Docker build with custom path and custom filename not working

user_11631999 0
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I am using Docker version 19.03.2 in Windows 10.

I have a directory C:\docker_test with files Dockerfile and Dockerfile_test. When I execute

PS C:\> docker build 'C:\docker_test'

in PowerShell, the image is built from Dockerfile, just as expected. However, when I want to build an image from Dockerfile_test like this

PS C:\> docker build -f Dockerfile_test 'C:\docker_test'

I get

unable to prepare context: unable to evaluate symlinks in Dockerfile path:
CreateFile C:\Dockerfile_test: The system cannot find the file specified.

I don't understand why Docker is looking for C:\Dockerfile_test although I specified a build path.

docker-build docker-desktop docker
2 Answers

You should state the path (the context) of your Dockerfile, like so

PS C:\> docker build -f 'C:\docker_test\Dockerfile_test' 'C:\docker_test'
user_16552450

There is already an answer to the question but this is to detail a bit

From the docs

The docker build command builds an image from a Dockerfile and a context. The build’s context is the set of files at a specified location PATH or URL

With C:\docker_test you speficied the context.

From the same docs

Traditionally, the Dockerfile is called Dockerfile and located in the root of the context. You use the -f flag with docker build to point to a Dockerfile anywhere in your file system.

Therefore if you specify the -f flag docker will search for the given file. In your case you have a file without path therefore docker will search in the current directory.

To make it work use the command as suggested by @Arik

user_84824790
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