Here we have compiled the most probable DevOps interview questions asked in the industry. You will learn about software version control, Git repository, reverting a commit in Git, Vagrant, continuous testing elements, and the importance of continuous integration, testing, and deployment. These questions are curated after discussing with many interviewers and DevOps Training experts.
In a linux machine Docker volumes are stored at this location:
Important states of Docker container are as listed below:
Docker Swarm is an orchestration tool for Docker containers. Docker Swarm is used to scale up/down nodes in a cluster. Even clusters can be created by Docker Swarm. It uses a network for internal communication among containers. Docker Swarm is native clustering for Docker. It turns a container pool of Docker hosts into a single Docker host. Docker Swarm manages the Docker API as well.
Yes, but only if you modify /etc/docker/daemon.json and set the ipv6 key to "true". IPv6 networking is supported only on Docker daemons run on Linux hosts.
Communication between Docker client and Docker Daemon happens with the combination of Rest API, socket.IO, and TCP.
Docker can build images by reading the instructions given in a file called Dockerfile. A Dockerfile is a text document that contains all the commands in a sequence. This "docker build -t < Dockerfile/path > .", command will execute several instructions written in Dockerfile in a sequence to create Docker images. The common commands used in Dockerfile are: FROM, MAINTENANCE, COPY, RUN, and CMD.
By using an orchestration tool like docker-compose, you can run multiple containers using a single service. All docker-compose files use yaml language.
Docker Compose contains information about the services, networks, and volumes for setting up the Docker application. So, you can use Docker Compose to create separate containers, and host them and get them to communicate with each other. Make sure that each container should expose a port for communicating with others. Docker Compose is written in YAML format.
Yes, JSON can be used instead of YAML for a Docker Compose file. we have to specify the filename with the command:
"docker-compose -f docker-compose.json up".
The namespace is one of the features in linux and an important concept of containers. Namespace in Docker is a technique which offers isolated workspaces in Containers. In order to remain portable Docker provides various namespaces and does not affect the host system. Few Namespace types supported by Docker are as: – PID, IPC, NET, MNT, UTS, User accounts, Mount, Process Tree, Network etc.