Top 50 Docker Interview Questions and Answers

To login docker registry, use the docker login command with the registry URL, username, and password.

• Use the docker login command followed by the registry URL

• Enter the username and password when prompted

• Example: docker login myregistry.com -u usernam...read more

The most commonly used instructions in a Dockerfile include FROM, RUN, COPY, and CMD.

• FROM: Specifies the base image for the container

• RUN: Executes commands in the container

• COPY: Copies files and directories from the host to the container

• CMD: Specifie...read more

Yes, I have experience working with Docker and Kubernetes.

• I have used Docker to containerize applications for easier deployment and scaling.

• I have experience with Kubernetes for managing containerized applications in a clustered environment.

• I have se...read more

Docker Swarm is simpler and easier to set up, while Kubernetes is more powerful and feature-rich for complex deployments.

• Docker Swarm is easier to set up and manage for smaller deployments

• Kubernetes is more powerful and feature-rich, suitable for com...read more

Namespace in Docker is a way to isolate resources and avoid naming conflicts.

• Namespaces provide a layer of isolation for containers

• Each namespace has its own set of resources

• Namespaces can be used for network, process, and mount isolation

• Example: doc...read more

To troubleshoot a dying docker container, we can use logs, inspect the container, and check resource usage.

• Check container logs using 'docker logs ' command

• Inspect the container using 'docker inspect ' command to check its status and configuration

• Che...read more

To see log of a complete request in docker, use docker logs command.

• Use 'docker logs ' command to see logs of a specific container

• Use '-f' flag to follow the logs in real-time

• Use '--tail' flag to specify the number of lines to show from the end of th...read more

To build and push a docker image to ECR, we need to create a Dockerfile, build the image, tag it, login to ECR, push the image to ECR.

• Create a Dockerfile with necessary configurations

• Build the image using docker build command

• Tag the image using docke...read more

Dockerfile is used to build a Docker image, while Docker Compose is used to define and run multi-container Docker applications.

• Dockerfile is a script that contains instructions to build a Docker image.

• Docker Compose is a YAML file that defines a mult...read more

Docker Namespaces are a feature in Docker that isolates containers from each other and the host system.

• Namespaces provide a way to isolate processes, network, and filesystem for containers.

• Examples of namespaces include PID (process IDs), NET (networ...read more

A Docker image registry is a repository for storing and managing Docker images.

• It allows users to push and pull Docker images to and from the registry.

• Popular Docker image registries include Docker Hub, Amazon ECR, and Google Container Registry.

• Regis...read more

Docker images can be copied from one host to another using 'docker save' and 'docker load' commands.

• Use 'docker save' command to save the image as a tar file on the source host

• Transfer the tar file to the destination host using SCP or any other file ...read more

Docker commands used inside a Dockerfile

• FROM - specifies the base image

• RUN - executes a command in the container

• COPY - copies files from host to container

• WORKDIR - sets the working directory for subsequent commands

• CMD - specifies the command to run w...read more

To check recent last 50 logs of docker, you can use the 'docker logs' command with the '--tail' option.

• Use the command 'docker logs --tail 50 ' to display the last 50 logs of a specific Docker container.

• If you want to follow the logs in real-time, yo...read more

A Dockerfile is a text file that contains instructions for building a Docker image for a Java application.

• Use a base image that includes Java, such as 'openjdk:8'

• Copy the application JAR file to the image using the 'COPY' instruction

• Set the working d...read more

Dockerfile to run a Python script

• Use a base Python image as the starting point

• Copy the Python script into the container

• Specify the command to run the Python script

Docker is a platform that allows you to package, distribute, and run applications in isolated containers.

• Docker containers are lightweight, portable, and self-sufficient environments that include everything needed to run an application.

• Docker uses co...read more

Create a docker file to make mongodb available for developers

• Use the official MongoDB Docker image as the base image

• Expose the default MongoDB port (27017)

• Set up any necessary environment variables or configurations

• Build the Docker image using the Do...read more

Using Docker image build and deployment in AKS with ACR

• Create a Dockerfile to define the image

• Build the Docker image using 'docker build' command

• Push the image to Azure Container Registry (ACR)

• Create a Kubernetes deployment manifest referencing the i...read more

A Dockerfile to build a microservices application

• Use a base image like Alpine Linux or Ubuntu

• Install necessary dependencies and libraries

• Copy the application code into the container

• Expose the required ports

• Specify the command to run the microservice

Docker is a platform for developing, shipping, and running applications in containers, while a server is a physical or virtual machine that hosts applications and services.

• Docker is a containerization platform that allows applications to run in isola...read more

Docker is a platform for developing, shipping, and running applications in containers.

• Docker allows developers to package applications and their dependencies into containers.

• Containers are lightweight, portable, and isolated environments that run on ...read more

Docker provides advantages such as portability, scalability, and isolation.

• Docker allows for easy portability of applications across different environments.

• Docker enables efficient use of resources and scalability through containerization.

• Docker prov...read more

Docker migration from one machine to another involves exporting the container as an image, transferring the image to the new machine, and then importing it.

• Export the Docker container as an image using 'docker save' command

• Transfer the image to the n...read more

Docker is a containerization platform used to package and run applications, while Ansible is a configuration management tool used for automating IT infrastructure tasks.

• Docker is used to create containers that encapsulate an application and its depen...read more

Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.

• Dockerfile is used to build Docker images by specifying a series of instructions.

• It includes commands like FROM, RUN, COPY, CMD, e...read more

Dockerfile to setup Nginx and expose it with port 8080

• Use the official Nginx image as the base image

• Copy the custom Nginx configuration file to the container

• Expose port 8080 in the Dockerfile

• Start Nginx in the foreground using the CMD instruction