1, to create a image from server instance, should  "openstack server image create <server>"


controller-0:~$ openstack image list
+--------------------------------------+--------------------------------------+--------+
| ID                                   | Name                                 | Status |
+--------------------------------------+--------------------------------------+--------+
| 8a019820-0b05-45ac-a004-d5f840b82dba | 16a4a42c-4040-47d8-84d5-69036169c4eb | queued |
| 8fab3b2a-61c8-492f-b48e-ec8485a9599d | 16a4a42c-4040-47d8-84d5-69036169c4eb | queued |
| 1b75cd76-da92-4994-bb56-33ec86c1d55b | cirros                               | active |
+--------------------------------------+--------------------------------------+--------+
controller-0:~$
controller-0:~$
controller-0:~$ openstack image delete 8fab3b2a-61c8-492f-b48e-ec8485a9599d
controller-0:~$
controller-0:~$
controller-0:~$ openstack server list
+--------------------------------------+------+---------+-----------------------------+--------+----------+
| ID                                   | Name | Status  | Networks                    | Image  | Flavor   |
+--------------------------------------+------+---------+-----------------------------+--------+----------+
| b2828194-2bb0-4bac-9a9a-67d33d986e36 | vm1  | ACTIVE  | public-net0=192.168.101.148 | cirros | m1.tinny |
| 16a4a42c-4040-47d8-84d5-69036169c4eb | vm0  | SHUTOFF | public-net0=192.168.101.100 | cirros | m1.tinny |
+--------------------------------------+------+---------+-----------------------------+--------+----------+

controller-0:~$ openstack image list
+--------------------------------------+--------------------------------------+--------+
| ID                                   | Name                                 | Status |
+--------------------------------------+--------------------------------------+--------+
| 8a019820-0b05-45ac-a004-d5f840b82dba | 16a4a42c-4040-47d8-84d5-69036169c4eb | queued |
| 1b75cd76-da92-4994-bb56-33ec86c1d55b | cirros                               | active |
| 85ba6fed-bfbb-4b09-9477-ea7a8c6118eb | vm0                                  | active |
+--------------------------------------+--------------------------------------+--------+



For "openstack image create", request argument "image-name" 

controller-0:~$ openstack image create
usage: openstack image create [-h] [-f {json,shell,table,value,yaml}]
                              [-c COLUMN] [--max-width <integer>]
                              [--fit-width] [--print-empty] [--noindent]
                              [--prefix PREFIX] [--id <id>]
                              [--container-format <container-format>]
                              [--disk-format <disk-format>]
                              [--min-disk <disk-gb>] [--min-ram <ram-mb>]
                              [--file <file> | --volume <volume>] [--force]
                              [--sign-key-path <sign-key-path>]
                              [--sign-cert-id <sign-cert-id>]
                              [--protected | --unprotected]
                              [--public | --private | --community | --shared]
                              [--property <key=value>] [--tag <tag>]
                              [--project <project>]
                              [--project-domain <project-domain>]
                              <image-name>