Install docker on your mac
Install docker on your mac using the following instructions. https://docs.docker.com/docker-for-mac/install/
Is it running?
Type in docker version to see if docker is running properly. You should see both the client and a server listed with no errors.
docker version Client: Docker Engine - Community Version: 19.03.12 API version: 1.40 Go version: go1.13.10 Git commit: 48a66213fe Built: Mon Jun 22 15:41:33 2020 OS/Arch: darwin/amd64 Experimental: false Server: Docker Engine - Community Engine: Version: 19.03.12 API version: 1.40 (minimum version 1.12) Go version: go1.13.10 Git commit: 48a66213fe Built: Mon Jun 22 15:49:27 2020 OS/Arch: linux/amd64 Experimental: false containerd: Version: v1.2.13 GitCommit: 7ad184331fa3e55e52b890ea95e65ba581ae3429 runc: Version: 1.0.0-rc10 GitCommit: dc9208a3303feef5b3839f4323d9beb36df0a9dd docker-init: Version: 0.18.0 GitCommit: fec3683
Docker help
If you type in docker --help you will get a list of docker commands and options.
docker --help
Usage: docker [OPTIONS] COMMAND
A self-sufficient runtime for containers
Options:
--config string Location of client config files (default "/Users/jbaileyugroup/.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 "/Users/jbaileyugroup/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/Users/jbaileyugroup/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/Users/jbaileyugroup/.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
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
Let create a Nginx server
Start a simple Nginx server by entering docker container run --publish 8080:80 nginx . Press ctrl+c to get back to the terminal.
docker container run --publish 8080:80 nginx Unable to find image 'nginx:latest' locally latest: Pulling from library/nginx bf5952930446: Pull complete cb9a6de05e5a: Pull complete 9513ea0afb93: Pull complete b49ea07d2e93: Pull complete a5e4a503d449: Pull complete Digest: sha256:b0ad43f7ee5edbc0effbc14645ae7055e21bc1973aee5150745632a24a752661 Status: Downloaded newer image for nginx:latest /docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration /docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/ /docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh 10-listen-on-ipv6-by-default.sh: Getting the checksum of /etc/nginx/conf.d/default.conf 10-listen-on-ipv6-by-default.sh: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf /docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh /docker-entrypoint.sh: Configuration complete; ready for start up
Go to your browser and enter localhost:8080. Congratulations you have created your first webserver in Docker!
Docker official images
In the previous example we added a Ngnix to our container and ran it. Since this is the first time we used Ngnix you probably noticed it was pulling the image down from the internet to your local computer. Docker can use many different types of images including various languages, databases, or almost anything that can run on a server. You can find a list of the official images here. https://github.com/docker-library/official-images/tree/master/library
You don’t have to start a container to pull down images you want to use. You can pull them yourself using the docker pull [containerName]. Once pulled these images will be used when creating new containers.
What Images do I currently have?
You can get a list of your current images by typing docker images -a. Notice that the Nginx image is 3 weeks old. This means that people at docker had updated the image 3 weeks ago. If you go to https://github.com/docker-library/official-images/tree/master/library you can confirm that the Ngnix image was updated 22 days ago.
docker images -a REPOSITORY TAG IMAGE ID CREATED SIZE nginx latest 4bb46517cac3 3 weeks ago 133MB
You can delete the image by typing docker rmi [imageName] . This failed for me at first because my container was still running.
docker rmi nginx Error response from daemon: conflict: unable to remove repository reference "nginx" (must force) - container d024b71d525b is using its referenced image 4bb46517cac3
I recommend not removing your images unless you want to reclaim space or want to clean up your Docker environment.
If you want to get the history of the image you can use docker history [imageName]
docker history nginx IMAGE CREATED CREATED BY SIZE COMMENT 4bb46517cac3 3 weeks ago /bin/sh -c #(nop) CMD ["nginx" "-g" "daemon… 0B <missing> 3 weeks ago /bin/sh -c #(nop) STOPSIGNAL SIGTERM 0B <missing> 3 weeks ago /bin/sh -c #(nop) EXPOSE 80 0B <missing> 3 weeks ago /bin/sh -c #(nop) ENTRYPOINT ["/docker-entr… 0B <missing> 3 weeks ago /bin/sh -c #(nop) COPY file:0fd5fca330dcd6a7… 1.04kB <missing> 3 weeks ago /bin/sh -c #(nop) COPY file:1d0a4127e78a26c1… 1.96kB <missing> 3 weeks ago /bin/sh -c #(nop) COPY file:e7e183879c35719c… 1.2kB <missing> 3 weeks ago /bin/sh -c set -x && addgroup --system -… 63.4MB <missing> 3 weeks ago /bin/sh -c #(nop) ENV PKG_RELEASE=1~buster 0B <missing> 3 weeks ago /bin/sh -c #(nop) ENV NJS_VERSION=0.4.3 0B <missing> 3 weeks ago /bin/sh -c #(nop) ENV NGINX_VERSION=1.19.2 0B <missing> 5 weeks ago /bin/sh -c #(nop) LABEL maintainer=NGINX Do… 0B <missing> 5 weeks ago /bin/sh -c #(nop) CMD ["bash"] 0B <missing> 5 weeks ago /bin/sh -c #(nop) ADD file:3af3091e7d2bb40bc… 69.2MB
Some useful docker container commands and parameters
To see a list of all containers running type docker container ls -a
docker container ls -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES d024b71d525b nginx "/docker-entrypoint.…" 14 minutes ago Exited (0) 13 minutes ago gifted_poincare
To stop a container type docker container stop plus the ID or name of the container. You only have to type enough characters of the ID to uniquely identify the container, in my case I typed d02 but d would have worked as well. If you choose to use the name the entire name “gifted_poincare” will have to be entered.
docker container stop d02 d02
Adding the — detach option with run the container and return to the command line.
docker container run --publish 8080:80 --detach nginx fa5d7012c7ac7a89ea355679007dc267e5b0a055a9cd5fa9eef1dc8aeca8b0a1
When you are detached you cannot see the logs. To see them enter docker container logs [containerName/ID]. Just like the before you only have to type in enough ID information to uniquely identify the container. In this case I just used “f” for the ID.
docker container logs f /docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration /docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/ /docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh 10-listen-on-ipv6-by-default.sh: Getting the checksum of /etc/nginx/conf.d/default.conf 10-listen-on-ipv6-by-default.sh: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf /docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh /docker-entrypoint.sh: Configuration complete; ready for start up
Remove containers using the rm command. The container must be stopped first. You can force the container to stop by adding the -f attribute. I believe it is good practice to stop the container first, so you don’t remove a container you want to keep running.
docker container stop f f docker container rm f f
You can specify a name for your container by adding the --name option as follows.
docker container run --publish 8080:80 --detach --name myfirstserver nginx c34fc8d388057ff0a15d02d524bc9b50f0e4182aefd985884b295ca6ad5ebd27
You can also get processes info about your container using docker container top [containerName/ID].
docker container top f PID USER TIME COMMAND 3990 root 0:00 nginx: master process nginx -g daemon off; 4044 101 0:00 nginx: worker process
Details of the container configuration can be listed by typing docker container inspect. This will give you a large JSON string with a bunch of configuration details.
A quick way to get stats and see how your containers are running can be achieved by typing in docker container stats [containerName/ID]. The main metrics shown are CPU and memory usage.
docker container stats CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS b9c569561b7b my_db 1.64% 324.4MiB / 1.945GiB 16.29% 936B / 0B 0B / 0B 38 c34fc8d38805 myfirstserver 0.00% 2.055MiB / 1.945GiB 0.10% 2.14kB / 1.27kB 0B / 0B 2
What if you are just playing around and want to just start something quickly and as soon as you stop it the container erases itself. To do this add the –rm option.
docker container run --name tempweb --rm --publish 8084:80 -d nginx docker container ls CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES aed468a94e33 nginx "/docker-entrypoint.…" 51 seconds ago Up 50 seconds 0.0.0.0:8084->80/tcp tempweb docker container stop tempweb tempweb docker container ls CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
MySQL
Next lets create a MySQL server by entering docker container run --publish 3306:3306 --detach --name [yourDBName] -e MYSQL_RANDOM_ROOT_PASSWORD=true mysql
docker container run --publish 3306:3306 --detach --name my_db -e MYSQL_RANDOM_ROOT_PASSWORD=true mysql
To get the password for your MySQL server enter docker container logs [yourDBName] and find the GENERATED ROOT PASSWORD: line.
docker container logs my_db ... 2020-09-05 18:33:48+00:00 [Note] [Entrypoint]: GENERATED ROOT PASSWORD: Eilael2wa7iefai9ukoomaxool2Beiz1 ...
Apache server
To start an apache server use “httpd” for the image name not “apache”. I made this mistake a couple of times. :). Plus use port 8081:80 to not conflict with your currently running Ngnix server.
docker container run -d --name my_webserver -p 8081:80 httpd
What containers are running so far
Now that we have several containers running enter docker container ls -a to see them. Pretty cool stuff.
docker container ls -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES f3620f5fc997 httpd "httpd-foreground" 12 seconds ago Up 12 seconds 0.0.0.0:8081->80/tcp my_webserver c4b962185d7c mysql "docker-entrypoint.s…" 6 minutes ago Up 6 minutes 0.0.0.0:3306->3306/tcp, 33060/tcp my_db c34fc8d38805 nginx "/docker-entrypoint.…" 2 hours ago Up 2 hours 0.0.0.0:8080->80/tcp myfirstserver
Curl
Instead of going to our browser to see our servers running we just type curl to see the html content using curl localhost:8080 and curl localhost:8081.
curl localhost:8080
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
curl localhost:8081
<html><body><h1>It works!</h1></body></html>
Docker documents
Find great documentation for docker here https://docs.docker.com/
Tip of the docker tail
We have just scratched the tip of the docker tail. Have fun. There is so much more to learn. In a future blog we will dive in deeper.