Some docker image tag as none

I build a docker image and push it to my custom registry with a relevant tag. But when I pull it from my registry it is shown below. Some images pulled from the official docker registry. Can anyone explain why the image tag is shown as ?

[root@host ~]# docker images
REPOSITORY                                      TAG                   IMAGE ID            CREATED             SIZE
my_registry_com/reposity_name/video-chat-app   <none>                a1dbe7adbec5        36 hours ago        179MB
my_registry_com/reposity_name/video-chat-app   <none>                227e89445050        3 days ago          179MB
my_registry_com/reposity_name/video-chat-app   <none>                61e974a9826a        3 days ago          179MB
my_registry_com/reposity_name/video-chat-app   <none>                31cff9189699        3 days ago          179MB
my_registry_com/reposity_name/video-chat-app   <none>                e162884209fd        3 days ago          179MB
my_registry_com/reposity_name/video-chat-app   <none>                a37971687a89        4 days ago          179MB
my_registry_com/reposity_name/video-chat-app   <none>                fb9a11b5a40f        4 days ago          179MB
my_registry_com/reposity_name/video-chat-app   <none>                0746e28687e5        4 days ago          179MB
my_registry_com/reposity_name/video-chat-app   <none>                8c021e37ffd7        10 days ago         179MB
my_registry_com/reposity_name/video-chat-app   <none>                f0be13d079af        2 weeks ago         179MB
my_registry_com/reposity_name/video-chat-app   <none>                274d8eae34c0        3 weeks ago         179MB
my_registry_com/reposity_name/video-chat-app   <none>                afdd961b2197        3 weeks ago         179MB
my_registry_com/reposity_name/video-chat-app   <none>                03b7fcb66d47        3 weeks ago         179MB
my_registry_com/reposity_name/video-chat-app   <none>                8a9ccad05594        3 weeks ago         179MB
my_registry_com/reposity_name/video-chat-app   <none>                77c4841c3086        3 weeks ago         179MB
my_registry_com/reposity_name/video-chat-app   <none>                d6bbf1b09f42        3 weeks ago         179MB
mysql                                          <none>                afa411733b0c        5 weeks ago         302MB
mariadb                                        <none>                b6184b68d1fd        5 weeks ago         357MB
mariadb                                        10.5.2                fd055a110f74        5 weeks ago         360MB
kelum_app                                      latest                57296b7b5a4f        5 weeks ago         137MB
kelum_ssl                                      latest                cbcbc204c4d6        5 weeks ago         21.7MB
nginx                                          1.17.9-alpine         377c0837328f        2 months ago        19.7MB
openjdk                                        8u212-jre-alpine3.9   f7a292bbb70c        12 months ago       84.9MB
[root@host ~]# 

Thanks

As for your “video-chat-app” it seems you haven’t set a tag. And even if you would have, when you run a “new container” with the same tag, the old will get renamed to “none” while the new one will take its name.

When we deploying applications with docker stack it did not update the tag name in docker images list

Instead of pulling an image by its tag, swarm “resolves” the tag and uses the unique sha256 hash of the image at that point in time to pull the image. This guaranties that the exact same image is consistently used if the service has more than one replica. This is still true for a service with a single replica, as you could scale up any moment.

Now imagine your service starts with a single replica and you decide to scale up a month later, but meanwhile the tag points to a different image. If the tags would be used, you would end up having replicas created from different images.

An image tag is “just a handle” that represents the unique sha256 of the image it points to at the point in time. The images in your list with tags are high likely pulled via plain docker or docker-compose.