Initial commit

14 files changed, 327 insertions, 0 deletions

diff --git a/dotbot/__init__.py b/dotbot/__init__.py
new file mode 100644
index 0000000..401da57
--- /dev/null
+++ b/dotbot/__init__.py
@@ -0,0 +1 @@
+from .cli import main
diff --git a/dotbot/cli.py b/dotbot/cli.py
new file mode 100644
index 0000000..b9cc528
--- /dev/null
+++ b/dotbot/cli.py
@@ -0,0 +1,46 @@
+from argparse import ArgumentParser
+from .config import ConfigReader, ReadingError
+from .dispatcher import Dispatcher, DispatchError
+from .messenger import Messenger
+from .messenger import Level
+
+def add_options(parser):
+    parser.add_argument('-Q', '--super-quiet', dest = 'super_quiet', action = 'store_true',
+        help = 'suppress almost all output')
+    parser.add_argument('-q', '--quiet', dest = 'quiet', action = 'store_true',
+        help = 'suppress most output')
+    parser.add_argument('-v', '--verbose', dest = 'verbose', action = 'store_true',
+        help = 'enable verbose output')
+    parser.add_argument('-d', '--base-directory', nargs = 1,
+        dest = 'base_directory', help = 'execute commands from within BASEDIR',
+        metavar = 'BASEDIR', required = True)
+    parser.add_argument('-c', '--config-file', nargs = 1, dest = 'config_file',
+        help = 'run commands given in CONFIGFILE', metavar = 'CONFIGFILE',
+        required = True)
+
+def read_config(config_file):
+    reader = ConfigReader(config_file)
+    return reader.get_config()
+
+def main():
+    log = Messenger()
+    try:
+        parser = ArgumentParser()
+        add_options(parser)
+        options = parser.parse_args()
+        if (options.super_quiet):
+            log.set_level(Level.WARNING)
+        if (options.quiet):
+            log.set_level(Level.INFO)
+        if (options.verbose):
+            log.set_level(Level.DEBUG)
+        tasks = read_config(options.config_file[0])
+        dispatcher = Dispatcher(options.base_directory[0])
+        success = dispatcher.dispatch(tasks)
+        if success:
+            log.info('\n==> All tasks executed successfully')
+        else:
+            raise DispatchError('\n==> Some tasks were not executed successfully')
+    except (ReadingError, DispatchError) as e:
+        log.error('%s' % e)
+        exit(1)
diff --git a/dotbot/config.py b/dotbot/config.py
new file mode 100644
index 0000000..79b735c
--- /dev/null
+++ b/dotbot/config.py
@@ -0,0 +1,19 @@
+import json
+
+class ConfigReader(object):
+    def __init__(self, config_file_path):
+        self._config = self._read(config_file_path)
+
+    def _read(self, config_file_path):
+        try:
+            with open(config_file_path) as fin:
+                data = json.load(fin)
+            return data
+        except Exception:
+            raise ReadingError('Could not read config file')
+
+    def get_config(self):
+        return self._config
+
+class ReadingError(Exception):
+    pass
diff --git a/dotbot/dispatcher.py b/dotbot/dispatcher.py
new file mode 100644
index 0000000..35b0889
--- /dev/null
+++ b/dotbot/dispatcher.py
@@ -0,0 +1,46 @@
+import os
+from .executor import *
+from .messenger import Messenger
+
+class Dispatcher(object):
+    PLUGIN_CLASS = Executor
+    PLUGIN_DIR = 'dotbot/executor'
+
+    def __init__(self, base_directory):
+        self._log = Messenger()
+        self._set_base_directory(base_directory)
+        self._load_plugins()
+
+    def _set_base_directory(self, base_directory):
+        path = os.path.abspath(os.path.realpath(
+            os.path.expanduser(base_directory)))
+        if os.path.exists(path):
+            self._base_directory = path
+        else:
+            raise DispatchError('Nonexistant base directory')
+
+    def dispatch(self, tasks):
+        success = True
+        for task in tasks:
+            for action in task:
+                handled = False
+                for plugin in self._plugins:
+                    if plugin.can_handle(action):
+                        try:
+                            success &= plugin.handle(action, task[action])
+                            handled = True
+                        except Exception:
+                            self._log.error(
+                                'An error was encountered while executing action %s' %
+                                action)
+                if not handled:
+                    success = False
+                    self._log.error('Action %s not handled' % action)
+        return success
+
+    def _load_plugins(self):
+        self._plugins = [plugin(self._base_directory)
+            for plugin in Executor.__subclasses__()]
+
+class DispatchError(Exception):
+    pass
diff --git a/dotbot/executor/__init__.py b/dotbot/executor/__init__.py
new file mode 100644
index 0000000..1762f78
--- /dev/null
+++ b/dotbot/executor/__init__.py
@@ -0,0 +1,3 @@
+from .executor import Executor
+from .linker import Linker
+from .commandrunner import CommandRunner
diff --git a/dotbot/executor/commandrunner.py b/dotbot/executor/commandrunner.py
new file mode 100644
index 0000000..3051ace
--- /dev/null
+++ b/dotbot/executor/commandrunner.py
@@ -0,0 +1,32 @@
+import os, subprocess
+from . import Executor
+
+class CommandRunner(Executor):
+    '''
+    Run arbitrary shell commands.
+    '''
+
+    def can_handle(self, directive):
+        return directive == 'shell'
+
+    def handle(self, directive, data):
+        if directive != 'shell':
+            raise ValueError('CommandRunner cannot handle directive %s' %
+                directive)
+        return self._process_commands(data)
+
+    def _process_commands(self, data):
+        success = True
+        with open(os.devnull, 'w') as devnull:
+            for cmd, msg in data:
+                self._log.lowinfo('%s [%s]' % (msg, cmd))
+                ret = subprocess.call(cmd, shell = True, stdout = devnull,
+                    stderr = devnull, cwd = self._base_directory)
+                if ret != 0:
+                    success = False
+                    self._log.warning('Command [%s] failed' % cmd)
+        if success:
+            self._log.info('All commands have been executed')
+        else:
+            self._log.error('Some commands were not sucessfully executed')
+        return success
diff --git a/dotbot/executor/executor.py b/dotbot/executor/executor.py
new file mode 100644
index 0000000..e6862c0
--- /dev/null
+++ b/dotbot/executor/executor.py
@@ -0,0 +1,24 @@
+from ..messenger import Messenger
+
+class Executor(object):
+    '''
+    Abstract base class for commands that process directives.
+    '''
+
+    def __init__(self, base_directory):
+        self._base_directory = base_directory
+        self._log = Messenger()
+
+    def can_handle(self, directive):
+        '''
+        Returns true if the Executor can handle the directive.
+        '''
+        raise NotImplementedError
+
+    def handle(self, directive, data):
+        '''
+        Executes the directive.
+
+        Returns true if the Executor successfully handled the directive.
+        '''
+        raise NotImplementedError
diff --git a/dotbot/executor/linker.py b/dotbot/executor/linker.py
new file mode 100644
index 0000000..9890ed5
--- /dev/null
+++ b/dotbot/executor/linker.py
@@ -0,0 +1,73 @@
+import os
+from . import Executor
+
+class Linker(Executor):
+    '''
+    Symbolically links dotfiles.
+    '''
+
+    def can_handle(self, directive):
+        return directive == 'link'
+
+    def handle(self, directive, data):
+        if directive != 'link':
+            raise ValueError('Linker cannot handle directive %s' % directive)
+        return self._process_links(data)
+
+    def _process_links(self, links):
+        success = True
+        for destination, source in links.items():
+            success &= self._link(source, destination)
+        if success:
+            self._log.info('All links have been set up')
+        else:
+            self._log.error('Some links were not successfully set up')
+        return success
+
+    def _is_link(self, path):
+        '''
+        Returns true if the path is a symbolic link.
+        '''
+        return os.path.islink(os.path.expanduser(path))
+
+    def _link_destination(self, path):
+        '''
+        Returns the absolute path to the destination of the symbolic link.
+        '''
+        path = os.path.expanduser(path)
+        rel_dest = os.readlink(path)
+        return os.path.join(os.path.dirname(path), rel_dest)
+
+    def _exists(self, path):
+        '''
+        Returns true if the path exists.
+        '''
+        path = os.path.expanduser(path)
+        return os.path.exists(path)
+
+    def _link(self, source, link_name):
+        '''
+        Links link_name to source.
+
+        Returns true if successfully linked files.
+        '''
+        success = False
+        source = os.path.join(self._base_directory, source)
+        if not self._exists(link_name) and self._is_link(link_name):
+            self._log.warning('Invalid link %s -> %s' %
+                (link_name, self._link_destination(link_name)))
+        elif not self._exists(link_name):
+            self._log.lowinfo('Creating link %s -> %s' % (link_name, source))
+            os.symlink(source, os.path.expanduser(link_name))
+            success = True
+        elif self._exists(link_name) and not self._is_link(link_name):
+            self._log.warning(
+                '%s already exists but is a regular file or directory' %
+                link_name)
+        elif self._link_destination(link_name) != source:
+            self._log.warning('Incorrect link %s -> %s' %
+                (link_name, self._link_destination(link_name)))
+        else:
+            self._log.lowinfo('Link exists %s -> %s' % (link_name, source))
+            success = True
+        return success
diff --git a/dotbot/messenger/__init__.py b/dotbot/messenger/__init__.py
new file mode 100644
index 0000000..38fc6bc
--- /dev/null
+++ b/dotbot/messenger/__init__.py
@@ -0,0 +1,2 @@
+from .messenger import Messenger
+from .level import Level
diff --git a/dotbot/messenger/color.py b/dotbot/messenger/color.py
new file mode 100644
index 0000000..193afb7
--- /dev/null
+++ b/dotbot/messenger/color.py
@@ -0,0 +1,8 @@
+class Color(object):
+    NONE = ''
+    RESET = '\033[0m'
+    RED = '\033[91m'
+    GREEN = '\033[92m'
+    YELLOW = '\033[93m'
+    BLUE = '\033[94m'
+    MAGENTA = '\033[95m'
diff --git a/dotbot/messenger/level.py b/dotbot/messenger/level.py
new file mode 100644
index 0000000..2c361f6
--- /dev/null
+++ b/dotbot/messenger/level.py
@@ -0,0 +1,7 @@
+class Level(object):
+    NOTSET = 0
+    DEBUG = 10
+    LOWINFO = 15
+    INFO = 20
+    WARNING = 30
+    ERROR = 40
diff --git a/dotbot/messenger/messenger.py b/dotbot/messenger/messenger.py
new file mode 100644
index 0000000..04081e7
--- /dev/null
+++ b/dotbot/messenger/messenger.py
@@ -0,0 +1,60 @@
+import sys
+from ..util.singleton import Singleton
+from .color import Color
+from .level import Level
+
+class Messenger(object):
+    __metaclass__ = Singleton
+
+    def __init__(self, level = Level.LOWINFO):
+        self.set_level(level)
+
+    def set_level(self, level):
+        self._level = level
+
+    def log(self, level, message):
+        if (level >= self._level):
+            print '%s%s%s' % (self._color(level), message, self._reset())
+
+    def debug(self, message):
+        self.log(Level.DEBUG, message)
+
+    def lowinfo(self, message):
+        self.log(Level.LOWINFO, message)
+
+    def info(self, message):
+        self.log(Level.INFO, message)
+
+    def warning(self, message):
+        self.log(Level.WARNING, message)
+
+    def error(self, message):
+        self.log(Level.ERROR, message)
+    
+    def _color(self, level):
+        '''
+        Get a color (terminal escape sequence) according to a level.
+        '''
+        if not sys.stdout.isatty():
+            return ''
+        elif level < Level.DEBUG:
+            return ''
+        elif Level.DEBUG <= level < Level.LOWINFO:
+            return Color.YELLOW
+        elif Level.LOWINFO <= level < Level.INFO:
+            return Color.BLUE
+        elif Level.INFO <= level < Level.WARNING:
+            return Color.GREEN
+        elif Level.WARNING <= level < Level.ERROR:
+            return Color.MAGENTA
+        elif Level.ERROR <= level:
+            return Color.RED
+
+    def _reset(self):
+        '''
+        Get a reset color (terminal escape sequence).
+        '''
+        if not sys.stdout.isatty():
+            return ''
+        else:
+            return Color.RESET
diff --git a/dotbot/util/__init__.py b/dotbot/util/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/dotbot/util/__init__.py
diff --git a/dotbot/util/singleton.py b/dotbot/util/singleton.py
new file mode 100644
index 0000000..d6cc857
--- /dev/null
+++ b/dotbot/util/singleton.py
@@ -0,0 +1,6 @@
+class Singleton(type):
+    _instances = {}
+    def __call__(cls, *args, **kwargs):
+        if cls not in cls._instances:
+            cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
+        return cls._instances[cls]