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ansible
Commit fc4ba46d by Michael DeHaan
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Add a ton of comments so folks can understand what runner does. More refactoring is 

certaintly possible too.
parent c0ac0e9b
Showing with 55 additions and 31 deletions
lib/ansible/runner.py
......@@ -58,6 +58,7 @@ class Runner(object):
remote_pass -- provide only if you don't want to use keys or ssh-agent
'''
# save input values
self.host_list = self._parse_hosts(host_list)
self.module_path = module_path
self.module_name = module_name
......@@ -71,18 +72,23 @@ class Runner(object):
def _parse_hosts(self, host_list):
''' parse the host inventory file if not sent as an array '''
# if the host list is given as a string load the host list
# from a file, one host per line
if type(host_list) != list:
host_list = os.path.expanduser(host_list)
return file(host_list).read().split("\n")
return host_list
def _matches(self, host_name, pattern=None):
''' returns if a hostname is matched by the pattern '''
# a pattern is in fnmatch format but more than one pattern
# can be strung together with semicolons. ex:
# atlanta-web*.example.com;dc-web*.example.com
if host_name == '':
return False
if not pattern:
pattern = self.pattern
subpatterns = pattern.split(";")
for subpattern in subpatterns:
if fnmatch.fnmatch(host_name, subpattern):
......@@ -98,48 +104,66 @@ class Runner(object):
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
try:
# try paramiko
ssh.connect(host, username=self.remote_user, allow_agent=True,
look_for_keys=True, password=self.remote_pass)
return [ True, ssh ]
except:
# it failed somehow, return the failure string
return [ False, traceback.format_exc() ]
def _return_from_module(self, conn, host, result):
''' helper function to handle JSON parsing of results '''
# disconnect from paramiko/SSH
conn.close()
try:
# try to parse the JSON response
return [ host, True, json.loads(result) ]
except:
# it failed, say so, but return the string anyway
return [ host, False, result ]
def _delete_remote_files(self, conn, files):
''' deletes one or more remote files '''
for filename in files:
self._exec_command(conn, "rm -f %s" % filename)
def _transfer_file(self, conn, source, dest):
''' transfers a remote file '''
self.remote_log(conn, 'COPY remote:%s local:%s' % (source, dest))
ftp = conn.open_sftp()
ftp.put(source, dest)
ftp.close()
sftp = conn.open_sftp()
sftp.put(source, dest)
sftp.close()
def _transfer_module(self, conn):
'''
transfers a module file to the remote side to execute it,
but does not execute it yet
'''
outpath = self._copy_module(conn)
self._exec_command(conn, "chmod +x %s" % outpath)
return outpath
def _execute_module(self, conn, outpath):
'''
runs a module that has already been transferred
'''
cmd = self._command(outpath)
result = self._exec_command(conn, cmd)
self._delete_remote_files(conn, [ outpath ])
return result
def _execute_normal_module(self, conn, host):
''' transfer a module, set it executable, and run it '''
'''
transfer & execute a module that is not 'copy' or 'template'
because those require extra work.
'''
module = self._transfer_module(conn)
result = self._execute_module(conn, module)
return self._return_from_module(conn, host, result)
def _parse_kv(self, args):
''' helper function to convert a string of key/value items to a dict '''
options = {}
for x in args:
if x.find("=") != -1:
......@@ -150,10 +174,12 @@ class Runner(object):
def _execute_copy(self, conn, host):
''' handler for file transfer operations '''
# transfer the file to a remote tmp location
# load up options
options = self._parse_kv(self.module_args)
source = options['src']
dest = options['dest']
# transfer the file to a remote tmp location
tmp_src = self._get_tmp_path(conn, dest.split("/")[-1])
self._transfer_file(conn, source, tmp_src)
......@@ -170,6 +196,7 @@ class Runner(object):
def _execute_template(self, conn, host):
''' handler for template operations '''
# load up options
options = self._parse_kv(self.module_args)
source = options['src']
dest = options['dest']
......@@ -199,6 +226,10 @@ class Runner(object):
or a traceback string
'''
# depending on whether it's a normal module,
# or a request to use the copy or template
# module, call the appropriate executor function
ok, conn = self._connect(host)
if not ok:
return [ host, False, conn ]
......@@ -209,19 +240,23 @@ class Runner(object):
elif self.module_name == 'template':
return self._execute_template(conn, host)
else:
# this would be a coding error in THIS module
# shouldn't occur
raise Exception("???")
def _command(self, outpath):
''' form up a command string '''
''' form up a command string for running over SSH '''
cmd = "%s %s" % (outpath, " ".join(self.module_args))
return cmd
def remote_log(self, conn, msg):
''' this is the function we use to log things '''
stdin, stdout, stderr = conn.exec_command('/usr/bin/logger -t ansible -p auth.info %r' % msg)
# TODO: doesn't actually call logger on the remote box, should though
# TODO: maybe make that optional
def _exec_command(self, conn, cmd):
''' execute a command over SSH '''
''' execute a command string over SSH, return the output '''
msg = '%s: %s' % (self.module_name, cmd)
self.remote_log(conn, msg)
stdin, stdout, stderr = conn.exec_command(cmd)
......@@ -229,11 +264,12 @@ class Runner(object):
return results
def _get_tmp_path(self, conn, file_name):
''' gets a temporary path on a remote box '''
output = self._exec_command(conn, "mktemp /tmp/%s.XXXXXX" % file_name)
return output.split("\n")[0]
def _copy_module(self, conn):
''' transfer a module over SFTP '''
''' transfer a module over SFTP, does not run it '''
in_path = os.path.expanduser(
os.path.join(self.module_path, self.module_name)
)
......@@ -244,17 +280,18 @@ class Runner(object):
sftp.close()
return out_path
def match_hosts(self, pattern=None):
''' return all matched hosts '''
def match_hosts(self, pattern):
''' return all matched hosts fitting a pattern '''
return [ h for h in self.host_list if self._matches(h, pattern) ]
def run(self):
''' xfer & run module on all matched hosts '''
# find hosts that match the pattern
hosts = self.match_hosts()
hosts = self.match_hosts(self.pattern)
# attack pool of hosts in N forks
# _executor_hook does all of the work
hosts = [ (self,x) for x in hosts ]
if self.forks > 1:
pool = multiprocessing.Pool(self.forks)
......@@ -263,7 +300,9 @@ class Runner(object):
results = [ _executor_hook(x) for x in hosts ]
# sort hosts by ones we successfully contacted
# and ones we did not
# and ones we did not so that we can return a
# dictionary containing results of everything
results2 = {
"contacted" : {},
"dark" : {}
......@@ -278,18 +317,3 @@ class Runner(object):
return results2
if __name__ == '__main__':
# test code...
r = Runner(
host_list = DEFAULT_HOST_LIST,
module_name='ping',
module_args='',
pattern='*',
forks=3
)
print r.run()
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