Docker

This is a page all about Docker and helpful commands.

Docker File

ARG These are arguments that can be used in side the docker file.

 ARG BASE_DIR=/opt/app
 ...
 COPY ./file.txt $BASE_DIR

Port To expose port to docker to be exposed, lol kind of redundant.

  EXPOSE 4000

Docker Images

List This will show a list of all docker images.

 docker images

Remove This will remove an image from the list.

 docker rmi {imagename}:{tag}

You might need to force it.

 docker rmi -f {imagename}:{tag}

Run The big difference between run and start. Run will create a container and then start it. Where start just starts up a container.

This is how you run an image

 docker run -it {imagename}:{tag}

Add environment variables to the container.

 docker run -it -e USERNAME='jdoe' {imagename}:{tag} 

To open the ports. Make sure you do this and have the ports exposed in your Dockerfile.

 docker run -p 8080:8080 -it {imagename}:{tag}

To run the image in a detacted container for it run in the background.

 docker run -d -it {imagename}:{tag}

To run an image and go right into bash for the starting point.

 docker run -it --entrypoint "/bin/bash" {imagename}:{tag}

To get into bash for a container.

 docker exec -it <container id> /bin/bash

To see a list of running containers

 docker ps

To see a list of containers running or stopped

 docker ps -a

Import Image To import an image that built by buildah in to docker.

 docker load -i image-buildah.tar

Modify Image Tages This will change the tag for an image.

 docker tag 304cf8d51e52 cs:latest

Docker Build Image

When you have a Dockerfile you want to build use the following command.

 docker build -t myimage .

Docker QuickStart Terminal

When using the QuickStart terminal, it creates a virtual machine to run docker in.

To get to this machine.

 docker-machine ssh default

A directory with persistent storage each time the machine starts up.

 /var/lib/boot2docker/

To create a startup scrip when the machine starts up. Create this file /var/lib/boot2docker/bootlocal.sh with execution permissions.

Tip: To sudo when in the machine

 sudo -s

I had an issue with an invalid ssl cert. To fix the issue you must have the docker-machine load a file called daemon.json and inside the file you add untrusted URL sources.

1. Log in to the docker-machine

 docker-machine ssh default

 sudo -s

3. Change directories to the persistent storage directory.

 cd /var/lib/boot2docker/

4. Create the daemon.json file.

 {
   "insecure-registries" : ["myregistrydomain.com:5000"]
 }

5. Create a boot script for the docker machine

 touch /var/lib/boot2docker/bootlocal.sh && chmod +x /var/lib/boot2docker/bootlocal.sh

6. Edit the file and copy the daemon.json file to the correct location.

 #!/bin/sh 
 cp /var/lib/boot2docker/daemon.json /etc/docker/daemon.json

7. Exit the docker-machine

8. Restart the docker machine

 docker-machine restart