Add documentation.

backend/remote-state/etcdv3/backend.go

@@ -45,7 +45,7 @@ func New() backend.Backend {
 			"lock": &schema.Schema{
 				Type:        schema.TypeBool,
 				Optional:    true,
-				Description: "Lock state access.",
+				Description: "Whether to lock state access.",
 				Default:     true,
 			},
 		},

website/docs/backends/types/etcd.html.md

@@ -3,7 +3,7 @@ layout: "backend-types"
 page_title: "Backend Type: etcd"
 sidebar_current: "docs-backends-types-standard-etcd"
 description: |-
-  Terraform can store state remotely in etcd.
+  Terraform can store state remotely in etcd 2.x.
 ---
 
 # etcd

website/docs/backends/types/etcdv3.html.md

@@ -0,0 +1,53 @@
+---
+layout: "backend-types"
+page_title: "Backend Type: etcdv3"
+sidebar_current: "docs-backends-types-standard-etcdv3"
+description: |-
+  Terraform can store state remotely in etcd 3.x.
+---
+
+# etcdv3
+
+**Kind: Standard (with locking)**
+
+Stores the state in the [etcd](https://coreos.com/etcd/) KV store wit a given prefix.
+
+This backend supports [state locking](/docs/state/locking.html).
+
+## Example Configuration
+
+```hcl
+terraform {
+  backend "etcdv3" {
+    endpoints = ["etcd-1:2379", "etcd-2:2379", "etcd-3:2379"]
+    lock      = true
+    prefix    = "terraform-state/"
+  }
+}
+```
+
+Note that for the access credentials we recommend using a
+[partial configuration](/docs/backends/config.html).
+
+## Example Referencing
+
+```hcl
+data "terraform_remote_state" "foo" {
+  backend = "etcdv3"
+  config {
+    endpoints = ["etcd-1:2379", "etcd-2:2379", "etcd-3:2379"]
+    lock      = true
+    prefix    = "terraform-state/"
+  }
+}
+```
+
+## Configuration variables
+
+The following configuration options / environment variables are supported:
+
+ * `endpoints` - (Required) The list of 'etcd' endpoints which to connect to.
+ * `username` - (Optional) Username used to connect to the etcd cluster.
+ * `password` - (Optional) Password used to connect to the etcd  cluster.
+ * `prefix` - (Optional) An optional prefix to be added to keys when to storing state in etcd. Defaults to `""`.
+ * `lock` - (Optional) Whether to lock state access. Defaults to `true`.