Disks Service

backend/disks/disk.py

@@ -0,0 +1,31 @@
+import pathlib
+import threading
+import weakref
+
+import disk_paths
+import disk_utils
+
+DICTIONARY_LOCK = threading.Lock()
+DISK_LOCKS = weakref.WeakValueDictionary()
+
+def create_disk(request):
+    paths = disk_paths.DiskPaths(request)
+    workstation = request['workstation']
+
+    with disk_lock(paths):
+        if not paths.target_path.exists():
+            disk_utils.create_os_disk(paths)
+
+        if workstation['cpu'] == 'ARM' and not paths.nvram_target_path.exists():
+            disk_utils.create_nvram_disk(paths)
+
+def delete_disk(request):
+    paths = disk_paths.DiskPaths(request)
+
+    with disk_lock(paths):
+        paths.target_path.unlink(missing_ok=True)
+        paths.nvram_target_path.unlink(missing_ok=True)
+
+def disk_lock(paths):
+    with DICTIONARY_LOCK:
+        return DISK_LOCKS.setdefault(paths.target_filename, threading.Lock())

backend/disks/disk_paths.py

@@ -0,0 +1,60 @@
+import pathlib
+
+class DiskPaths:
+    STORAGE_HOSTS_PATH = pathlib.Path("/var/opt/instant-workstation/storage-hosts")
+
+    def __init__(self, request):
+        self.persistence_type = request['persistence_type']
+        self.storage_host = request['storage_host']
+        self.workstation = request['workstation']
+        self.user_id = request['user_id']
+
+    @property
+    def nvram_filename(self):
+        return f"{self.workstation_key}_NVRAM.img"
+
+    @property
+    def nvram_path(self):
+        return self.storage_host_path / 'firmware' / self.nvram_filename
+
+    @property
+    def nvram_target_filename(self):
+        return f"{self.user_id}_{self.nvram_filename}"
+
+    @property
+    def nvram_target_path(self):
+        return self.storage_host_path / self.persistence_type / self.nvram_target_filename
+
+    @property
+    def staging_path(self):
+        return self.storage_host_path / 'staging'
+
+    @property
+    def storage_host_path(self):
+        return self.STORAGE_HOSTS_PATH / self.storage_host
+
+    @property
+    def target_filename(self):
+        return f"{self.user_id}_{self.template_filename}"
+
+    @property
+    def target_path(self):
+        return self.storage_host_path / self.persistence_type / self.target_filename
+
+    @property
+    def template_filename(self): 
+        return f"{self.workstation_key}.qcow2"
+
+    @property
+    def template_path(self):
+        return self.storage_host_path / 'template' / self.template_filename
+
+    @property
+    def workstation_key(self):
+        return (
+            f"{self.workstation['name']}_"
+            f"{self.workstation['version']}_"
+            f"{self.workstation['cpu']}_"
+            f"{self.workstation['bitness']}_"
+            f"{self.workstation['endianness']}"
+        )

backend/disks/disk_utils.py

@@ -0,0 +1,30 @@
+import pathlib
+import shutil
+import subprocess
+import tempfile
+
+def create_os_disk(paths):
+    with tempfile.TemporaryDirectory(dir=paths.staging_path) as temporary_directory:
+        temporary_path = pathlib.Path(temporary_directory) / 'disk.qcow2'
+
+        subprocess.run(
+            args=[
+                'qemu-img', 'create',
+                '--format', 'qcow2',
+                '--backing', paths.template_path,
+                '--backing-format', 'qcow2',
+                temporary_path
+            ],
+            check=True,
+            timeout=10
+        )
+
+        temporary_path.replace(paths.target_path)
+
+def create_nvram_disk(paths):
+    with tempfile.TemporaryDirectory(dir=paths.staging_path) as temporary_directory:
+        temporary_path = pathlib.Path(temporary_directory) / 'NVRAM.img'
+
+        shutil.copyfile(paths.nvram_path, temporary_path)
+        
+        temporary_path.replace(paths.nvram_target_path)

backend/disks/disks.py

@@ -0,0 +1,19 @@
+import http.server
+import signal
+
+import request_handler
+
+def shutdown(_signum, _frame):
+    raise SystemExit(0)
+
+SERVER_ADDRESS = ('', 50005)
+SERVER = http.server.ThreadingHTTPServer(SERVER_ADDRESS, request_handler.RequestHandler)
+SERVER.daemon_threads = False
+
+signal.signal(signal.SIGINT, shutdown)
+signal.signal(signal.SIGTERM, shutdown)
+
+try:
+    SERVER.serve_forever()
+finally:
+    SERVER.server_close()

backend/disks/request_handler.py

@@ -0,0 +1,41 @@
+import http.server
+import json
+
+import disk
+
+class RequestHandler(http.server.BaseHTTPRequestHandler):
+    protocol_version = 'HTTP/1.1'
+    timeout = 10
+
+    def do_DELETE(self):
+        try:
+            disk.delete_disk(self.body())
+
+        except Exception as error:
+            self.log_error("Disk deletion failed: %s", error)
+            self.send_error(500)
+            return
+
+        self.send_success()
+
+    def do_POST(self):
+        try:
+            disk.create_disk(self.body())
+
+        except Exception as error:
+            self.log_error("Disk creation failed: %s", error)
+            self.send_error(500)
+            return
+
+        self.send_success()
+
+    def body(self):
+        content_length = int(self.headers.get('Content-Length', 0))
+        return json.loads(self.rfile.read(content_length))
+
+    def send_success(self):
+        self.close_connection = True
+        self.send_response(200)
+        self.send_header('Content-Length', '0')
+        self.send_header('Connection', 'close')
+        self.end_headers()