[xa-prep-tasks] Support autoprovision with brew 1.2 (#595)

jonpryor · web-flow · commit cbc654799aaa · 2017-05-16T16:28:58.000-04:00
We got a new macOS Jenkins machine, running brew 1.2. (Our other machines have brew 1.0 installed.) When attempting to build on this new machine, [things broke][0]: Executing: sudo brew install 'p7zip' Error: Running Homebrew as root is extremely dangerous. As Homebrew does not drop privileges on installation you are giving all build scripts full access to your system. As a result of the macOS sandbox not handling the root user correctly HOMEBREW_NO_SANDBOX has been set so the sandbox will not be used. If we have not merged a pull request to add privilege dropping by November 1st 2016 running Homebrew as root will be disabled. No Homebrew maintainers plan to work on this functionality. In short, using `sudo brew` doesn't work...on brew 1.2. It's currently *required* to use `sudo brew` on brew 1.0. After some crying, split this difference by running `brew --version`, and only use `sudo brew` when using brew 1.0. [0]: https://jenkins.mono-project.com/view/Xamarin.Android/job/xamarin-android-pr-builder/942/
diff --git a/build-tools/xa-prep-tasks/Xamarin.Android.BuildTools.PrepTasks/PrepareInstall.cs b/build-tools/xa-prep-tasks/Xamarin.Android.BuildTools.PrepTasks/PrepareInstall.cs
@@ -24,9 +24,7 @@ public class PrepareInstall : Task
 		[Output]
 		public  ITaskItem           DownloadUrl         { get; set; }
 
-		string Sudo {
-			get {return (UseSudo && HostOS != "Windows") ? "sudo " : "";}
-		}
+		string Sudo;
 
 		public override bool Execute ()
 		{
@@ -36,6 +34,7 @@ public override bool Execute ()
 			Log.LogMessage (MessageImportance.Low, $"  {nameof (Program)}: {Program}");
 			Log.LogMessage (MessageImportance.Low, $"  {nameof (UseSudo)}: {UseSudo}");
 
+			SetSudo ();
 			SetDownloadUrl ();
 			SetInstallCommand ();
 
@@ -50,6 +49,27 @@ string GetHostProperty (string property)
 			return Which.GetHostProperty (Program, property, HostOS, HostOSName);
 		}
 
+		void SetSudo ()
+		{
+			if (!UseSudo || string.Equals ("Windows", HostOS, StringComparison.OrdinalIgnoreCase))
+				return;
+
+			if (!string.Equals ("Darwin", HostOS, StringComparison.OrdinalIgnoreCase)) {
+				Sudo = "sudo ";
+				return;
+			}
+			string brewFilename;
+			var brewPath = Which.GetProgramLocation ("brew", out brewFilename);
+			if (string.IsNullOrEmpty (brewPath)) {
+				return;
+			}
+			var brewVersion	= Which.GetProgramVersion (HostOS, $"{brewPath} --version");
+			if (brewVersion < new Version (1, 1)) {
+				Sudo = "sudo ";
+				return;
+			}
+		}
+
 		void SetDownloadUrl ()
 		{
 			var minUrl = GetHostProperty ("MinimumUrl");
@@ -78,7 +98,7 @@ void SetInstallCommand ()
 				InstallCommand = Sudo + install;
 				return;
 			}
-			if (HostOS == "Darwin") {
+			if (string.Equals (HostOS, "Darwin", StringComparison.OrdinalIgnoreCase)) {
 				var brew    = Program.GetMetadata ("Homebrew");
 				if (!string.IsNullOrEmpty (brew)) {
 					InstallCommand = $"{Sudo}brew install '{brew}'";
diff --git a/build-tools/xa-prep-tasks/Xamarin.Android.BuildTools.PrepTasks/Which.cs b/build-tools/xa-prep-tasks/Xamarin.Android.BuildTools.PrepTasks/Which.cs
@@ -142,11 +142,17 @@ bool NeedInstall ()
 
 		Version GetCurrentVersion ()
 		{
-			string shell, format;
-			GetShell (out shell, out format);
-
 			var command = GetHostProperty (Program, "CurrentVersionCommand", HostOS, HostOSName)
 				?? Program.ItemSpec + " --version";
+
+			return GetProgramVersion (HostOS, command);
+		}
+
+		internal static Version GetProgramVersion (string hostOS, string command)
+		{
+			string shell, format;
+			GetShell (hostOS, out shell, out format);
+
 			var psi = new ProcessStartInfo (shell, string.Format (format, command)) {
 				CreateNoWindow = true,
 				UseShellExecute = false,
@@ -171,9 +177,9 @@ Version GetCurrentVersion ()
 				: new Version (curVersion);
 		}
 
-		void GetShell (out string shell, out string format)
+		static void GetShell (string hostOS, out string shell, out string format)
 		{
-			if (HostOS == "Windows") {
+			if (string.Equals (hostOS, "Windows", StringComparison.OrdinalIgnoreCase)) {
 				shell = "cmd.exe";
 				format = "/c \"{0}\"";
 				return;
