def init(self, environment):
""" Writes an AppScalefile in the local directory, that contains common
configuration parameters.
Args:
environment: A str that indicates whether the AppScalefile to write should
be tailed to a 'cloud' environment or a 'cluster' environment.
Raises:
AppScalefileException: If there already is an AppScalefile in the local
directory.
"""
# first, make sure there isn't already an AppScalefile in this
# directory
appscalefile_location = self.get_appscalefile_location()
if os.path.exists(appscalefile_location):
raise AppScalefileException(
"There is already an AppScalefile" +
" in this directory. Please remove it and run 'appscale init'"
+ " again to generate a new AppScalefile.")
# next, see if we're making a cloud template file or a cluster
# template file
if environment == 'cloud':
template_file = self.TEMPLATE_CLOUD_APPSCALEFILE
elif environment == 'cluster':
template_file = self.TEMPLATE_CLUSTER_APPSCALEFILE
else:
raise BadConfigurationException(
"The environment you specified " +
"was invalid. Valid environments are 'cloud' and " +
"'cluster'.")
# finally, copy the template AppScalefile there
shutil.copy(template_file, appscalefile_location)
def read_appscalefile(self):
""" Checks the local directory for an AppScalefile and reads its
contents.
Raises:
AppScalefileException: If there is no AppScalefile in the
local directory.
Returns:
The contents of the AppScalefile in the current working directory.
"""
try:
with open(self.get_appscalefile_location()) as file_handle:
return file_handle.read()
except IOError:
raise AppScalefileException("No AppScalefile found in this " +
"directory. Please run 'appscale init' to generate one and try " +
"again.")
def ensure_appscalefile_is_up_to_date(cls):
""" Examines the AppScalefile in the current working directory to make sure
it specifies a keyname and group, updating it if it does not.
This scenario can occur if the user wants us to automatically generate a
keyname and group for them (in which case they don't specify either).
Returns:
True if the AppScalefile was up to date, or False if there were changes
made to make it up to date.
Raises:
AppScalefileException: If there is no AppScalefile in the current working
directory.
"""
appscalefile_path = os.getcwd() + os.sep + "AppScalefile"
if not os.path.exists(appscalefile_path):
raise AppScalefileException("Couldn't find an AppScale file at {0}" \
.format(appscalefile_path))
file_contents = ''
with open(appscalefile_path) as file_handle:
file_contents = file_handle.read()
yaml_contents = yaml.safe_load(file_contents)
# Don't write to the AppScalefile if there are no changes to make to it.
if 'keyname' in yaml_contents and 'group' in yaml_contents:
return True
file_contents += "\n# Automatically added by the AppScale Tools: "
random_suffix = str(uuid.uuid4()).replace('-', '')
cloud_name = "appscale{0}".format(random_suffix)
if 'keyname' not in yaml_contents:
file_contents += "\nkeyname : {0}".format(cloud_name)
if 'group' not in yaml_contents:
file_contents += "\ngroup : {0}".format(cloud_name)
with open(appscalefile_path, 'w') as file_handle:
file_handle.write(file_contents)
return False
def read_appscalefile(self):
"""Checks the local directory for an AppScalefile and reads its
contents.
Raises:
AppScalefileException: If there is no AppScalefile in the
local directory.
Returns:
The contents of the AppScalefile in the current working directory.
"""
# Don't check for existence and then open it later - this lack of
# atomicity is potentially a TOCTOU vulnerability.
try:
with open(self.get_appscalefile_location()) as file_handle:
return file_handle.read()
except IOError:
raise AppScalefileException(
"No AppScalefile found in this " +
"directory. Please run 'appscale init' to generate one and try "
+ "again.")