Move install script error handling to a common function

All of our install/admin scripts had a try/except block calling the
main function and handling common exceptions. These were copy-pasted
from each other and modified to various levels of sophistication.
This refactors them out of installers to a single function, which
includes a final pass/fail message for all of the scripts.

Non-install scripts that set up the same log handler levels for
stderr and log file are not changed, as it's not possible to log
to only the logfile without changing the logger configuration.

https://fedorahosted.org/freeipa/ticket/2071

1 files changed, 129 insertions, 1 deletions

diff --git a/ipaserver/install/installutils.py b/ipaserver/install/installutils.py
index 362723614..313761777 100644
--- a/ipaserver/install/installutils.py
+++ b/ipaserver/install/installutils.py
@@ -30,13 +30,18 @@ import netaddr
 import time
 import tempfile
 import shutil
+from ConfigParser import SafeConfigParser
+import traceback
+
 from dns import resolver, rdatatype
 from dns.exception import DNSException
+import ldap
 
-from ConfigParser import SafeConfigParser
 from ipapython import ipautil, sysrestore
 from ipapython.ipa_log_manager import *
 from ipalib.util import validate_hostname
+from ipapython import config
+from ipalib import errors
 
 # Used to determine install status
 IPA_MODULES = ['httpd', 'kadmin', 'dirsrv', 'pki-cad', 'pkids', 'install', 'krb5kdc', 'ntpd', 'named', 'ipa_memcached']
@@ -56,6 +61,18 @@ class HostReverseLookupError(HostLookupError):
 class HostnameLocalhost(HostLookupError):
     pass
 
+
+class ScriptError(StandardError):
+    """An exception that records an error message and a return value
+    """
+    def __init__(self, msg = '', rval = 1):
+        self.msg = msg
+        self.rval = rval
+
+    def __str__(self):
+        return self.msg
+
+
 class ReplicaConfig:
     def __init__(self):
         self.realm_name = ""
@@ -655,3 +672,114 @@ def is_ipa_configured():
         root_logger.debug('filestore is tracking no files')
 
     return installed
+
+
+def run_script(main_function, operation_name, log_file_name=None,
+        fail_message=None):
+    """Run the given function as a command-line utility
+
+    This function:
+
+    - Runs the given function
+    - Formats any errors
+    - Exits with the appropriate code
+
+    :param main_function: Function to call
+    :param log_file_name: Name of the log file (displayed on unexpected errors)
+    :param operation_name: Name of the script
+    :param fail_message: Optional message displayed on failure
+    """
+
+    root_logger.info('Starting script: %s', operation_name)
+    try:
+        try:
+            return_value = main_function()
+        except BaseException, e:
+            if isinstance(e, SystemExit) and (e.code is None or e.code == 0):
+                # Not an error after all
+                root_logger.info('The %s command was successful',
+                    operation_name)
+            else:
+                # Log at the INFO level, which is not output to the console
+                # (unless in debug/verbose mode), but is written to a logfile
+                # if one is open.
+                tb = sys.exc_info()[2]
+                root_logger.info('\n'.join(traceback.format_tb(tb)))
+                root_logger.info('The %s command failed, exception: %s: %s',
+                    operation_name, type(e).__name__, e)
+                exception = e
+                if fail_message and not isinstance(e, SystemExit):
+                    print fail_message
+                raise
+        else:
+            if return_value:
+                root_logger.info('The %s command failed, return value %s',
+                    operation_name, return_value)
+            else:
+                root_logger.info('The %s command was successful',
+                    operation_name)
+            sys.exit(return_value)
+
+    except BaseException, error:
+        handle_error(error, log_file_name)
+
+
+def handle_error(error, log_file_name=None):
+    """Handle specific errors"""
+
+    if isinstance(error, SystemExit):
+        sys.exit(error)
+    if isinstance(error, RuntimeError):
+        sys.exit(error)
+    if isinstance(error, KeyboardInterrupt):
+        print >> sys.stderr, "Cancelled."
+        sys.exit(1)
+
+    if isinstance(error, ScriptError):
+        if error.msg:
+            print >> sys.stderr, error.msg
+        sys.exit(error.rval)
+
+    if isinstance(error, socket.error):
+        print >> sys.stderr, error
+        sys.exit(1)
+
+    if isinstance(error, ldap.INVALID_CREDENTIALS):
+        print >> sys.stderr, "Invalid password"
+        sys.exit(1)
+    if isinstance(error, ldap.INSUFFICIENT_ACCESS):
+        print >> sys.stderr, "Insufficient access"
+        sys.exit(1)
+    if isinstance(error, ldap.LOCAL_ERROR):
+        print >> sys.stderr, error.args[0]['info']
+        sys.exit(1)
+    if isinstance(error, ldap.SERVER_DOWN):
+        print >> sys.stderr, error.args[0]['desc']
+        sys.exit(1)
+    if isinstance(error, ldap.LDAPError):
+        print >> sys.stderr, 'LDAP error: %s' % type(error).__name__
+        print >> sys.stderr, error.args[0]['info']
+        sys.exit(1)
+
+    if isinstance(error, config.IPAConfigError):
+        print >> sys.stderr, "An IPA server to update cannot be found. Has one been configured yet?"
+        print >> sys.stderr, "The error was: %s" % error
+        sys.exit(1)
+    if isinstance(error, errors.LDAPError):
+        print >> sys.stderr, "An error occurred while performing operations: %s" % error
+        sys.exit(1)
+
+    if isinstance(error, HostnameLocalhost):
+        print >> sys.stderr, "The hostname resolves to the localhost address (127.0.0.1/::1)"
+        print >> sys.stderr, "Please change your /etc/hosts file so that the hostname"
+        print >> sys.stderr, "resolves to the ip address of your network interface."
+        print >> sys.stderr, ""
+        print >> sys.stderr, "Please fix your /etc/hosts file and restart the setup program"
+        sys.exit(1)
+
+    if log_file_name:
+        print >> sys.stderr, "Unexpected error - see %s for details:" % log_file_name
+    else:
+        print >> sys.stderr, "Unexpected error"
+    print >> sys.stderr, '%s: %s' % (type(error).__name__, error)
+    sys.exit(1)