draft schema for inventory scripts (ansible#39454)

* draft schema for inventory scripts

used by the script inventory plugin

* fixes and details for vars

* proper escape

* restrict additional

examples/inventory_script_schema.json

@@ -0,0 +1,53 @@
+{
+  "$schema": "http://json-schema.org/draft-06/schema#",
+  "title": "Ansible Inventory",
+  "description" : "Ansible Inventory for the script inventory plugin",
+  "type": "object",
+  "patternProperties": {
+	"^\\w$":{
+		"type": "object",
+		"properties": {
+			"hosts": {
+				"description" : "list of hosts that are part of this group",
+				"type": "array",
+				"items": { "type": "string" }
+			},
+			"vars": {
+				"type": "object",
+				"description": "Variables to assign to hosts that are part of this group" ,
+				"patternProperties": {
+					"^\\w$":{ "type": "object", "description" : "Vars for this hosts in this group" }
+				}
+			},
+			"children": {
+				"description" : "list of groups that are children of this group, their hosts will be added to this group",
+				"type": "array",
+				"items": { "type": "string" }
+			}
+		},
+		"additionalProperties": false
+	},
+	"_meta":{
+		"type": "object",
+		"description" : "Key that avoids calling the script per host",
+		"required": ["hostvars"],
+		"properties": {
+			"hostvars": {
+				"type": "object",
+				"description" : "Each key is a hostname and the value is a dictionary of the variables for that host",
+				"patternProperties": {
+					"^\\w$":{
+						"type": "object",
+						"description" : "Hosts with their associated vars",
+						"patternProperties": {
+							"^\\w$":{ "type": "object", "description" : "Vars for this host" }
+						}
+					}
+				}
+			}
+		},
+		"additionalProperties": false
+     }
+  },
+  "additionalProperties": false
+}