From 453899c46a8e7f9ded8dce9b7d737665d004f808 Mon Sep 17 00:00:00 2001
From: ibizaman <ibizapeanut@gmail.com>
Date: Wed, 9 Nov 2022 20:34:15 -0800
Subject: [PATCH] fix nixos-rebuild involving udev

---
 haproxy/configcreator.nix | 181 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 181 insertions(+)
 create mode 100644 haproxy/configcreator.nix

diff --git a/haproxy/configcreator.nix b/haproxy/configcreator.nix
new file mode 100644
index 0000000..1f64763
--- /dev/null
+++ b/haproxy/configcreator.nix
@@ -0,0 +1,181 @@
+{ lib
+}:
+
+with builtins;
+with lib.attrsets;
+with lib.lists;
+with lib.strings;
+rec {
+  default =
+    { user
+    , group
+    , certPath
+    , stats ? null
+    , debug ? false
+    }: {
+      global = {
+        # Silence a warning issued by haproxy. Using 2048
+        # instead of the default 1024 makes the connection stronger.
+        "tune.ssl.default-dh-param" = 2048;
+
+        maxconn = 20000;
+
+        inherit user group;
+
+        log = "/dev/log local0 info";
+      };
+
+      defaults = {
+        log = "global";
+        option = "httplog";
+
+        timeout = {
+          connect = "10s";
+          client = "15s";
+          server = "30s";
+          queue = "100s";
+        };
+      };
+
+      frontend = {
+        http-to-https = {
+          mode = "http";
+          bind = "*:80";
+          rules = [
+            {
+              redirect = true;
+              scheme = "https";
+              code = 301;
+              condition = "!{ ssl_fc }";
+            }
+          ];
+        };
+
+        https = {
+          mode = "http";
+          bind = {
+            addr = "*:443";
+            ssl = true;
+            crt = certPath;
+          };
+        } // optionalAttrs (debug) {
+          log-format = "%ci:%cp [%tr] %ft %b/%s %TR/%Tw/%Tc/%Tr/%Ta %ST %B %CC %CS %tsc %ac/%fc/%bc/%sc/%rc %sq/%bq %hr %hs %{+Q}r %sslv %sslc %[ssl_fc_cipherlist_str]";
+        };
+      } // optionalAttrs (stats != null)
+        (let
+          stats_ = {
+            port = 8404;
+            uri = "/stats";
+            refresh = "10s";
+            prometheusUri = null;
+          } // stats;
+        in
+          {
+            stats = {
+              bind = "localhost:${toString stats_.port}";
+              mode = "http";
+              stats = {
+                enable = true;
+                hide-version = false;
+                uri = stats_.uri;
+                refresh = stats_.refresh;
+              } // optionalAttrs (stats_.prometheusUri != null) {
+                http-request = [
+                  "use-service prometheus-exporter if { path ${stats_.prometheusUri} }"
+                ];
+              };
+            };
+          });
+    };
+
+  mkRule =
+    { redirect ? false
+    , scheme ? "https"
+    , code ? null
+    , condition ? null
+    }:
+    concatStringsSep " " (flatten [
+      (optional redirect "redirect")
+        scheme
+        (optional (code != null) "code ${toString code}")
+        (optional (condition != null) "if ${condition}")
+    ]);
+
+  mkBind =
+    { addr
+    , ssl ? false
+    , crt ? null
+    }:
+    concatStringsSep " " (flatten [
+      addr
+      (optional ssl "ssl")
+      (optional (crt != null) "crt ${crt}")
+    ]);
+
+  augmentedContent = fieldName: rules: set:
+    let
+      print = {rule = k: v:
+        assert lib.assertMsg (isString v || isInt v) "cannot print key '${k}' of type '${typeOf v}', should be string or int instead";
+        "${k} ${toString v}";};
+
+      matchingRule = k: v: findFirst (rule: rule.match k v) print rules;
+
+      augment = k: v:
+        let
+          match = matchingRule k v;
+          rule = if hasAttr "rule" match then match.rule else null;
+          rules = if hasAttr "rules" match then match.rules else null;
+        in
+          if rule != null
+          then rule k v
+          else
+            assert lib.assertMsg (isAttrs v) "attempt to apply rules on key '${k}' which is a '${typeOf v}' but should be a set";
+            augmentedContent k rules v;
+    in
+      flatten (mapAttrsToList augment (
+        assert lib.assertMsg (isAttrs set) "attempt to apply rules on field ${fieldName} having type '${typeOf set}'";
+        set
+      ));
+
+  # mkSection = name: config:
+  schema = [
+    {
+      match = k: v: k == "defaults";
+      rules = [
+        {
+          match = k: v: k == "timeout";
+          rule = k: v: mapAttrsToList (k1: v1: "${k}.${k1} ${v1}") v;
+        }
+      ];
+    }
+    {
+      match = k: v: k == "global";
+      rules = [];
+    }
+    {
+      match = k: v: k == "frontend";
+      rules = [
+        {
+          match = k: v: true;
+          rules = [
+            {
+              match = k: v: k == "rules";
+              rule = k: v: map mkRule v;
+            }
+            {
+              match = k: v: k == "bind" && isAttrs v;
+              rule = k: v: mkBind v;
+            }
+            {
+              match = k: v: k == "http-request" || k == "http-response";
+              rule = k: v: v;
+            }
+          ];
+        }
+      ];
+    }
+  ];
+
+  render = config:
+    concatStringsSep "\n" (augmentedContent name schema config);
+}