[root@jenkins ~]# docker
Usage: docker COMMAND
A self-sufficient runtime for containers
Options:
–config string Location of client config files (default “/root/.docker”)
-D, –debug Enable debug mode
–help Print usage
-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:
config Manage Docker configs
container Manage containers
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
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.
[root@jenkins ~]# docker run –help
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG…]
Run a command in a new container
Options:
–add-host list Add a custom host-to-IP mapping (host:ip)
-a, –attach list Attach to STDIN, STDOUT or STDERR
–blkio-weight uint16 Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)
–blkio-weight-device list Block IO weight (relative device weight) (default [])
–cap-add list Add Linux capabilities
–cap-drop list Drop Linux capabilities
–cgroup-parent string Optional parent cgroup for the container
–cidfile string Write the container ID to the file
–cpu-period int Limit CPU CFS (Completely Fair Scheduler) period
–cpu-quota int Limit CPU CFS (Completely Fair Scheduler) quota
–cpu-rt-period int Limit CPU real-time period in microseconds
–cpu-rt-runtime int Limit CPU real-time runtime in microseconds
-c, –cpu-shares int CPU shares (relative weight)
–cpus decimal Number of CPUs
–cpuset-cpus string CPUs in which to allow execution (0-3, 0,1)
–cpuset-mems string MEMs in which to allow execution (0-3, 0,1)
-d, –detach Run container in background and print container ID
–detach-keys string Override the key sequence for detaching a container
–device list Add a host device to the container
–device-cgroup-rule list Add a rule to the cgroup allowed devices list
–device-read-bps list Limit read rate (bytes per second) from a device (default [])
–device-read-iops list Limit read rate (IO per second) from a device (default [])
–device-write-bps list Limit write rate (bytes per second) to a device (default [])
–device-write-iops list Limit write rate (IO per second) to a device (default [])
–disable-content-trust Skip image verification (default true)
–dns list Set custom DNS servers
–dns-option list Set DNS options
–dns-search list Set custom DNS search domains
–entrypoint string Overwrite the default ENTRYPOINT of the image
-e, –env list Set environment variables
–env-file list Read in a file of environment variables
–expose list Expose a port or a range of ports
–group-add list Add additional groups to join
–health-cmd string Command to run to check health
–health-interval duration Time between running the check (ms|s|m|h) (default 0s)
–health-retries int Consecutive failures needed to report unhealthy
–health-start-period duration Start period for the container to initialize before starting health-retries countdown (ms|s|m|h)
(default 0s)
–health-timeout duration Maximum time to allow one check to run (ms|s|m|h) (default 0s)
–help Print usage
-h, –hostname string Container host name
–init Run an init inside the container that forwards signals and reaps processes
-i, –interactive Keep STDIN open even if not attached
–ip string IPv4 address (e.g., 172.30.100.104)
–ip6 string IPv6 address (e.g., 2001:db8::33)
–ipc string IPC namespace to use
–isolation string Container isolation technology
–kernel-memory bytes Kernel memory limit
-l, –label list Set meta data on a container
–label-file list Read in a line delimited file of labels
–link list Add link to another container
–link-local-ip list Container IPv4/IPv6 link-local addresses
–log-driver string Logging driver for the container
–log-opt list Log driver options
–mac-address string Container MAC address (e.g., 92:d0:c6:0a:29:33)
-m, –memory bytes Memory limit
–memory-reservation bytes Memory soft limit
–memory-swap bytes Swap limit equal to memory plus swap: ‘-1’ to enable unlimited swap
–memory-swappiness int Tune container memory swappiness (0 to 100) (default -1)
–mount mount Attach a filesystem mount to the container
–name string Assign a name to the container
–network string Connect a container to a network (default “default”)
–network-alias list Add network-scoped alias for the container
–no-healthcheck Disable any container-specified HEALTHCHECK
–oom-kill-disable Disable OOM Killer
–oom-score-adj int Tune host’s OOM preferences (-1000 to 1000)
–pid string PID namespace to use
–pids-limit int Tune container pids limit (set -1 for unlimited)
–privileged Give extended privileges to this container
-p, –publish list Publish a container’s port(s) to the host
-P, –publish-all Publish all exposed ports to random ports
–read-only Mount the container’s root filesystem as read only
–restart string Restart policy to apply when a container exits (default “no”)
–rm Automatically remove the container when it exits
–runtime string Runtime to use for this container
–security-opt list Security Options
–shm-size bytes Size of /dev/shm
–sig-proxy Proxy received signals to the process (default true)
–stop-signal string Signal to stop a container (default “SIGTERM”)
–stop-timeout int Timeout (in seconds) to stop a container
–storage-opt list Storage driver options for the container
–sysctl map Sysctl options (default map[])
–tmpfs list Mount a tmpfs directory
-t, –tty Allocate a pseudo-TTY
–ulimit ulimit Ulimit options (default [])
-u, –user string Username or UID (format: <name|uid>[:<group|gid>])
–userns string User namespace to use
–uts string UTS namespace to use
-v, –volume list Bind mount a volume
–volume-driver string Optional volume driver for the container
–volumes-from list Mount volumes from the specified container(s)
-w, –workdir string Working directory inside the container
Dockerfiles
Each Dockerfile is a script, composed of various commands (instructions) and arguments listed successively to automatically perform actions on a base image in order to create (or form) a new one. They are used for organizing things and greatly help with deployments by simplifying the process start-to-finish.
Each Dockerfile is a script, composed of various commands (instructions) and arguments listed successively to automatically perform actions on a base image in order to create (or form) a new one. They are used for organizing things and greatly help with deployments by simplifying the process start-to-finish.
Dockerfiles begin with defining an image FROM which the build process starts. Followed by various other methods, commands and arguments (or conditions), in return, provide a new image which is to be used for creating docker containers.
Dockerfile Syntax
Dockerfile syntax consists of two kind of main line blocks: comments and commands + arguments.
# Print “Hello docker!”
RUN echo “Hello docker!”
| Command | Description |
|---|---|
| ADD | Copies a file from the host system onto the container |
| CMD | The command that runs when the container starts |
| ENTRYPOINT | |
| ENV | Sets an environment variable in the new container |
| EXPOSE | Opens a port for linked containers |
| FROM | The base image to use in the build. This is mandatory and must be the first command in the file. |
| MAINTAINER | An optional value for the maintainer of the script |
| ONBUILD | A command that is triggered when the image in the Dcokerfile is used as a base for another image |
| RUN | Executes a command and save the result as a new layer |
| USER | Sets the default user within the container |
| VOLUME | Creates a shared volume that can be shared among containers or by the host machine |
| WORKDIR | Set the default working directory for the container |
Dockerfiles begin with defining an image FROM which the build process starts. Followed by various other methods, commands and arguments (or conditions), in return, provide a new image which is to be used for creating docker containers.
Dockerfile Syntax
Dockerfile syntax consists of two kind of main line blocks: comments and commands + arguments.
# Print “Hello docker!”
RUN echo “Hello docker!”
ADD
The ADD command gets two arguments: a source and a destination. It basically copies the files from the source on the host into the container’s own filesystem at the set destination.
ADD [destination directory]
CMD
The command CMD, similarly to RUN, can be used for executing a specific command. However, unlike RUN it is not executed during build, but when a container is instantiated using the image being built. Therefore, it should be considered as an initial, default command that gets executed (i.e. run) with the creation of containers based on the image.
CMD “echo” “Hello docker!”
ENTRYPOINT
ENTRYPOINT argument sets the concrete default application that is used every time a container is created using the image. For example, if you have installed a specific application inside an image and you will use this image to only run that application, you can state it with ENTRYPOINT and whenever a container is created from that image, your application will be the target.
ENTRYPOINT echo
ENV
The ENV command is used to set the environment variables (one or more). These variables consist of “key = value” pairs which can be accessed within the container by scripts and applications alike. This functionality of docker offers an enormous amount of flexibility for running programs.
ENV SERVER_WORKS 4
EXPOSE
The EXPOSE command is used to associate a specified port to enable networking between the running process inside the container and the outside world (i.e. the host).
EXPOSE 8080
FROM
FROM directive is probably the most crucial amongst all others for Dockerfiles. It defines the base image to use to start the build process. It can be any image, including the ones you have created previously. If a FROM image is not found on the host, docker will try to find it (and download) from the docker image index. It needs to be the first command declared inside a Dockerfile.
FROM ubuntu
MAINTAINER
One of the commands that can be set anywhere in the file – although it would be better if it was declared on top – is MAINTAINER. This non-executing command declares the author, hence setting the author field of the images. It should come nonetheless after FROM.
MAINTAINER authors_name
RUN
The RUN command is the central executing directive for Dockerfiles. It takes a command as its argument and runs it to form the image. Unlike CMD, it actually is used to build the image (forming another layer on top of the previous one which is committed).
RUN aptitude install -y riak
USER
The USER directive is used to set the UID (or username) which is to run the container based on the image being built.
USER 751
VOLUME
The VOLUME command is used to enable access from your container to a directory on the host machine (i.e. mounting it).
VOLUME [“/my_files”]
WORKDIR
The WORKDIR directive is used to set where the command defined with CMD is to be executed.
WORKDIR ~/
https://github.com/kstaken/dockerfile-examples
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