Init

fallback.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+
+import uvicorn
+from fastapi import FastAPI, Request, HTTPException
+from fastapi.responses import RedirectResponse, FileResponse
+import requests
+import datetime
+
+app = FastAPI()
+hosts = [
+    "SERVER1",
+    "SERVER2",
+    "SERVER3",
+    "SERVER4"
+    ]
+cache = {}
+
+def find_fit(parent):
+    print(cache)
+    hosts_local = hosts.copy()
+    if parent in cache.keys():
+        print(f"DEBUG: Cache Hit {parent}: {cache[parent]}")
+        idx = hosts.index(cache[parent])
+        if idx:
+            hosts_local[idx], hosts_local[0] = hosts_local[0], hosts_local[idx]
+
+    for host in hosts_local:
+        try:
+            print(f"DEBUG: Tesing for http://{host}/{parent}")
+            if requests.head(f"http://{host}/{parent}", allow_redirects=True).status_code == 200:
+                cache[parent] = host
+                return host
+            else:
+                cache[parent] = ""
+        except Exception:
+            pass
+    return None
+
+def log(level, status_code, path, header):
+    print(f'{level}: [{datetime.datetime.now()}] "{status_code} {path} "{header.get("User-Agent")}"')
+
+@app.get("/{path:path}")
+async def index(request: Request, path: str):
+    if path in [None, "", "favicon.ico", "index.html"]:
+        if path in [None, ""]:
+            path = "index.html"
+        print(f'RETURN: [{datetime.datetime.now()}] "200 {path} "{request.headers.get("User-Agent")}"')
+        return FileResponse(path)
+    
+    server = find_fit(path.split("/")[0])
+    
+    if server:
+        print(f'RETURN: [{datetime.datetime.now()}] "301 http://{server}/{path}" "{request.headers.get("User-Agent")}"')
+        return RedirectResponse(url=f"http://{server}/{path}")
+    else:
+        print(f'RETURN: [{datetime.datetime.now()}] "404 Not found" "{request.headers.get("User-Agent")}"')
+        raise HTTPException(status_code=404, detail="No available server.")
+
+if __name__=="__main__":
+    print('Starting Server...')
+    uvicorn.run(
+        "fallback:app",
+        host="0.0.0.0",
+        port=8080,
+        log_level="info",
+        reload=True,
+    )
+