Add VM snapshot send (initial)

Modifies pvcapid to run under Gunicorn when in non-debug mode, instead
of the Flask development server. This is proper practice for one, and
also helps increase performance slightly in some workloads (file uploads
mainly).

api-daemon/pvcapid.py

@@ -19,6 +19,13 @@
 #
 ###############################################################################
 
+import sys
+from os import path
+
+# Ensure current directory (/usr/share/pvc) is in the system path for Gunicorn
+current_dir = path.dirname(path.abspath(__file__))
+sys.path.append(current_dir)
+
 import pvcapid.Daemon  # noqa: F401
 
 pvcapid.Daemon.entrypoint()

api-daemon/pvcapid/Daemon.py

@@ -19,15 +19,15 @@
 #
 ###############################################################################
 
-
+import sys
+import os
+import subprocess
 from ssl import SSLContext, TLSVersion
-
 from distutils.util import strtobool as dustrtobool
-
 import daemon_lib.config as cfg
 
 # Daemon version
-version = "0.9.100"
+version = "0.9.100~git-73c0834f"
 
 # API version
 API_VERSION = 1.0
@@ -37,7 +37,6 @@ API_VERSION = 1.0
 # Helper Functions
 ##########################################################
 
-
 def strtobool(stringv):
     if stringv is None:
         return False
@@ -53,7 +52,6 @@ def strtobool(stringv):
 # Configuration Parsing
 ##########################################################
 
-
 # Get our configuration
 config = cfg.get_configuration()
 config["daemon_name"] = "pvcapid"
@@ -61,22 +59,15 @@ config["daemon_version"] = version
 
 
 ##########################################################
-# Entrypoint
+# Flask App Creation for Gunicorn
 ##########################################################
 
-
+def create_app():
-def entrypoint():
+    """
-    import pvcapid.flaskapi as pvc_api  # noqa: E402
+    Create and return the Flask app and SSL context if necessary.
-
+    """
-    if config["api_ssl_enabled"]:
+    # Import the Flask app from pvcapid.flaskapi after adjusting the path
-        context = SSLContext()
+    import pvcapid.flaskapi as pvc_api
-        context.minimum_version = TLSVersion.TLSv1
-        context.get_ca_certs()
-        context.load_cert_chain(
-            config["api_ssl_cert_file"], keyfile=config["api_ssl_key_file"]
-        )
-    else:
-        context = None
 
     # Print our startup messages
     print("")
@@ -102,9 +93,59 @@ def entrypoint():
     print("")
 
     pvc_api.celery_startup()
-    pvc_api.app.run(
+
-        config["api_listen_address"],
+    return pvc_api.app
-        config["api_listen_port"],
+
-        threaded=True,
+
-        ssl_context=context,
+##########################################################
-    )
+# Entrypoint
+##########################################################
+
+def entrypoint():
+    if config['debug']:
+        app = create_app()
+
+        if config["api_ssl_enabled"]:
+            ssl_context = SSLContext()
+            ssl_context.minimum_version = TLSVersion.TLSv1
+            ssl_context.get_ca_certs()
+            ssl_context.load_cert_chain(
+                config["api_ssl_cert_file"], keyfile=config["api_ssl_key_file"]
+            )
+        else:
+            ssl_context = None
+
+        app.run(
+            config["api_listen_address"],
+            config["api_listen_port"],
+            threaded=True,
+            ssl_context=ssl_context,
+        )
+    else:
+        # Build the command to run Gunicorn
+        gunicorn_cmd = [
+            'gunicorn',
+            '--workers', '1',
+            '--threads', '8',
+            '--timeout', '86400',
+            '--bind', '{}:{}'.format(config["api_listen_address"], config["api_listen_port"]),
+            'pvcapid.Daemon:create_app()',
+            '--log-level', 'info',
+            '--access-logfile', '-',
+            '--error-logfile', '-',
+        ]
+
+        if config["api_ssl_enabled"]:
+            gunicorn_cmd += [
+                '--certfile', config["api_ssl_cert_file"],
+                '--keyfile', config["api_ssl_key_file"]
+            ]
+
+        # Run Gunicorn
+        try:
+            subprocess.run(gunicorn_cmd)
+        except KeyboardInterrupt:
+            exit(0)
+        except Exception as e:
+            print(e)
+            exit(1)

api-daemon/pvcapid/flaskapi.py

@@ -2801,7 +2801,7 @@ class API_VM_Locks(Resource):
           - vm
         responses:
           202:
-            description: OK
+            description: Accepted
             schema:
                 type: string
                 description: The Celery job ID of the task
@@ -2924,11 +2924,11 @@ class API_VM_Device(Resource):
             required: true
             description: The raw Libvirt XML definition of the device to attach
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Bad request
             schema:
@@ -2978,11 +2978,11 @@ class API_VM_Device(Resource):
             required: true
             description: The raw Libvirt XML definition of the device to detach
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Bad request
             schema:
@@ -3234,11 +3234,11 @@ class API_VM_Snapshot(Resource):
             required: false
             description: A custom name for the snapshot instead of autogeneration by date
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Execution error
             schema:
@@ -3292,11 +3292,11 @@ class API_VM_Snapshot(Resource):
             required: true
             description: The name of the snapshot to remove
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Execution error
             schema:
@@ -3356,11 +3356,11 @@ class API_VM_Snapshot_Rollback(Resource):
             required: true
             description: The name of the snapshot to roll back to
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Execution error
             schema:
@@ -3436,15 +3436,15 @@ class API_VM_Snapshot_Export(Resource):
             description: The absolute file path to export the snapshot to on the active primary coordinator
           - in: query
             name: incremental_parent
-            type: boolean
+            type: string
             required: false
             description: A snapshot name to generate an incremental diff from
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Execution error
             schema:
@@ -3529,11 +3529,11 @@ class API_VM_Snapshot_Import(Resource):
             default: true
             description: Whether or not to retain the (parent, if incremental) volume snapshot after restore
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Execution error
             schema:
@@ -3572,6 +3572,220 @@ class API_VM_Snapshot_Import(Resource):
 api.add_resource(API_VM_Snapshot_Import, "/vm/<vm>/snapshot/import")
 
 
+# /vm/<vm>/snapshot/send
+class API_VM_Snapshot_Send(Resource):
+    @RequestParser(
+        [
+            {
+                "name": "snapshot_name",
+                "required": True,
+                "helptext": "A snapshot name must be specified",
+            },
+            {
+                "name": "destination_api_uri",
+                "required": True,
+                "helptext": "A destination API URI must be specified",
+            },
+            {
+                "name": "destination_api_key",
+                "required": True,
+                "helptext": "A destination API key must be specified",
+            },
+            {
+                "name": "destination_api_verify_ssl",
+                "required": False,
+            },
+            {
+                "name": "incremental_parent",
+                "required": False,
+            },
+            {
+                "name": "destination_storage_pool",
+                "required": False,
+            },
+        ]
+    )
+    @Authenticator
+    def post(self, vm, reqargs):
+        """
+        Send a snapshot of a VM's disks and configuration to another PVC cluster
+        ---
+        tags:
+          - vm
+        parameters:
+          - in: query
+            name: snapshot_name
+            type: string
+            required: true
+            description: The name of the snapshot to export (must exist)
+          - in: query
+            name: destination_api_uri
+            type: string
+            required: true
+            description: The base API URI of the destination PVC cluster (with prefix if applicable)
+          - in: query
+            name: destination_api_key
+            type: string
+            required: true
+            description: The API authentication key of the destination PVC cluster
+          - in: query
+            name: destination_api_verify_ssl
+            type: boolean
+            required: false
+            default: true
+            description: Whether or not to validate SSL certificates for an SSL-enabled destination API
+          - in: query
+            name: incremental_parent
+            type: string
+            required: false
+            description: A snapshot name to generate an incremental diff from; incremental send only if unset
+          - in: query
+            name: destination_storage_pool
+            type: string
+            required: false
+            default: source storage pool name
+            description: The remote cluster storage pool to create RBD volumes in, if different from the source storage pool
+        responses:
+          202:
+            description: Accepted
+            schema:
+                type: string
+                description: The Celery job ID of the task
+          400:
+            description: Execution error
+            schema:
+              type: object
+              id: Message
+          404:
+            description: Not found
+            schema:
+              type: object
+              id: Message
+        """
+        snapshot_name = reqargs.get("snapshot_name", None)
+        destination_api_uri = reqargs.get("destination_api_uri", None)
+        destination_api_key = reqargs.get("destination_api_key", None)
+        destination_api_verify_ssl = vool(strtobool(reqargs.get("destination_api_verify_ssl", "true")))
+        incremental_parent = reqargs.get("incremental_parent", None)
+        destination_storage_pool = reqargs.get("destination_storage_pool", None)
+
+        task = run_celery_task(
+            "vm.send_snapshot",
+            domain=vm,
+            snapshot_name=snapshot_name,
+            destination_api_uri=destination_api_uri,
+            destination_api_key=destination_api_key,
+            destination_api_verify_ssl=destination_api_verify_ssl,
+            incremental_parent=incremental_parent,
+            destination_storage_pool=destination_storage_pool,
+            run_on="primary",
+        )
+
+        return (
+            {
+                "task_id": task.id,
+                "task_name": "vm.send_snapshot",
+                "run_on": f"{get_primary_node()} (primary)",
+            },
+            202,
+            {"Location": Api.url_for(api, API_Tasks_Element, task_id=task.id)},
+        )
+
+
+api.add_resource(API_VM_Snapshot_Send, "/vm/<vm>/snapshot/send")
+
+
+# /vm/<vm>/snapshot/receive/block
+class API_VM_Snapshot_Receive_Block(Resource):
+    @RequestParser(
+        [
+            {
+                "name": "pool",
+                "required": True,
+            },
+            {
+                "name": "volume",
+                "required": True,
+            },
+            {
+                "name": "snapshot",
+                "required": True,
+            },
+            {
+                "name": "size",
+                "required": True,
+            },
+            {
+                "name": "source_snapshot",
+                "required": False,
+            },
+        ]
+    )
+    @Authenticator
+    def post(self, vm, reqargs):
+        """
+        Receive a snapshot of a single RBD volume from another PVC cluster; may be full or incremental
+
+        NOTICE: This is an API-internal endpoint used by /vm/<vm>/snapshot/send; it should never be called by a client.
+        ---
+        tags:
+          - vm
+        parameters:
+          - in: query
+            name: pool
+            type: string
+            required: true
+            description: The name of the destination Ceph RBD data pool
+          - in: query
+            name: volume
+            type: string
+            required: true
+            description: The name of the destination Ceph RBD volume
+          - in: query
+            name: snapshot
+            type: string
+            required: true
+            description: The name of the destination Ceph RBD volume snapshot
+          - in: query
+            name: size
+            type: integer
+            required: true
+            description: The size in bytes of the Ceph RBD volume
+          - in: query
+            name: source_snapshot
+            type: string
+            required: false
+            description: The name of the destination Ceph RBD volume snapshot parent for incremental transfers
+        responses:
+          200:
+            description: OK
+            schema:
+              type: object
+              id: Message
+          400:
+            description: Execution error
+            schema:
+              type: object
+              id: Message
+          404:
+            description: Not found
+            schema:
+              type: object
+              id: Message
+        """
+        return api_helper.vm_snapshot_receive_block(
+            reqargs.get("pool"),
+            reqargs.get("volume") + "_recv",
+            reqargs.get("snapshot"),
+            int(reqargs.get("size")),
+            flask.request.stream,
+            source_snapshot=reqargs.get("source_snapshot"),
+        )
+
+
+api.add_resource(API_VM_Snapshot_Receive_Block, "/vm/<vm>/snapshot/receive/block")
+
+
 # /vm/autobackup
 class API_VM_Autobackup_Root(Resource):
     @RequestParser(
@@ -3601,14 +3815,11 @@ class API_VM_Autobackup_Root(Resource):
               type: string
               example: "user@domain.tld"
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              properties:
+                description: The Celery job ID of the task
-                task_id:
-                  type: string
-                  description: Task ID for the provisioner Celery worker
           400:
             description: Bad request
             schema:
@@ -5173,11 +5384,16 @@ class API_Storage_Ceph_Benchmark(Resource):
             required: true
             description: The PVC storage pool to benchmark
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
                 type: string
-                description: The Celery job ID of the benchmark (unused elsewhere)
+                description: The Celery job ID of the task
+          400:
+            description: Bad request
+            schema:
+              type: object
+              id: Message
         """
         # Verify that the pool is valid
         _list, code = api_helper.ceph_pool_list(
@@ -5301,11 +5517,11 @@ class API_Storage_Ceph_OSDDB_Root(Resource):
             required: true
             description: The block device (e.g. "/dev/sdb", "/dev/disk/by-path/...", etc.) or detect string ("detect:NAME:SIZE:ID") to create the OSD DB volume group on
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Bad request
             schema:
@@ -5500,11 +5716,11 @@ class API_Storage_Ceph_OSD_Root(Resource):
             required: false
             description: If set, create this many OSDs on the block device instead of 1; usually 2 or 4 depending on size
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Bad request
             schema:
@@ -5615,11 +5831,11 @@ class API_Storage_Ceph_OSD_Element(Resource):
             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:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Bad request
             schema:
@@ -5673,11 +5889,11 @@ class API_Storage_Ceph_OSD_Element(Resource):
             required: true
             description: The block device (e.g. "/dev/sdb", "/dev/disk/by-path/...", etc.) or detect string ("detect:NAME:SIZE:ID") that the OSD should be using
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           400:
             description: Bad request
             schema:
@@ -5731,7 +5947,7 @@ class API_Storage_Ceph_OSD_Element(Resource):
           - in: query
             name: force
             type: boolean
-            required: flase
+            required: false
             description: Force removal even if some step(s) fail
           - in: query
             name: yes-i-really-mean-it
@@ -5739,11 +5955,11 @@ class API_Storage_Ceph_OSD_Element(Resource):
             required: true
             description: A confirmation string to ensure that the API consumer really means it
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              id: Message
+                description: The Celery job ID of the task
           404:
             description: Not found
             schema:
@@ -6331,7 +6547,7 @@ class API_Storage_Ceph_Volume_Root(Resource):
             name: force
             type: boolean
             required: false
-            default: flase
+            default: false
             description: Force action if volume creation would violate 80% full soft cap on the pool
         responses:
           200:
@@ -6408,7 +6624,7 @@ class API_Storage_Ceph_Volume_Element(Resource):
             name: force
             type: boolean
             required: false
-            default: flase
+            default: false
             description: Force action if volume creation would violate 80% full soft cap on the pool
         responses:
           200:
@@ -6460,7 +6676,7 @@ class API_Storage_Ceph_Volume_Element(Resource):
             name: force
             type: boolean
             required: false
-            default: flase
+            default: false
             description: Force action if new volume size would violate 80% full soft cap on the pool
         responses:
           200:
@@ -6585,7 +6801,7 @@ class API_Storage_Ceph_Volume_Element_Clone(Resource):
             name: force
             type: boolean
             required: false
-            default: flase
+            default: false
             description: Force action if clone volume size would violate 80% full soft cap on the pool
         responses:
           200:
@@ -9440,14 +9656,11 @@ class API_Provisioner_Create_Root(Resource):
             type: string
             description: Script install() function keywork argument in "arg=data" format; may be specified multiple times to add multiple arguments
         responses:
-          200:
+          202:
-            description: OK
+            description: Accepted
             schema:
-              type: object
+                type: string
-              properties:
+                description: The Celery job ID of the task
-                task_id:
-                  type: string
-                  description: Task ID for the provisioner Celery worker
           400:
             description: Bad request
             schema:

api-daemon/pvcapid/helper.py

@@ -1280,7 +1280,7 @@ def vm_flush_locks(zkhandler, vm):
         zkhandler, None, None, None, vm, is_fuzzy=False, negate=False
     )
 
-    if retdata[0].get("state") not in ["stop", "disable"]:
+    if retdata[0].get("state") not in ["stop", "disable", "mirror"]:
         return {"message": "VM must be stopped to flush locks"}, 400
 
     retflag, retdata = pvc_vm.flush_locks(zkhandler, vm)
@@ -1294,6 +1294,58 @@ def vm_flush_locks(zkhandler, vm):
     return output, retcode
 
 
+def vm_snapshot_receive_block(pool, volume, snapshot, size, stream, source_snapshot=None):
+    try:
+        import rados
+        import rbd
+
+        cluster = rados.Rados(conffile='/etc/ceph/ceph.conf')
+        cluster.connect()
+        ioctx = cluster.open_ioctx(pool)
+
+        if not source_snapshot:
+            rbd_inst = rbd.RBD()
+            rbd_inst.create(ioctx, volume, size)
+
+        image = rbd.Image(ioctx, volume)
+
+        last_chunk = 0
+        chunk_size = 1024 * 1024 * 128
+
+        if source_snapshot:
+            # Receiving diff data
+            print(f"Applying diff between {source_snapshot} and {snapshot}")
+            while True:
+                chunk = stream.read(chunk_size)
+                if not chunk:
+                    break
+
+                # Extract the offset and length (8 bytes each) and the data
+                offset = int.from_bytes(chunk[:8], 'big')
+                length = int.from_bytes(chunk[8:16], 'big')
+                data = chunk[16:16 + length]
+                image.write(data, offset)
+
+            image.create_snap(snapshot)
+        else:
+            # Receiving full image
+            print(f"Importing full snapshot {snapshot}")
+            while True:
+                chunk = flask.request.stream.read(chunk_size)
+                if not chunk:
+                    break
+                image.write(chunk, last_chunk)
+                last_chunk += len(chunk)
+
+            image.create_snap(snapshot)
+
+        image.close()
+        ioctx.close()
+        cluster.shutdown()
+    except Exception as e:
+        return {"message": f"Failed to import block device: {e}"}, 400
+
+
 #
 # Network functions
 #

client-cli/pvc/cli/formatters.py

@@ -206,12 +206,12 @@ def cli_cluster_status_format_pretty(CLI_CONFIG, data):
 
     output.append(f"{ansii['purple']}Nodes:{ansii['end']}          {nodes_string}")
 
-    vm_states = ["start", "disable"]
+    vm_states = ["start", "disable", "mirror"]
     vm_states.extend(
         [
             state
             for state in data.get("vms", {}).keys()
-            if state not in ["total", "start", "disable"]
+            if state not in ["total", "start", "disable", "mirror"]
         ]
     )
 
@@ -221,7 +221,7 @@ def cli_cluster_status_format_pretty(CLI_CONFIG, data):
             continue
         if state in ["start"]:
             state_colour = ansii["green"]
-        elif state in ["migrate", "disable", "provision"]:
+        elif state in ["migrate", "disable", "provision", "mirror"]:
             state_colour = ansii["blue"]
         elif state in ["stop", "fail"]:
             state_colour = ansii["red"]

client-cli/pvc/lib/vm.py

@@ -1760,6 +1760,7 @@ def format_info(config, domain_information, long_output):
         "provision": ansiprint.blue(),
         "restore": ansiprint.blue(),
         "import": ansiprint.blue(),
+        "mirror": ansiprint.blue(),
     }
     ainformation.append(
         "{}State:{}              {}{}{}".format(

daemon-common/cluster.py

@@ -1160,6 +1160,7 @@ def get_resource_metrics(zkhandler):
             "fail": 8,
             "import": 9,
             "restore": 10,
+            "mirror": 99,
         }
         state = vm["state"]
         output_lines.append(

daemon-common/common.py

@@ -85,6 +85,7 @@ vm_state_combinations = [
     "provision",
     "import",
     "restore",
+    "mirror",
 ]
 ceph_osd_state_combinations = [
     "up,in",

daemon-common/vm.py

@@ -24,6 +24,7 @@ import re
 import os.path
 import lxml.objectify
 import lxml.etree
+import subprocess
 
 from concurrent.futures import ThreadPoolExecutor
 from datetime import datetime
@@ -580,7 +581,7 @@ def rename_vm(zkhandler, domain, new_domain):
 
     # Verify that the VM is in a stopped state; renaming is not supported otherwise
     state = zkhandler.read(("domain.state", dom_uuid))
-    if state not in ["stop", "disable"]:
+    if state not in ["stop", "disable", "mirror"]:
         return (
             False,
             'ERROR: VM "{}" is not in stopped state; VMs cannot be renamed while running.'.format(
@@ -1125,6 +1126,7 @@ def get_list(
             "migrate",
             "unmigrate",
             "provision",
+            "mirror",
         ]
         if state not in valid_states:
             return False, 'VM state "{}" is not valid.'.format(state)
@@ -1903,10 +1905,10 @@ def vm_worker_flush_locks(zkhandler, celery, domain, force_unlock=False):
 
     # Check that the domain is stopped (unless force_unlock is set)
     domain_state = zkhandler.read(("domain.state", dom_uuid))
-    if not force_unlock and domain_state not in ["stop", "disable", "fail"]:
+    if not force_unlock and domain_state not in ["stop", "disable", "fail", "mirror"]:
         fail(
             celery,
-            f"VM state {domain_state} not in [stop, disable, fail] and not forcing",
+            f"VM state {domain_state} not in [stop, disable, fail, mirror] and not forcing",
         )
         return False
 
@@ -2329,7 +2331,7 @@ def vm_worker_rollback_snapshot(zkhandler, celery, domain, snapshot_name):
 
     # Verify that the VM is in a stopped state; renaming is not supported otherwise
     state = zkhandler.read(("domain.state", dom_uuid))
-    if state not in ["stop", "disable"]:
+    if state not in ["stop", "disable", "mirror"]:
         fail(
             celery,
             f"VM '{domain}' is not stopped or disabled; VMs cannot be rolled back while running",
@@ -3118,3 +3120,389 @@ def vm_worker_import_snapshot(
         current=current_stage,
         total=total_stages,
     )
+
+
+def vm_worker_send_snapshot(
+    zkhandler,
+    celery,
+    domain,
+    snapshot_name,
+    destination_api_uri,
+    destination_api_key,
+    destination_api_verify_ssl=True,
+    incremental_parent=None,
+    destination_storage_pool=None,
+):
+    import requests
+    from packaging.version import parse as parse_version
+
+    current_stage = 0
+    total_stages = 1
+    start(
+        celery,
+        f"Sending snapshot '{snapshot_name}' of VM '{domain}' to remote cluster '{destination_api_uri}'",
+        current=current_stage,
+        total=total_stages,
+    )
+
+    # Validate that VM exists in cluster
+    dom_uuid = getDomainUUID(zkhandler, domain)
+    if not dom_uuid:
+        fail(
+            celery,
+            f"Could not find VM '{domain}' in the cluster",
+        )
+        return False
+
+    # Get our side's VM configuration details
+    vm_detail = get_list(zkhandler, limit=dom_uuid, is_fuzzy=False)[1][0]
+    if not isinstance(vm_detail, dict):
+        fail(celery, f"VM listing returned invalid data: {vm_detail}",)
+        return False
+
+    # Check if the snapshot exists
+    if not zkhandler.exists(
+        ("domain.snapshots", dom_uuid, "domain_snapshot.name", snapshot_name)
+    ):
+        fail(
+            celery,
+            f"Could not find snapshot '{snapshot_name}' of VM '{domain}'",
+        )
+        return False
+
+    # Check if the incremental parent exists
+    if incremental_parent is not None and not zkhandler.exists(
+        ("domain.snapshots", dom_uuid, "domain_snapshot.name", incremental_parent)
+    ):
+        fail(
+            celery,
+            f"Could not find snapshot '{snapshot_name}' of VM '{domain}'",
+        )
+        return False
+
+    # Validate that the destination cluster can be reached
+    destination_api_timeout = (3.05, 172800)
+    destination_api_headers = {
+        "X-Api-Key": destination_api_key,
+        "Content-Type": "application/octet-stream",
+    }
+
+    try:
+        # Hit the API root; this should return "PVC API version x"
+        response = requests.get(
+            f"{destination_api_uri}/",
+            timeout=destination_api_timeout,
+            headers=None,
+            params=None,
+            data=None,
+            verify=destination_api_verify_ssl,
+        )
+        if "PVC API" not in response.json().get("message"):
+            raise ValueError("Remote API is not a PVC API or incorrect URI given")
+    except requests.exceptions.ConnectionError as e:
+        fail(
+            celery,
+            f"Connection to remote API timed out: {e}",
+        )
+        return False
+    except ValueError as e:
+        fail(
+            celery,
+            f"Connection to remote API is not valid: {e}",
+        )
+        return False
+    except Exception as e:
+        fail(
+            celery,
+            f"Connection to remote API failed: {e}",
+        )
+        return False
+
+    # Hit the API "/status" endpoint to validate API key and cluster status
+    response = requests.get(
+        f"{destination_api_uri}/status",
+        timeout=destination_api_timeout,
+        headers=destination_api_headers,
+        params=None,
+        data=None,
+        verify=destination_api_verify_ssl,
+    )
+    destination_cluster_status = response.json()
+    current_destination_pvc_version = destination_cluster_status.get(
+        "pvc_version", None
+    )
+    if current_destination_pvc_version is None:
+        fail(
+            celery,
+            "Connection to remote API failed: no PVC version information returned",
+        )
+        return False
+
+    expected_destination_pvc_version = "0.9.100"  # TODO: 0.9.101 when completed
+    if parse_version(current_destination_pvc_version) < parse_version(
+        expected_destination_pvc_version
+    ):
+        fail(
+            celery,
+            f"Remote PVC cluster is too old: requires version {expected_destination_pvc_version} or higher",
+        )
+        return False
+
+    # Check if the VM already exists on the remote
+    response = requests.get(
+        f"{destination_api_uri}/vm/{domain}",
+        timeout=destination_api_timeout,
+        headers=destination_api_headers,
+        params=None,
+        data=None,
+        verify=destination_api_verify_ssl,
+    )
+    destination_vm_status = response.json()
+    current_destination_vm_state = destination_vm_status.get(
+        "state", None
+    )
+    if current_destination_vm_state is not None and current_destination_vm_state != "mirror":
+        fail(
+            celery,
+            f"Remote PVC VM exists and is not a mirror",
+        )
+        return False
+
+    # Get details about VM snapshot
+    _, snapshot_timestamp, snapshot_xml, snapshot_rbdsnaps = zkhandler.read_many(
+        [
+            (
+                (
+                    "domain.snapshots",
+                    dom_uuid,
+                    "domain_snapshot.name",
+                    snapshot_name,
+                )
+            ),
+            (
+                (
+                    "domain.snapshots",
+                    dom_uuid,
+                    "domain_snapshot.timestamp",
+                    snapshot_name,
+                )
+            ),
+            (
+                (
+                    "domain.snapshots",
+                    dom_uuid,
+                    "domain_snapshot.xml",
+                    snapshot_name,
+                )
+            ),
+            (
+                (
+                    "domain.snapshots",
+                    dom_uuid,
+                    "domain_snapshot.rbd_snapshots",
+                    snapshot_name,
+                )
+            ),
+        ]
+    )
+    snapshot_rbdsnaps = snapshot_rbdsnaps.split(",")
+
+    # Get details about remote VM snapshots
+    destination_vm_snapshots = destination_vm_status.get("snapshots", [])
+    latest_destination_vm_snapshot = destination_vm_snapshots[0]
+
+    # Check if this snapshot is in the remote list already
+    if snapshot_name in [s['name'] for s in destination_vm_snapshots]:
+        fail(
+            celery,
+            f"Snapshot {snapshot_name} already exists on the target",
+        )
+        return False
+
+    # Check if this snapshot is older than the latest remote VM snapshot
+    if snapshot_timestamp < latest_destination_vm_snapshot["timestamp"]:
+        fail(
+            celery,
+            f"Target has a newer snapshot ({latest_destination_vm_snapshot['name']}); cannot send old snapshot {snapshot_name}",
+        )
+        return False
+
+    # Check that our incremental parent exists on the remote VM
+    if incremental_parent is not None:
+        if increment_parent not in [s['name'] for s in destination_vm_snapshots]:
+            fail(
+                celery,
+                f"Can not send incremental for a snapshot ({incremental_parent}) which does not exist on the target",
+            )
+            return False
+
+    # Set send type
+    send_type = "incremental" if incremental_parent is not None else "full"
+
+    # Begin send, set stages
+    total_stages = 2 + (2 * len(snapshot_rbdsnaps)) + (len(snapshot_rbdsnaps) if current_destination_vm_state is None else 0)
+
+    # Create the block devices on the remote side if this is a new VM send
+    for rbd in [r for r in vm_detail["disks"] if r['type'] == 'rbd']:
+        pool, volume = rbd["name"].split('/')
+
+        current_stage += 1
+        update(
+            celery,
+            f"Preparing remote volume for {rbd}@{snapshot_name}",
+            current=current_stage,
+            total=total_stages,
+        )
+
+        # Get the storage volume details
+        retcode, retdata = ceph.get_list_volume(zkhandler, pool, volume, is_fuzzy=False)
+        if not retcode or len(retdata) != 1:
+            if len(retdata) < 1:
+                error_message = f"No detail returned for volume {rbd}"
+            elif len(retdata) > 1:
+                error_message = f"Multiple details returned for volume {rbd}"
+            else:
+                error_message = f"Error getting details for volume {rbd}"
+            fail(
+                celery,
+                error_message,
+            )
+            return False
+
+        try:
+            size_bytes = ceph.format_bytes_fromhuman(retdata[0]["stats"]["size"])
+        except Exception as e:
+            error_message = f"Failed to get volume size for {rbd}: {e}"
+
+        if destination_storage_pool is not None:
+            pool = destination_storage_pool
+
+        if current_destination_vm_state is None:
+            current_stage += 1
+            update(
+                celery,
+                f"Creating remote volume {pool}/{volume} for {rbd}@{snapshot_name}",
+                current=current_stage,
+                total=total_stages,
+            )
+
+            # Check if the volume exists on the target
+            response = requests.get(
+                f"{destination_api_uri}/storage/ceph/volume/{pool}/{volume}",
+                timeout=destination_api_timeout,
+                headers=destination_api_headers,
+                params=None,
+                data=None,
+                verify=destination_api_verify_ssl,
+            )
+            if response.status_code != 404:
+                fail(
+                    celery,
+                    f"Remote storage pool {pool} already contains volume {volume}",
+                )
+                return False
+
+            # Create the volume on the target
+            params = {
+                "size": size_bytes,
+            }
+            response = requests.post(
+                f"{destination_api_uri}/storage/ceph/volume/{pool}/{volume}",
+                timeout=destination_api_timeout,
+                headers=destination_api_headers,
+                params=params,
+                data=None,
+                verify=destination_api_verify_ssl,
+            )
+            destination_volume_create_status = response.json()
+            if response.status_code != 200:
+                fail(
+                    celery,
+                    f"Failed to create volume {pool}/{volume} on target: {destination_volume_create_status['message']}",
+                )
+                return False
+
+        # Send the volume to the remote
+        cluster = rados.Rados(conffile='/etc/ceph/ceph.conf')
+        cluster.connect()
+        ioctx = cluster.open_ioctx(pool)
+        image = rbd.Image(ioctx, name=volume, snapshot=snapshot, read_only=True)
+        size = image.size()
+        chunk_size_mb = 128
+
+        if incremental_parent is not None:
+            # Diff between incremental_parent and snapshot
+            def diff_chunker():
+                def diff_cb(offset, length, exists):
+                    """ Callback to handle diff regions """
+                    if exists:
+                        data = image.read(offset, length)
+                        yield (offset.to_bytes(8, 'big') + length.to_bytes(8, 'big') + data)
+    
+                image.set_snap(incremental_parent)
+                image.diff_iterate(0, size, source_snapshot, diff_cb)
+            data_stream = diff_chunker()
+            celery_message = f"Sending diff between {incremental_parent} and {snapshot_name} for {rbd}")
+        else:
+            # Full image transfer
+            def chunker():
+                d_start = time.time()
+                chunk_size = 1024 * 1024 * chunk_size_mb
+                current_chunk = 0 
+                while current_chunk < size:
+                    t_end = time.time()
+                    t_tot = t_end - t_start
+                    chunk = image.read(current_chunk, chunk_size)
+                    yield chunk
+                    current_chunk += chunk_size
+            data_stream = chunker()
+            celery_message = f"Sending full image of {rbd}@{snapshot_name}"
+
+        current_stage += 1
+        update(
+            celery,
+            f"Sending volume {rbd}@{snapshot_name} to target ({send_type})",
+            current=current_stage,
+            total=total_stages,
+        )
+
+        send_params = {
+            'pool': pool,
+            'volume': volume,
+            'snapshot': snapshot_name,
+            'size': size,
+            'source_snapshot': incremental_parent,
+        }
+        send_headers = {
+            'X-Api-Key': destination_api_key,,
+            'Content-Type': 'application/octet-stream',
+            'Transfer-Encoding': None  # Disable chunked transfer encoding
+        }
+        try:
+            response = requests.post(
+                f"{destination_api_uri}/storage/ceph/volume/{pool}/{volume}",
+                timeout=destination_api_timeout,
+                headers=send_headers,
+                params=send_params,
+                data=data_stream,
+                verify=destination_api_verify_ssl,
+            )
+            response.raise_for_status()
+        except Exception as e:
+            fail(
+                celery,
+                f"Failed to send snapshot: {e}",
+            )
+            return False
+        finally:
+            image.close()
+            ioctx.close()
+            cluster.shutdown()
+
+    # Send the VM configuration
+    if current_destination_vm_state is None:
+        # This is a new VM, so define it
+        #response = requests.post()
+    else:
+        # This is a modification
+        #response = requests.post()

debian/control

@@ -32,7 +32,7 @@ Description: Parallel Virtual Cluster worker daemon
 
 Package: pvc-daemon-api
 Architecture: all
-Depends: systemd, pvc-daemon-common, python3-yaml, python3-flask, python3-flask-restful, python3-celery, python3-distutils, python3-redis, python3-lxml, python3-flask-migrate
+Depends: systemd, pvc-daemon-common, gunicorn, python3-gunicorn, python3-yaml, python3-flask, python3-flask-restful, python3-celery, python3-distutils, python3-redis, python3-lxml, python3-flask-migrate
 Description: Parallel Virtual Cluster API daemon
  A KVM/Zookeeper/Ceph-based VM and private cloud manager
  .

worker-daemon/pvcworkerd/Daemon.py

@@ -33,6 +33,7 @@ from daemon_lib.vm import (
     vm_worker_rollback_snapshot,
     vm_worker_export_snapshot,
     vm_worker_import_snapshot,
+    vm_worker_send_snapshot,
 )
 from daemon_lib.ceph import (
     osd_worker_add_osd,
@@ -227,6 +228,39 @@ def vm_import_snapshot(
     )
 
 
+@celery.task(name="vm.send_snapshot", bind=True, routing_key="run_on")
+def vm_send_snapshot(
+    self,
+    domain=None,
+    snapshot_name=None,
+    destination_api_uri="",
+    destination_api_key="",
+    destination_api_verify_ssl=True,
+    incremental_parent=None,
+    destination_storage_pool=None,
+    run_on="primary",
+):
+    @ZKConnection(config)
+    def run_vm_send_snapshot(
+        zkhandler, self, domain, snapshot_name, destination_api_uri, destination_api_key, destination_api_verify_ssl=True, incremental_parent=None, destination_storage_pool=None,
+    ):
+        return vm_worker_send_snapshot(
+            zkhandler,
+            self,
+            domain,
+            snapshot_name,
+            destination_api_uri,
+            destination_api_key,
+            destination_api_verify_ssl=destination_api_verify_ssl,
+            incremental_parent=incremental_parent,
+            destination_storage_pool=destination_storage_pool,
+        )
+
+    return run_vm_send_snapshot(
+        self, domain, snapshot_name, destination_api_uri, destination_api_key, destination_api_verify_ssl=destination_api_verify_ssl, incremental_parent=incremental_parent, destination_storage_pool=destination_storage_pool
+    )
+
+
 @celery.task(name="osd.add", bind=True, routing_key="run_on")
 def osd_add(
     self,