implemented startup sanity checks on core models

invokeai/app/api_app.py

@@ -203,7 +203,10 @@ def invoke_api():
                 return find_port(port=port + 1)
             else:
                 return port
-
+            
+    from invokeai.backend.install.check_root import check_invokeai_root
+    check_invokeai_root(app_config)  # note, may exit with an exception if root not set up
+    
     port = find_port(app_config.port)
     if port != app_config.port:
         logger.warn(f"Port {app_config.port} in use, using port {port}")

invokeai/backend/install/check_root.py

@@ -0,0 +1,29 @@
+"""
+Check that the invokeai_root is correctly configured and exit if not.
+"""
+import sys
+from invokeai.app.services.config import (
+    InvokeAIAppConfig,
+)
+
+def check_invokeai_root(config: InvokeAIAppConfig):
+    try:
+        assert config.model_conf_path.exists()
+        assert config.db_path.exists()
+        assert config.models_path.exists()
+        for model in [
+                'CLIP-ViT-bigG-14-laion2B-39B-b160k',
+                'bert-base-uncased',
+                'clip-vit-large-patch14',
+                'sd-vae-ft-mse',
+                'stable-diffusion-2-clip',
+                'stable-diffusion-safety-checker']:
+            assert (config.models_path / f'core/convert/{model}').exists()
+    except:
+        print()
+        print('== STARTUP ABORTED ==')
+        print('** One or more necessary files is missing from your InvokeAI root directory **')
+        print('** Please rerun the configuration script to fix this problem. From the launcher, this is option [7] **')
+        input('Press any key to continue...')
+        sys.exit(0)
+