move check_inst out of bindinstance.py

create a new platform utils module which imports a proper implementation
from platform.PLATFORM.instances.utils. Move the current check_inst to the
fedora16 package and create debian implementation which uses dpkg-query
to check for bind9 and bind-dyndb-ldap packages.

ipapython/platform/base/instances/bind.py

@@ -36,31 +36,6 @@ from ipalib.constants import DNS_ZONE_REFRESH
 import ipalib
 from ipalib import api, util, errors
 
-def check_inst(unattended):
-    has_bind = True
-    # So far this file is always present in both RHEL5 and Fedora if all the necessary
-    # bind packages are installed (RHEL5 requires also the pkg: caching-nameserver)
-    if not os.path.exists('/etc/named.rfc1912.zones'):
-        print "BIND was not found on this system"
-        print "Please install the 'bind' package and start the installation again"
-        has_bind = False
-
-    # Also check for the LDAP BIND plug-in
-    if not os.path.exists('/usr/lib/bind/ldap.so') and \
-       not os.path.exists('/usr/lib64/bind/ldap.so'):
-        print "The BIND LDAP plug-in was not found on this system"
-        print "Please install the 'bind-dyndb-ldap' package and start the installation again"
-        has_bind = False
-
-    if not has_bind:
-        return False
-
-    if not unattended and os.path.exists('/etc/named.conf'):
-        msg = "Existing BIND configuration detected, overwrite?"
-        return ipautil.user_input(msg, False)
-
-    return True
-
 def normalize_zone(zone):
     if zone[-1] != '.':
         return zone + '.'

ipapython/platform/debian/instances/utils.py

@@ -0,0 +1,45 @@
+import os
+import subprocess
+
+import ipautil
+
+from hashutil import md5
+
+def bind_check_installation(unattended):
+    # files in /etc/ are not being deleted on package removal, so we can't
+    # rely on them to check if BIND is installed. Also, because Debian has
+    # switched to the multiarch filesystem layout there is no easy way
+    # to look for the ldap.so BIND plugin. But we can query dpkg database
+    # to see if both packages are installed, it actually feels like a cleaner
+    # solution.
+    dpkg_query = ['/usr/bin/dpkg-query', '-W', '-f', '${Package}']
+    try:
+        ipautil.run(dpkg_query + ['bind'], raiseonerr=True):
+    except ipautil.CalledProcessError:
+        print "BIND was not found on this system"
+        print "Please install the 'bind9' package and start the installation again"
+        has_bind = False
+
+    try:
+        ipautil.run(dpkg_query + ['bind-dyndb-ldap'], raiseonerr=True)
+    except ipautil.CalledProcessError:
+        print "The BIND LDAP plug-in was not found on this system"
+        print "Please install the 'bind-dyndb-ldap' package and start the installation again"
+        has_bind = False
+
+    if not has_bind:
+        return False
+
+    dpkg_query = ['/usr/bin/dpkg-query', '-W', '-f', '${Conffiles}']
+    stdout, stderr, ret = ipautil.run(dpkg_query)
+    # convert dpkg-query output into a mapping fname->md5sum
+    conf_files = dict([p.strip().split(' ') for p in stdout.split('\n')])
+
+    # IPA installation modified named.local so lets check it for local changes
+    fname = '/etc/bind/named.local'
+    hash = md5.new(open(fname, 'rb').read()).digest()
+    if conf_files[fname] != hash:
+        msg = "Existing BIND configuration detected, overwrite?"
+        return ipautil.user_input(msg, False)
+
+    return True

ipapython/platform/fedora16/instances/utils.py

@@ -0,0 +1,28 @@
+import os
+
+import ipautil
+
+def bind_check_installation(unattended):
+    has_bind = True
+    # So far this file is always present in both RHEL5 and Fedora if all the necessary
+    # bind packages are installed (RHEL5 requires also the pkg: caching-nameserver)
+    if not os.path.exists('/etc/named.rfc1912.zones'):
+        print "BIND was not found on this system"
+        print "Please install the 'bind' package and start the installation again"
+        has_bind = False
+
+    # Also check for the LDAP BIND plug-in
+    if not os.path.exists('/usr/lib/bind/ldap.so') and \
+       not os.path.exists('/usr/lib64/bind/ldap.so'):
+        print "The BIND LDAP plug-in was not found on this system"
+        print "Please install the 'bind-dyndb-ldap' package and start the installation again"
+        has_bind = False
+
+    if not has_bind:
+        return False
+
+    if not unattended and os.path.exists('/etc/named.conf'):
+        msg = "Existing BIND configuration detected, overwrite?"
+        return ipautil.user_input(msg, False)
+
+    return True

ipapython/platform/utils.py

@@ -0,0 +1,9 @@
+"""small utils used by other instances that require platform-dependent
+implementations"""
+
+from .SUPPORTED_PLATFORM.utils import *
+
+def bind_check_installation(unattended):
+    """checks if the bind server has been properly installed."""
+    raise NotImplementedError("this function has to be implemented"
+                              "in the platform module")