Un-hardcode list of Windows versions

ue4docker/build.py

@@ -138,13 +138,8 @@ def build():
 				logger.error('https://unrealcontainers.com/docs/concepts/windows-containers', False)
 				sys.exit(1)
 
-			# Verify that the user is not attempting to build images with a newer kernel version than the host OS
-			if WindowsUtils.isNewerBaseTag(config.hostBasetag, config.basetag):
-				logger.error('Error: cannot build container images with a newer kernel version than that of the host OS!')
-				sys.exit(1)
-
 			# Check if the user is building a different kernel version to the host OS but is still copying DLLs from System32
-			differentKernels = WindowsUtils.isInsiderPreview() or config.basetag != config.hostBasetag
+			differentKernels = config.basetag != config.hostBasetag
 			if config.pullPrerequisites == False and differentKernels == True and config.dlldir == config.defaultDllDir:
 				logger.error('Error: building images with a different kernel version than the host,', False)
 				logger.error('but a custom DLL directory has not specified via the `-dlldir=DIR` arg.', False)

ue4docker/diagnostics/base.py

@@ -60,8 +60,7 @@ def _generateWindowsBuildArgs(self, logger, basetagOverride=None, isolationOverr
 		'''
 
 		# Determine the appropriate container image base tag for the host system release unless the user specified a base tag
-		buildArgs = []
-		defaultBaseTag = WindowsUtils.getReleaseBaseTag(WindowsUtils.getWindowsRelease())
+		defaultBaseTag = WindowsUtils.getWindowsRelease()
 		baseTag = basetagOverride if basetagOverride is not None else defaultBaseTag
 		buildArgs = ['--build-arg', 'BASETAG={}'.format(baseTag)]
 

ue4docker/infrastructure/BuildConfiguration.py

@@ -228,29 +228,30 @@ def _generateWindowsConfig(self):
 		self.dlldir = self.args.dlldir if self.args.dlldir is not None else self.defaultDllDir
 
 		# Determine base tag for the Windows release of the host system
-		self.hostRelease = WindowsUtils.getWindowsRelease()
-		self.hostBasetag = WindowsUtils.getReleaseBaseTag(self.hostRelease)
+		self.hostBasetag = WindowsUtils.getWindowsRelease()
 
 		# Store the tag for the base Windows Server Core image
 		self.basetag = self.args.basetag if self.args.basetag is not None else self.hostBasetag
 		self.baseImage = 'mcr.microsoft.com/windows/servercore:' + self.basetag
 		self.prereqsTag = self.basetag
 
+		validBaseTags = WindowsUtils.getValidBaseTags()
+
 		# Verify that any user-specified base tag is valid
-		if WindowsUtils.isValidBaseTag(self.basetag) == False:
-			raise RuntimeError('unrecognised Windows Server Core base image tag "{}", supported tags are {}'.format(self.basetag, WindowsUtils.getValidBaseTags()))
+		if self.basetag not in validBaseTags:
+			raise RuntimeError('unrecognised Windows Server Core base image tag "{}", supported tags are {}'.format(self.basetag, validBaseTags))
 
 		# Verify that any user-specified tag suffix does not collide with our base tags
-		if WindowsUtils.isValidBaseTag(self.suffix) == True:
-			raise RuntimeError('tag suffix cannot be any of the Windows Server Core base image tags: {}'.format(WindowsUtils.getValidBaseTags()))
+		if self.suffix in validBaseTags:
+			raise RuntimeError('tag suffix cannot be any of the Windows Server Core base image tags: {}'.format(validBaseTags))
 
 		# If the user has explicitly specified an isolation mode then use it, otherwise auto-detect
 		if self.args.isolation is not None:
 			self.isolation = self.args.isolation
 		else:
 
 			# If we are able to use process isolation mode then use it, otherwise fallback to the Docker daemon's default isolation mode
-			differentKernels = WindowsUtils.isInsiderPreview() or self.basetag != self.hostBasetag
+			differentKernels = self.basetag != self.hostBasetag
 			hostSupportsProcess = WindowsUtils.supportsProcessIsolation()
 			dockerSupportsProcess = parse_version(DockerUtils.version()['Version']) >= parse_version('18.09.0')
 			if not differentKernels and hostSupportsProcess and dockerSupportsProcess:

ue4docker/infrastructure/WindowsUtils.py

@@ -1,18 +1,12 @@
 from .DockerUtils import DockerUtils
 from pkg_resources import parse_version
-import platform, sys
+import platform, requests, sys
 
 if platform.system() == 'Windows':
 	import winreg
 
 class WindowsUtils(object):
 
-	# The latest Windows build version we recognise as a non-Insider build
-	_latestReleaseBuild = 19042
-
-	# The list of Windows Server Core base image tags that we recognise, in ascending version number order
-	_validTags = ['ltsc2016', '1709', '1803', 'ltsc2019', '1903', '1909', '2004', '20H2']
-
 	# The list of Windows Server and Windows 10 host OS releases that are blacklisted due to critical bugs
 	# (See: <https://unrealcontainers.com/docs/concepts/windows-containers>)
 	_blacklistedReleases = ['1903', '1909']
@@ -76,7 +70,13 @@ def getWindowsRelease() -> str:
 		'''
 		Determines the Windows 10 / Windows Server release (1607, 1709, 1803, etc.) of the Windows host system
 		'''
-		return WindowsUtils._getVersionRegKey('ReleaseId')
+		try:
+			# Starting with Windows 20H2 (also known as 2009), Microsoft stopped updating ReleaseId
+			# and instead updates DisplayVersion
+			return WindowsUtils._getVersionRegKey('DisplayVersion')
+		except FileNotFoundError:
+			# Fallback to ReleaseId for pre-20H2 releases that didn't have DisplayVersion
+			return WindowsUtils._getVersionRegKey('ReleaseId')
 
 	@staticmethod
 	def getWindowsBuild() -> int:
@@ -112,55 +112,12 @@ def isWindowsServer() -> bool:
 		# TODO: Replace this with something more reliable
 		return 'Windows Server' in WindowsUtils._getVersionRegKey('ProductName')
 
-	@staticmethod
-	def isInsiderPreview() -> bool:
-		'''
-		Determines if the Windows host system is a Windows Insider preview build
-		'''
-		return WindowsUtils.getWindowsBuild() > WindowsUtils._latestReleaseBuild
-
-	@staticmethod
-	def getReleaseBaseTag(release: str) -> str:
-		'''
-		Retrieves the tag for the Windows Server Core base image matching the specified Windows 10 / Windows Server release
-		'''
-
-		# For Windows Insider preview builds, build the latest release tag
-		if WindowsUtils.isInsiderPreview():
-			return WindowsUtils._validTags[-1]
-
-		# This lookup table is based on the list of valid tags from <https://hub.docker.com/r/microsoft/windowsservercore/>
-		return {
-			'1709': '1709',
-			'1803': '1803',
-			'1809': 'ltsc2019',
-			'1903': '1903',
-			'1909': '1909',
-			'2004': '2004',
-			'2009': '20H2',
-			'20H2': '20H2'
-		}.get(release, 'ltsc2016')
-
 	@staticmethod
 	def getValidBaseTags() -> [str]:
 		'''
 		Returns the list of valid tags for the Windows Server Core base image, in ascending chronological release order
 		'''
-		return WindowsUtils._validTags
-
-	@staticmethod
-	def isValidBaseTag(tag: str) -> bool:
-		'''
-		Determines if the specified tag is a valid Windows Server Core base image tag
-		'''
-		return tag in WindowsUtils._validTags
-
-	@staticmethod
-	def isNewerBaseTag(older: str, newer: str) -> bool:
-		'''
-		Determines if the base tag `newer` is chronologically newer than the base tag `older`
-		'''
-		return WindowsUtils._validTags.index(newer) > WindowsUtils._validTags.index(older)
+		return requests.get('https://mcr.microsoft.com/v2/windows/servercore/tags/list').json()['tags']
 
 	@staticmethod
 	def supportsProcessIsolation() -> bool: