change log shipper interface

* it's now a command not a service
* shipper is expected to open() the fifo passed as $LOG_FIFO instead of
  getting logs on stdin

logtap determines that remote logs are getting sent when there's a
reader on the fifo it's writing, but opening the fifo as stdin of
s6-tcpclient is too early as it hasn't even connected to the remote
log server at that time

examples/rotuer.nix

@@ -129,6 +129,32 @@ rec {
     s6
   ];
 
+  services.qemu-hyp-route =
+    let
+      interface = config.hardware.networkInterfaces.wan;
+      addr = svc.network.address.build {
+        inherit interface;
+        family = "inet";
+        address = "10.0.0.10";
+        prefixLength = 24;
+      };
+    in
+    svc.network.route.build {
+      target = "10.0.0.1";
+      inherit interface;
+      via = "10.0.0.10";
+      metric = 1;
+      dependencies = [ addr ];
+    };
+
+  logging.shipping = {
+    enable = true;
+    command = ''
+      ${pkgs.s6-networking}/bin/s6-tcpclient 10.0.0.1 9428 ${pkgs.logshippers}/bin/victorialogsend http://loaclhost:9428/insert/jsonline
+      '';
+    dependencies = [services.qemu-hyp-route];
+  };
+
   programs.busybox = {
     applets = [
       "fdisk"

modules/s6/default.nix

@@ -242,9 +242,17 @@ in
           type = types.path;
           default = "/run/.log-shipping.sock";
         };
-        service = mkOption {
-          description = "log shipper service";
-          type = pkgs.liminix.lib.types.service;
+        command = mkOption {
+          description = "log shipping command, should open the file named by the environment variable $LOG_FIFO";
+          type = types.lines;
+          example = lib.literalExpression ''
+            ''${pkgs.s6-networking}/bin/s6-tcpclient loghost 9428 ''${pkgs.logshippers}/bin/victorialogsend http://loghost:9428/insert/jsonline
+          '';
+        };
+        dependencies = mkOption {
+          description = "services required by the shipping script";
+          type = types.listOf pkgs.liminix.lib.types.service;
+          default = [];
         };
       };
       script = mkOption {
@@ -268,32 +276,17 @@ in
         ...
       }:
       let
-        cfg = config.logging;
-        pipeline =
-          shipper:
-          bundle {
-            name = "log-shipping-pipe";
-            contents =
-              let
-                eat = longrun {
-                  name = "log-shipping-pipe-eat";
-                  run = ''
-                    cat ${cfg.shipping.socket}
-                  '';
-                  producer-for = spew.name;
-                };
-                spew = shipper.override {
-                  consumer-for = "log-shipping-pipe-eat";
-                };
-              in
-              [
-                eat
-                spew
-              ];
-          };
+        cfg = config.logging.shipping;
       in
-      mkIf cfg.shipping.enable {
-        services.${cfg.shipping.service.name} = pipeline cfg.shipping.service;
+      mkIf cfg.enable {
+        services.log-shipper = longrun {
+          name = "log-shipper";
+          run = ''
+            export LOG_FIFO=${cfg.socket}
+            ${cfg.command}
+          '';
+          inherit (cfg) dependencies;
+        };
       }
     )
   ];

pkgs/logshippers/victorialogsend.fnl

@@ -88,13 +88,14 @@ Host: %s\
 
 (fn run []
   (let [{ : auth : url } (parse-args arg)
-        in-fd 6
-        out-fd 7]
-    (writefd out-fd (http-header url.host url.path auth))
-    (while (case (io.stdin:read "l")
-             line (writefd out-fd (process-line line))))
-    (writefd out-fd (chunk ""))
-    (io.stderr:write (ll.read in-fd))))
+        http-response-fd 6
+        http-req-fd 7]
+    (writefd http-req-fd (http-header url.host url.path auth))
+    (with-open [logs (assert (io.open (os.getenv "LOG_FIFO") :r))]
+      (while (case (logs:read "l")
+               line (writefd http-req-fd (process-line line)))))
+    (writefd http-req-fd (chunk ""))
+    (io.stderr:write (ll.read http-response-fd))))
 
 
 { : run }