promise/plugin: Implement check_file_state promise plugin

slapos/promise/plugin/check_file_state.py

+from zope import interface as zope_interface
+from slapos.grid.promise import interface
+from slapos.grid.promise.generic import GenericPromise
+
+
+class RunPromise(GenericPromise):
+
+  zope_interface.implements(interface.IPromise)
+
+  def __init__(self, config):
+    GenericPromise.__init__(self, config)
+    # SR can set custom periodicity
+    self.setPeriodicity(float(self.getConfig('frequency', 2)))
+
+  def sense(self):
+    """
+      Check state of the filename
+
+      state can be empty or not-empty
+    """
+
+    filename = self.getConfig('filename')
+    state = self.getConfig('state')
+    url = self.getConfig('url').strip()
+
+    try:
+      result = open(filename).read()
+    except Exception as e:
+      self.logger.error(
+        "ERROR %r during opening and reading file %r" % (e, filename))
+      return
+
+    if state == 'empty' and result != '':
+      message_list = ['ERROR %r not empty' % (filename,)]
+      if url:
+        message_list.append(', content available at %s' % (url,))
+      self.logger.error(''.join(message_list))
+    elif state == 'not-empty' and result == '':
+      self.logger.error(
+          "ERROR %r empty" % (filename,))
+    else:
+      self.logger.info("OK %r state %r" % (filename, state))
+
+  def anomaly(self):
+    return self._anomaly(result_count=3, failure_amount=3)

slapos/test/promise/plugin/test_check_file_state.py

+##############################################################################
+#
+# Copyright (c) 2019 Vifib SARL and Contributors. All Rights Reserved.
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsibility of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# guarantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# This program is Free Software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 3
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+##############################################################################
+
+from slapos.grid.promise import PromiseError
+from slapos.test.promise.plugin import TestPromisePluginMixin
+
+import tempfile
+import os
+import unittest
+import shutil
+
+
+class TestCheckFileState(TestPromisePluginMixin):
+  def setUp(self):
+    TestPromisePluginMixin.setUp(self)
+    self.tempdir = tempfile.mkdtemp()
+    self.promise_name = "check-file-state.py"
+
+    self.base_content = """from slapos.promise.plugin.check_file_state import RunPromise
+
+extra_config_dict = {
+  'filename': %(filename)r,
+  'state': %(state)r,
+  'url': %(url)r,
+}
+"""
+
+  def tearDown(self):
+    TestPromisePluginMixin.tearDown(self)
+    shutil.rmtree(self.tempdir)
+
+  def test_check_file_directory(self):
+    filename = os.path.join(self.tempdir, 'test.file')
+    os.mkdir(filename)
+    content = self.base_content % {
+      'filename': filename,
+      'state': 'not-empty',
+      'url': 'https://www.example.com/',
+    }
+    self.writePromise(self.promise_name, content)
+    self.configureLauncher()
+    with self.assertRaises(PromiseError):
+      self.launcher.run()
+    result = self.getPromiseResult(self.promise_name)
+    self.assertEqual(result['result']['failed'], True)
+    self.assertEqual(
+      result['result']['message'],
+      "ERROR IOError(21, 'Is a directory') "
+      "during opening and reading file %r" % (filename,)
+    )
+
+  def test_check_file_not_exists(self):
+    filename = os.path.join(self.tempdir, 'test.file')
+    content = self.base_content % {
+      'filename': filename,
+      'state': 'not-empty',
+      'url': 'https://www.example.com/',
+    }
+    self.writePromise(self.promise_name, content)
+    self.configureLauncher()
+    with self.assertRaises(PromiseError):
+      self.launcher.run()
+    result = self.getPromiseResult(self.promise_name)
+    self.assertEqual(result['result']['failed'], True)
+    self.assertEqual(
+      result['result']['message'],
+      "ERROR IOError(2, 'No such file or directory') "
+      "during opening and reading file %r" % (filename,)
+    )
+
+  def test_check_file_empty(self):
+    filename = os.path.join(self.tempdir, 'test.file')
+    with open(filename, 'w') as fh:
+      fh.write('')
+    content = self.base_content % {
+      'filename': filename,
+      'state': 'empty',
+      'url': 'https://www.example.com/',
+    }
+    self.writePromise(self.promise_name, content)
+    self.configureLauncher()
+    self.launcher.run()
+    result = self.getPromiseResult(self.promise_name)
+    self.assertEqual(result['result']['failed'], False)
+    self.assertEqual(
+      result['result']['message'],
+      "OK %r state 'empty'" % (filename,)
+    )
+
+  def test_check_file_not_empty_fail(self):
+    filename = os.path.join(self.tempdir, 'test.file')
+    with open(filename, 'w') as fh:
+      fh.write('')
+    content = self.base_content % {
+      'filename': filename,
+      'state': 'not-empty',
+      'url': 'https://www.example.com/',
+    }
+    self.writePromise(self.promise_name, content)
+    self.configureLauncher()
+    with self.assertRaises(PromiseError):
+      self.launcher.run()
+    result = self.getPromiseResult(self.promise_name)
+    self.assertEqual(result['result']['failed'], True)
+    self.assertEqual(
+      result['result']['message'],
+      "ERROR %r empty" % (filename,)
+    )
+
+  def test_check_file_not_empty(self):
+    filename = os.path.join(self.tempdir, 'test.file')
+    with open(filename, 'w') as fh:
+      fh.write('content')
+    content = self.base_content % {
+      'filename': filename,
+      'state': 'not-empty',
+      'url': 'https://www.example.com/',
+    }
+    self.writePromise(self.promise_name, content)
+    self.configureLauncher()
+    self.launcher.run()
+    result = self.getPromiseResult(self.promise_name)
+    self.assertEqual(result['result']['failed'], False)
+    self.assertEqual(
+      result['result']['message'],
+      "OK %r state 'not-empty'" % (filename,)
+    )
+
+  def test_check_file_empty_fail(self):
+    filename = os.path.join(self.tempdir, 'test.file')
+    with open(filename, 'w') as fh:
+      fh.write('content')
+    content = self.base_content % {
+      'filename': filename,
+      'state': 'empty',
+      'url': 'https://www.example.com/',
+    }
+    self.writePromise(self.promise_name, content)
+    self.configureLauncher()
+    with self.assertRaises(PromiseError):
+      self.launcher.run()
+    result = self.getPromiseResult(self.promise_name)
+    self.assertEqual(result['result']['failed'], True)
+    self.assertEqual(
+      result['result']['message'],
+      "ERROR %r not empty, content available at "
+      "https://www.example.com/" % (filename,)
+    )
+
+
+if __name__ == '__main__':
+  unittest.main()

[Łukasz Nowak]

This promise can be used to check if files produced during instance deployment or run are in given state.

In case of expected empty files it will post the file content to the monitor.

[Łukasz Nowak]

WIPed, as I am not sure if it is good idea to post a lot of changing text to the monitor. Maybe the system shall expose the file (password protected?) and just give the URL in the monitor? (But as it is frontend, it would have to be over insecure SSL).

[Thomas Gambier]

WIPed, as I am not sure if it is good idea to post a lot of changing text to the monitor. Maybe the system shall expose the file (password protected?) and just give the URL in the monitor? (But as it is frontend, it would have to be over insecure SSL).

Indeed, it's better to copy the file inside private directory and put a link inside the promise.

[Łukasz Nowak]

Indeed, it's better to copy the file inside private directory and put a link inside the promise.

Indeed.

But what about the fact that it is chicken and egg problem? The frontend needs already deployed frontend to serve anything.

This problem is already seen with the monitor stack for the frontend, so I am going to reuse monitor stack for it (I already saw some places, where it is done like this -- files are moved to monitor public/private place and are published with monitor).

[Łukasz Nowak]

@tomo ready for merge IMHO.

[Thomas Gambier]

Is it normal that the promise doesn't copy the content of the file inside the private directory somewhere ? You expect to have the file already accessible by the url ?

[Thomas Gambier]

Ah OK, I looked at slapos!577 (merged) and I see what you intend to do so it's OK for me.