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Docker Interview Preparation Course

Docker is one of the fastest growing software in technology world. Till now 4 billion Docker containers have been used. This course is designed to help you achieve your goals in Docker field. Engineers with Docker knowledge may get more

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How will you monitor Docker in production?

Docker provides tools like docker stats and docker events to monitor Docker in production. We can get reports on important statistics with these commands. Docker stats: When we call docker stats with a container id, we get the CPU, memory

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What are the Cloud platforms that support Docker?

Some of the popular cloud platforms that support Docker are: Amazon AWS <li>Google Cloud Platform</li> <li>Microsoft Azure</li> <li>IBM Bluemix</li>

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How can we control the startup order of services in Docker compose?

In Docker compose we can use the depends_on option to control the startup order of services. With compose, the services will start in the dependency order. Dependencies can be defined in the options like- depends_on, links, volumes_from, network_mode etc. But

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Why Docker compose does not wait for a container to be ready before moving on to start next service in dependency order?

The problem with waiting for a container to be ready is that in a Distributed system, some services or hosts may become unavailable sometimes. Similarly during startup also some services may also be down. Therefore, we have to build resiliency

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How will you customize Docker compose file for different environments?

In Docker compose there are two files docker-compose.yml and docker-compose.override.yml. We specify our base configuration in docker-compose.yml file. For any environment specific customization we use docker-compose.override.yml file. We can specify a service in both the files. Docker compose will merge

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What are the most common instructions in Dockerfile?

Some of the common instructions in Dockerfile are as follows: FROM: We use FROM to set the base image for subsequent instructions. In every valid Dockerfile, FROM is the first instruction. LABEL: We use LABEL to organize our images as

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What is the purpose of EXPOSE command in Dockerfile?

We use EXPOSE command to inform Docker that Container will listen on a specific network port during runtime. But these ports on Container may not be accessible to the host. We can use –p to publish a range of ports

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What are the different kinds of namespaces available in a Container?

In a Container we have an isolated environment with namespace for each resource that a kernel provides. There are mainly six types of namespaces in a Container. UTS Namespace: UTS stands for Unix Timesharing System. In UTS namespace every container

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What is ONBUILD command in Docker?

We use ONBUILD command in Docker to run the instructions that have to execute after the completion of current Dockerfile build. It is used to build a hierarchy of images that have to be build after the parent image is

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