Q1. Title – List of 15 popular commands of docker

1. Which Docker version
   $ docker –version
2. Images – list of images on docker
   $ docker images
3. Downloading image from repository
   $ docker pull httpd
4. ‘ps -a’ – List all the docker containers running/exited/stopped with container details.
   $ docker ps -a
5. exec – Access the docker container and run commands inside the container.
   $ docker exec -it
6. Run – Run the docker image mentioned in the command.
   $ docker run -it -d httpd
7. Removing container – Remove the docker container with container id mentioned in the command.
   $ docker rm containerID
8. Remove image
   $ docker rmi imageID
9. Stopping Docker – Docker stop command stops the container gracefully
   $ docker stop containerID
10. Restart Docker
    $ docker restart containerID
11. Kill – Stop the docker container immediately.
    $ docker kill containerID
12. Checking history – history of a docker image with the image name mentioned in the command.
    $ docker history httpd
13. Logs – Show the logs of the docker container with contained id mentioned in the command.
    $ docker logs containerID
14. Installing plugin – Install a docker plugin $ docker plugin install pluginName

15. Updating configuration – Update container configurations.
    $ docker update [options]

Q2. Title – How to configure SMTP server in Sonarqube?

In Sonarqube – go to Configuration >> General Settings >> Email.

Fill in the fields with your e-mail server configuration and then click on the Save Email Settings button

Q3. Title – List of most popular plugins of Jenkins from plugins.jenkins.io/

1. Mailer – This plugin allows you to configure email notifications for build results. This is a break-out of the original core based email component.
2. Script Security – Allows Jenkins administrator to control what in-process scripts can be run by less-privileged users.
3. JUnit – Allows JUnit format test results to be published.
4. Pipeline: API – Plugin that defines Pipeline API.
5. Git client: Utility plugin for Git support in Jenkins.