From 3c33750722a49bdae226d355a9576953e0997fdd Mon Sep 17 00:00:00 2001
From: Bryan Ramos <bryan@ramos.codes>
Date: Thu, 12 Mar 2026 22:19:41 -0400
Subject: [PATCH] electrs

---
 src/system/machines/server/system.nix         |  5 +-
 .../modules/bitcoin/config/bitcoin.conf       |  3 +-
 src/system/modules/bitcoin/default.nix        |  5 ++
 .../modules/electrum/config/config.toml       | 14 +++
 .../bitcoin/modules/electrum/default.nix      | 89 +++++++++++++++++++
 5 files changed, 114 insertions(+), 2 deletions(-)
 create mode 100644 src/system/modules/bitcoin/modules/electrum/config/config.toml
 create mode 100644 src/system/modules/bitcoin/modules/electrum/default.nix

diff --git a/src/system/machines/server/system.nix b/src/system/machines/server/system.nix
index 155098a..7d2652b 100644
--- a/src/system/machines/server/system.nix
+++ b/src/system/machines/server/system.nix
@@ -9,7 +9,10 @@
     forgejo.enable = true;
     frigate.enable = false;
     immich.enable = true;
-    bitcoin.enable = true;
+    bitcoin = {
+      enable = true;
+      electrum.enable = true;
+    };
 
     backup = {
       enable = true;
diff --git a/src/system/modules/bitcoin/config/bitcoin.conf b/src/system/modules/bitcoin/config/bitcoin.conf
index 72ca181..756bfc1 100644
--- a/src/system/modules/bitcoin/config/bitcoin.conf
+++ b/src/system/modules/bitcoin/config/bitcoin.conf
@@ -1,6 +1,7 @@
 server=1
 
-rpcauth=btc:a5070cab96db882e8f63cb131ce3bbfa$20c7fd4653597b0c4ffc2c47b2d5d6751a6725ff644dd0d0ffcb9bebff96b913
+rpccookiefile=/var/lib/bitcoin/.cookie
+rpccookieperms=group
 rpcbind=127.0.0.1
 rpcallowip=127.0.0.1
 
diff --git a/src/system/modules/bitcoin/default.nix b/src/system/modules/bitcoin/default.nix
index 020045c..060f07b 100644
--- a/src/system/modules/bitcoin/default.nix
+++ b/src/system/modules/bitcoin/default.nix
@@ -61,6 +61,11 @@ in
       };
     };
 
+    # Make data dir group-accessible so electrs/clightning can read cookie
+    systemd.tmpfiles.rules = [
+      "d ${home} 0750 btc bitcoin -"
+    ];
+
     systemd.services.bitcoind-mainnet = {
       wants = [ "tor.service" ];
       after = [ "tor.service" ];
diff --git a/src/system/modules/bitcoin/modules/electrum/config/config.toml b/src/system/modules/bitcoin/modules/electrum/config/config.toml
new file mode 100644
index 0000000..00961c5
--- /dev/null
+++ b/src/system/modules/bitcoin/modules/electrum/config/config.toml
@@ -0,0 +1,14 @@
+network = "bitcoin"
+
+electrum_rpc_addr = "127.0.0.1:50001"
+
+cookie_file = "/var/lib/bitcoin/.cookie"
+
+db_dir = "/var/lib/electrs"
+
+log_filters = "INFO"
+timestamp = true
+
+daemon_rpc_addr = "127.0.0.1:8332"
+daemon_p2p_addr = "127.0.0.1:8333"
+daemon_dir = "/var/lib/bitcoin"
diff --git a/src/system/modules/bitcoin/modules/electrum/default.nix b/src/system/modules/bitcoin/modules/electrum/default.nix
new file mode 100644
index 0000000..8f1220a
--- /dev/null
+++ b/src/system/modules/bitcoin/modules/electrum/default.nix
@@ -0,0 +1,89 @@
+{ lib, pkgs, config, ... }:
+
+with lib;
+let
+  cfg = config.modules.system.bitcoin.electrum;
+  home = "/var/lib/electrs";
+
+  btc = config.modules.system.bitcoin;
+
+  electrsConfig = pkgs.writeTextFile {
+    name = "config.toml";
+    text = builtins.readFile ./config/config.toml;
+  };
+
+in
+{ options.modules.system.bitcoin.electrum = { enable = mkEnableOption "Electrs Server"; };
+  config = mkIf (cfg.enable && btc.enable) {
+    #TODO: Fix the failing overlay due to `cargoHash/cargoSha256`
+    #nixpkgs.overlays = [
+    #  (final: prev: {
+    #    electrs = prev.electrs.overrideAttrs (old: rec {
+    #      pname = "electrs";
+    #      version = "0.10.8";
+    #      src = pkgs.fetchFromGitHub {
+    #        owner = "romanz";
+    #        repo = pname;
+    #        rev = "v${version}";
+    #        hash = "sha256-L26jzAn8vwnw9kFd6ciyYS/OLEFTbN8doNKy3P8qKRE=";
+    #      };
+    #      #cargoDeps = old.cargoDeps.overrideAttrs (const {
+    #      #  name = "electrs-${version}.tar.gz";
+    #      #  inherit src;
+    #      #  sha256 = "";
+    #      #});
+    #      cargoHash = "sha256-lBRcq73ri0HR3duo6Z8PdSjnC8okqmG5yWeHxH/LmcU=";
+    #    });
+    #  })
+    #];
+
+    environment.systemPackages = with pkgs; [
+      electrs
+    ];
+
+    users = {
+      users = {
+        "electrs" = {
+          inherit home;
+          description = "Electrs system user";
+          isSystemUser = true;
+          group = "bitcoin";
+          createHome = true;
+        };
+      };
+      groups = {
+        "bitcoin" = {
+          members = mkAfter [
+            "electrs"
+          ];
+        };
+      };
+    };
+
+
+    systemd.services.electrs = {
+      description = "Electrs Bitcoin Indexer";
+      wantedBy = [ "multi-user.target" ];
+
+      script = "${pkgs.electrs}/bin/electrs";
+      scriptArgs = "--conf=${electrsConfig}";
+
+      wants = [ "bitcoind-mainnet.service" ];
+      after = [
+        "bitcoind-mainnet.service"
+        "network.target"
+      ];
+
+      serviceConfig = {
+        User = "electrs";
+        Group = "bitcoin";
+
+        Type = "simple";
+        KillMode = "process";
+        TimeoutSec = 60;
+        Restart = "always";
+        RestartSec = 60;
+      };
+    };
+  };
+}