nixpkgs/nixos/tests/binary-cache.nix

import ./make-test-python.nix (
  { lib, pkgs, ... }:

  {
    name = "binary-cache";
    meta.maintainers = with lib.maintainers; [ thomasjm ];

    nodes.machine =
      { pkgs, ... }:
      {
        imports = [ ../modules/installer/cd-dvd/channel.nix ];
        environment.systemPackages = [ pkgs.python3 ];
        system.extraDependencies = [ pkgs.hello.inputDerivation ];
        nix.extraOptions = ''
          experimental-features = nix-command
        '';
      };

    testScript = ''
      # Build the cache, then remove it from the store
      cachePath = machine.succeed("nix-build --no-out-link -E 'with import <nixpkgs> {}; mkBinaryCache { rootPaths = [hello]; }'").strip()
      machine.succeed("cp -r %s/. /tmp/cache" % cachePath)
      machine.succeed("nix-store --delete " + cachePath)

      # Sanity test of cache structure
      status, stdout = machine.execute("ls /tmp/cache")
      cache_files = stdout.split()
      assert ("nix-cache-info" in cache_files)
      assert ("nar" in cache_files)

      # Nix store ping should work
      machine.succeed("nix store ping --store file:///tmp/cache")

      # Cache should contain a .narinfo referring to "hello"
      grepLogs = machine.succeed("grep -l 'StorePath: /nix/store/[[:alnum:]]*-hello-.*' /tmp/cache/*.narinfo")

      # Get the store path referenced by the .narinfo
      narInfoFile = grepLogs.strip()
      narInfoContents = machine.succeed("cat " + narInfoFile)
      import re
      match = re.match(r"^StorePath: (/nix/store/[a-z0-9]*-hello-.*)$", narInfoContents, re.MULTILINE)
      if not match: raise Exception("Couldn't find hello store path in cache")
      storePath = match[1]

      # Delete the store path
      machine.succeed("nix-store --delete " + storePath)
      machine.succeed("[ ! -d %s ] || exit 1" % storePath)

      # Should be able to build hello using the cache
      logs = machine.succeed("nix-build -A hello '<nixpkgs>' --option require-sigs false --option trusted-substituters file:///tmp/cache --option substituters file:///tmp/cache 2>&1")
      logLines = logs.split("\n")
      if not "this path will be fetched" in logLines[0]: raise Exception("Unexpected first log line")
      def shouldBe(got, desired):
        if got != desired: raise Exception("Expected '%s' but got '%s'" % (desired, got))
      shouldBe(logLines[1], "  " + storePath)
      shouldBe(logLines[2], "copying path '%s' from 'file:///tmp/cache'..." % storePath)
      shouldBe(logLines[3], storePath)

      # Store path should exist in the store now
      machine.succeed("[ -d %s ] || exit 1" % storePath)
    '';
  }
)