Add diagnostic for IPv6 support (see #357)

src/ue4docker/diagnostics/__init__.py

@@ -1,4 +1,5 @@
 from .diagnostic_all import allDiagnostics
 from .diagnostic_8gig import diagnostic8Gig
 from .diagnostic_20gig import diagnostic20Gig
+from .diagnostic_ipv6 import diagnosticIPv6
 from .diagnostic_network import diagnosticNetwork

src/ue4docker/diagnostics/base.py

@@ -37,7 +37,7 @@ def _printAndRun(self, logger, prefix, command, check=False):
         logger.info(prefix + "Run: {}".format(command), False)
         subprocess.run(command, check=check)
 
-    def _checkPlatformMistmatch(self, logger, containerPlatform):
+    def _checkPlatformMistmatch(self, logger, containerPlatform, linuxFlagSupported):
         """
         Verifies that the user isn't trying to test Windows containers under Windows 10 when in Linux container mode (or vice versa)
         """
@@ -51,12 +51,13 @@ def _checkPlatformMistmatch(self, logger, containerPlatform):
                 ),
                 False,
             )
-            logger.error(
-                "[{}] Use the --linux flag if you want to test Linux containers instead.".format(
-                    prefix
-                ),
-                False,
-            )
+            if linuxFlagSupported:
+                logger.error(
+                    "[{}] Use the --linux flag if you want to test Linux containers instead.".format(
+                        prefix
+                    ),
+                    False,
+                )
             raise RuntimeError
         elif containerPlatform == "linux" and dockerPlatform == "windows":
             logger.error(
@@ -65,12 +66,13 @@ def _checkPlatformMistmatch(self, logger, containerPlatform):
                 ),
                 False,
             )
-            logger.error(
-                "[{}] Remove the --linux flag if you want to test Windows containers instead.".format(
-                    prefix
-                ),
-                False,
-            )
+            if linuxFlagSupported:
+                logger.error(
+                    "[{}] Remove the --linux flag if you want to test Windows containers instead.".format(
+                        prefix
+                    ),
+                    False,
+                )
             raise RuntimeError
 
     def _generateWindowsBuildArgs(

src/ue4docker/diagnostics/diagnostic_8gig.py

@@ -80,7 +80,7 @@ def run(self, logger, args=[]):
 
         # Verify that the user isn't trying to test Windows containers under Windows 10 when in Linux container mode (or vice versa)
         try:
-            self._checkPlatformMistmatch(logger, containerPlatform)
+            self._checkPlatformMistmatch(logger, containerPlatform, True)
         except RuntimeError:
             return False
 

src/ue4docker/diagnostics/diagnostic_all.py

@@ -1,6 +1,7 @@
 from .base import DiagnosticBase
 from .diagnostic_8gig import diagnostic8Gig
 from .diagnostic_20gig import diagnostic20Gig
+from .diagnostic_ipv6 import diagnosticIPv6
 from .diagnostic_network import diagnosticNetwork
 
 
@@ -27,6 +28,7 @@ def run(self, logger, args=[]):
         diagnostics = [
             diagnostic8Gig(),
             diagnostic20Gig(),
+            diagnosticIPv6(),
             diagnosticNetwork(),
         ]
         for index, diagnostic in enumerate(diagnostics):

src/ue4docker/diagnostics/diagnostic_ipv6.py

@@ -0,0 +1,76 @@
+from .base import DiagnosticBase
+
+
+class diagnosticIPv6(DiagnosticBase):
+    # The tag we use for built images
+    IMAGE_TAG = "adamrehn/ue4-docker/diagnostics:ipv6"
+
+    def __init__(self):
+        pass
+
+    def getName(self):
+        """
+        Returns the human-readable name of the diagnostic
+        """
+        return "Check that Linux containers can access the IPv6 loopback address"
+
+    def getDescription(self):
+        """
+        Returns a description of what the diagnostic does
+        """
+        return "\n".join(
+            [
+                "This diagnostic determines whether Linux containers are able to access the IPv6,",
+                "loopback address ::1, which is required by Unreal Engine 5.4 and newer for",
+                "local ZenServer communication.",
+                "",
+                "This should work automatically under Docker 26.0.0 and newer, but older versions",
+                "require manual configuration by the user.",
+            ]
+        )
+
+    def getPrefix(self):
+        """
+        Returns the short name of the diagnostic for use in log output
+        """
+        return "ipv6"
+
+    def run(self, logger, args=[]):
+        """
+        Runs the diagnostic
+        """
+
+        # This diagnostic only applies to Linux containers
+        containerPlatform = "linux"
+
+        # Verify that the user isn't trying to test Linux containers under Windows 10 when in Windows container mode
+        try:
+            self._checkPlatformMistmatch(logger, containerPlatform, False)
+        except RuntimeError:
+            return False
+
+        # Attempt to build the Dockerfile
+        logger.action(
+            "[network] Attempting to build an image that accesses the IPv6 loopback address...",
+            False,
+        )
+        built = self._buildDockerfile(
+            logger, containerPlatform, diagnosticIPv6.IMAGE_TAG, []
+        )
+
+        # Inform the user of the outcome of the diagnostic
+        if built == True:
+            logger.action(
+                "[network] Diagnostic succeeded! Linux containers can access the IPv6 loopback address without any issues.\n"
+            )
+        else:
+            logger.error(
+                "[network] Diagnostic failed! Linux containers cannot access the IPv6 loopback address. Update to Docker 26.0.0+ or manually enable IPv6:",
+                True,
+            )
+            logger.error(
+                "[network] https://docs.docker.com/config/daemon/ipv6/#use-ipv6-for-the-default-bridge-network\n",
+                False,
+            )
+
+        return built

src/ue4docker/diagnostics/diagnostic_network.py

@@ -70,7 +70,7 @@ def run(self, logger, args=[]):
 
         # Verify that the user isn't trying to test Windows containers under Windows 10 when in Linux container mode (or vice versa)
         try:
-            self._checkPlatformMistmatch(logger, containerPlatform)
+            self._checkPlatformMistmatch(logger, containerPlatform, True)
         except RuntimeError:
             return False
 

src/ue4docker/diagnostics_cmd.py

@@ -9,6 +9,7 @@ def diagnostics():
         "all": allDiagnostics(),
         "8gig": diagnostic8Gig(),
         "20gig": diagnostic20Gig(),
+        "ipv6": diagnosticIPv6(),
         "network": diagnosticNetwork(),
     }
 

src/ue4docker/dockerfiles/diagnostics/ipv6/linux/Dockerfile

@@ -0,0 +1,7 @@
+FROM alpine:latest
+
+# Add a sentinel label so we can easily identify intermediate images
+LABEL com.adamrehn.ue4-docker.sentinel="1"
+
+# Test that we can ping the IPv6 loopback address
+RUN ping6 -c 5 '::1'