#DOCKER RUN IMAGE EXAMPLE HOW TO#
#DOCKER RUN IMAGE EXAMPLE INSTALL#

If your application does not have any state (and most web applications work like this) then you donвЂ™t need to use volumes. Volumes should be managed with docker-compose or вЂњdocker runвЂќ commands. It is specially relevant to mention is that defining Volumes in a Dockerfile can lead to issues. New Volumes get populated with the pre-existing contents of the specified location in the image.

VOLUME вЂ“ Creates a mount point within the Container linking it back to file systems accessible by the Docker Host.

USER вЂ“ Define the default User all commands will be run as within any Container created from your Image.

#DOCKER RUN IMAGE EXAMPLE INSTALL#

RUN apt-get update & apt-get upgrade -y & apt-get install -y nginx & rm -rf /var/lib/apt/lists/*.

This is one of the most important dockerfile directives. These are the commands you would run at the command line to install and configure your application. This includes updating packages, installing software, adding users, creating an initial database, setting up certificates, etc.

LABEL RUN вЂ“ Specify commands to make changes to your Image and subsequently the Containers started from this Image.

This is just a label (it used to be a dedicated Docker directive).

LABEL maintainer вЂ“ Optional field to let you identify yourself as the maintainer of this image.

FROM вЂ“ Select the base image to build the new image on top of.

EXPOSE вЂ“ Define which Container ports to expose.

ENV вЂ“ Set/modify the environment variables within Containers created from the Image.

If used in conjunction with CMD, you can remove the application and just define the arguments there

ENTRYPOINT вЂ“ Sets the default application used every time a Container is created from the Image.

CMD вЂ“ This is the command that will run when the Container starts.

local/config.file /etc/service/config.file

ADD вЂ“ Defines files to copy from the Host file system onto the Container.

# Last is the actual command to start up NGINX within our Container LABEL Update the image to the latest packages # The line below states we will base our new image on the Latest Official Ubuntu # Lines preceeded by # are regarded as comments and ignored # Each instruction in this file generates a new layer that gets pushed to your local image cache

Dockerfile is the default name but you can use any filename that you want (and even have multiple dockerfiles in the same folder) Simple Dockerfile for NGINX # The name of the fileДoes not really matter. The docker build command processes this file generating a Docker Image in your Local Image Cache, which you can then start-up using the docker run command, or push to a permanent Image Repository.Д¬reating a Dockerfile is as easy as creating a new file named вЂњDockerfileвЂќ with your text editor of choice and defining some instructions.It describes step-by-step instructions of all the commands you need to run to assemble a Docker Image.A Dockerfile is a text configuration file written using a special syntax.

#DOCKER RUN IMAGE EXAMPLE HOW TO#

What it is, how to create one, and how to configure the basics to bring up your own Dockerized app. In this guide weвЂ™ll learn about the Dockerfile.

Docker run image example