docs: add node meta command docs (#16828)

* docs: add node meta command docs

Fixes #16758

* it helps if you actually add the files to git

* fix typos and examples vs usage

command/node_meta_apply.go

@@ -37,7 +37,7 @@ Node Meta Apply Options:
     the request will be used by default.
 
   -unset key1,...,keyN
-    Unset the command separated list of keys.
+    Unset the comma separated list of keys.
 
   Example:
     $ nomad node meta apply -unset testing,tempvar ready=1 role=preinit-db

website/content/docs/commands/node/index.mdx

@@ -23,9 +23,12 @@ subcommands are available:
 - [`node eligibility`][eligibility] - Toggle scheduling eligibility on a given
   node
 
+- [`node meta`][meta] - Interact with node metadata
+
 - [`node status`][status] - Display status information about nodes
 
 [config]: /nomad/docs/commands/node/config 'View or modify client configuration details'
 [drain]: /nomad/docs/commands/node/drain 'Set drain mode on a given node'
 [eligibility]: /nomad/docs/commands/node/eligibility 'Toggle scheduling eligibility on a given node'
+[meta]: /nomad/docs/commands/node/meta 'Interact with node metadata'
 [status]: /nomad/docs/commands/node/status 'Display status information about nodes'

website/content/docs/commands/node/meta/apply.mdx

@@ -0,0 +1,41 @@
+---
+layout: docs
+page_title: 'Commands: node meta apply'
+description: |
+  The node meta apply command updates node metadata.
+---
+
+# Command: node meta apply
+
+Modify a node's metadata. This command only applies to client agents, and can
+be used to update the scheduling metadata the node registers.
+
+~> Changes are batched and may take up to 10 seconds to propagate to the
+   servers and affect scheduling.
+
+This command uses the [`/v1/client/metadata` HTTP API][api].
+
+## Usage
+
+```plaintext
+nomad node meta apply [-node-id ...] [-unset ...] key1=value1 ... kN=vN
+```
+
+## General Options
+
+@include 'general_options.mdx'
+
+## Node Meta Apply Options
+
+- `-node-id` - Updates metadata on the specified node. If not specified the
+  node receiving the request will be used by default.
+
+- `-unset` - Unset the comma separated list of keys.
+
+## Examples
+
+```shell-session
+$ nomad node meta apply -unset testing,tempvar ready=1 role=preinit-db
+```
+
+[api]: /nomad/api-docs/client#update-node-metadata

website/content/docs/commands/node/meta/index.mdx

@@ -0,0 +1,29 @@
+---
+layout: docs
+page_title: 'Commands: node meta'
+description: |
+  The node meta commands are used to read and update node metadata.
+---
+
+# Command: node meta
+
+The `meta` command is used to read and update node metadata. This metadata is
+available for [interpolation using the `${meta.<key>}` syntax in jobs][interp].
+
+## Usage
+
+Usage: `nomad node meta <subcommand> [options]`
+
+The `apply` subcommand allows for dynamically updating node metadata. The
+`read` subcommand allows reading all of the metadata set on the client. All
+commands interact directly with a client and allow setting a custom target with
+the `-node-id` option.
+
+Please see the individual subcommand help for detailed usage information:
+
+ - [`apply`][apply] - Modify node metadata
+ - [`read`][read] - Read node metadata
+
+[interp]: /nomad/docs/runtime/interpolation#node-attributes
+[apply]: /nomad/docs/commands/node/meta/apply
+[read]: /nomad/docs/commands/node/meta/read

website/content/docs/commands/node/meta/read.mdx

@@ -0,0 +1,62 @@
+---
+layout: docs
+page_title: 'Commands: node meta read'
+description: |
+  The node meta read command reads node metadata.
+---
+
+# Command: node meta read
+
+Read a node's metadata. This command only works on client agents. The node
+status command can be used to retrieve node metadata from any agent.
+
+Changes via the "node meta apply" subcommand are batched and may take up to
+10 seconds to propagate to the servers and affect scheduling. This command
+will always return the most recent node metadata while the "node status"
+command can be used to view the metadata that is currently being used for
+scheduling.
+
+This command uses the [`/v1/client/metadata` HTTP API][api].
+
+## Usage
+
+```plaintext
+nomad node meta read [-json] [-node-id ...]
+```
+
+## General Options
+
+@include 'general_options.mdx'
+
+## Node Meta Read Options
+
+- `-node-id` - Reads metadata on the specified node. If not specified the
+  node receiving the request will be used by default.
+
+- `-json` - Output the node metadata in its JSON format.
+
+- `-t` : Format and display node using a Go template.
+
+## Example
+
+```shell-session
+$ nomad node meta read -node-id 3b58b0a6
+
+All Meta
+connect.gateway_image     = envoyproxy/envoy:v${NOMAD_envoy_version}
+connect.log_level         = info
+connect.proxy_concurrency = 1
+connect.sidecar_image     = envoyproxy/envoy:v${NOMAD_envoy_version}
+example                   = a
+
+Dynamic Meta
+example = a
+
+Static Meta
+connect.gateway_image     = envoyproxy/envoy:v${NOMAD_envoy_version}
+connect.log_level         = info
+connect.proxy_concurrency = 1
+connect.sidecar_image     = envoyproxy/envoy:v${NOMAD_envoy_version}
+```
+
+[api]: /nomad/api-docs/client#read-node-metadata

website/data/docs-nav-data.json

@@ -649,6 +649,23 @@
             "title": "eligibility",
             "path": "commands/node/eligibility"
           },
+          {
+            "title": "meta",
+            "routes": [
+              {
+                "title": "Overview",
+                "path": "commands/node/meta"
+              },
+              {
+                "title": "apply",
+                "path": "commands/node/meta/apply"
+              },
+              {
+                "title": "read",
+                "path": "commands/node/meta/read"
+              }
+            ]
+          },
           {
             "title": "status",
             "path": "commands/node/status"