Fixes #5469 Refactor sysctl module into object oriented code,

and add a sysctl_set parameter to manage the values in /proc

library/system/sysctl

@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 
 # (c) 2012, David "DaviXX" CHANIAL <david.chanial@gmail.com>
+# (c) 2014, James Tanner <tanner.jc@gmail.com>
 #
 # This file is part of Ansible
 #
@@ -41,19 +42,9 @@ options:
         aliases: [ 'val' ]
     state:
         description:
-            - Whether the entry should be present or absent.
+            - Whether the entry should be present or absent in the sysctl file.
         choices: [ "present", "absent" ]
         default: present
-    checks:
-        description:
-            - If C(none), no smart/facultative checks will be made. If
-              C(before), some checks are performed before any update (i.e. is
-              the sysctl key writable?). If C(after), some checks are performed
-              after an update (i.e. does kernel return the set value?). If
-              C(both), all of the smart checks (C(before) and C(after)) are
-              performed.
-        choices: [ "none", "before", "after", "both" ]
-        default: both
     reload:
         description:
             - If C(yes), performs a I(/sbin/sysctl -p) if the C(sysctl_file) is
@@ -66,6 +57,13 @@ options:
             - Specifies the absolute path to C(sysctl.conf), if not C(/etc/sysctl.conf).
         required: false
         default: /etc/sysctl.conf
+    sysctl_set:
+        description:
+            - Verify token value with the sysctl command and set with -w if necessary
+        choices: [ "yes", "no" ]
+        required: false
+        version_added: 1.5
+        default: False
 notes: []
 requirements: []
 author: David "DaviXX" CHANIAL <david.chanial@gmail.com>
@@ -78,10 +76,14 @@ EXAMPLES = '''
 # Remove kernel.panic entry from /etc/sysctl.conf
 - sysctl: name=kernel.panic state=absent sysctl_file=/etc/sysctl.conf
 
-# Set kernel.panic to 3 in /tmp/test_sysctl.conf, check if the sysctl key
-# seems writable, but do not reload sysctl, and do not check kernel value
-# after (not needed, because the real /etc/sysctl.conf was not updated)
-- sysctl: name=kernel.panic value=3 sysctl_file=/tmp/test_sysctl.conf checks=before reload=no
+# Set kernel.panic to 3 in /tmp/test_sysctl.conf
+- sysctl: name=kernel.panic value=3 sysctl_file=/tmp/test_sysctl.conf reload=no
+
+# Set ip fowarding on in /proc and do not reload the sysctl file
+- sysctl: name="net.ipv4.ip_forward" value=1 sysctl_set=yes
+
+# Set ip forwarding on in /proc and in the sysctl file and reload if necessary
+- sysctl: name="net.ipv4.ip_forward" value=1 sysctl_set=yes state=present reload=yes
 '''
 
 # ==============================================================
@@ -90,137 +92,168 @@ import os
 import tempfile
 import re
 
-# ==============================================================
-
-def reload_sysctl(module, **sysctl_args):
-    # update needed ?
-    if not sysctl_args['reload']:
-        return 0, ''
-
-    # do it
-    if get_platform().lower() == 'freebsd':
-        # freebsd doesn't support -p, so reload the sysctl service
-        rc,out,err = module.run_command('/etc/rc.d/sysctl reload')
-    else:
-        # system supports reloading via the -p flag to sysctl, so we'll use that 
-        sysctl_cmd = module.get_bin_path('sysctl', required=True)
-        rc,out,err = module.run_command([sysctl_cmd, '-p', sysctl_args['sysctl_file']])
-        
-    return rc,out+err
-
-# ==============================================================
-
-def write_sysctl(module, lines, **sysctl_args):
-    # open a tmp file
-    fd, tmp_path = tempfile.mkstemp('.conf', '.ansible_m_sysctl_', os.path.dirname(sysctl_args['sysctl_file']))
-    f = open(tmp_path,"w")
-    try:
-        for l in lines:
-            f.write(l)
-    except IOError, e:
-        module.fail_json(msg="Failed to write to file %s: %s" % (tmp_path, str(e)))
-    f.flush()
-    f.close()
-
-    # replace the real one
-    module.atomic_move(tmp_path, sysctl_args['sysctl_file']) 
-
-    # end
-    return sysctl_args
-
-# ==============================================================
-
-def sysctl_args_expand(**sysctl_args):
-    if get_platform().lower() == 'freebsd':
-        # FreeBSD does not use the /proc file system, and instead
-        # just uses the sysctl command to set the values
-        sysctl_args['key_path'] = None
-    else:
-        sysctl_args['key_path'] = sysctl_args['name'].replace('.' ,'/')
-        sysctl_args['key_path'] = '/proc/sys/' + sysctl_args['key_path']
-    return sysctl_args
-
-# ==============================================================
-
-def sysctl_args_collapse(**sysctl_args):
-    # go ahead
-    if sysctl_args.get('key_path') is not None:
-        del sysctl_args['key_path']
-    if sysctl_args['state'] == 'absent' and 'value' in sysctl_args:
-        del sysctl_args['value']
-    
-    # end
-    return sysctl_args
-
-# ==============================================================
-
-def sysctl_check(module, current_step, **sysctl_args):
-    
-    # no smart checks at this step ?
-    if sysctl_args['checks'] == 'none':
-        return 0, ''
-    if current_step == 'before' and sysctl_args['checks'] not in ['before', 'both']:
-        return 0, ''
-    if current_step == 'after' and sysctl_args['checks'] not in ['after', 'both']:
-        return 0, ''
-
-    # checking coherence
-    if sysctl_args['state'] == 'absent' and sysctl_args['value'] is not None:
-        return 1, 'value=x must not be supplied when state=absent'
-    
-    if sysctl_args['state'] == 'present' and sysctl_args['value'] is None:
-        return 1, 'value=x must be supplied when state=present'
-    
-    if not sysctl_args['reload'] and sysctl_args['checks'] in ['after', 'both']:
-        return 1, 'checks cannot be set to after or both if reload=no'
-
-    if sysctl_args['key_path'] is not None:
-        # getting file stat
-        if not os.access(sysctl_args['key_path'], os.F_OK):
-            return 1, 'key_path is not an existing file, key %s seems invalid' % sysctl_args['key_path']
-        if not os.access(sysctl_args['key_path'], os.R_OK):
-            return 1, 'key_path is not a readable file, key seems to be uncheckable'
-
-    # checks before
-    if current_step == 'before' and sysctl_args['checks'] in ['before', 'both']:
-        if sysctl_args['key_path'] is not None and not os.access(sysctl_args['key_path'], os.W_OK):
-            return 1, 'key_path is not a writable file, key seems to be read only'
-        return 0, ''
-
-    # checks after
-    if current_step == 'after' and sysctl_args['checks'] in ['after', 'both']:
-        if sysctl_args['value'] is not None:
-            if sysctl_args['key_path'] is not None:
-                # reading the virtual file
-                f = open(sysctl_args['key_path'],'r')
-                output = f.read()
-                f.close()
-            else:
-                # we're on a system without /proc (ie. freebsd), so just
-                # use the sysctl command to get the currently set value
-                sysctl_cmd = module.get_bin_path('sysctl', required=True)
-                rc,output,stderr = module.run_command("%s -n %s" % (sysctl_cmd, sysctl_args['name']))
-                if rc != 0:
-                    return 1, 'failed to lookup the value via the sysctl command'
-
-            output = output.strip(' \t\n\r')
-            output = re.sub(r'\s+', ' ', output)
-
-            # normal case, found value must be equal to the submitted value, and 
-            # we compare the exploded values to handle any whitepsace differences
-            if output.split() != sysctl_args['value'].split():
-                return 1, 'key seems not set to value even after update/sysctl, founded : <%s>, wanted : <%s>' % (output, sysctl_args['value'])
-
-            return 0, ''
+class SysctlModule(object):
+
+    def __init__(self, module):
+        self.module = module 
+        self.args = self.module.params
+
+        self.sysctl_cmd = self.module.get_bin_path('sysctl', required=True)
+        self.sysctl_file = self.args['sysctl_file']
+
+        self.proc_value = None  # current token value in proc fs
+        self.file_value = None  # current token value in file
+        self.file_lines = []    # all lines in the file
+        self.file_values = {}   # dict of token values
+
+        self.changed = False    # will change occur
+        self.set_proc = False   # does sysctl need to set value
+        self.write_file = False # does the sysctl file need to be reloaded
+
+        self.process()
+
+    # ==============================================================
+    #   LOGIC
+    # ==============================================================
+
+    def process(self):
+
+        # Whitespace is bad
+        self.args['name'] = self.args['name'].strip()
+        self.args['value'] = self.args['value'].strip()
+
+        thisname = self.args['name']
+
+        # get the current proc fs value
+        self.proc_value = self.get_token_curr_value(thisname)
+
+        # get the currect sysctl file value
+        self.read_sysctl_file()
+        if thisname not in self.file_values:
+            self.file_values[thisname] = None
+
+        # update file contents with desired token/value
+        self.fix_lines()
+
+        # what do we need to do now?
+        if self.file_values[thisname] is None and self.args['state'] == "present":
+            self.changed = True
+            self.write_file = True
+        elif self.file_values[thisname] != self.args['value']:
+            self.changed = True
+            self.write_file = True
+        if self.args['sysctl_set']:            
+            if self.proc_value is None:
+                self.changed = True
+            elif self.proc_value != self.args['value']:
+                self.changed = True 
+                self.set_proc = True
+
+        # Do the work
+        if not self.module.check_mode:
+            if self.write_file:
+                self.write_sysctl()
+            if self.write_file and self.args['reload']:
+                self.reload_sysctl()
+            if self.set_proc:
+                self.set_token_value(self.args['name'], self.args['value'])
+
+    # ==============================================================
+    #   SYSCTL COMMAND MANAGEMENT
+    # ==============================================================
+
+    # Use the sysctl command to find the current value 
+    def get_token_curr_value(self, token):
+        thiscmd = "%s -e -n %s" % (self.sysctl_cmd, token)
+        rc,out,err = self.module.run_command(thiscmd)    
+        if rc != 0:
+            return None
+        else:
+            return shlex.split(out)[-1]
+
+    # Use the sysctl command to set the current value
+    def set_token_value(self, token, value):
+        thiscmd = "%s -w %s=%s" % (self.sysctl_cmd, token, value)
+        rc,out,err = self.module.run_command(thiscmd)
+        if rc != 0:
+            self.module.fail_json(msg='setting %s failed: %s' (token, out + err))
+        else:
+            return rc
+
+    # Run sysctl -p
+    def reload_sysctl(self):
+        # do it
+        if get_platform().lower() == 'freebsd':
+            # freebsd doesn't support -p, so reload the sysctl service
+            rc,out,err = self.module.run_command('/etc/rc.d/sysctl reload')
         else:
-            # no value was supplied, so we're checking to make sure
-            # the associated name is absent. We just fudge this since 
-            # the sysctl isn't really gone, just removed from the conf 
-            # file meaning it will be whatever the system default is
-            return 0, ''
+            # system supports reloading via the -p flag to sysctl, so we'll use that 
+            rc,out,err = self.module.run_command([self.sysctl_cmd, '-p', self.sysctl_file])
+            
+        return rc,out+err
+
+    # ==============================================================
+    #   SYSCTL FILE MANAGEMENT
+    # ==============================================================
+
+    # Get the token value from the sysctl file
+    def read_sysctl_file(self):
+        lines = open(self.sysctl_file, "r").readlines()
+        for line in lines:
+            line = line.strip()
+            self.file_lines.append(line)
+
+            # don't split empty lines or comments
+            if not line or line.startswith("#"):
+                continue 
+
+            k, v = line.split('=',1)
+            k = k.strip()
+            v = v.strip()
+            self.file_values[k] = v.strip()
+
+    # Fix the value in the sysctl file content
+    def fix_lines(self):
+        checked = []
+        self.fixed_lines = []
+        for line in self.file_lines:
+            if not line.strip() or line.strip().startswith("#"):
+                self.fixed_lines.append(line)
+                continue
+            tmpline = line.strip()            
+            k, v = line.split('=',1)
+            k = k.strip()
+            v = v.strip()
+            if k not in checked:
+                checked.append(k)
+                if k == self.args['name']:
+                    if self.args['state'] == "present":
+                        new_line = "%s = %s\n" % (k, self.args['value'])
+                        self.fixed_lines.append(new_line)                    
+                else:
+                    new_line = "%s = %s\n" % (k, v)
+                    self.fixed_lines.append(new_line)                    
+
+        if self.args['name'] not in checked and self.args['state'] == "present":
+            new_line = "%s = %s\n" % (self.args['name'], self.args['value'])
+            self.fixed_lines.append(new_line)                    
+
+    # Completely rewrite the sysctl file
+    def write_sysctl(self):
+        # open a tmp file
+        fd, tmp_path = tempfile.mkstemp('.conf', '.ansible_m_sysctl_', os.path.dirname(self.sysctl_file))
+        f = open(tmp_path,"w")
+        try:
+            for l in self.fixed_lines:
+                f.write(l)
+        except IOError, e:
+            self.module.fail_json(msg="Failed to write to file %s: %s" % (tmp_path, str(e)))
+        f.flush()
+        f.close()
+
+        # replace the real one
+        self.module.atomic_move(tmp_path, self.sysctl_file) 
 
-    # weird end
-    return 1, 'unexpected position reached'
 
 # ==============================================================
 # main
@@ -233,110 +266,16 @@ def main():
             name = dict(aliases=['key'], required=True),
             value = dict(aliases=['val'], required=False),
             state = dict(default='present', choices=['present', 'absent']),
-            checks = dict(default='both', choices=['none', 'before', 'after', 'both']),
             reload = dict(default=True, type='bool'),
+            sysctl_set = dict(default=True, type='bool'),
             sysctl_file = dict(default='/etc/sysctl.conf')
-        )
+        ),
+        supports_check_mode=True
     )
 
-    # defaults
-    sysctl_args = {
-        'changed': False,
-        'name': module.params['name'],
-        'state': module.params['state'],
-        'checks': module.params['checks'],
-        'reload': module.params['reload'],
-        'value': module.params.get('value'),
-        'sysctl_file': module.params['sysctl_file']
-    }
-    
-    # prepare vars
-    sysctl_args = sysctl_args_expand(**sysctl_args)
-    if get_platform().lower() == 'freebsd':
-        # freebsd does not like spaces around the equal sign
-        pattern = "%s=%s\n"
-    else:
-        pattern = "%s = %s\n" 
-    new_line = pattern % (sysctl_args['name'], sysctl_args['value'])
-    to_write = []
-    founded = False
-   
-    # make checks before act
-    res,msg = sysctl_check(module, 'before', **sysctl_args)
-    if res != 0:
-        module.fail_json(msg='checks_before failed with: ' + msg)
-
-    if not os.access(sysctl_args['sysctl_file'], os.W_OK):
-        try:
-            f = open(sysctl_args['sysctl_file'],'w')
-            f.close()
-        except IOError, e:
-            module.fail_json(msg='unable to create supplied sysctl file (destination directory probably missing)')
-
-    # reading the file
-    for line in open(sysctl_args['sysctl_file'], 'r').readlines():
-        if not line.strip():
-            to_write.append(line)
-            continue
-        if line.strip().startswith('#'):
-            to_write.append(line)
-            continue
-
-        # write line if not the one searched
-        ld = {}
-        ld['name'], ld['val'] = line.split('=',1)
-        ld['name'] = ld['name'].strip()
-
-        if ld['name'] != sysctl_args['name']:
-            to_write.append(line)
-            continue
-
-        # should be absent ?
-        if sysctl_args['state'] == 'absent':
-            # not writing the founded line
-            # mark as changed
-            sysctl_args['changed'] = True
-                
-        # should be present
-        if sysctl_args['state'] == 'present':
-            # is the founded line equal to the wanted one ?
-            ld['val'] = ld['val'].strip()
-            if ld['val'] == sysctl_args['value']:
-                # line is equal, writing it without update (but cancel repeats)
-                if sysctl_args['changed'] == False and founded == False:
-                    to_write.append(line)
-                    founded = True
-            else:
-                # update the line (but cancel repeats)
-                if sysctl_args['changed'] == False and founded == False:
-                    to_write.append(new_line)
-                    sysctl_args['changed'] = True
-                continue
+    result = SysctlModule(module)    
 
-    # if not changed, but should be present, so we have to add it
-    if sysctl_args['state'] == 'present' and sysctl_args['changed'] == False and founded == False:
-        to_write.append(new_line)
-        sysctl_args['changed'] = True
-
-    # has changed ?
-    res = 0
-    if sysctl_args['changed'] == True:
-        sysctl_args = write_sysctl(module, to_write, **sysctl_args)
-        res,msg = reload_sysctl(module, **sysctl_args)
-        
-        # make checks after act
-        res,msg = sysctl_check(module, 'after', **sysctl_args)
-        if res != 0:
-            module.fail_json(msg='checks_after failed with: ' + msg)
-
-    # look at the next link to avoid this workaround
-    # https://groups.google.com/forum/?fromgroups=#!topic/ansible-project/LMY-dwF6SQk
-    changed = sysctl_args['changed']
-    del sysctl_args['changed']
-
-    # end
-    sysctl_args = sysctl_args_collapse(**sysctl_args)
-    module.exit_json(changed=changed, **sysctl_args)
+    module.exit_json(changed=result.changed)
     sys.exit(0)
 
 # import module snippets