- What is Docker Run command?
- What is the difference between run and CMD in Docker?
- How do I run Docker locally?
- What is the command to stop a container?
- How do I pass an environment variable in Docker run?
- How do I set an environment variable in Docker?
- What is environment variable in Kubernetes?
- When would you use a ConfigMap?
- How does ConfigMap work in Kubernetes?
What is Docker Run command?
The docker run command creates a container from a given image and starts the container using a given command.
It is one of the first commands you should become familiar with when starting to work with Docker..
What is the difference between run and CMD in Docker?
RUN executes command(s) in a new layer and creates a new image. E.g., it is often used for installing software packages. CMD sets default command and/or parameters, which can be overwritten from command line when docker container runs. ENTRYPOINT configures a container that will run as an executable.
How do I run Docker locally?
docker commandsbuild docker image. docker build -t image-name .run docker image. docker run -p 80:80 -it image-name.stop all docker containers. docker stop $(docker ps -a -q)remove all docker containers. docker rm $(docker ps -a -q)remove all docker images. … port bindings of a specific container. … build. … run.More items…•
What is the command to stop a container?
To stop a container you use the docker stop command and pass the name of the container and the number of seconds before a container is killed. The default number of seconds the command will wait before the killing is 10 seconds.
How do I pass an environment variable in Docker run?
You can pass the values of environment variables from the host to your containers without much effort. Simply don’t specify a value in the command line, and make sure that the environment variable is named the same as the variable the containerized app expects: $ docker run -e var_name (…)
How do I set an environment variable in Docker?
Using docker-compose , you can inherit env variables in docker-compose. yml and subsequently any Dockerfile(s) called by docker-compose to build images. This is useful when the Dockerfile RUN command should execute commands specific to the environment. Use -e or –env value to set environment variables (default ).
What is environment variable in Kubernetes?
Environment variables provide a way to specify parameters for deployed services that vary from environment to environment. Kubernetes allows users to provide environment variables when defining Pods. A Pod definition generally looks like so: apiVersion: v1. kind: Pod.
When would you use a ConfigMap?
Use a ConfigMap to keep your application code separate from your configuration. It is an important part of creating a Twelve-Factor Application. This lets you change easily configuration depending on the environment (development, production, testing) and to dynamically change configuration at runtime.
How does ConfigMap work in Kubernetes?
A ConfigMap is an API object that lets you store configuration for other objects to use. Unlike most Kubernetes objects that have a spec , a ConfigMap has data and binaryData fields. These fields accepts key-value pairs as their values. Both the data field and the binaryData are optional.