Add custom cache server

configuration.nix

@@ -39,6 +39,9 @@
 
       # include adb settings
       ./dev-environment/adb.nix
+
+      # include custom cache server settings
+      ./misc/custom-cache-server.nix
     ];
 
   networking.hostName = systemSettings.hostname; # Define your hostname.

misc/custom-cache-server.nix

@@ -0,0 +1,34 @@
+# This config is used to define a custom cache server setting for the system
+# It is useful when your build time is slow due to the network latency
+{ userSettings, ... }:
+{
+  nix.settings = {
+    # main user has access to modify trusted cache server
+    trusted-users = [ userSettings.username ];
+
+    substituters = [
+      # cache mirror located in China
+      # status: https://mirror.sjtu.edu.cn/
+      # "https://mirror.sjtu.edu.cn/nix-channels/store"
+      # status: https://mirrors.ustc.edu.cn/status/
+      # "https://mirrors.ustc.edu.cn/nix-channels/store"
+
+      # default cache server
+      "https://cache.nixos.org"
+      # nix community's cache server
+      "https://nix-community.cachix.org"
+    ];
+
+    trusted-public-keys = [
+      # nix community's cache server public key
+      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+    ];
+  };
+  # Use socks5 proxy for nix-daemon
+  # To accelerate downloads
+  systemd.services.nix-daemon.environment = {
+    # socks5h means that the hostname is resolved by the SOCKS server
+    https_proxy = "socks5h://localhost:7891";
+    # https_proxy = "http://localhost:7890"; # or use http protocol instead of socks5
+  };
+}