How to find all image tags of a running Docker container?

Question

I have a bunch of Docker containers running on a server and I used the \"latest\" tag or no tag at all for all of them. Now I want to freeze the image versions, but I have no id

Answer 1

I think this is a better approach without inspecting the container, as docker ps already printing the docker image tag form which the container is created.

docker inspect $(docker ps  | awk '{print $2}' | grep -v ID) | jq .[].RepoTags

So first this gets the list of running containers, then inspect each image being used by running container and using jq get all repo tags of that image.

Here is the output.

Updated:

Here is you go using skopeo , you can do using API but will do the effort, so why if you have skopeo

You do not need to install skopeo you can run the container and then or remove once get the result, or you can install, script support both

running_container=$(docker ps  | awk '{print $2}' | grep -v ID) 
echo "running container: $running_container"
for image in $running_container
do
local_tag=$(echo "$image" | awk -F":" '{print $2}')
if [ -z $local_tag ]; then
# if tag is empty then tag is latest
local_tag="latest"
image="$image":"$local_tag"
fi
local_digest=$(docker inspect $image | jq '.[].RepoDigests[]' | awk -F"@" '{print $2}' | tr -d '"')
echo "Local digest is:" $local_digest
remote_digest=$(docker run --rm --env image=$image alexeiled/skopeo:latest ash -c "skopeo inspect docker://docker.io/$image" | jq '.Digest' | tr -d '"' )
echo $remote_digest 

# option2 install the skopeo on your local system
# remote_digest=$(skopeo inspect docker://docker.io/$image | jq '.Digest' | tr -d '"')
echo "Remote digest is : "$remote_digest

if [ "${local_digest}" == "${remote_digest}" ]; then
echo "local image is up to date with remote"
else
echo "Remote image is updated; please run docker pull $image"
fi
done