Add reloader

Dockerfile.py2

@@ -2,7 +2,7 @@
 
 FROM python:2
 
-RUN pip install pytest six pyyaml jinja2 colorlog
+RUN pip install pytest six pyyaml jinja2 colorlog watchdog pytest-mock
 
 ENV PYTHONPATH /opt/
 

Dockerfile.py3

@@ -2,7 +2,7 @@
 
 FROM python:3
 
-RUN pip3 install pytest six pyyaml jinja2 colorlog
+RUN pip3 install pytest six pyyaml jinja2 colorlog watchdog pytest-mock
 
 ENV PYTHONPATH /opt/
 

README.md

@@ -117,12 +117,26 @@ pre_conf_commands:
 post_conf_commands:
     - echo "something else" > to_this_another_file
 
+# Reload service when configuration change by sending a signal to process
+reload:
+    signal: SIGHUP # Optional, signal to send, default is SIGHUP
+    pid: 1 # Optional, pid to send signal, default is 1
+    watch_config_files: true # Optional, watch defined config files, default True
+    files: # Optional, list of files to watch
+        - /etc/conf/to/watch
+# can also be enabled like this:
+reload: true
+
+
 # Cleanup environment from variables created by linked containers
 # before running command (True by default)
-clean_env: True
+clean_env: true
 
 # Enable debug to debug
 debug: true
+
+# Do not output anything except error
+quiet: false
 ```
 
 ### Config templates

docs/config.rst

@@ -35,13 +35,13 @@ This is an example of ``entrypoint-config.yml`` file.
         - .ssh/config.tpl # Will apply to ".ssh/config"
         - /tmp/id_rsa: .ssh/id_rsa # Will apply "/tmp/id_rsa" template to ".ssh/id_rsa"
 
-
     # These environment variables will be wiped before
     # exec command to keep them secret
     # CAUTION: if the container is linked to another one,
     # theses variables will passed to it anyway
     secret_env:
         - SSHKEY
+        - '*' # Support globbing, all environment will be wiped
 
     # Links are handled here
     # Port, name, protocol or env variable can be used to identify the links
@@ -51,7 +51,7 @@ This is an example of ``entrypoint-config.yml`` file.
             port: 22
             name: 'ssh*'
             protocol: tcp
-            # env can be list, dictionary or string
+            # env can be list, dict or string
             env:
                 FOO: bar
             # Single doesn't allow multiple links for this ID
@@ -69,13 +69,26 @@ This is an example of ``entrypoint-config.yml`` file.
     post_conf_commands:
         - echo "something else" > to_this_another_file
 
+    # Reload service when configuration change by sending a signal to process
+    reload:
+        signal: SIGHUP # Optional, signal to send, default is SIGHUP
+        watch_config_files: true # Optional, watch defined config files, default True
+        files: # Optional, list of files to watch
+            - /etc/conf/to/watch
+    # can also be enabled with a boolean:
+    reload: true
+
     # Cleanup environment from variables created by linked containers
     # before running command (True by default)
-    clean_env: True
+    clean_env: true
 
     # Enable debug to debug
     debug: true
 
+    # Do not output anything except error
+    quiet: false
+
+
 yaml references
 ~~~~~~~~~~~~~~~
 
@@ -209,6 +222,23 @@ List of shell commands to run after applying configuration
     post_conf_commands:
         - echo "something else" > to_this_another_file
 
+reload
+^^^^^^
+
+Send SIGHUP to PID 1 to reload service when configuration change
+
+Accept boolean or dictionary
+
+.. code:: yaml
+
+    reload:
+        signal: SIGHUP # Optional, signal to send, default is SIGHUP
+        watch_config_files: true # Optional, watch defined config files, default True
+        files: # Optional, list of files to watch
+            - /etc/conf/to/watch
+    # can also be enabled with a boolean:
+    reload: true
+
 clean_env
 ^^^^^^^^^
 
@@ -219,3 +249,8 @@ debug
 ^^^^^
 
 Print some debug.
+
+quiet
+^^^^^
+
+Do not output anything except error

docs/index.rst

@@ -16,6 +16,7 @@ This tool avoids writing shell scripts to:
 - Auto configure container using `jinja2` templates
 - Run commands before starting service
 - Clean environment before running service
+- Reload service when configuration has changed
 - Increase security by setuid/setgid service
 
 Contents:

entrypoint-config.yml

@@ -24,8 +24,8 @@ group: 1000
 # and should be jinja templated.
 config_files:
     - /etc/gitconfig
-    - .ssh/config
-    - .ssh/id_rsa
+    - .ssh/config.tpl # Will apply to ".ssh/config"
+    - /tmp/id_rsa: .ssh/id_rsa # Will apply "/tmp/id_rsa" template to ".ssh/id_rsa"
 
 # These environment variables will be wiped before
 # exec command to keep them secret
@@ -59,9 +59,22 @@ pre_conf_commands:
 post_conf_commands:
     - echo something even useless
 
+# Reload service when configuration change by sending a signal to process
+reload:
+    signal: SIGHUP # Optional, signal to send, default is SIGHUP
+    pid: 1 # Optional, pid to send signal, default is 1
+    watch_config_files: true # Optional, watch defined config files, default True
+    files: # Optional, list of files to watch
+        - /etc/conf/to/watch
+# can also be enabled with a boolean:
+reload: true
+
 # Cleanup environment from variables created by linked containers
 # before running command (True by default)
-clean_env: True
+clean_env: true
 
 # Enable debug to debug
 debug: true
+
+# Do not output anything except error
+quiet: false

pyentrypoint/command.py

@@ -81,6 +81,11 @@ class Command(object):
         ))
         os.execvpe(self.args[0], self.args, self.env)
 
+    def _run_reloader(self):
+        if self.config.reload:
+            self.log.debug('Launching reloader process')
+            self.config.reload.run_in_process()
+
     def run(self):
         if not self.is_handled:
             self._exec()
@@ -99,4 +104,5 @@ class Command(object):
         if not self.args or \
                 [p for p in subcom if fnmatch(self.args[0], p)]:
             self.args.insert(0, self.command)
+        self._run_reloader()
         self._exec()

pyentrypoint/config.py

@@ -18,6 +18,7 @@ from .constants import ENTRYPOINT_FILE
 from .docker_links import DockerLinks
 from .links import Links
 from .logs import Logs
+from .reloader import Reloader
 
 __all__ = ['Config']
 
@@ -44,9 +45,25 @@ class ConfigMeta(object):
                     template = list(item.keys())[0]
                     outfile = item[template]
                 yield (template, outfile)
-        if isinstance(config_files, dict):
+        else:
             raise Exception("config_files setup missformated.")
 
+    def get_reloader(self):
+        """Setup and get reloader"""
+        config_files = [file[1] for file in self.get_templates()]
+        reload = self._config['reload']
+        if isinstance(reload, bool):
+            return Reloader(files=config_files)
+        if isinstance(reload, dict):
+            signal = reload.get('signal', 'SIGHUP')
+            watch_config_files = bool(reload.get('watch_config_files'))
+            files = reload.get('files', [])
+            if not isinstance(files, list):
+                raise Exception('Reload files is not a list')
+            if watch_config_files:
+                files.extend(config_files)
+            return Reloader(files=files, sig=signal)
+
     def _check_config(self):
         for key in self._config:
             if not hasattr(Config, key) or key == '__init__':
@@ -71,6 +88,7 @@ class Config(ConfigMeta):
         self._args = args
         self._links = None
         self._command = None
+        self._reload = None
         self._config_file = conf
         if not os.path.isfile(self._config_file):
             self.log.critical('Entrypoint config file does not provided')
@@ -155,6 +173,16 @@ class Config(ConfigMeta):
         """Return list of postconf commands"""
         return self._return_item_lst('post_conf_commands')
 
+    @property
+    def reload(self):
+        """Return Reloader object if reload is set"""
+        if self._reload:
+            return self._reload
+        if not self._config.get('reload'):
+            return None
+        self._reload = self.get_reloader()
+        return self._reload
+
     @property
     def clean_env(self):
         """Clean env from linked containers before running command"""
@@ -170,3 +198,12 @@ class Config(ConfigMeta):
         if 'debug' in self._config:
             return bool(self._config['debug'])
         return False
+
+    @property
+    def quiet(self):
+        """Disable logging"""
+        if self.debug:
+            return False
+        if 'ENTRYPOINT_QUIET' in os.environ:
+            return True
+        return bool(self._config.get('quiet', False))

pyentrypoint/entrypoint.py

@@ -44,6 +44,8 @@ class Entrypoint(object):
         else:
             if self.config.debug:
                 Logs.set_debug()
+            if self.config.quiet:
+                Logs.set_critical()
         self.args = args
 
     @property

pyentrypoint/links.py

@@ -56,7 +56,7 @@ class Links(object):
     _def_options = {'single': False,
                     'required': True}
 
-    def __init__(self, config=None, links=None):
+    def __init__(self, config={}, links=None):
         if not links or len(links.links()) is 0:
             pass
 
@@ -72,7 +72,7 @@ class Links(object):
         self._conf = config
 
     def _get_link(self, name):
-        config = self._conf[name]
+        config = self._conf.get(name, {})
         links = self._links
         options = dict(self._def_options)
         for key, val in config.items():

pyentrypoint/logs.py

@@ -82,12 +82,12 @@ class Logs(object):
 
     @classmethod
     def set_warning(cls):
-        """Set log level to info"""
+        """Set log level to warning"""
         cls.lvl = logging.WARNING
         cls.log.setLevel(cls.lvl)
 
     @classmethod
     def set_critical(cls):
-        """Set log level to info"""
+        """Set log level to critical"""
         cls.lvl = logging.CRITICAL
         cls.log.setLevel(cls.lvl)

pyentrypoint/reloader.py

@@ -0,0 +1,91 @@
+"""
+    Send signal to pid 1 to reload service
+"""
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+import os
+import signal
+from multiprocessing import Process
+
+from watchdog.events import FileSystemEventHandler
+from watchdog.observers import Observer
+
+from .logs import Logs
+
+
+class Reload(FileSystemEventHandler):
+
+    """Reload object"""
+
+    def __init__(self, sig, files, pid=1):
+        self.signal = sig
+        self.files = files
+        self.pid = pid
+        self.log = Logs().log
+
+    def on_any_event(self, event):
+        if event.src_path in self.files:
+            self.log.info(
+                'File {file} has changed, send sig {sig} to pid {pid}'.format(
+                    file=event.src_path,
+                    sig=self.signal,
+                    pid=self.pid,
+                )
+            )
+            os.kill(self.pid, self.signal)
+
+
+class Reloader(object):
+
+    """Reload service when files change"""
+
+    def __init__(self, sig='SIGHUP', files=[]):
+        if not files:
+            raise Exception('No file to watch for reload')
+
+        self.proc = None
+        self._files = files
+        sig_attr = getattr(signal, sig)
+        try:
+            assert int(sig_attr)
+        except:
+            raise Exception('Wrong signal provided for reload')
+        self.observer = Observer()
+        rel = Reload(sig=sig_attr, files=self.files)
+        for dir in self.dirs:
+            self.observer.schedule(rel, dir, recursive=False)
+
+    def _get_files(self):
+        """Return iterator of tuples (path, file)"""
+        for f in self._files:
+            if os.path.isdir(f):
+                yield (f, f)
+            yield (os.path.dirname(f), f)
+
+    @property
+    def files(self):
+        """Return list of watched files"""
+        return list(set([files[1] for files in self._get_files()]))
+
+    @property
+    def dirs(self):
+        """Return list of watched directories"""
+        return list(set([files[0] for files in self._get_files()]))
+
+    def run(self, ret=False):
+        while True:
+            self.observer.start()
+            if ret:
+                return self.observer
+            self.observer.join()
+
+    def run_in_process(self):
+        self.proc = Process(target=self.run)
+        self.proc.start()
+
+    def stop(self):
+        if self.proc:
+            self.proc.stop()
+        else:
+            self.observer.stop()

setup.py

@@ -5,7 +5,7 @@ from setuptools import setup
 
 # Thanks Sam and Max
 
-__version__ = '0.3.8'
+__version__ = '0.4.0'
 
 if __name__ == '__main__':
     setup(
@@ -28,7 +28,8 @@ if __name__ == '__main__':
                           'PyYAML>=3.11',
                           'colorlog>=2.6.1',
                           'argparse>=1.4.0',
-                          'six>=1.10.0'],
+                          'six>=1.10.0',
+                          'watchdog>=0.8.3'],
 
         include_package_data=True,
 

tests/configs/reloader/reloader.yml

@@ -0,0 +1,4 @@
+config_files:
+    - /tmp/test_template2.yml.tpl: /tmp/reload
+
+reload: true

tests/configs/reloader/reloader_config.yml

@@ -0,0 +1,10 @@
+config_files:
+    - /tmp/test_template2.yml.tpl: /tmp/reload
+
+reload:
+    watch_config_files: false
+    files:
+        - /tmp/reload_custom
+
+pre_conf_commands:
+    - touch /tmp/reload_custom

tests/reloader_test.py

@@ -0,0 +1,44 @@
+"Tests for reloader"
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+
+try:
+    # Python2
+    import mock
+except ImportError:
+    # Python3
+    from unittest import mock
+
+from pyentrypoint import Entrypoint
+
+import subprocess
+
+from signal import SIGHUP
+
+from time import sleep
+
+
+def test_reloader():
+
+    with mock.patch('os.kill') as os_kill:
+        entry = Entrypoint(conf='configs/reloader/reloader.yml')
+        entry.apply_conf()
+        entry.config.reload.run(ret=True)
+        subprocess.check_call(['touch', '/tmp/reload'])
+        sleep(1)
+        entry.config.reload.stop()
+        os_kill.assert_called_once_with(1, SIGHUP)
+
+
+def test_reloader_custom():
+
+    with mock.patch('os.kill') as os_kill:
+        entry = Entrypoint(conf='configs/reloader/reloader_config.yml')
+        entry.apply_conf()
+        entry.run_pre_conf_cmds()
+        entry.config.reload.run(ret=True)
+        subprocess.check_call(['touch', '/tmp/reload', '/tmp/reload_custom'])
+        sleep(1)
+        entry.config.reload.stop()
+        os_kill.assert_called_once_with(1, SIGHUP)