Complete initial cleanup for refactoring/rework.

Some of the cleanups were the following

1. Using standard (logged) utility functions for sub process work, writing, reading files, and other file system/operating system options
2. Having distrobutions impelement there own subclasses to handle system specifics (if applicable)
3. Having a cloud wrapper that provides just the functionality we want to expose (cloud.py)
4. Using a path class instead of globals for all cloud init paths (it is configured via config)
5. Removal of as much shared global state as possible (there should be none, minus a set of constants)
6. Other various cleanups that remove transforms/handlers/modules from reading/writing/chmoding there own files. 
 a. They should be using util functions to take advantage of the logging that is now enabled in those util functions (very useful for debugging)
7. Urls being read and checked from a single module that serves this and only this purpose (+1 for code organization)
8. Updates to log whenever a transform decides not to run
9. Ensure whenever a exception is thrown (and possibly captured) that the util.logexc function is called 
 a. For debugging, tracing this is important to not just drop them on the floor.
10. Code shuffling into utils.py where it makes sense (and where it could serve a benefit for other code now or in the future)

1 files changed, 64 insertions, 44 deletions

diff --git a/cloudinit/transforms/cc_set_passwords.py b/cloudinit/transforms/cc_set_passwords.py
index 9d0bbdb8..4f2cdb97 100644
--- a/cloudinit/transforms/cc_set_passwords.py
+++ b/cloudinit/transforms/cc_set_passwords.py
@@ -18,13 +18,18 @@
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import cloudinit.util as util
 import sys
-import random
-from string import letters, digits  # pylint: disable=W0402
 
+from cloudinit import util
 
-def handle(_name, cfg, _cloud, log, args):
+from string import letters, digits
+
+# We are removing certain 'painful' letters/numbers
+pw_set = (letters.translate(None, 'loLOI') +
+          digits.translate(None, '01'))
+
+
+def handle(_name, cfg, cloud, log, args):
     if len(args) != 0:
         # if run from command line, and give args, wipe the chpasswd['list']
         password = args[0]
@@ -62,68 +67,83 @@ def handle(_name, cfg, _cloud, log, args):
 
         ch_in = '\n'.join(plist_in)
         try:
+            log.debug("Changing password for %s:", users)
             util.subp(['chpasswd'], ch_in)
-            log.debug("changed password for %s:" % users)
         except Exception as e:
             errors.append(e)
-            log.warn("failed to set passwords with chpasswd: %s" % e)
+            util.logexc(log, "Failed to set passwords with chpasswd for %s", users)
 
         if len(randlist):
-            sys.stdout.write("%s\n%s\n" % ("Set the following passwords\n",
+            sys.stderr.write("%s\n%s\n" % ("Set the following 'random' passwords\n",
                 '\n'.join(randlist)))
 
         if expire:
-            enum = len(errors)
+            expired_users = []
             for u in users:
                 try:
                     util.subp(['passwd', '--expire', u])
+                    expired_users.append(u)
                 except Exception as e:
                     errors.append(e)
-                    log.warn("failed to expire account for %s" % u)
-            if enum == len(errors):
-                log.debug("expired passwords for: %s" % u)
+                    util.logexc(log, "Failed to set 'expire' for %s", u)
+            if expired_users:
+                log.debug("Expired passwords for: %s users", expired_users)
 
+    change_pwauth = False
+    pw_auth = None
     if 'ssh_pwauth' in cfg:
-        val = str(cfg['ssh_pwauth']).lower()
-        if val in ("true", "1", "yes"):
-            pw_auth = "yes"
-            change_pwauth = True
-        elif val in ("false", "0", "no"):
-            pw_auth = "no"
-            change_pwauth = True
-        else:
-            change_pwauth = False
+        change_pwauth = True
+        if util.is_true_str(cfg['ssh_pwauth']):
+            pw_auth = 'yes'
+        if util.is_false_str(cfg['ssh_pwauth']):
+            pw_auth = 'no'
 
     if change_pwauth:
-        pa_s = "\(#*\)\(PasswordAuthentication[[:space:]]\+\)\(yes\|no\)"
-        msg = "set PasswordAuthentication to '%s'" % pw_auth
-        try:
-            cmd = ['sed', '-i', 's,%s,\\2%s,' % (pa_s, pw_auth),
-                   '/etc/ssh/sshd_config']
-            util.subp(cmd)
-            log.debug(msg)
-        except Exception as e:
-            log.warn("failed %s" % msg)
-            errors.append(e)
+        new_lines = []
+        replaced_auth = False
+        replacement = "PasswordAuthentication %s" % (pw_auth)
+
+        # See http://linux.die.net/man/5/sshd_config
+        old_lines = util.load_file('/etc/ssh/sshd_config').splitlines()
+        for i, line in enumerate(old_lines):
+            if not line.strip() or line.startswith("#"):
+                new_lines.append(line)
+                continue
+            splitup = line.split(None, 1)
+            if len(splitup) <= 1:
+                new_lines.append(line)
+                continue
+            (cmd, args) = splitup
+            # Keywords are case-insensitive and arguments are case-sensitive
+            cmd = cmd.lower().strip()
+            if cmd == 'passwordauthentication':
+                log.debug("Replacing auth line %s with %s", i + 1, replacement)
+                replaced_auth = True
+                new_lines.append(replacement)
+            else:
+                new_lines.append(line)
+
+        if not replaced_auth:
+            log.debug("Adding new auth line %s", replacement)
+            replaced_auth = True
+            new_lines.append(replacement)
+
+        new_contents = "\n".join(new_lines)
+        util.write_file('/etc/ssh/sshd_config', new_contents)
 
         try:
-            p = util.subp(['service', cfg.get('ssh_svcname', 'ssh'),
-                           'restart'])
-            log.debug("restarted sshd")
+            cmd = ['service']
+            cmd.append(cloud.distro.get_option('ssh_svcname', 'ssh'))
+            cmd.append('restart')
+            util.subp(cmd)
+            log.debug("Restarted the ssh daemon")
         except:
-            log.warn("restart of ssh failed")
+            util.logexc(log, "Restarting of the ssh daemon failed")
 
     if len(errors):
-        raise(errors[0])
-
-    return
-
-
-def rand_str(strlen=32, select_from=letters + digits):
-    return("".join([random.choice(select_from) for _x in range(0, strlen)]))
+        log.debug("%s errors occured, re-raising the last one", len(errors))
+        raise errors[-1]
 
 
 def rand_user_password(pwlen=9):
-    selfrom = (letters.translate(None, 'loLOI') +
-               digits.translate(None, '01'))
-    return(rand_str(pwlen, select_from=selfrom))
+    return util.rand_str(pwlen, select_from=pw_set)