Service privileges: CLI reference docs & completion

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

contrib/completion/bash/docker

@@ -3091,6 +3091,7 @@ _docker_service_update() {
 # and `docker service update`
 _docker_service_update_and_create() {
 	local options_with_args="
+		--credential-spec
 		--endpoint-mode
 		--entrypoint
 		--env -e

docs/reference/commandline/service_create.md

@@ -23,6 +23,7 @@ Create a new service
 Options:
       --constraint list                    Placement constraints
       --container-label list               Container labels
+      --credential-spec                    Credential spec for managed service account (Windows only)
   -d, --detach                             Exit immediately instead of waiting for the service to converge (default true)
       --dns list                           Set custom DNS servers
       --dns-option list                    Set DNS options
@@ -779,6 +780,24 @@ $ docker service create --name dns-cache -p 53:53/tcp -p 53:53/udp dns-cache
 $ docker service create --name dns-cache -p 53:53/udp dns-cache
 ```
 
+### Provide credential specs for managed service accounts (Windows only)
+
+This option is only used for services using Windows containers. The
+`--credential-spec` must be in the format `file://<filename>` or
+`registry://<value-name>`.
+
+When using the `file://<filename>` format, the referenced file must be
+present in the `CredentialSpecs` subdirectory in the docker data directory,
+which defaults to `C:\ProgramData\Docker\` on Windows. For example,
+specifying `file://spec.json` loads `C:\ProgramData\Docker\CredentialSpecs\spec.json`.
+
+When using the `registry://<value-name>` format, the credential spec is
+read from the Windows registry on the daemon's host. The specified
+registry value must be located in:
+
+    HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization\Containers\CredentialSpecs
+
+
 ### Create services using templates
 
 You can use templates for some flags of `service create`, using the syntax

docs/reference/commandline/service_update.md

@@ -26,6 +26,7 @@ Options:
       --constraint-rm list                 Remove a constraint
       --container-label-add list           Add or update a container label
       --container-label-rm list            Remove a container label by its key
+      --credential-spec                    Credential spec for managed service account (Windows only)
   -d, --detach                             Exit immediately instead of waiting for the service to converge (default true)
       --dns-add list                       Add or update a custom DNS server
       --dns-option-add list                Add or update a DNS option