LimitRange prevent deleting ImageTag if the number of the ImageTag after deletion is still above the configured maximum limit.

4.14

Always

$ oc new-project test
$ oc new-app http://github.com/nekop/hello-sinatra
$ oc patch bc/hello-sinatra -p '{"spec": {"output": {"to": {"name": "hello-sinatra:v1"}}}}'
$ oc start-build hello-sinatra
$ oc patch bc/hello-sinatra -p '{"spec": {"output": {"to": {"name": "hello-sinatra:v2"}}}}'
$ oc start-build hello-sinatra
$ oc patch bc/hello-sinatra -p '{"spec": {"output": {"to": {"name": "hello-sinatra:v3"}}}}'
$ oc start-build hello-sinatra
$ oc patch bc/hello-sinatra -p '{"spec": {"output": {"to": {"name": "hello-sinatra:v4"}}}}'
$ oc start-build hello-sinatra
$ oc get is
NAME            IMAGE REPOSITORY                                                      TAGS                 UPDATED
hello-sinatra   image-registry.openshift-image-registry.svc:5000/test/hello-sinatra   v4,v3,v2,v1,latest   22 seconds ago
$ oc get istag
NAME                   IMAGE REFERENCE                                                                                                                               UPDATED
hello-sinatra:v1       image-registry.openshift-image-registry.svc:5000/test/hello-sinatra@sha256:1c37bea2b248365fd01eadaa3ef7cb7cd5ae8e91b18d01163be50e17206d6dae   3 minutes ago
hello-sinatra:v2       image-registry.openshift-image-registry.svc:5000/test/hello-sinatra@sha256:81c4313c8b9417177834b6f3dd292c56d321b8d834bde90a8103396caa4fcc31   2 minutes ago
hello-sinatra:v3       image-registry.openshift-image-registry.svc:5000/test/hello-sinatra@sha256:84b5a94f95e52e5826a4916dce866bc5e86fb55d4783748014560de8255e7bc4   2 minutes ago
hello-sinatra:v4       image-registry.openshift-image-registry.svc:5000/test/hello-sinatra@sha256:ef72970bb6be4bad75399ff72b744fa9dd8dd86bb0f4be597c83e90f4a03cee1   About a minute ago
hello-sinatra:latest   image-registry.openshift-image-registry.svc:5000/test/hello-sinatra@sha256:1ac1ef3da31c6acf99422b26d89ef81b387675d637f47eeb37d62517e829f39f   12 minutes ago
$ oc get imagetag
NAME                   SPEC   STATUS                                                                          HISTORY   UPDATED
hello-sinatra:latest   Push   image/sha256:1ac1ef3da31c6acf99422b26d89ef81b387675d637f47eeb37d62517e829f39f   1         12 minutes ago
hello-sinatra:v1       Push   image/sha256:1c37bea2b248365fd01eadaa3ef7cb7cd5ae8e91b18d01163be50e17206d6dae   1         3 minutes ago
hello-sinatra:v2       Push   image/sha256:81c4313c8b9417177834b6f3dd292c56d321b8d834bde90a8103396caa4fcc31   1         3 minutes ago
hello-sinatra:v3       Push   image/sha256:84b5a94f95e52e5826a4916dce866bc5e86fb55d4783748014560de8255e7bc4   1         2 minutes ago
hello-sinatra:v4       Push   image/sha256:ef72970bb6be4bad75399ff72b744fa9dd8dd86bb0f4be597c83e90f4a03cee1   1         About a minute ago
$ cat limitrange.yaml
apiVersion: "v1"
kind: "LimitRange"
metadata:
  name: "resource-limits"
spec:
  limits:
    - type: openshift.io/ImageStream
      max:
        openshift.io/images: 3
$ oc create -f limitrange.yaml
limitrange/resource-limits created
$ oc tag -d hello-sinatra:v4
The ImageStream "hello-sinatra" is invalid: []: Internal error: ImageStream.image.openshift.io "hello-sinatra" is forbidden: requested usage of openshift.io/images exceeds the maximum limit per openshift.io/ImageStream (4 > 3)
$ oc delete imagetag hello-sinatra:v4
The ImageStream "hello-sinatra" is invalid: []: Internal error: ImageStream.image.openshift.io "hello-sinatra" is forbidden: requested usage of openshift.io/images exceeds the maximum limit per openshift.io/ImageStream (4 > 3)
$ oc delete istag hello-sinatra:v4
The ImageStream "hello-sinatra" is invalid: []: Internal error: ImageStream.image.openshift.io "hello-sinatra" is forbidden: requested usage of openshift.io/images exceeds the maximum limit per openshift.io/ImageStream (4 > 3) 

The ImageTag cannot be deleted.

The ImageTag can be deleted.