From 3ed43b1b8afa4cbe7170d9175252fc0c37bb8b53 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Sat, 1 Feb 2025 15:45:58 -0500
Subject: [PATCH] Configure rustup toolchain, cargo credentials, and put
 dependencies under cargo.

---
 nix/configuration/roles/rust/default.nix      | 93 ++++++++++++++++++-
 .../roles/rust/files/rustup_settings.toml     |  5 +
 2 files changed, 93 insertions(+), 5 deletions(-)
 create mode 100644 nix/configuration/roles/rust/files/rustup_settings.toml

diff --git a/nix/configuration/roles/rust/default.nix b/nix/configuration/roles/rust/default.nix
index 1a97976..a2853f5 100644
--- a/nix/configuration/roles/rust/default.nix
+++ b/nix/configuration/roles/rust/default.nix
@@ -1,3 +1,6 @@
+# MANUAL: rustup target add x86_64-unknown-linux-musl
+# MANUAL: rustup target add wasm32-unknown-unknown
+# MANUAL: rustup component add rustc-codegen-cranelift
 {
   config,
   lib,
@@ -5,6 +8,14 @@
   ...
 }:
 
+let
+  cargo_wrapped =
+    package: prog:
+    pkgs.writeShellScriptBin "${prog}" ''
+      export PATH="$PATH:${lib.makeBinPath [ pkgs.clang ]}"
+      exec ${package}/bin/${prog} "''${@}"
+    '';
+in
 {
   imports = [ ];
 
@@ -37,17 +48,89 @@
               ".cargo/config.toml" = {
                 source = ./files/cargo_config.toml;
               };
-              # # TODO: Figure out what to do with credentials.
-              # ".cargo/credentials.toml" = {
-              #   source = ./files/cargo_credentials.toml;
-              # };
+              ".rustup/settings.toml" = {
+                source = ./files/rustup_settings.toml;
+              };
             };
           };
 
+        environment.persistence."/state" = lib.mkIf (!config.me.buildingIso) {
+          hideMounts = true;
+          users.talexander = {
+            directories = [
+              {
+                directory = ".rustup";
+                user = "talexander";
+                group = "talexander";
+                mode = "0755";
+              }
+              {
+                directory = ".cargo/registry";
+                user = "talexander";
+                group = "talexander";
+                mode = "0755";
+              }
+            ];
+          };
+        };
+
+        systemd.services.link-rust-creds = {
+          # Contains credentials so it cannot be added to the nix store
+          enable = true;
+          description = "link-rust-creds";
+          wantedBy = [ "multi-user.target" ];
+          wants = [ "multi-user.target" ];
+          after = [ "multi-user.target" ];
+          # path = with pkgs; [
+          #   zfs
+          # ];
+          unitConfig.DefaultDependencies = "no";
+          serviceConfig = {
+            Type = "oneshot";
+            RemainAfterExit = "yes";
+          };
+          script = ''
+            if [ -e /persist/manual/rust/cargo_credentials.toml ]; then
+              install --directory --owner talexander --group talexander --mode 0755 /home/talexander/.cargo
+              ln -s /persist/manual/rust/cargo_credentials.toml /home/talexander/.cargo/credentials.toml
+            fi
+          '';
+          preStop = ''
+            rm -f /home/talexander/.cargo/credentials.toml
+          '';
+        };
+
+        nixpkgs.overlays = [
+          (final: prev: {
+            rustup = pkgs.symlinkJoin {
+              name = "rustup";
+              paths =
+                (builtins.map (cargo_wrapped prev.rustup) [
+                  "cargo"
+                  "cargo-clippy"
+                  "cargo-fmt"
+                  "cargo-miri"
+                  "clippy-driver"
+                  "rls"
+                  "rust-analyzer"
+                  "rust-gdb"
+                  "rust-gdbgui"
+                  "rust-lldb"
+                  "rustc"
+                  "rustdoc"
+                  "rustfmt"
+                  "rustup"
+                ])
+                ++ [
+                  prev.rustup
+                ];
+              buildInputs = [ pkgs.makeWrapper ];
+            };
+          })
+        ];
       }
     ]
   );
 }
 
 # TODO: Install clippy, cranelift, rust-src
-# TODO: Install rust targets x86_64-unknown-linux-musl and wasm32-unknown-unknown
diff --git a/nix/configuration/roles/rust/files/rustup_settings.toml b/nix/configuration/roles/rust/files/rustup_settings.toml
new file mode 100644
index 0000000..22f2e5c
--- /dev/null
+++ b/nix/configuration/roles/rust/files/rustup_settings.toml
@@ -0,0 +1,5 @@
+default_toolchain = "nightly-x86_64-unknown-linux-gnu"
+profile = "default"
+version = "12"
+
+[overrides]