Merge branch 'add-initial-android-devshell'

5 files changed, 412 insertions, 2 deletions

diff --git a/android/BuildInstructions.md b/android/BuildInstructions.md
index b287342fd4..a58a993b49 100644
--- a/android/BuildInstructions.md
+++ b/android/BuildInstructions.md
@@ -177,6 +177,22 @@ Run the following command to build a debug build:
    ../android/build.sh --app-bundle
    ```
 
+## Build using nix devshell
+1. Install the nix package manager by following the [official instructions](https://nixos.org/download/).
+2. Enable the experimental `nix-command` and `flake` features by following [these instructions](https://nixos.wiki/wiki/flakes).
+3. Launch a devshell (in `<repository>/android`) by running:
+   ```bash
+   nix develop
+   ```
+4. Build the app as usual by running for example:
+   ```bash
+   ./build.sh --dev-build
+   ```
+   or
+   ```bash
+   ./gradlew assembleOssProdDebug
+   ```
+
 ## Configure signing key
 1. Create a directory to store the signing key, keystore and its configuration:
    ```
diff --git a/android/flake.lock b/android/flake.lock
new file mode 100644
index 0000000000..a9ee199ccc
--- /dev/null
+++ b/android/flake.lock
@@ -0,0 +1,193 @@
+{
+  "nodes": {
+    "android-nixpkgs": {
+      "inputs": {
+        "devshell": "devshell",
+        "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1752524595,
+        "narHash": "sha256-BQw78e4yNYtzn0+CIvNCyWuh6Q1FHY8hebn+jv4kC6E=",
+        "owner": "tadfisher",
+        "repo": "android-nixpkgs",
+        "rev": "5b4a9a71371280b3d95263bf0fc8dcffedec0df8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "tadfisher",
+        "repo": "android-nixpkgs",
+        "type": "github"
+      }
+    },
+    "devshell": {
+      "inputs": {
+        "nixpkgs": [
+          "android-nixpkgs",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1741473158,
+        "narHash": "sha256-kWNaq6wQUbUMlPgw8Y+9/9wP0F8SHkjy24/mN3UAppg=",
+        "owner": "numtide",
+        "repo": "devshell",
+        "rev": "7c9e793ebe66bcba8292989a68c0419b737a22a0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "devshell",
+        "type": "github"
+      }
+    },
+    "devshell_2": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1741473158,
+        "narHash": "sha256-kWNaq6wQUbUMlPgw8Y+9/9wP0F8SHkjy24/mN3UAppg=",
+        "owner": "numtide",
+        "repo": "devshell",
+        "rev": "7c9e793ebe66bcba8292989a68c0419b737a22a0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "devshell",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1722073938,
+        "narHash": "sha256-OpX0StkL8vpXyWOGUD6G+MA26wAXK6SpT94kLJXo6B4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e36e9f57337d0ff0cf77aceb58af4c805472bfae",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1752480373,
+        "narHash": "sha256-JHQbm+OcGp32wAsXTE/FLYGNpb+4GLi5oTvCxwSoBOA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "62e0f05ede1da0d54515d4ea8ce9c733f12d9f08",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "android-nixpkgs": "android-nixpkgs",
+        "devshell": "devshell_2",
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs_2",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1752547600,
+        "narHash": "sha256-0vUE42ji4mcCvQO8CI0Oy8LmC6u2G4qpYldZbZ26MLc=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "9127ca1f5a785b23a2fc1c74551a27d3e8b9a28b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/android/flake.nix b/android/flake.nix
new file mode 100644
index 0000000000..0d75da2038
--- /dev/null
+++ b/android/flake.nix
@@ -0,0 +1,104 @@
+{
+  description = "Mullvad Android app build flake";
+
+  inputs = {
+    # Unstable is currently needed for protoc-gen-grpc-java.
+    # We should switch to a stable channel once it's avaiable on those.
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+    devshell.url = "github:numtide/devshell";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    android-nixpkgs = {
+      url = "github:tadfisher/android-nixpkgs";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = {
+    self,
+    nixpkgs,
+    android-nixpkgs,
+    rust-overlay,
+    flake-utils,
+    devshell,
+  }:
+    flake-utils.lib.eachDefaultSystem (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [
+          (import rust-overlay)
+          devshell.overlays.default
+        ];
+      };
+
+      rust-toolchain = (pkgs.buildPackages.rust-bin.fromRustupToolchainFile
+        ../rust-toolchain.toml).override {
+        extensions = ["rust-analyzer"];
+        targets = [
+          "aarch64-linux-android"
+          "armv7-linux-androideabi"
+          "x86_64-linux-android"
+          "i686-linux-android"
+        ];
+      };
+
+      patchedGo_1_21_3 =
+        (import (fetchTarball {
+          url = "https://github.com/NixOS/nixpkgs/archive/b392079f5fd051926a834c878d27ceec4f139dce.tar.gz";
+          sha256 = "16dkk98fs9pw2amz0vpjsc7ks85cw3hc5rlpbp27llq6x7lwpjaz";
+        }) {inherit system;}).go_1_21.overrideAttrs (oldAttrs: {
+          patches = (oldAttrs.patches or []) ++ [./docker/goruntime-boottime-over-monotonic.diff];
+        });
+
+      versions =
+        (builtins.fromTOML (
+          builtins.concatStringsSep "\n" (
+            builtins.filter (line: !(builtins.match "^[[:space:]]*#" line != null))
+            (nixpkgs.lib.splitString "\n" (builtins.readFile ./gradle/libs.versions.toml))
+          )
+        )).versions;
+
+      compileSdkVersion = versions."compile-sdk";
+      buildToolsVersion = versions."build-tools";
+      minSdkVersion = versions."min-sdk";
+      ndkVersion = versions.ndk;
+
+      android-sdk = android-nixpkgs.sdk.${system} (sdkPkgs:
+        with sdkPkgs; [
+          (builtins.getAttr "platforms-android-${compileSdkVersion}" sdkPkgs)
+          (builtins.getAttr "build-tools-${builtins.replaceStrings ["."] ["-"] buildToolsVersion}" sdkPkgs)
+          (builtins.getAttr "ndk-${builtins.replaceStrings ["."] ["-"] ndkVersion}" sdkPkgs)
+          cmdline-tools-latest
+          platform-tools
+        ]);
+    in {
+      overlay = final: prev: {
+        inherit (self.packages.${system}) android-sdk;
+      };
+
+      packages = {
+        inherit android-sdk;
+      };
+
+      devShells.default = pkgs.devshell.mkShell {
+        name = "mullvad-android-devshell";
+        packages = [
+          android-sdk
+          rust-toolchain
+          patchedGo_1_21_3
+          pkgs.protoc-gen-grpc-java
+          pkgs.gcc
+          pkgs.gnumake
+          pkgs.protobuf
+          pkgs.jdk17
+          pkgs.python3Full
+        ];
+        env = import ./nix/env-vars.nix {
+          inherit pkgs android-sdk buildToolsVersion ndkVersion minSdkVersion;
+        };
+      };
+    });
+}
diff --git a/android/lib/daemon-grpc/build.gradle.kts b/android/lib/daemon-grpc/build.gradle.kts
index d4a6d0e7a2..cadd126830 100644
--- a/android/lib/daemon-grpc/build.gradle.kts
+++ b/android/lib/daemon-grpc/build.gradle.kts
@@ -44,8 +44,21 @@ android {
 protobuf {
     protoc { artifact = libs.plugins.protobuf.protoc.get().toString() }
     plugins {
-        create("java") { artifact = libs.plugins.grpc.protoc.gen.grpc.java.get().toString() }
-        create("grpc") { artifact = libs.plugins.grpc.protoc.gen.grpc.java.get().toString() }
+        val grpcPluginPath = System.getenv("PROTOC_GEN_GRPC_JAVA_PLUGIN")
+        create("java") {
+            if (grpcPluginPath != null) {
+                path = grpcPluginPath
+            } else {
+                artifact = libs.plugins.grpc.protoc.gen.grpc.java.get().toString()
+            }
+        }
+        create("grpc") {
+            if (grpcPluginPath != null) {
+                path = grpcPluginPath
+            } else {
+                artifact = libs.plugins.grpc.protoc.gen.grpc.java.get().toString()
+            }
+        }
         create("grpckt") { artifact = libs.plugins.grpc.protoc.gen.grpc.kotlin.get().toString() }
     }
     generateProtoTasks {
diff --git a/android/nix/env-vars.nix b/android/nix/env-vars.nix
new file mode 100644
index 0000000000..e9f5d6aa62
--- /dev/null
+++ b/android/nix/env-vars.nix
@@ -0,0 +1,84 @@
+{
+  pkgs,
+  android-sdk,
+  buildToolsVersion,
+  ndkVersion,
+  minSdkVersion,
+}: [
+  {
+    name = "JAVA_HOME";
+    value = "${pkgs.jdk17}";
+  }
+  {
+    name = "PROTOC_GEN_GRPC_JAVA_PLUGIN";
+    prefix = "${pkgs.protoc-gen-grpc-java}/bin/protoc-gen-grpc-java";
+  }
+  {
+    name = "GRADLE_OPTS";
+    value = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${android-sdk}/share/android-sdk/build-tools/${buildToolsVersion}/aapt2";
+  }
+  {
+    name = "ANDROID_HOME";
+    value = "${android-sdk}/share/android-sdk";
+  }
+  {
+    name = "ANDROID_SDK_ROOT";
+    value = "${android-sdk}/share/android-sdk";
+  }
+  {
+    name = "ANDROID_NDK_ROOT";
+    value = "${android-sdk}/share/android-sdk/ndk/${ndkVersion}";
+  }
+  {
+    name = "NDK_TOOLCHAIN_DIR";
+    value = "${android-sdk}/share/android-sdk/ndk/${ndkVersion}/toolchains/llvm/prebuilt/linux-x86_64/bin";
+  }
+  {
+    name = "AR_aarch64_linux_android";
+    value = "$NDK_TOOLCHAIN_DIR/llvm-ar";
+  }
+  {
+    name = "CC_aarch64_linux_android";
+    value = "$NDK_TOOLCHAIN_DIR/aarch64-linux-android${minSdkVersion}-clang";
+  }
+  {
+    name = "CARGO_TARGET_aarch64_LINUX_ANDROID_LINKER";
+    value = "$NDK_TOOLCHAIN_DIR/aarch64-linux-android${minSdkVersion}-clang";
+  }
+  {
+    name = "AR_armv7_linux_androideabi";
+    value = "$NDK_TOOLCHAIN_DIR/llvm-ar";
+  }
+  {
+    name = "CC_armv7_linux_androideabi";
+    value = "$NDK_TOOLCHAIN_DIR/armv7-linux-androideabi${minSdkVersion}-clang";
+  }
+  {
+    name = "CARGO_TARGET_armv7_LINUX_ANDROID_LINKER";
+    value = "$NDK_TOOLCHAIN_DIR/armv7-linux-androideabi${minSdkVersion}-clang";
+  }
+  {
+    name = "AR_x86_64_linux_android";
+    value = "$NDK_TOOLCHAIN_DIR/llvm-ar";
+  }
+  {
+    name = "CC_x86_64_linux_android";
+    value = "$NDK_TOOLCHAIN_DIR/x86_64-linux-android${minSdkVersion}-clang";
+  }
+  {
+    name = "CARGO_TARGET_x86_64_LINUX_ANDROID_LINKER";
+    value = "$NDK_TOOLCHAIN_DIR/x86_64-linux-android${minSdkVersion}-clang";
+  }
+  {
+    name = "AR_i686_linux_android";
+    value = "$NDK_TOOLCHAIN_DIR/llvm-ar";
+  }
+  {
+    name = "CC_i686_linux_android";
+    value = "$NDK_TOOLCHAIN_DIR/i686-linux-android${minSdkVersion}-clang";
+  }
+  {
+    name = "CARGO_TARGET_i686_LINUX_ANDROID_LINKER";
+    value = "$NDK_TOOLCHAIN_DIR/i686-linux-android${minSdkVersion}-clang";
+  }
+]