Invalid reference format: repository name must be lowercase in Docker

Dung Do Tien Jun 08 2022 439

Hello you guys. I'm deploying an Asp.Net on Docker Ubuntu 20.04. After pulling the source code from GitHub I try to create a docker image by using the command below:

docker build -f app:latest -t QDM.CMS/QDM.App /Dockerfile .

But I see an error like this: invalid argument for "-t, --tag" flag: invalid reference format: repository name must be lowercase.

root@faqsdev:~/FAQsDev/QDM.CMS# cd ..
root@faqsdev:~/FAQsDev# docker build -f app:latest -t QDM.CMS/QDM.App /Dockerfile .
invalid argument "QDM.CMS/QDM.App" for "-t, --tag" flag: invalid reference format: repository name must be lowercase

I feel the syntax is wrong but I don't know how to change it. This syntax already worked for me on other servers.

I am using Docker version 20.10.17, build 100c701

Please help me if you have any idea about this issue.

I really appreciate any help you can provide.

Have 1 answer(s) found.
  • E

    Erdi Dede Jun 08 2022

    Yes, Sure you are the wrong syntax, with Docker version 20, you can use the command below to help create a docker image:

     docker build -t [image_name] . -f [path_to_docker_file]/Dockerfile

    For example:

    docker build -t app:latest . -f QDM.App/Dockerfile

    It's already worked for me. Hope it is helpful for you.

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