Add ephemeral_disk docs

website/source/docs/job-specification/ephemeral_disk.html.md

@@ -0,0 +1,67 @@
+---
+layout: "docs"
+page_title: "ephemeral_disk Stanza - Job Specification"
+sidebar_current: "docs-job-specification-ephemeral_disk"
+description: |-
+  The "ephemeral_disk" stanza instructs Nomad to utilize an ephemeral disk
+  instead of a hard disk requirement, and can also enable sticky volumes and
+  live data migrations.
+---
+
+# `ephemeral_disk` Stanza
+
+<table class="table table-bordered table-striped">
+  <tr>
+    <th width="120">Placement</th>
+    <td>
+      <code>job -> group -> **ephemeral_disk**</code>
+    </td>
+  </tr>
+</table>
+
+The `ephemeral_disk` stanza instructs Nomad to utilize an ephemeral disk instead
+of a hard disk requirement. Clients using this stanza should not specify disk
+requirements in the [resources stanza][resources] of the task. All tasks in this
+group will share the same ephemeral disk.
+
+```hcl
+job "docs" {
+  group "example" {
+    ephemeral_disk {
+      migrate = true
+      size    = "500"
+      sticky  = true
+    }
+  }
+}
+```
+
+## `ephemeral_disk` Parameters
+
+- `migrate` `(bool: false)` - Specifies that the Nomad client should make a
+  best-effort attempt to migrate the data from a remote machine if placement
+  should fail. During data migration, the task will block starting until the
+  data migration has completed.
+
+- `size` `(int: 300)` - Specifies the size of the ephemeral disk in MB.
+
+- `sticky` `(bool: false)` - Specifies that Nomad should make a best-effort
+  attempt to place the updated allocation on the same machine. This will move
+  the `local/` and `alloc/data` directories to the new allocation.
+
+## `ephemeral_disk` Examples
+
+The following examples only show the `ephemeral_disk` stanzas. Remember that the
+`ephemeral_disk` stanza is only valid in the placements listed above.
+
+### Sticky Volumes
+
+This example shows enabling sticky volumes with Nomad using ephemeral disks:
+
+```hcl
+ephemeral_disk {
+  sticky = true
+}
+```
+
+[resources]: /docs/job-specification/resources.html "Nomad resources Job Specification"

website/source/layouts/docs.erb

@@ -51,6 +51,9 @@
             <li<%= sidebar_current("docs-job-specification-env")%>>
               <a href="/docs/job-specification/env.html">env</a>
             </li>
+            <li<%= sidebar_current("docs-job-specification-ephemeral_disk")%>>
+              <a href="/docs/job-specification/ephemeral_disk.html">ephemeral_disk</a>
+            </li>
             <li<%= sidebar_current("docs-job-specification-group")%>>
               <a href="/docs/job-specification/group.html">group</a>
             </li>