Improve UI.

module.nix

@@ -48,6 +48,20 @@ in
           The user the service will use.
         '';
       };
+
+      globalCacheTTL = lib.mkOption {
+        type = types.nullOr types.int;
+        default = null;
+        description = ''
+          How long should nix store narinfo files.
+
+          If not defined, the module will not reconfigure the entry.
+          If it is defined, this will define how many seconds a cache entry will
+          be stored.
+
+          By default not given, as it affects the UX of the nix installation.
+        '';
+      }
     };
   };
 
@@ -120,6 +134,11 @@ in
       binaryCachePublicKeys = lib.mkIf (cfg.publicKeyFile != null) [
         (builtins.readFile cfg.publicKeyFile)
       ];
+
+      extraOptions = lib.mkIf (cfg.globalCacheTTL != null) ''
+        narinfo-cache-negative-ttl ${cfg.globalCacheTTL}
+        narinfo-cache-positive-ttl ${cfg.globalCacheTTL}
+      '';
     };
 
     networking.firewall = lib.mkIf (cfg.openFirewall) {

peerix/__main__.py

@@ -1,19 +1,36 @@
+import os
 import logging
 import asyncio
+import argparse
 
 import uvloop
 from hypercorn import Config
 from hypercorn.asyncio import serve
 
-from peerix.app import app
+from peerix.app import app, setup_stores
 
 
+parser = argparse.ArgumentParser(description="Peerix nix binary cache.")
+parser.add_argument("--verbose", action="store_const", const=logging.DEBUG, default=logging.INFO, dest="loglevel")
+parser.add_argument("--port", default=12304, type=int)
+parser.add_argument("--private-key", required=False)
+
 def run():
-    logging.basicConfig()
+    args = parser.parse_args()
+    os.environ["NIX_SECRET_KEY_FILE"] = os.path.abspath(os.path.expanduser(args.private_key))
+
+    logging.basicConfig(level=args.loglevel)
     uvloop.install()
+
+    asyncio.run(main(args.port))
+
+
+async def main(port: int):
     config = Config()
-    config.bind = ["0.0.0.0:12304"]
-    asyncio.run(serve(app, config))
+    config.bind = [f"0.0.0.0:{port}"]
+
+    async with setup_stores(port):
+        await serve(app, config)
 
 
 if __name__ == "__main__":

peerix/app.py

@@ -1,4 +1,5 @@
 import logging
+import datetime
 import contextlib
 
 from starlette.requests import Request
@@ -12,27 +13,18 @@ from peerix.prefix import PrefixStore
 
 
 @contextlib.asynccontextmanager
-async def _setup_stores(local_port: int):
+async def setup_stores(local_port: int):
     global l_access, r_access
     async with local() as l:
         l_access = PrefixStore("local/nar", l)
         lp = PrefixStore("local", l)
         async with remote(lp, local_port, "0.0.0.0", lp.prefix) as r:
-            r_access = PrefixStore("remote", r)
+            r_access = PrefixStore("v2/remote", r)
             yield
-setup_store = _setup_stores(12304)
 
 
 app = Starlette()
 
-@app.on_event("startup")
-async def _setup_stores_init():
-    await setup_store.__aenter__()
-
-@app.on_event("shutdown")
-async def _setup_stores_deinit():
-    await setup_store.__aexit__(None, None, None)
-
 
 @app.route("/nix-cache-info")
 async def cache_info(_: Request) -> Response:
@@ -43,10 +35,14 @@ async def cache_info(_: Request) -> Response:
 
 @app.route("/{hash:str}.narinfo")
 async def narinfo(req: Request) -> Response:
+
     if req.client.host != "127.0.0.1":
         return Response(content="Permission denied.", status_code=403)
     
+    # We do not cache nar-infos.
+    # Therefore, dynamically recompute expires at.
     ni = await r_access.narinfo(req.path_params["hash"])
+
     if ni is None:
         return Response(content="Not found", status_code=404)
 
@@ -62,9 +58,18 @@ async def access_narinfo(req: Request) -> Response:
 
 @app.route("/local/nar/{path:str}")
 async def push_nar(req: Request) -> Response:
-    return StreamingResponse(l_access.nar(f"local/nar/{req.path_params['path']}"), media_type="text/plain")
+    try:
+        return StreamingResponse(
+                await l_access.nar(f"local/nar/{req.path_params['path']}"),
+                media_type="text/plain"
+        )
+    except FileNotFoundError:
+        return Response(content="Gone", status_code=404)
 
-
-@app.route("/remote/{path:path}")
+# Paths must be versioned as nix is caching the NAR urls.
+@app.route("/v2/remote/{path:path}")
 async def pull_nar(req: Request) -> Response:
-    return StreamingResponse(r_access.nar(f"remote/{req.path_params['path']}"), media_type="text/plain")
+    try:
+        return StreamingResponse(await r_access.nar(f"remote/{req.path_params['path']}"), media_type="text/plain")
+    except FileNotFoundError:
+        return Response(content="Gone", status_code=404)

peerix/local.py

@@ -67,13 +67,20 @@ class LocalStore(Store):
             info = NarInfo.parse(await resp.text())
         return info._replace(url=base64.b64encode(info.storePath.encode("utf-8")).replace(b"/", b"_").decode("ascii")+".nar")
 
-    async def nar(self, sp: str) -> t.AsyncIterable[bytes]:
+    async def nar(self, sp: str) -> t.Awaitable[t.AsyncIterable[bytes]]:
         if sp.endswith(".nar"):
             sp = sp[:-4]
         path = base64.b64decode(sp.replace("_", "/")).decode("utf-8")
         if not path.startswith((await self.cache_info()).storeDir):
             raise FileNotFoundError()
 
+        if not os.path.exists(path):
+            raise FileNotFoundError()
+
+        return self._nar_pull(path)
+
+    async def _nar_pull(self, path: str) -> t.AsyncIterable[bytes]:
+        logger.info(f"Serving {path}")
         process = await asyncio.create_subprocess_exec(
                 nix, "dump-path", "--", path,
                 stdout=subprocess.PIPE,
@@ -85,11 +92,19 @@ class LocalStore(Store):
         while not process.stdout.at_eof():
             yield await process.stdout.read(10*1024*1024)
 
+        logger.debug(f"Served {path}")
+        try:
+            process.terminate()
+        except ProcessLookupError:
+            pass
+
 
 @contextlib.asynccontextmanager
 async def local():
     with tempfile.TemporaryDirectory() as tmpdir:
         sock = f"{tmpdir}/server.sock"
+
+        logger.info("Launching nix-serve.")
         process = await asyncio.create_subprocess_exec(
             nix_serve, "--listen", sock,
             stdin=subprocess.DEVNULL,
@@ -108,5 +123,10 @@ async def local():
             async with aiohttp.ClientSession(connector_owner=True, connector=connector) as session:
                 yield LocalStore(session)
         finally:
+            try:
                 process.terminate()
+            except ProcessLookupError:
+                pass
+
+            logger.info("nix-serve exited.")
 

peerix/prefix.py

@@ -16,10 +16,9 @@ class PrefixStore(Store):
             return None
         return info._replace(url=f"{self.prefix}/{info.url}")
 
-    async def nar(self, path: str) -> t.AsyncIterable[bytes]:
+    def nar(self, path: str) -> t.Awaitable[t.AsyncIterable[bytes]]:
         if not path.startswith(self.prefix + "/"):
             raise FileNotFoundError("Not found.")
 
-        async for chunk in self.backend.nar(path[len(self.prefix)+1:]):
-            yield chunk
+        return self.backend.nar(path[len(self.prefix)+1:])
 

peerix/remote.py

@@ -126,17 +126,41 @@ class DiscoveryProtocol(asyncio.DatagramProtocol, Store):
                 return
             info = NarInfo.parse(await resp.text())
 
-        return info._replace(url = f"{addr[0]}/{port}/{info.url}")
+        return info._replace(url = f"{addr[0]}/{port}/{hsh}/{info.url}")
 
-    async def nar(self, sp: str) -> t.AsyncIterable[bytes]:
-        addr1, addr2, p = sp.split("/", 2)
-        async with self.session.get(f"http://{addr1}:{addr2}/{p}") as resp:
-            if resp.status != 200:
-                raise FileNotFoundError("Not found.")
+    async def nar(self, sp: str) -> t.Awaitable[t.AsyncIterable[bytes]]:
+        try:
+            return await self._nar_req(sp)
+        except FileNotFoundError:
+            addr1, addr2, hsh, _ = sp.split("/", 2)
+            logging.warn(f"Remote({addr1}:{addr2})-store path is dead: {sp}")
+            pass
+
+        _, _, hsh, _ = sp.split("/", 2)
+        narinfo = await self.narinfo(hsh)
+        if narinfo is None:
+            logging.warn(f"All sources are gone.")
+            raise FileNotFoundError()
+
+        return await self._nar_req(narinfo.url)
+
+    async def _nar_req(self, url: str) -> t.Awaitable[t.AsyncIterable[bytes]]:
+        addr1, addr2, _, p = url.split("/", 2)
+        resp = await self.session.get(f"http://{addr1}:{addr2}/{p}")
+        if resp.status == 200:
+            return self._nar_direct(resp)
+        else:
+            raise FileNotFoundError()
+
+
+    async def _nar_direct(self, resp: aiohttp.ClientResponse) -> t.AsyncIterable[bytes]:
+        try:
             content = resp.content
             while not content.at_eof():
                 yield await content.readany()
-
+        finally:
+            resp.close()
+            await resp.wait_for_close()
 
 
 @contextlib.asynccontextmanager

peerix/store.py

@@ -86,6 +86,6 @@ class Store:
     async def narinfo(self, hsh: str) -> t.Optional[NarInfo]:
         raise NotImplementedError()
 
-    async def nar(self, url: str) -> t.AsyncIterable[bytes]:
+    def nar(self, url: str) -> t.Awaitable[t.AsyncIterable[bytes]]:
         raise NotImplementedError()