diff --git a/docs/reference/commandline/node_update.md b/docs/reference/commandline/node_update.md index ed3dc60d02..f90b40cc97 100644 --- a/docs/reference/commandline/node_update.md +++ b/docs/reference/commandline/node_update.md @@ -25,6 +25,38 @@ Options: --role string Role of the node (worker/manager) ``` +### Add label metadata to a node + +Add metadata to a swarm node using node labels. You can specify a node label as +a key with an empty value: + +``` bash +$ docker node update --label-add foo worker1 +``` + +To add multiple labels to a node, pass the `--label-add` flag for each label: + +``` bash +$ docker node update --label-add foo --label-add bar worker1 +``` + +When you [create a service](service_create.md), +you can use node labels as a constraint. A constraint limits the nodes where the +scheduler deploys tasks for a service. + +For example, to add a `type` label to identify nodes where the scheduler should +deploy message queue service tasks: + +``` bash +$ docker node update --label-add type=queue worker1 +``` + +The labels you set for nodes using `docker node update` apply only to the node +entity within the swarm. Do not confuse them with the docker daemon labels for +[dockerd]( ../../userguide/labels-custom-metadata.md#daemon-labels). + +For more information about labels, refer to [apply custom +metadata](../../userguide/labels-custom-metadata.md). ## Related information diff --git a/docs/reference/commandline/service_create.md b/docs/reference/commandline/service_create.md index 1bb1ea62fe..561a5a4d6d 100644 --- a/docs/reference/commandline/service_create.md +++ b/docs/reference/commandline/service_create.md @@ -131,7 +131,7 @@ $ docker service create \ ``` For more information about labels, refer to [apply custom -metadata](../../userguide/labels-custom-metadata.md) +metadata](../../userguide/labels-custom-metadata.md). ### Set service mode @@ -162,7 +162,7 @@ follows: `engine.labels` apply to Docker Engine labels like operating system, drivers, etc. Swarm administrators add `node.labels` for operational purposes by -using the `docker node update` command. +using the [`docker node update`](node_update.md) command. For example, the following limits tasks for the redis service to nodes where the node type label equals queue: