## .
## ## ## ==
## ## ## ## ===
/""""""""""""""""___/ ===
~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ / ===- ~~~
\______ o __/
\ \ __/
\____\______/
docker inspect whalesay
[
{
"Id": "sha256:6b362a9f73eb8c33b48c95f4fcce1b6637fc25646728cf7fb0679b2da273c3f4",
"RepoTags": [
"docker/whalesay:latest"
],
"RepoDigests": [
"docker/whalesay@sha256:178598e51a26abbc958b8a2e48825c90bc22e641de3d31e18aaf55f3258ba93b"
],
"Parent": "",
"Comment": "",
"Created": "2015-05-25T22:04:23.303454458Z",
"Container": "5460b2353ce4e2b3e3e81b4a523a61c5adc238ae21d3ec3a5774674652e6317f",
"ContainerConfig": {
"Hostname": "9ec8c01a6a48",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
],
"Cmd": [
"/bin/sh",
"-c",
"#(nop) ENV PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
],
"Image": "5d5bd9951e26ca0301423625b19764bda914ae39c3f2bfd6f1824bf5354d10ee",
"Volumes": null,
"WorkingDir": "/cowsay",
"Entrypoint": null,
"OnBuild": [],
"Labels": {}
},
"DockerVersion": "1.6.0",
"Author": "",
"Config": {
"Hostname": "9ec8c01a6a48",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
],
"Cmd": [
"/bin/bash"
],
"Image": "5d5bd9951e26ca0301423625b19764bda914ae39c3f2bfd6f1824bf5354d10ee",
"Volumes": null,
"WorkingDir": "/cowsay",
"Entrypoint": null,
"OnBuild": [],
"Labels": {}
},
"Architecture": "amd64",
"Os": "linux",
"Size": 247049019,
"VirtualSize": 247049019,
"GraphDriver": {
"Name": "aufs",
"Data": null
},
"RootFS": {
"Type": "layers",
"Layers": [
"sha256:1154ba695078d29ea6c4e1adb55c463959cd77509adf09710e2315827d66271a",
"sha256:528c8710fd95f61d40b8bb8a549fa8dfa737d9b9c7c7b2ae55f745c972dddacd",
"sha256:37ee47034d9b78f10f0c5ce3a25e6b6e58997fcadaf5f896c603a10c5f35fb31",
"sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef",
"sha256:b26122d57afa5c4a2dc8db3f986410805bc8792af3a4fa73cfde5eed0a8e5b6d",
"sha256:091abc5148e4d32cecb5522067509d7ffc1e8ac272ff75d2775138639a6c50ca",
"sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef",
"sha256:d511ed9e12e17ab4bfc3e80ed7ce86d4aac82769b42f42b753a338ed9b8a566d",
"sha256:d061ee1340ecc8d03ca25e6ca7f7502275f558764c1ab46bd1f37854c74c5b3f",
"sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef"
]
}
}
]
There is a lifecycle associated with starting, stopping, restarting etc.
docker run -d --name LifeCycle1 nginx:latest
docker attach LifeCycle1
// exec if the container started indirectly
docker exec -it LifeCycle1 /bin/bash
We don't have to attach to the container with the exec command. We can just connect to is just to execute a command - like a ssh prompt!
# remove the image
docker rmi image-name
# remove all containers
docker rm `docker ps -a -q`
Ports
Ports are exposed in a container so that you can connect via the container IP but must be exposed via the dockerfile.
We can direct the port for a http container to a port on the underlying host.
docker run -d -P --name:webserver nginx:latest
To find all the address redirection, we can write docker port WebServer1 $CONTAINERPORT
okeeffe_d@dok ~$ docker port WebServer1 $CONTAINERPORT
443/tcp -> 0.0.0.0:32768
80/tcp -> 0.0.0.0:32769
docker run -d -p 8080:80 --name=webserver nginx:latest is also useful for a variety of reasons.
We no longer have to worry about routing - we can do dev/set up the correct ports. We no longer have to do any static routing.
No we can pass stuff to the host without having to copy it.
This means we can mount underlying directories.
docker run -d -p 8080:80 --name=webserver -v /mnt/data nginx:latest # mount data
Good practise is to keep the container as emphemeral as possible. It should not contain things that won't stick around. We want to run a command and start a container without a complex configuration.
// 15 min mark
If we create a basic file and create a HTML page, we could then run
docker run -d -p 8080:80 --name=webserver -v /home/user/www:/usr/share/nginx/html nginx:latest
// this will mount the file and mount it to that directory. We can push multiple mounts!
Very few times will you start with a generic list of packages for a base image and creating it from nothing.
You'll base on it on things like debian, ubuntu etc.
The Dockerfile is an easy to read, easy to write script to build an image following instructions.
You can name it whatever, but will probably just be stored in Dockerfile anyway.
Note, things will cache if they've already been done!
Example Dockerfile:
# most have FROM which image
FROM debian:stable
MAINTAINER dockerhubid <email>
# best practise is to combined commands
RUN apt-get update && age-get upgrade - y && apt-get install -y apache2 telnet elinks ssh openssh-server
ENV MYVALUE my-value
Then docker run!
docker run -it dockerhubid/myapache:latest /bin/bash
> echo MYVALUE
my-value
Exposing or preventing exposing ports
# most have FROM which image
FROM debian:stable
MAINTAINER dockerhubid <email>
# best practise is to combined commands
RUN apt-get update && age-get upgrade - y && apt-get install -y apache2 telnet elinks ssh openssh-server
ENV MYVALUE my-value
EXPOSE 80
EXPOSE 22
CMD ["/usr/sbin/apache2tl","-D","FOREGROUND"]
Now if we Docker inspect on the file and find the IPAddr, we can see that the Apache website is now running!