services/router: init

2026-09-17 08:57:32 +07:00
parent b85d6637f1
commit 60aac6efb2
39 changed files with 1831 additions and 929 deletions
@@ -0,0 +1,104 @@
+# Internal reverse proxy for the gateway: Caddy terminates TLS for
+# <service>.<site><siteId>.<proxy.domain> (e.g. omada.cnx1.cnx.network) and
+# forwards to backends by their internal address. The cert is a real Let's
+# Encrypt wildcard (*.<site><siteId>.<domain>) obtained via ACME DNS-01
+# against proxy.acme.nameserver with a gateway-scoped TSIG key, so browsers
+# trust it without any CA install; the names only *resolve* internally —
+# Blocky answers them with the router's LAN address, the public zone never
+# carries them.
+#
+# The TSIG secret is the shared dns-acme-<hostname>-secret generator
+# (acme-secret.nix, declared here via default.nix); the nameserver machine
+# must declare the same generator and load the key (this fleet: ns1).
+{ settings }:
+{ config, lib, ... }:
+let
+  cfg = settings;
+  hostname = config.networking.hostName;
+  tsigKey = "acme_${lib.replaceStrings [ "-" ] [ "_" ] hostname}";
+  certName = "${cfg.site}${toString cfg.siteId}.${cfg.proxy.domain}";
+  nameserver = "${cfg.proxy.acme.nameserver}:53";
+in
+{
+  config = lib.mkIf cfg.proxy.enable {
+    assertions = [
+      {
+        assertion = lib.all (v: cfg.vlans ? ${v}) cfg.proxy.allowVlans;
+        message = "router: proxy.allowVlans must name VLANs defined in vlans.";
+      }
+    ];
+
+    # Render the shared per-gateway TSIG secret into a lego rfc2136 env file,
+    # scoped on the nameserver to _acme-challenge.<site><siteId> TXT records.
+    clan.core.vars.generators."dns-acme-${hostname}-rfc2136" = {
+      files."rfc2136.env".secret = true; # root-owned; systemd reads it as root
+      dependencies = [ "dns-acme-${hostname}-secret" ];
+      script = ''
+        printf 'RFC2136_NAMESERVER=${nameserver}\nRFC2136_TSIG_ALGORITHM=hmac-sha256.\nRFC2136_TSIG_KEY=${tsigKey}\nRFC2136_TSIG_SECRET=%s\n' \
+          "$(cat "$in"/dns-acme-${hostname}-secret/secret)" > "$out"/rfc2136.env
+      '';
+    };
+
+    security.acme = {
+      acceptTerms = true;
+      defaults.email = cfg.proxy.acme.email;
+      # One wildcard for every proxied service; DNS-01, so issuance works
+      # behind PPPoE with no inbound reachability at all.
+      certs.${certName} = {
+        domain = "*.${certName}";
+        dnsProvider = "rfc2136";
+        environmentFile =
+          config.clan.core.vars.generators."dns-acme-${hostname}-rfc2136".files."rfc2136.env".path;
+        # Only that nameserver accepts this key's UPDATE; check propagation
+        # against it directly rather than a public resolver.
+        dnsResolver = nameserver;
+        # Caddy reads the cert from explicit file paths (tls directive below),
+        # so it won't notice a renewal on its own.
+        reloadServices = [ "caddy.service" ];
+      };
+    };
+
+    # The lego-issued cert is owned group=acme; Caddy needs to read the key.
+    users.users.caddy.extraGroups = [ "acme" ];
+
+    # The explicit `tls cert key` points Caddy at the wildcard cert and disables
+    # its automatic ACME, so no extra issuance happens.
+    services.caddy = {
+      enable = true;
+      virtualHosts = lib.mapAttrs' (
+        name: svc:
+        lib.nameValuePair "${name}.${certName}" {
+          extraConfig = ''
+            tls /var/lib/acme/${certName}/cert.pem /var/lib/acme/${certName}/key.pem
+            ${
+              if svc.insecureSkipVerify then
+                ''
+                  reverse_proxy ${svc.backend} {
+                    transport http {
+                      tls_insecure_skip_verify
+                    }
+                  }''
+              else
+                "reverse_proxy ${svc.backend}"
+            }
+          '';
+        }
+      ) cfg.proxy.services;
+    };
+
+    # Blocky answers <anything>.<site><siteId>.cnx.network (customDNS covers
+    # subdomains) with the router's LAN address — clients on any allowed VLAN
+    # reach that address through the router's input path.
+    services.blocky.settings.customDNS.mapping.${certName} = cfg.vlans.lan.address;
+
+    # 443 serves the proxy; 80 only carries Caddy's automatic HTTP->HTTPS
+    # redirect. mgmt is already a trusted interface; listed anyway so shrinking
+    # trustedInterfaces later doesn't silently break the proxy.
+    networking.firewall.interfaces = lib.genAttrs (map (v: "vlan-${v}") cfg.proxy.allowVlans) (_: {
+      allowedTCPPorts = [
+        80
+        443
+      ];
+    });
+  };
+}