Docker Interview Questions and Answers
Question - 1 : - What is Docker?
Answer - 1 : -
Docker is an open-source lightweight containerization technology. It has gained widespread popularity in the cloud and application packaging world. It allows you to automate the deployment of applications in lightweight and portable containers.
Question - 2 : - What are the advantages of using Docker container?
Answer - 2 : -
Here, are a major advantage of using Docker.
- Offers an efficient and easy initial set up
- Allows you to describe your application lifecycle in detail
- Simple configuration and interacts with Docker Compose.
- Documentation provides every bit of information.
Question - 3 : - What are the important features of Docker?
Answer - 3 : -
Here are the essential features of Docker:
- Easy Modeling
- Version control
- Placement/Affinity
- Application Agility
- Developer Productivity
- Operational Efficiencies
Question - 4 : - What are the main drawbacks of Docker?
Answer - 4 : -
Some notable drawbacks of Docker are:
- Doesn’t provide a storage option
- Offer a poor monitoring option.
- No automatic rescheduling of inactive Nodes
- Complicated automatic horizontal scaling set up
Question - 5 : - What are docker images?
Answer - 5 : -
They are executable packages(bundled with application code & dependencies, software packages, etc.) for the purpose of creating containers. Docker images can be deployed to any docker environment and the containers can be spun up there to run the application.
Question - 6 : - What is a DockerFile?
Answer - 6 : -
It is a text file that has all commands which need to be run for building a given image.
Question - 7 : - Can you tell what is the functionality of a hypervisor?
Answer - 7 : -
A hypervisor is a software that makes virtualization happen because of which is sometimes referred to as the Virtual Machine Monitor. This divides the resources of the host system and allocates them to each guest environment installed.
This means that multiple OS can be installed on a single host system. Hypervisors are of 2 types:
1. Native Hypervisor: This type is also called a Bare-metal Hypervisor and runs directly on the underlying host system which also ensures direct access to the host hardware which is why it does not require base OS.
2. Hosted Hypervisor: This type makes use of the underlying host operating system which has the existing OS installed.
Question - 8 : - What can you tell about Docker Compose?
Answer - 8 : -
It is a YAML file consisting of all the details regarding various services, networks, and volumes that are needed for setting up the Docker-based application. So, docker-compose is used for creating multiple containers, host them and establish communication between them. For the purpose of communication amongst the containers, ports are exposed by each and every container.
Question - 9 : - Can you tell something about docker namespace?
Answer - 9 : -
A namespace is basically a Linux feature that ensures OS resources partition in a mutually exclusive manner. This forms the core concept behind containerization as namespaces introduce a layer of isolation amongst the containers. In docker, the namespaces ensure that the containers are portable and they don't affect the underlying host. Examples for namespace types that are currently being supported by Docker – PID, Mount, User, Network, IPC.
Question - 10 : - What is the docker command that lists the status of all docker containers?
Answer - 10 : -
In order to get the status of all the containers, we run the below command:
docker ps -a