How to GET list of tags using registry-alias & repository for Public ECR?

Question

I am attempting a REST API call to GET list of image & its tags by providing registry-alias & repository-name as path parameters, for public registry of ECR. I tried below endpoint and I am unsuccessful to get response. I am also unable to get any information related to whether I am doing this right from  AWS API reference or other online articles. Any guidance related to getting this working is greatly appreciated.

**My expectation:- **As developer, I should be able GET list of images and tags over REST API, even when I am not authenticated with AWS account.

It will be nice to have more documentation; like for example, what are the endpoints that are supported for public ECR, similar to [DockerHub](https://docs.docker.com/docker-hub/api/latest/#operation/GetNamespacesRepositoriesImages) and [Microsoft](https://github.com/microsoft/ContainerRegistry#browsing-mcr-content).

**REST API that I tried:-**

`GET https://public.ecr.aws/:registry-alias/:repository-name/tags/list`

`GET https://public.ecr.aws/v2/:registry-alias/:repository-name/tags/list`

**Response I received:-**

`{
    "errors": [
        {
            "code": "DENIED",
            "message": "Not Authorized"
        }
    ]
}`

**Reference I went through:-**

https://aws.amazon.com/blogs/aws/amazon-ecr-public-a-new-public-container-registry/

https://gallery.ecr.aws

https://docs.aws.amazon.com/AmazonECR/latest/public/public-registries.html

https://docs.aws.amazon.com/AmazonECRPublic/latest/APIReference/Welcome.html

Answer

I think your question was well described.
As a developer I want to be able to get this info *the standard way* using curl against the API, without the need of calling an operating system command that needs to be properly installed and setup.
I still would like an answer to that :)

Answer

Hi,

to get a list of the available tags of a given repository within a given registry, you can do a POST request to this URL: https://api.us-east-1.gallery.ecr.aws/describeImageTags with the following body:

```
{
  "registryAliasName": "my-registry",
  "repositoryName": "my-repository"
}
```

To get a list of the available repositories within a registry, you can do a POST request to https://api.us-east-1.gallery.ecr.aws/describeRepositoryCatalogData with the following body:

```
{
  "registryAliasName": "my-registry"
}
```

I found these URLs by analyzing the requests that my browser sent when I visited https://gallery.ecr.aws/cloudwatch-agent?page=1 and https://gallery.ecr.aws/cloudwatch-agent/cloudwatch-agent.

Answer

Hi!  You can use the ecr public Describe Images API command:  https://docs.aws.amazon.com/cli/latest/reference/ecr-public/describe-images.html which will go to the ecr-public and api.ecr-public endpoints.

How to GET list of tags using registry-alias & repository for Public ECR?

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