Define exit codes in rhsmcertd-worker

This patch creates a system for exit codes used by the worker. This way
the C wrapper may be able to understand what happened inside of the
application and alter its behavior.

src/subscription_manager/scripts/rhsmcertd_worker.py

@@ -10,6 +10,7 @@
 # Red Hat trademarks are not licensed under GPLv2. No permission is
 # granted to use or replicate Red Hat trademarks that are incorporated
 # in this software or its documentation.
+import enum
 import logging
 import random
 import signal
@@ -38,6 +39,39 @@
 from subscription_manager.utils import generate_correlation_id
 
 
+class ExitStatus(enum.IntEnum):
+    """Well-known exit codes.
+
+    WARNING: THIS IS NOT A PUBLIC API.
+    Values of these errors should not be used by any external applications, they are subject
+    to change at any time without warning.
+    External applications should only differentiate between zero and non-zero exit codes.
+    """
+
+    OK = 0
+
+    RHSMCERTD_DISABLED = 5
+    """rhsmcertd has been disabled through the config file."""
+    LOCAL_CORRUPTION = 6
+    """Local data have been corrupted."""
+
+    NO_CLOUD_PROVIDER = 10
+    """No public cloud provider has been detected."""
+    NO_CLOUD_METADATA = 11
+    """Public cloud provider has been detected, but metadata could not be obtained."""
+
+    NO_REGISTRATION_TOKEN = 20
+    """Registration token could not be obtained: server or cache are unavailable or broken."""
+    BAD_TOKEN_TYPE = 21
+    """Registration token was received, but is not recognized."""
+
+    REGISTRATION_FAILED = 30
+    """The system registration was not successful."""
+
+    UNKNOWN_ERROR = -1
+    """An unknown error occured."""
+
+
 if TYPE_CHECKING:
     import argparse
     from rhsm.config import RhsmConfigParser
@@ -52,7 +86,7 @@
 
 
 def exit_on_signal(_signumber, _stackframe):
-    sys.exit(0)
+    sys.exit(ExitStatus.OK)
 
 
 def _is_registered() -> bool:
@@ -130,13 +164,13 @@ def _auto_register(cp_provider: "CPProvider") -> None:
             "This system does not run on any supported cloud provider. "
             "Automatic registration cannot be performed."
         )
-        sys.exit(1)
+        sys.exit(ExitStatus.NO_CLOUD_PROVIDER)
 
     # When some cloud provider(s) were detected, then try to collect metadata and signature
     cloud_info = _collect_cloud_info(cloud_list)
     if len(cloud_info) == 0:
         log.warning("Cloud metadata could not be collected. Unable to perform automatic registration.")
-        sys.exit(1)
+        sys.exit(ExitStatus.NO_CLOUD_METADATA)
 
     # Get connection not using any authentication
     uep: "UEPConnection" = cp_provider.get_no_auth_cp()
@@ -151,31 +185,31 @@ def _auto_register(cp_provider: "CPProvider") -> None:
         )
     except Exception:
         log.exception("Cloud token could not be obtained. Unable to perform automatic registration.")
-        sys.exit(1)
+        sys.exit(ExitStatus.NO_REGISTRATION_TOKEN)
 
     if token["tokenType"] == "CP-Cloud-Registration":
         try:
             _auto_register_standard(uep=uep, token=token)
         except Exception:
             log.exception("Standard automatic registration failed.")
-            sys.exit(1)
+            sys.exit(ExitStatus.REGISTRATION_FAILED)
         else:
             log.info("Standard automatic registration was successful.")
-            sys.exit(0)
+            sys.exit(ExitStatus.OK)
 
     if token["tokenType"] == "CP-Anonymous-Cloud-Registration":
         try:
             _auto_register_anonymous(uep=uep, token=token)
             cache.CloudTokenCache.delete_cache()
         except Exception:
             log.exception("Anonymous automatic registration failed.")
-            sys.exit(1)
+            sys.exit(ExitStatus.REGISTRATION_FAILED)
         else:
             log.info("Anonymous automatic registration was successful.")
-            sys.exit(0)
+            sys.exit(ExitStatus.OK)
 
     log.error(f"Unsupported token type for automatic registration: {token['tokenType']}.")
-    sys.exit(1)
+    sys.exit(ExitStatus.BAD_TOKEN_TYPE)
 
 
 def _auto_register_standard(uep: "UEPConnection", token: Dict[str, str]) -> None:
@@ -279,7 +313,7 @@ def _main(options: "argparse.Namespace"):
     log.debug("check for rhsmcertd disable")
     if cfg.get("rhsmcertd", "disable") == "1" and not options.force:
         log.warning("The rhsmcertd process has been disabled by configuration.")
-        sys.exit(-1)
+        sys.exit(ExitStatus.RHSMCERTD_DISABLED)
 
     # Was script executed with --auto-register option
     if options.auto_register is True:
@@ -290,7 +324,7 @@ def _main(options: "argparse.Namespace"):
             "Either the consumer is not registered or the certificates"
             + " are corrupted. Certificate update using daemon failed."
         )
-        sys.exit(-1)
+        sys.exit(ExitStatus.LOCAL_CORRUPTION)
     print(_("Updating entitlement certificates & repositories"))
 
     cp: UEPConnection = cp_provider.get_consumer_auth_cp()
@@ -384,11 +418,11 @@ def main():
         # stack trace. We need to check the code, since we want to signal
         # exit with failure to the caller. Otherwise, we will exit with 0
         if se.code:
-            sys.exit(-1)
+            sys.exit(ExitStatus.UNKNOWN_ERROR)
     except Exception:
         log.exception("Error while updating certificates using daemon")
         print(_("Unable to update entitlement certificates and repositories"))
-        sys.exit(-1)
+        sys.exit(ExitStatus.UNKNOWN_ERROR)
 
 
 if __name__ == "__main__":