Updated on September 20, 2022 in #dev-environment, #docker, #linux

Using Docker's v2 API to Get a List of Tags with the Help of jq

Docker deprecated their v1 API in September 2022, now we can get a lot more details about each tag using the v2 API.

In the past I’ve made a video about setting up a shell alias to easily list all available tags for a specific Docker image. That post is here. I’ve updated it for v2 but the video no longer matches the alias since the video was made years ago using the v1 API.

Here’d a revised video that uses v2 and goes over the basics of using jq too.

# Demo Video

Timestamps

• 0:15 – Docker turned off their Docker Hub API v1 endpoint in September 2022
• 0:53 – Parsing the v2 API with this new alias using the jq tool
• 1:33 – Checking out the dtags alias real quick
• 4:22 – curling the API manually
• 5:00 – Using jq to parse the JSON response
• 6:41 – Sorting the results in a reasonable way
• 8:00 – Checking out Docker’s API documentation
• 9:08 – Docker’s documented max per page limit might be wrong

Code snippets

dtags () {
    local image="${1}"

    curl --silent \
        "https://registry.hub.docker.com/v2/repositories/library/${image}/tags?page_size=1000" \
        | jq -r ".results[].name" | sort --version-sort
}

Reference Links

• https://www.docker.com/blog/docker-hub-v1-api-deprecation/
• https://stedolan.github.io/jq/download/
• https://github.com/nickjj/dotfiles
• The alias in my dotfiles
• https://docs.docker.com/docker-hub/api/latest/#tag/repositories
• https://www.docker.com/captains/nick-janetakis/

What other Docker API endpoints do you use regularly?