DevOps Classroomnotes 10/Jun/2022

Docker

• Installing Docker on a Linux Server
  • Create your own linux instance and install docker
  • Use Docker Playground Refer Here. You need to create a Docker Hub account Refer Here
• Docker has two major components
  • Client
  • Engine/Runtime/Server
    
    
• Activity 1: Now lets assume we want to run nginx inside a container.
  • We need docker image to create a container.
  • We can search for existing images Refer Here Refer Here
  • The name of the image is nginx
  • To create a container run the following command docker container run -d -P nginx
    
  • Now lets create another nginx container
    
  • If we anlayze what has happened the following image will help you with details
    
  • Takeaway: To create a container i need an image.
  • If we need to run the application developed by our dev team inside containers we need to create image of it.
  • Creating the docker image for an application is called as containerizing and this is our first activity as a devops engineer.
• Activity 2: I want to run a postgressql inside a container
  • Refer Here for the postgres image
  • The command is docker container run -d -P postgres

How do i build Docker images?

• As learnt in the demo, when ever dev team makes changes in the code, we are expected to create a docker image
  
• Since there will be lot of changes, we need to maintain multiple versions.
• A version in docker image is referred as tag.
• Ideally the docker image build should be done along with code developed by dev team.
• Will be continued in the next session

Exercises

• Create a docker hub account
• Download any cheatsheats of docker
• Create a free Azure Account Refer Here
• Refer Here