Reputation: 3775

Docker error: invalid reference format: repository name must be lowercase

Ran into this Docker error with one of my projects:

invalid reference format: repository name must be lowercase

What are the various causes for this generic message?

I already figured it out after some effort, so I'm going to answer my own question in order to document it here as the solution doesn't come up right away when doing a web search and also because this error message doesn't describe the direct problem Docker encounters.

Upvotes: 229

Answers (30)

Brian Wright

Reputation: 193

If you are using an automatically generated CI/CD variable with uppercase characters—such as ${CI_PROJECT_PATH} in Gitlab—for a tag, it's possible there is another similar predefined variable for this purpose. In this specific case, switch the variable to ${CI_PROJECT_PATH_SLUG} to ~~resolve the error~~ get a new error. (Namely, the slash between your user/group name and repository name gets replaced with a dash, so registry access is denied.)

Unless someone cracks this nut, define the registry URL manually and use that for each tag argument.

Upvotes: 0

Abhishek Ghosh

Reputation: 193

This error can also appear if you are running a docker run command in a gitlab pipeline which wraps over multiple lines in the pipeline editor. The error is caused when there is a space in one of the parameter names. To find it out, copy over the command to an editor with word wrap switched off, find the offending space and then go back to the same location in the gitlab pipeline editor and keep hitting backspace until the entire parameter name appears together in the same line.

Upvotes: 0

Mauricio Gracia Gutierrez

Reputation: 10844

If you are using docker-compose and you get that error, check the name of your services, no upper case letters allowed

Upvotes: 0

jfl

Reputation: 41

Similar to other answers, there was a syntax error in my run command. I typed a space instead of an underscore in an environment variable, ENABLE SASLAUTHD vs ENABLE_SASLAUTHD.
Adding the underscore _ fixed the issue.

Upvotes: 0

madhead

Reputation: 33374

If you come here after encountering this error in your GitHub Actions worflows…

Make sure to use docker/metadata-action action to handle repository naming for you. Just call it before docker/build-push-action:

# Add this
- id: docker-metadata
  uses: docker/metadata-action@v4
  with:
    images: ghcr.io/${{ github.repository }}

# Use the extracted metadata
- uses: docker/build-push-action@v3
  with:
    tags: ${{ steps.docker-metadata.outputs.tags }}
    labels: ${{ steps.docker-metadata.outputs.labels }}
    … other properties …

Upvotes: 2

Kristian Marlowe Ole

Reputation: 39

If you encounter this problem in go-swagger (Windows).

@echo off
echo.
docker run --rm -it --env GOPATH=/go -v %CD%:/go/src -w /go/src quay.io/goswagger/swagger %*

Use this instead: (add quote)

@echo off
echo.
docker run --rm -it --env GOPATH=/go -v "%CD%:/go/src" -w /go/src quay.io/goswagger/swagger %*

Upvotes: 3

Garvit

Reputation: 400

I've encountered the same issue while using docker with mlflow.

In my case, the directory name containing my Dockerfile was "My Project" which I changed to myproject or my_project and It worked for me.
Also, follow the same naming format for all the root/super directories under which, the Dockerfile resides.

Not only for docker, but it's also good practice (especially in Unix based OS) to avoid the following while defining a directory name:-

white spaces
camel-case
upper-case

Upvotes: 3

m_i_rite

Reputation: 38

Another possible cause of this error is that in your Dockerfile you have mixed capitalization in the syntax declaration itself. For example: # syntax=docker/Dockerfile:1 instead of # syntax=docker/dockerfile:1

Upvotes: 0

Mackarevic

Reputation: 1

You need to enter the Name of the Docker-Image and not your File Name :P

$ docker run {your image}

Upvotes: 0

BMitch

Reputation: 263469

A "reference" in docker is a pointer to an image. It may be an image name, an image ID, include a registry server in the name, use a sha256 tag to pin the image, and anything else that can be used to point to the image you want to run.

The invalid reference format error message means docker cannot convert the string you've provided to an image. This may be an invalid name, or it may be from a parsing error earlier in the docker run command line if that's how you run the image.

If the name itself is invalid, the repository name must be lowercase means you use upper case characters in your registry or repository name, e.g. YourImageName:latest should be yourimagename:latest.

With the docker run command line, this is often the result in not quoting parameters with spaces, missing the value for an argument, and mistaking the order of the command line. The command line is ordered as:

docker ${args_to_docker} run ${args_to_run} image_ref ${cmd_to_exec}

The most common error in passing args to the run is a volume mapping expanding a path name that includes a space in it, and not quoting the path or escaping the space. E.g.

docker run -v $(pwd):/data image_ref

Where if you're in the directory /home/user/Some Project Dir, that would define an anonymous volume /home/user/Some in your container, and try to run Project:latest with the command Dir:/data image_ref. And the fix is to quote the argument:

docker run -v "$(pwd):/data" image_ref

Other common places to miss quoting include environment variables:

docker run -e SOME_VAR=Value With Spaces image_ref

which docker would interpret as trying to run the image With:latest and the command Spaces image_ref. Again, the fix is to quote the environment parameter:

docker run -e "SOME_VAR=Value With Spaces" image_ref

With a compose file, if you expand a variable in the image name, that variable may not be expanding correctly. So if you have:

version: 2
services:
  app:
    image: ${your_image_name}

Then double check that your_image_name is defined to an all lower case string.

Upvotes: 245

Fernando Zuniga

Reputation: 11

I solve this changing some uppercase words on my Dockerfile like:

FROM Base as Build
RUN npm run Build:prod

FROM base as build
RUN npm run build:prod

Another place:

FROM Base as Release
COPY --from=Build /usr/path/here/dist/ ./dist

FROM base as Release
COPY --from=build /usr/path/here/dist/ ./dist

Upvotes: 1

MikeSchinkel

Reputation: 5036

In my case I had a naked --env switch, i.e. one without an actual variable name or value, e.g.:

docker run \
   --env \       <----- This was the offending item
   --rm \
   --volume "/home/shared:/shared" "$(docker build . -q)"

Upvotes: 2

Kumar Sambhav Pandey

Reputation: 1743

In my case DockerFile contained the image name in mixed case instead of lower case.

Earlier line in my DockerFile

FROM CentOs

and when I changed above to FROM centos, it worked smoothly.

Upvotes: 0

Keet Sugathadasa

Reputation: 13502

A reference in Docker is what points to an image. This could be in a remote registry or the local registry. Let me describe the error message first and then show the solutions for this.

invalid reference format

This means that the reference we have used is not a valid format. This means, the reference (pointer) we have used to identify an image is invalid. Generally, this is followed by a description as follows. This will make the error much clearer.

invalid reference format: repository name must be lowercase

This means the reference we are using should not have uppercase letters. Try running docker run Ubuntu (wrong) vs docker run ubuntu (correct). Docker does not allow any uppercase characters as an image reference. Simple troubleshooting steps.

1) Dockerfile contains a capital letters as images.

FROM Ubuntu (wrong)
FROM ubuntu (correct)

2) Image name defined in the docker-compose.yml had uppercase letters

3) If you are using Jenkins or GoCD for deploying your docker container, please check the run command, whether the image name includes a capital letter.

Please read this document written specifically for this error.

Upvotes: 4

Jöcker

Reputation: 6718

In my case was the -e before the parameters for mysql docker

docker run --name mysql-standalone -e MYSQL_ROOT_PASSWORD=hello -e MYSQL_DATABASE=hello -e MYSQL_USER=hello -e MYSQL_PASSWORD=hello -d mysql:5.6

Check also if there are missing whitespaces

Upvotes: 67

shadrack Mwangi

Reputation: 803

Most of the answers above did not work for my case, so I will document this in case somebody finds it helpful. The first line in the dockerfile FROM node:10 for my case, the word node should not be uppercase i.e FROM NODE:10. I made that change and it worked.

Upvotes: 0

jamshid

Reputation: 1775

I wish the error message would output the problem string. I was getting this due to a weird copy and paste problem of a "docker run" command. A space-like character was being used before the repo and image name.

Upvotes: 0

gaurav arora

Reputation: 315

sometimes you miss -e flag while specific multiple env vars inline

e.g. bad: docker run --name somecontainername -e ENV_VAR1=somevalue1 ENV_VAR2=somevalue2 -d -v "mypath:containerpath" <imagename e.g. postgres>

good: docker run --name somecontainername -e ENV_VAR1=somevalue1 -e ENV_VAR2=somevalue2 -d -v "mypath:containerpath" <imagename e.g. postgres>

Upvotes: 3

Mohammed Siddiq

Reputation: 558

In my case I was trying to run postgres through docker. Initially I was running as :

docker run -d -p 5432:5432 -e POSTGRES_PASSWORD=test_password POSTGRES_USER=test_user POSTGRES_DB=test_db --rm -v ~/docker/volumes/postgres:/var/lib/postgresql/data --name pg-docker postgres

I was missing -e after each environment variable. Changing the above command to the one below worked

docker run -d -p 5432:5432 -e POSTGRES_PASSWORD=test_password -e POSTGRES_USER=test_user -e POSTGRES_DB=test_db --rm -v ~/docker/volumes/postgres:/var/lib/postgresql/data --name pg-docker postgres

Upvotes: 0

HizikNewton

Reputation: 1

Docker can build images automatically by reading the instructions from a Dockerfile. A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image. example: FROM python:3.7-alpine The 'python' should be in lowercase

Upvotes: 0

Karthik Wodeyar

Reputation: 1

"docker build -f Dockerfile -t SpringBoot-Docker ." As in the above commend, we are creating an image file for docker container. commend says create image use file(-f refer to docker file) and -t for the target of the image file we are going to push to docker. the "." represents the current directory

solution for the above problem: provide target image name in lowercase

Upvotes: 0

user279838

Reputation: 71

On MacOS when your are working on an iCloud drive, your $PWD will contain a directory "Mobile Documents". It does not seem to like the space!

As a workaround, I copied my project to local drive where there is no space in the path to my project folder.

I do not see a way you can get around changnig the default path to iCloud which is ~/Library/Mobile Documents/com~apple~CloudDocs

The space in the path in "Mobile Documents" seems to be what docker run does not like.

Upvotes: 7

Oliver

Reputation: 1269

Let me emphasise that Docker doesn't even allow mixed characters.

Good: docker build -t myfirstechoimage:0.1 .

Bad: docker build -t myFirstEchoImage:0.1 .

Upvotes: 49

Otheus

Reputation: 1032

Indeed, the docker registry as of today (sha 2e2f252f3c88679f1207d87d57c07af6819a1a17e22573bcef32804122d2f305) does not handle paths containing upper-case characters. This is obviously a poor design choice, probably due to wanting to maintain compatible with certain operating systems that do not distinguish case at the file level (ie, windows).

If one authenticates for a scope and tries to fetch a non-existing repository with all lowercase, the output is

(auth step not shown)
curl -s -H "Authorization: Bearer $TOKEN" -X GET https://$LOCALREGISTRY/v2/test/someproject/tags/list
{"errors":[{"code":"UNAUTHORIZED","message":"authentication required","detail":[{"Type":"repository","Class":"","Name":"test/someproject","Action":"pull"}]}]}

However, if one tries to do this with an uppercase component, only 404 is returned:

(authorization step done but not shown here)
$ curl -s -H "Authorization: Bearer $TOKEN" -X GET https://docker.uibk.ac.at:443/v2/test/Someproject/tags/list

404 page not found

Upvotes: 1

Ritwik

Reputation: 1725

This is happening because of the spaces in the current working directory that came from $(pwd) for map volumes. So, I used docker-compose instead.

The docker-compose.yml file.

version: '3'
services:
  react-app:
    build:
      context: .
      dockerfile: Dockerfile.dev
    ports:
      - "3000:3000"
    volumes:
      - /app/node_modules
      - .:/app

Upvotes: 0

Vipul Malgotra

Reputation: 61

For me the issue was with the space in volume mapping that was not escaped. The jenkins job which was running the docker run command had a space in it and as a result docker engine was not able to understand the docker run command.

Upvotes: 1

Colin Claverie

Reputation: 819

had a space in the current working directory and usign $(pwd) to map volumes. Doesn't like spaces in directory names.

Upvotes: 30

kenneho

Reputation: 711

I had the same error, and for some reason it appears to have been cause by uppercase letters in the Jenkins job that ran the docker run command.

Upvotes: 0

nandithakw

Reputation: 1029

Replacing image: ${DOCKER_REGISTRY}notificationsapi with image:notificationsapi or image: ${docker_registry}notificationsapi in docker-compose.yml did solves the issue

file with error

  version: '3.4'

services:
  notifications.api:
    image: ${DOCKER_REGISTRY}notificationsapi
    build:
      context: .
      dockerfile: ../Notifications.Api/Dockerfile

file without error

version: '3.4'

services:
 notifications.api:
    image: ${docker_registry}notificationsapi
    build:
      context: .
      dockerfile: ../Notifications.Api/Dockerfile

So i think error was due to non lower case letters it had

Upvotes: 2

josip.k

Reputation: 171

In my case the problem was in parameters arrangement. Initially I had --name parameter after environment parameters and then volume and attach_dbs parameters, and image at the end of command like below.

docker run -p 1433:1433 -e sa_password=myComplexPwd -e ACCEPT_EULA=Y --name sql1 -v c:/temp/:c:/temp/ attach_dbs="[{'dbName':'TestDb','dbFiles':['c:\\temp\\TestDb.mdf','c:\\temp\\TestDb_log.ldf']}]" -d microsoft/mssql-server-windows-express

After rearranging the parameters like below everything worked fine (basically putting --name parameter followed by image name).

docker run -d -p 1433:1433 -e sa_password=myComplexPwd -e ACCEPT_EULA=Y --name sql1 microsoft/mssql-server-windows-express -v C:/temp/:C:/temp/ attach_dbs="[{'dbName':'TestDb','dbFiles':['C:\\temp\\TestDb.mdf','C:\\temp\\TestDb_log.ldf']}]"

Upvotes: 11

Docker error: invalid reference format: repository name must be lowercase

Answers (30)

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