bazelisk-env: init

flake.nix

@@ -170,6 +170,17 @@
           })
         ];
       };
+
+      bazelisk = nixpkgs.lib.nixosSystem {
+        system = "x86_64-linux";
+        specialArgs.inputs = inputs;
+        modules = self.nixosModules.default ++ [
+          (import ./os/bazelisk/configuration.nix)
+          ({
+            nixpkgs.overlays = [ self.overlays.default ];
+          })
+        ];
+      };
     };
 
     templates.default = {

os/bazelisk/configuration.nix

@@ -0,0 +1,17 @@
+{ config, pkgs, lib, inputs, modulesPath, ... }: {
+  imports =
+    [
+      ../incus/configuration.nix
+    ];
+
+  environment.systemPackages = with pkgs; [
+    git
+    bazelisk-env
+  ];
+
+  networking.hostName = "bazelisk";
+
+  users.users.test = {
+    isNormalUser = true;
+  };
+}

os/bazelisk/reset.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -euxo pipefail
+
+if [ ! -e /tmp/mgit ]; then
+  git clone git@ci.mgit.at:mgit/mgit /tmp/mgit
+fi
+incus exec bazelisk -- rm -rf /home/test/mgit
+incus exec bazelisk -- rm -rf /home/test/.cache
+incus file push /tmp/mgit bazelisk/home/test -r

os/bazelisk/setup.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+set -euxo pipefail
+
+cd "$(dirname "$(readlink -f "$0")")"
+BASE=$(git rev-parse --show-toplevel)
+
+incus launch images:nixos/unstable bazelisk -c security.nesting=true
+incus config device add bazelisk nixos-common disk "source=$BASE" "path=/etc/nixos"
+sleep 10s # allow it some time to boot
+incus exec bazelisk -- nix shell --extra-experimental-features "nix-command flakes" nixpkgs#git --command git config --global --add safe.directory /etc/nixos || true
+incus exec bazelisk -- nix shell --extra-experimental-features "nix-command flakes" nixpkgs#git --command nixos-rebuild switch --flake /etc/nixos#bazelisk || true
+bash reset.sh
+incus restart bazelisk

os/bazelisk/shell.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+set -euxo pipefail
+
+cd "$(dirname "$(readlink -f "$0")")"
+BASE=$(git rev-parse --show-toplevel)
+
+incus exec bazelisk -- su test -l -c "USE_SHELL=1 bazelisk-env"

os/bazelisk/test.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+set -euxo pipefail
+
+cd "$(dirname "$(readlink -f "$0")")"
+BASE=$(git rev-parse --show-toplevel)
+
+incus exec bazelisk -- nixos-rebuild switch
+incus restart bazelisk # kill old bazel processes
+sleep 5s # allow it some time to boot
+incus exec bazelisk -- sh -c "cd /home/test/mgit && su test -c 'bazelisk-env build //... --sandbox_debug --verbose_failures --keep_going'"

pkgs/bazelisk-env/default.nix

@@ -0,0 +1,61 @@
+{
+  buildFHSUserEnv,
+}:
+
+buildFHSUserEnv {
+  name = "bazelisk-env";
+  extraOutputsToInstall = ["include" "dev"]; # TODO: make it saner?
+
+  # this is necesarry to make sure we don't inherit things from nixos that we don't want to inherit
+  # like non-FHS bash interactive from /run/current-system/sw/bin
+  extraBwrapArgs = [
+    # for debugging
+    "--ro-bind" "/run" "/.host-run"
+
+    "--tmpfs" "/run"
+    # dns
+    "--ro-bind" "/run/systemd" "/run/systemd"
+    # several things, including dns
+    "--ro-bind" "/run/nscd" "/run/nscd"
+  ];
+
+  # for go build
+  multiArch = true;
+
+  # NOTE: since /run/current-system is inaccessible
+  # EVERY required tool must be specified here
+  targetPkgs = pkgs: with pkgs; [
+    # include no more than this
+    # crt1.o is already taken care of by buildFHSEnv.nix
+    gcc_multi.out
+    binutils
+    pkg-config
+    python3
+    coreutils-full # is not multi since takes forever to build and no cache available
+    bazelisk
+    git
+    which
+    python3
+    patch
+    iputils
+    host
+  ];
+
+  # everything that we need both 64bit and 32bit versions of
+  multiPkgs = pkgs: with pkgs; [
+    zlib
+  ];
+
+  profile = ''
+    export BAZELISK_ENV=1
+    export CC=$(which gcc)
+
+    CMD=bazelisk
+
+    if [ -v USE_SHELL ]; then
+      CMD="/usr/bin/bash"
+    fi
+  '';
+
+  runScript = "$CMD"; # $@ will already be appended by nix
+}