Commit 0ee7c2c2 authored by Stavros Sachtouris's avatar Stavros Sachtouris
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Create a config section in devs documentation

Explain config accessors, emphasize on cloud handling
parent 534e7bbb
The Configuration module
========================
Kamaki CLI offers a configuration module named *config*. It features:
* The global dict *DEFAULTS* with all the configuration settings needed to run
a kamaki CLI and their default values
* The class *Config* is a ConfigParser extension adjusted to offer
kamaki-specific functionalities (e.g., cloud management)
Types of configuration options
------------------------------
There are at least two sections of configuration options i.e., the *global*
and the *cloud*. The *global* section is not special, but is used as the
default kamaki section by convention. The *Config* class is semantically
aware of the *cloud* types and handles them in a special way. Other
configuration types can also be created and managed in the same fashion as the
*global* ones.
Kamaki preset global options, as they appear in the configuration file::
[global]
default_cloud=
colors=off
log_file=${HOME}/.kamaki.log
log_token=off
log_data=off
log_pid=off
max_threads=7
history_file=${HOME}/.kamaki.history
user_cli=astakos
file_cli=pithos
server_cli=cyclades
flavor_cli=cyclades
network_cli=cyclades
ip_cli=cyclades
image_cli=image
config_cli=config
history_cli=history
A cloud configuration is required to make kamaki run. The
`setup guide <../setup.html>`_ can help when setting one or more cloud
configurations.
Suppose that a cloud service is available with *https://main.example.com* as
the authentication URL and *s0m3-t0k3n* as the user token. In this example, the
user has already configured kamaki to refer to the service by the name "main"::
[cloud "main"]
url=https://main.example.com
token=s0m3-t0k3n
Suppose that a different cloud service is also available with
*https://alternative.example.com* as the authentication URL and
*s0m3-0th3r-t0k3n* as the user token. Again, the user configured kamaki to
refer to this service as "alternative"::
[cloud "alternative"]
url=https://alternative.example.com
token=s0m3-0th3r-t0k3n
If the user picks one of these clouds to be the default, the configuration file
will contain the following::
[global]
default_cloud=main
... <omitted for clarity>
[cloud "main"]
url=https://main.example.com
token=s0m3-t0k3n
[cloud "alternative"]
url=https://alternative.example.com
token=s0m3-0th3r-t0k3n
The Config class
----------------
The *kamaki.cli.config.Config* class (extends *RawConfigParser* which extends
`ConfigParser <http://docs.python.org/release/2.7/library/configparser.html>`_
) offers the methods of the RawConfigParser class (e.g., *get*, *set*), as well
as some default settings for kamaki and some additional functionality for
managing cloud configurations.
.. code-block:: python
# Initialize two Config instances. Only the first will contain kamaki
# default values
from kamaki.cli.config import Config
my_config = Config('/some/local/file.cnf')
config_without_default_values = Config(with_defaults=False)
.. note:: The *with_defaults* flag can be used to omit all default settings
from a kamaki Config instance e.g., in case of an external application that
does not need any of the kamaki globals.
Here are the general purpose accessors offered by Config:
* get(section, option): get the *value* of an *option* in the specified
*section* e.g.,
.. code-block:: python
# Example: get the default cloud (global.default_cloud option)
thread_limit = my_config.get('global', 'default_cloud')
* set(section, option, value): set the *value* for an *option* in the specified
*section* e.g.,
.. code-block:: python
# Example: set the default_cloud to "main"
my_config.set('global', 'default_cloud', 'main')
* remove_option(section, option): remove an option from a section e.g.,
.. code-block:: python
# Example: remove the default_cloud option - Config will resort to the
# default value for this option
my_config.remove_option('global', 'default_cloud')
Global options
--------------
The global options are used to specify the kamaki CLI and client behavior. A
detailed catalog can be found at the
`setup section <../setup.html#available-options>`_ .
In the Config context, the global options are just the options under the
*global* section.
Cloud options
-------------
Cloud options are used to configure one or more cloud services.
The following methods are cloud-specific:
* get_cloud(cloud, option): Get the value of a cloud option e.g.,
.. code-block:: python
# Get the Auth URL and token for the cloud "main"
auth_url = my_config.get_cloud('main', 'url')
auth_token = my_config.get_cloud('main', 'token')
* set_cloud(cloud, option, value): Set the value of a cloud option e.g.,
.. code-block:: python
# Example: set a new authenticate URL and token for cloud "main"
my_config.set_cloud('main', 'url', 'https://new.example.com')
my_config.set_cloud('main', 'token', 'n3e-t0k3n-f0r-m41n')
* remove_from_cloud(cloud, option): Remove an option from the specified cloud
e.g.,
.. code-block:: python
# Example: remove the token of the main cloud, for safety reasons
my_config.remove_from_cloud('main', 'url')
.. warning:: A get/set/remove_option with a "cloud" section is not valid. There
is a way of using the general purpose accessors for cloud configuration,
and it is presented bellow, but programmers are discouraged from using it::
my_config.get('cloud.main', 'url')
my_config.set('cloud.main', 'url', 'https://new.example.com')
my_config.remove_option('cloud.main', 'url')
Examples
--------
Get the default cloud values from a configuration file
""""""""""""""""""""""""""""""""""""""""""""""""""""""
.. code-block:: python
from kamaki.cli.config import Config
CONFIG_FILE_PATH = '/home/user/my.cnf'
cnf = Config(CONFIG_FILE_PATH)
try:
CLOUD_NAME = cnf.get('global', 'default_cloud')
AUTH_URL = cnf.get_cloud(CLOUD_NAME, 'url')
AUTH_TOKEN = cnf.get_cloud(CLOUD_NAME, 'token')
except KeyError:
print 'Error: no valid configuration of a default cloud'
Set a new cloud, name it "new_cloud" and set it as default
""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.. code-block:: python
from kamaki.cli.config import Config
CONFIG_FILE_PATH = '/home/user/my.cnf'
CLOUD_NAME = 'new_cloud'
AUTH_URL = 'https://new.cloud.example.com'
AUTH_TOKEN = 'n3w-cl0ud-t0k3n'
cnf = Config(CONFIG_FILE_PATH)
cnf.set_cloud(CLOUD_NAME, 'url', AUTH_URL)
cnf.set_cloud(CLOUD_NAME, 'token', AUTH_TOKEN)
cnf.set('global', 'default_cloud', CLOUD_NAME)
# Push the changes to the configuration file
cnf.write()
List all clouds with their URLs, let the user pick one
""""""""""""""""""""""""""""""""""""""""""""""""""""""
.. note:: In this example, the default kamaki config file path will be used.
This is stored at *kamaki.cli.config.CONFIG_PATH*
.. code-block:: python
from kamaki.cli.config import Config
cnf = Config()
for name, cloud in cnf.items('cloud'):
print 'Cloud', name, cloud['url']
choice = raw_input('Type your cloud name, pls: ')
if choice in cnf.keys('cloud'):
cnf.set('global', 'default_cloud', choice)
else:
print 'No such cloud configured'
......@@ -6,6 +6,7 @@ Developers Guide
:glob:
developers/clients-api
developers/config
developers/logging
developers/adding-commands
developers/extending-clients-api
......
......@@ -411,8 +411,12 @@ The [*global*] group is treated by kamaki as a generic group for kamaki
settings, namely command cli specifications, the thread limit, console colors,
history and log files, log detail options and pithos-specific options.
* global.default_cloud <cloud name>
pick a cloud configuration as default. It must refer to an existing cloud.
* global.colors <on|off>
enable / disable colors in command line based uis. Requires ansicolors, otherwise it is ignored
enable / disable colors in command line based uis. Requires ansicolors,
otherwise it is ignored
* global.log_file <logfile full path>
set a custom location for kamaki logging. Default value is ~/.kamaki.log
......@@ -441,11 +445,16 @@ history and log files, log detail options and pithos-specific options.
kamaki UIs. Don't touch this unless you know what you are doing.
* global.network_cli <UI command specifications for virtual networks>
a special package that is used to load cyclades virtual network commands to
kamaki UIs. Don't touch this unless you know what you are doing.
a special package that is used to load cyclades virtual network commands.
Don't touch this unless you know what you are doing.
* global.ip_cli <UI command specifications for floating IPs>
a special package that is used to load cyclades floating IP commands. Don't
touch this unless you know what you are doing.
* global.image_cli <UI command specs for Plankton or Compute image service>
a special package that is used to load image-related commands to kamaki UIs. Don't touch this unless you know what you are doing.
a special package that is used to load image-related commands to kamaki UIs.
Don't touch this unless you know what you are doing.
* global.user_cli <UI command specs for Astakos authentication service>
a special package that is used to load astakos-related commands to kamaki
......
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