OpenShift Image Streams (is)

An OpenShift image stream is made up of any number of container images identified by tags.  It presents a single virtual view of the the images.  Using image streams prevents your application from breaking if the upstream image’s update introduced errors.  Image change triggers and periodic imports can be configured at the image stream’s level.  Image streams are pointers to images in other repositories.
Log into the project to get the list of image streams
$ oc login -u <user>
$ oc get is
if you switch to the openshift project and get the list of image streams you will see all the default image streams that are installed.
oc get is
NAME         DOCKER REPO                            TAGS                          UPDATED
dotnet       172.30.1.1:5000/openshift/dotnet       2.0,latest                    2 months ago
httpd        172.30.1.1:5000/openshift/httpd        2.4,latest                    2 months ago
jenkins      172.30.1.1:5000/openshift/jenkins      1,2,latest                    2 months ago
mariadb      172.30.1.1:5000/openshift/mariadb      10.1,10.2,latest              2 months ago
mongodb      172.30.1.1:5000/openshift/mongodb      2.4,2.6,3.2 + 3 more...       2 months ago
Image stream mongodb pings to 172.30.1.1:5000/openshift/mongodb
Use describe to get the list of tags
$oc describe is/python
Name:            python
Namespace:        openshift
Created:        2 months ago
Labels:            <none>
Annotations:        kubectl.kubernetes.io/last-applied-configuration={"apiVers........
            openshift.io/display-name=Python
            openshift.io/image.dockerRepositoryCheck=2019-05-04T19:07:33Z
Docker Pull Spec:    172.30.1.1:5000/openshift/python
Image Lookup:        local=false
Unique Images:        5
Tags:            6
3.6 (latest)
  tagged from docker.io/centos/python-36-centos7:latest
    prefer registry pullthrough when referencing this tag
  Build and run Python 3.6 applications on CentOS 7. For more information about using this builder image, including OpenShift considerations, see https://github.com/sclorg/s2i-python-container/blob/master/3.6/README.md.
  Tags: builder, python
  Supports: python:3.6, python
  Example Repo: https://github.com/openshift/django-ex.git

  * docker.io/centos/python-36-centos7@sha256:d10c46b6db436357965a96716e9f5d230d9b1a58c6db1f0c4f43c1fb1994cd79
      2 months ago
3.5
  tagged from docker.io/centos/python-35-centos7:latest
    prefer registry pullthrough when referencing this tag
  Build and run Python 3.5 applications on CentOS 7. For more information about using this builder image, including OpenShift considerations, see https://github.com/sclorg/s2i-python-container/blob/master/3.5/README.md.
  Tags: builder, python
  Supports: python:3.5, python
  Example Repo: https://github.com/openshift/django-ex.git
  * docker.io/centos/python-35-centos7@sha256:d2018907a8ffa94644fccc8e3821a0945c600a16337c11c1a761e86159d69870
      2 months ago
Image stream python:3.6 points to docker.io/centos/python-36-centos7:latest
Image stream python:3.5 points to docker.io/centos/python-35-centos7:latest
Image Streams can be created by importing images from externa registries to the internal registries
$ oc import-image django --confirm
imagestream.image.openshift.io/django imported
Name:            django
Namespace:        openshift
Created:        Less than a second ago
Labels:            <none>
Annotations:        openshift.io/image.dockerRepositoryCheck=2019-07-21T22:35:53Z
Docker Pull Spec:    172.30.1.1:5000/openshift/django
Image Lookup:        local=false
Unique Images:        1
Tags:            1
latest
  tagged from django
  * django@sha256:5bfd3f442952463f5bc97188b7f43cfcd6c2f631a017ee2a6fca3cb8992501e8
      Less than a second ago
Image Name:    django:latest
Docker Image:    django@sha256:5bfd3f442952463f5bc97188b7f43cfcd6c2f631a017ee2a6fca3cb8992501e8
Name:        sha256:5bfd3f442952463f5bc97188b7f43cfcd6c2f631a017ee2a6fca3cb8992501e8
Created:    Less than a second ago
Annotations:    image.openshift.io/dockerLayersOrder=ascending
Image Size:    158MB in 6 layers
Layers:        51.36MB    sha256:75a822cd7888e394c49828b951061402d31745f596b1f502758570f2d0ee79e2
        3.339MB    sha256:e4665cede9d1cf30769226da349e1f7e35bf16f75d90688b9cab8569ce00ab79
        19.62MB    sha256:202a45aa091cf861e5386d46a4b55c0015df3135850c8a920cb7615e6e10dda0
        266B    sha256:7799136eb56180bd9f5f64c4854f5bf36a603da3c849be202045329a223d0d8b
        68.27MB    sha256:7a7f9ca3fd40be6ec30a1b27cba2eec6ecebbbc58e4dcf24c3716f2c8c401fdb
        15.44MB    sha256:412f2d081014e91977d969a4076744ae04cc7d52f793ab9d49a3a0f1ca4ffcc1
Image Created:    2 years ago
Author:        <none>
Arch:        amd64
Command:    python3
Working Dir:    <none>
User:        <none>
Exposes Ports:    <none>
Docker Labels:    <none>
Environment:    PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
        LANG=C.UTF-8
        GPG_KEY=97FC712E4C024BBEA48A61ED3A5CA953F73C700D
        PYTHON_VERSION=3.4.5
        PYTHON_PIP_VERSION=9.0.1
        DJANGO_VERSION=1.10.4
We can do the oc get is to show the imported django
$ oc get is
NAME         DOCKER REPO                            TAGS                              UPDATED
django       172.30.1.1:5000/openshift/django       latest                            17 seconds ago
dotnet       172.30.1.1:5000/openshift/dotnet       latest,2.0                        2 months ago
httpd        172.30.1.1:5000/openshift/httpd        latest,2.4                        2 months ago
jenkins      172.30.1.1:5000/openshift/jenkins      1,2,latest                        2 months ago
mariadb      172.30.1.1:5000/openshift/mariadb      10.2,latest,10.1                  2 months ago
To add a tag to the imported images
$ oc tag django:latest django:1.10.4
Tag django:1.10.4 set to django@sha256:5bfd3f442952463f5bc97188b7f43cfcd6c2f631a017ee2a6fca3cb8992501e8.
$ oc get is
NAME         DOCKER REPO                            TAGS                           UPDATED
django       172.30.1.1:5000/openshift/django       1.10.4,latest                  3 seconds ago
dotnet       172.30.1.1:5000/openshift/dotnet       2.0,latest                     2 months ago
httpd        172.30.1.1:5000/openshift/httpd        2.4,latest                     2 months ago
jenkins      172.30.1.1:5000/openshift/jenkins      1,2,latest                     2 months ago