Tuesday, September 26, 2017

Books: Docker in Action

It's an excellent book, highly recommended, Jeff Nickoloff is a great author.

Here some notes from the exercises

docker run dockerinaction/hello_world

docker help

Usage: docker COMMAND

A self-sufficient runtime for containers

--config string Location of client config files (default "/home/centos/.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 "/home/centos/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/home/centos/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/home/centos/.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

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.

interesting demo of Portainer https://portainer.io/overview.html#demo , I have installed and run locally to manage my environment

docker run --detach --name web nginx:latest

docker run --interactive --tty --link web:web --name web_test busybox:latest /bin/sh

wget -O - http://web:80/

(CTRL-P CTRL-Q to run interactively a process and then detach)

#this example is WRONG in the book!
docker run -d --name mailer dockerinaction/ch2_mailer

docker run -it --name agent --link web:insideweb --link mailer:insidemailer dockerinaction/ch2_agent

#connect to a running instance in interactive mode
docker start -i "CID"

docker restart web
docker restart mailer
docker restart agent

docker run -d --name namespaceA busybox:latest /bin/sh -c "sleep 30000"
docker run -d --name namespaceB busybox:latest /bin/sh -c "nc -l -p"

docker exec namespaceA ps
docker exec namespaceB ps

#creating a conflict by NOT using namespaces
docker run -d --name webConflict nginx:latest
docker logs webConflict
docker exec webConflict nginx -g 'daemon off;'

#avoiding conflicts by using namespaces
docker run -d --name webA nginx:latest
docker logs webA
docker run -d --name webB nginx:latest
docker logs webB

docker rename webA webPippo

#create is like run, but it's created in stopped state
CID=$(docker create nginx)
echo $CID

docker create --cidfile /tmp/web.cid nginx

#running 3 containers linked to each other - in reverse order
MAILER_CID=$(docker run -d dockerinaction/ch2_mailer)
WEB_CID=$(docker run -d nginx)
AGENT_CID=$(docker run -d --link $WEB_CID:insideweb --link $MAILER_CID:insidemailer dockerinaction/ch2_agent)

#check status of container
docker inspect $CID

docker search postgres

docker pull busybox:latest
docker save -o myfile.tar busybox:latest
docker rmi busybox
docker load -i myfile.tar

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