Update OSD replacement functionality

1. Simplify this by leveraging the existing remove_osd/add_osd
functions, since its task was functionally identical to those two in
sequential order.
2. Add support for split OSDs within the command (replacing all OSDs on
the block device(s) as required).
3. Add additional configurability and flexibility around the old device,
weight, and external DB LVs.

api-daemon/pvcapid/flaskapi.py

@@ -4379,14 +4379,25 @@ class API_Storage_Ceph_OSD_Element(Resource):
     @RequestParser(
         [
             {
-                "name": "device",
+                "name": "new_device",
                 "required": True,
                 "helptext": "A valid device or detect string must be specified.",
             },
+            {
+                "name": "old_device",
+                "required": False,
+            },
             {
                 "name": "weight",
-                "required": True,
-                "helptext": "An OSD weight must be specified.",
+                "required": False,
+            },
+            {
+                "name": "ext_db_ratio",
+                "required": False,
+            },
+            {
+                "name": "ext_db_size",
+                "required": False,
             },
             {
                 "name": "yes-i-really-mean-it",
@@ -4405,15 +4416,30 @@ class API_Storage_Ceph_OSD_Element(Resource):
           - storage / ceph
         parameters:
           - in: query
-            name: device
+            name: new_device
             type: string
             required: true
             description: The block device (e.g. "/dev/sdb", "/dev/disk/by-path/...", etc.) or detect string ("detect:NAME:SIZE:ID") to replace the OSD onto
+          - in: query
+            name: old_device
+            type: string
+            required: false
+            description: The block device (e.g. "/dev/sdb", "/dev/disk/by-path/...", etc.) or detect string ("detect:NAME:SIZE:ID") of the original OSD
           - in: query
             name: weight
             type: number
-            required: true
-            description: The Ceph CRUSH weight for the replaced OSD
+            required: false
+            description: The Ceph CRUSH weight for the replacement OSD
+          - in: query
+            name: ext_db_ratio
+            type: float
+            required: false
+            description: If set, creates an OSD DB LV for the replcement OSD with this decimal ratio of DB to total OSD size (usually 0.05 i.e. 5%); if unset, use existing ext_db_size
+          - in: query
+            name: ext_db_size
+            type: float
+            required: false
+            description: If set, creates an OSD DB LV for the replacement OSD with this explicit size in human units (e.g. 1024M, 20G); if unset, use existing ext_db_size
         responses:
           200:
             description: OK
@@ -4428,8 +4454,11 @@ class API_Storage_Ceph_OSD_Element(Resource):
         """
         return api_helper.ceph_osd_replace(
             osdid,
-            reqargs.get("device", None),
+            reqargs.get("new_device"),
+            reqargs.get("old_device", None),
             reqargs.get("weight", None),
+            reqargs.get("ext_db_ratio", None),
+            reqargs.get("ext_db_size", None),
         )
 
     @RequestParser(