kcadm.sh: add page (#9272)

pages/common/kcadm.sh.md

@@ -0,0 +1,20 @@
+# kcadm.sh
+
+> Perform administration tasks from the command-line interface (CLI).
+> More information: <https://www.keycloak.org/docs/latest/server_admin/#admin-cli>.
+
+- Start an authenticated session:
+
+`kcadm.sh config credentials --server {{host}} --realm {{realm_name}} --user {{username}} --password {{password}}`
+
+- Create a user:
+
+`kcadm.sh create users -s username={{username}} -r {{realm_name}}`
+
+- List all realms:
+
+`kcadm.sh get realms`
+
+- Update a realm with JSON config:
+
+`kcadm.sh update realms/{{realm_name}} -f {{path/to/file.json}}`