refactor(ops): Split //ops/nixos into different locations

Splits //ops/nixos into:

* //ops/nixos.nix - utility functions for building systems
* //ops/machines - shared machine definitions (read by readTree)
* //ops/modules - shared NixOS modules (skipped by readTree)

This simplifies working with the configuration fixpoint in whitby, and
is overall a bit more in line with how NixOS systems in user folders
currently work.

Change-Id: I1322ec5cc76c0207c099c05d44828a3df0b3ffc1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2931
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: glittershark <grfn@gws.fyi>

ops/modules/www/b.tvl.fyi.nix

@@ -0,0 +1,32 @@
+{ config, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."b-shortlink" = {
+      serverName = "b";
+      extraConfig = "return 302 https://b.tvl.fyi$request_uri;";
+    };
+
+    services.nginx.virtualHosts."b.tvl.fyi" = {
+      serverName = "b.tvl.fyi";
+      serverAliases = [ "b.tvl.su" ];
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        # Forward short links to issues to the issue itself (b/32)
+        location ~ ^/(\d+)$ {
+          return 302 https://b.tvl.fyi/issues$request_uri;
+        }
+
+        location / {
+          proxy_pass http://localhost:${toString config.services.depot.panettone.port};
+        }
+      '';
+    };
+  };
+}

ops/modules/www/base.nix

@@ -0,0 +1,36 @@
+{ config, pkgs, ... }:
+
+{
+  config = {
+    services.nginx = {
+      enable = true;
+      enableReload = true;
+
+      recommendedTlsSettings = true;
+      recommendedGzipSettings = true;
+      recommendedProxySettings = true;
+    };
+
+    # NixOS 20.03 broke nginx and I can't be bothered to debug it
+    # anymore, all solution attempts have failed, so here's a
+    # brute-force fix.
+    #
+    # TODO(tazjin): Find a link to the upstream issue and see if
+    # they've sorted it after ~20.09
+    systemd.services.fix-nginx = {
+      script = "${pkgs.coreutils}/bin/chown -f -R nginx: /var/spool/nginx /var/cache/nginx";
+
+      serviceConfig = {
+        User = "root";
+        Type = "oneshot";
+      };
+    };
+
+    systemd.timers.fix-nginx = {
+      wantedBy = [ "multi-user.target" ];
+      timerConfig = {
+        OnCalendar = "minutely";
+      };
+    };
+  };
+}

ops/modules/www/cache.tvl.su.nix

@@ -0,0 +1,26 @@
+{ config, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."cache.tvl.su" = {
+      serverName = "cache.tvl.su";
+      serverAliases = [ "cache.tvl.fyi" ];
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        location = /cache-key.pub {
+          alias /etc/secrets/nix-cache-key.pub;
+        }
+
+        location / {
+          proxy_pass http://localhost:${toString config.services.nix-serve.port};
+        }
+      '';
+    };
+  };
+}

ops/modules/www/cl.tvl.fyi.nix

@@ -0,0 +1,30 @@
+{ config, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."cl-shortlink" = {
+      serverName = "cl";
+      extraConfig = "return 302 https://cl.tvl.fyi$request_uri;";
+    };
+
+    services.nginx.virtualHosts.gerrit = {
+      serverName = "cl.tvl.fyi";
+      serverAliases = [ "cl.tvl.su" ];
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        location / {
+          proxy_pass http://localhost:4778;
+          proxy_set_header  X-Forwarded-For $remote_addr;
+          # The :443 suffix is a workaround for https://b.tvl.fyi/issues/88.
+          proxy_set_header  Host $host:443;
+        }
+      '';
+    };
+  };
+}

ops/modules/www/code.tvl.fyi.nix

@@ -0,0 +1,35 @@
+{ depot, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts.cgit = {
+      serverName = "code.tvl.fyi";
+      serverAliases = [ "code.tvl.su" ];
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        # Serve the rendered Tvix component SVG.
+        #
+        # TODO(tazjin): Implement a way of serving this dynamically
+        location = /about/tvix/docs/component-flow.svg {
+            alias ${depot.tvix.docs.svg}/component-flow.svg;
+        }
+
+        # Static assets must always hit the root.
+        location ~ ^/(favicon\.ico|cgit\.(css|png))$ {
+           proxy_pass http://localhost:2448;
+        }
+
+        # Everything else hits the depot directly.
+        location / {
+            proxy_pass http://localhost:2448/cgit.cgi/depot/;
+        }
+      '';
+    };
+  };
+}

ops/modules/www/cs.tvl.fyi.nix

@@ -0,0 +1,31 @@
+{ config, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."cs.tvl.fyi" = {
+      serverName = "cs.tvl.fyi";
+      serverAliases = [ "cs.tvl.su" ];
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        location = / {
+          return 301 https://cs.tvl.fyi/depot;
+        }
+
+        location / {
+          proxy_set_header X-Sg-Auth "Anonymous";
+          proxy_pass http://localhost:${toString config.services.depot.sourcegraph.port};
+        }
+
+        location /users/Anonymous/settings {
+          return 301 https://cs.tvl.fyi;
+        }
+      '';
+    };
+  };
+}

ops/modules/www/login.tvl.fyi.nix

@@ -0,0 +1,24 @@
+{ ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."login.tvl.fyi" = {
+      serverName = "login.tvl.fyi";
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        location / {
+          proxy_pass http://localhost:8443;
+          proxy_set_header X-Forwarded-For $remote_addr;
+          proxy_set_header X-Forwarded-Proto https;
+          proxy_set_header Host $host;
+        }
+      '';
+    };
+  };
+}

ops/modules/www/tazj.in.nix

@@ -0,0 +1,40 @@
+# serve tazjin's website & blog
+{ depot, config, lib, pkgs, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."tazj.in" = {
+      enableACME = true;
+      forceSSL = true;
+      root = depot.users.tazjin.homepage;
+
+      extraConfig = ''
+        ${depot.users.tazjin.blog.oldRedirects}
+        location /blog/ {
+          alias ${depot.users.tazjin.blog.rendered}/;
+
+          if ($request_uri ~ ^/(.*)\.html$) {
+            return 302 /$1;
+          }
+
+          try_files $uri $uri.html $uri/ =404;
+        }
+
+        # Temporary place for serving static files.
+        location /blobs/ {
+          alias /var/lib/tazjins-blobs/;
+        }
+      '';
+    };
+
+    services.nginx.virtualHosts."git.tazj.in" = {
+      enableACME = true;
+      forceSSL = true;
+      extraConfig = "return 301 https://code.tvl.fyi$request_uri;";
+    };
+  };
+}

ops/modules/www/todo.tvl.fyi.nix

@@ -0,0 +1,25 @@
+{ depot, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."todo.tvl.fyi" = {
+      serverName = "todo.tvl.fyi";
+      serverAliases = [ "todo.tvl.su" ];
+      root = depot.web.todolist;
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
+
+        location ~* \.(webp|woff2)$ {
+          add_header Cache-Control "public, max-age=31536000";
+        }
+      '';
+    };
+  };
+}

ops/modules/www/tvl.fyi.nix

@@ -0,0 +1,30 @@
+{ depot, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."tvl.fyi" = {
+      serverName = "tvl.fyi";
+      root = depot.web.tvl;
+      enableACME = true;
+      forceSSL = true;
+
+      extraConfig = ''
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
+
+        rewrite ^/builds/?$ https://buildkite.com/tvl/depot/ last;
+
+        rewrite ^/monorepo-doc/?$ https://docs.google.com/document/d/1nnyByXcH0F6GOmEezNOUa2RFelpeRpDToBLYD_CtjWE/edit?usp=sharing last;
+
+        rewrite ^/irc/?$ ircs://chat.freenode.net:6697/##tvl last;
+
+        location ~* \.(webp|woff2)$ {
+          add_header Cache-Control "public, max-age=31536000";
+        }
+      '';
+    };
+  };
+}

ops/modules/www/wigglydonke.rs.nix

@@ -0,0 +1,15 @@
+{ depot, lib, pkgs, ... }:
+
+{
+  imports = [
+    ./base.nix
+  ];
+
+  config = {
+    services.nginx.virtualHosts."wigglydonke.rs" = {
+      enableACME = true;
+      forceSSL = true;
+      root = "${depot.depotPath}/users/glittershark/wigglydonke.rs";
+    };
+  };
+}