Merge lp:~ericsnowcurrently/fake-juju/python-lib-classes into lp:~landscape/fake-juju/trunk-old

[Eric Snow]

Add the FakeJuju and Failures classes.

Add the FakeJuju and Failures classes.

Testing instructions:

Run the unit tests.

[🤖 Landscape Builder (landscape-builder)]

review: Abstain (executing tests)

[🤖 Landscape Builder (landscape-builder)]

Command: make ci-test
Result: Success
Revno: 48
Branch: lp:~ericsnowcurrently/fake-juju/python-lib-classes
Jenkins: https://ci.lscape.net/job/latch-test-xenial/17/

review: Approve (test results)

[Free Ekanayaka (free.ekanayaka)]

Looks mostly good to me, marking as N/I just to see what you think of the comments, but I'll be also happy to approve this MP as it is, in case.

review: Needs Information

[Free Ekanayaka (free.ekanayaka)]

+1 with a comment about YAGNI-ing the logsdir parameter.

review: Approve

[lp:~ericsnowcurrently/fake-juju/python-lib-classes]

49. By Eric Snow on 2016-10-13

Merge from parent.

[🤖 Landscape Builder (landscape-builder)]

review: Abstain (executing tests)

[🤖 Landscape Builder (landscape-builder)]

Command: make ci-test
Result: Success
Revno: 49
Branch: lp:~ericsnowcurrently/fake-juju/python-lib-classes
Jenkins: https://ci.lscape.net/job/latch-test-xenial/20/

review: Approve (test results)

[lp:~ericsnowcurrently/fake-juju/python-lib-classes]

50. By Eric Snow on 2016-10-17

Failures() doesn' do any coercion.

51. By Eric Snow on 2016-10-17

FakeJuju() doesn't do any coercion.

52. By Eric Snow on 2016-10-17

Do not use namedtuple for FakeJuju.

53. By Eric Snow on 2016-10-17

Fix a docstring.

[🤖 Landscape Builder (landscape-builder)]

review: Abstain (executing tests)

[🤖 Landscape Builder (landscape-builder)]

Command: make ci-test
Result: Success
Revno: 53
Branch: lp:~ericsnowcurrently/fake-juju/python-lib-classes
Jenkins: https://ci.lscape.net/job/latch-test-xenial/72/

review: Approve (test results)

=== modified file 'python/fakejuju/__init__.py'
--- python/fakejuju/__init__.py	2016-10-13 18:20:43 +0000
+++ python/fakejuju/__init__.py	2016-10-17 15:55:46 +0000
@@ -45,6 +45,14 @@
 
 """
 
+from .fakejuju import get_filename, set_envvars, FakeJuju
+
+
+__all__ = [
+    "__version__",
+    "get_bootstrap_spec", "get_filename", "set_envvars",
+    "FakeJuju",
+    ]
 
 __version__ = "0.9.0b1"
 
 
=== added file 'python/fakejuju/failures.py'
--- python/fakejuju/failures.py	1970-01-01 00:00:00 +0000
+++ python/fakejuju/failures.py	2016-10-17 15:55:46 +0000
@@ -0,0 +1,65 @@
+# Copyright 2016 Canonical Limited.  All rights reserved.
+
+import errno
+import os
+import os.path
+
+
+class Failures(object):
+    """The collection of injected failures to use with a fake-juju.
+
+    The failures are tracked here as well as injected into any
+    fake-juju using the initial config dir (aka "juju home").
+
+    Note that fake-juju provides only limited capability for
+    failure injection.
+    """
+
+    def __init__(self, cfgdir, entities=None):
+        """
+        @param cfgdir: The "juju home" directory into which the
+            failures will be registered for injection.
+        @param entities: The entity names to start with, if any.
+        """
+        filename = os.path.join(cfgdir, "juju-failures")
+        entities = set(entities or ())
+
+        self._filename = filename
+        self._entities = entities
+
+    @property
+    def filename(self):
+        """The path to the failures file the fake-juju reads."""
+        return self._filename
+
+    @property
+    def entities(self):
+        """The IDs of the failing entities."""
+        return set(self._entities)
+
+    def _flush(self):
+        """Write the failures to disk."""
+        data = "\n".join(self._entities) + "\n"
+        try:
+            file = open(self._filename, "w")
+        except IOError:
+            dirname = os.path.dirname(self._filename)
+            if not os.path.exists(dirname):
+                os.makedirs(dirname)
+            file = open(self._filename, "w")
+        with file:
+            file.write(data)
+
+    def fail_entity(self, tag):
+        """Inject a global failure for the identified Juju entity."""
+        self._entities.add(tag)
+        self._flush()
+
+    def clear(self):
+        """Remove all injected failures."""
+        try:
+            os.remove(self._filename)
+        except OSError as e:
+            if e.errno != errno.ENOENT:
+                raise
+        self._entities.clear()
 
=== modified file 'python/fakejuju/fakejuju.py'
--- python/fakejuju/fakejuju.py	2016-10-13 18:20:43 +0000
+++ python/fakejuju/fakejuju.py	2016-10-17 15:55:46 +0000
@@ -2,6 +2,10 @@
 
 import os.path
 
+import txjuju.cli
+
+from .failures import Failures
+
 
 def get_filename(version, bindir=None):
     """Return the full path to the fake-juju binary for the given version.
@@ -30,3 +34,99 @@
     """
     envvars["FAKE_JUJU_FAILURES"] = failures_filename or ""
     envvars["FAKE_JUJU_LOGS_DIR"] = logsdir or ""
+
+
+class FakeJuju(object):
+    """The fundamental details for fake-juju."""
+
+    @classmethod
+    def from_version(cls, version, cfgdir,
+                     logsdir=None, failuresdir=None, bindir=None):
+        """Return a new instance given the provided information.
+
+        @param version: The Juju version to fake.
+        @param cfgdir: The "juju home" directory to use.
+        @param logsdir: The directory where logs will be written.
+            This defaults to cfgdir.
+        @params failuresdir: The directory where failure injection
+            is managed.
+        @param bindir: The directory containing the fake-juju binary.
+            This defaults to /usr/bin.
+        """
+        if logsdir is None:
+            logsdir = cfgdir
+        if failuresdir is None:
+            failuresdir = cfgdir
+        filename = get_filename(version, bindir=bindir)
+        failures = Failures(failuresdir)
+        return cls(filename, version, cfgdir, logsdir, failures)
+
+    def __init__(self, filename, version, cfgdir, logsdir=None, failures=None):
+        """
+        @param filename: The path to the fake-juju binary.
+        @param version: The Juju version to fake.
+        @param cfgdir: The "juju home" directory to use.
+        @param logsdir: The directory where logs will be written.
+            This defaults to cfgdir.
+        @param failures: The set of fake-juju failures to use.
+        """
+        logsdir = logsdir if logsdir is not None else cfgdir
+        if failures is None and cfgdir:
+            failures = Failures(cfgdir)
+
+        if not filename:
+            raise ValueError("missing filename")
+        if not version:
+            raise ValueError("missing version")
+        if not cfgdir:
+            raise ValueError("missing cfgdir")
+        if not logsdir:
+            raise ValueError("missing logsdir")
+        if failures is None:
+            raise ValueError("missing failures")
+
+        self.filename = filename
+        self.version = version
+        self.cfgdir = cfgdir
+        self.logsdir = logsdir
+        self.failures = failures
+
+    @property
+    def logfile(self):
+        """The path to fake-juju's log file."""
+        return os.path.join(self.logsdir, "fake-juju.log")
+
+    @property
+    def infofile(self):
+        """The path to fake-juju's data cache."""
+        return os.path.join(self.cfgdir, "fakejuju")
+
+    @property
+    def fifo(self):
+        """The path to the fifo file that triggers shutdown."""
+        return os.path.join(self.cfgdir, "fifo")
+
+    @property
+    def cacertfile(self):
+        """The path to the API server's certificate."""
+        return os.path.join(self.cfgdir, "cert.ca")
+
+    def cli(self, envvars=None):
+        """Return the txjuju.cli.CLI for this fake-juju.
+
+        Currently fake-juju supports only the following juju subcommands:
+
+        * bootstrap
+          Not that this only supports the dummy provider and the local
+          system is only minimally impacted.
+        * api-info
+          Note that passwords are always omited, even if requested.
+        * api-endpoints
+        * destroy-environment
+        """
+        if envvars is None:
+            envvars = os.environ
+        envvars = dict(envvars)
+        set_envvars(envvars, self.failures._filename, self.logsdir)
+        return txjuju.cli.CLI.from_version(
+            self.filename, self.version, self.cfgdir, envvars)
 
=== added file 'python/fakejuju/tests/test_failures.py'
--- python/fakejuju/tests/test_failures.py	1970-01-01 00:00:00 +0000
+++ python/fakejuju/tests/test_failures.py	2016-10-17 15:55:46 +0000
@@ -0,0 +1,101 @@
+# Copyright 2016 Canonical Limited.  All rights reserved.
+
+import os
+import os.path
+import shutil
+import tempfile
+import unittest
+
+from fakejuju.failures import Failures
+
+
+class FailuresTests(unittest.TestCase):
+
+    def setUp(self):
+        super(FailuresTests, self).setUp()
+        self.dirname = tempfile.mkdtemp(prefix="fakejuju-test-")
+
+    def tearDown(self):
+        shutil.rmtree(self.dirname)
+        super(FailuresTests, self).tearDown()
+
+    def test_full(self):
+        """Failures() works correctly when given all args."""
+        entities = [u"x", u"y", u"z"]
+        failures = Failures(u"/some/dir", entities)
+
+        self.assertEqual(failures.filename, u"/some/dir/juju-failures")
+        self.assertEqual(failures.entities, set(entities))
+
+    def test_minimal(self):
+        """Failures() works correctly when given minimal args."""
+        failures = Failures(u"/some/dir")
+
+        self.assertEqual(failures.filename, u"/some/dir/juju-failures")
+        self.assertEqual(failures.entities, set())
+
+    def test_conversion(self):
+        """Failures() doesn't convert any values."""
+        failures_str = Failures("/some/dir", ["x", "y", "z"])
+        failures_unicode = Failures(u"/some/dir", [u"x", u"y", u"z"])
+
+        self.assertIsInstance(failures_str.filename, str)
+        self.assertIsInstance(failures_unicode.filename, unicode)
+        for id in failures_str.entities:
+            self.assertIsInstance(id, str)
+        for id in failures_unicode.entities:
+            self.assertIsInstance(id, unicode)
+
+    def test_file_not_created_initially(self):
+        """Failures() doesn't create a missing cfgdir until necessary."""
+        failures = Failures(self.dirname)
+
+        self.assertFalse(os.path.exists(failures.filename))
+
+    def test_cfgdir_created(self):
+        """Failures() creates a missing cfgdir as soon as it's needed."""
+        dirname = os.path.join(self.dirname, "subdir")
+        self.assertFalse(os.path.exists(dirname))
+        failures = Failures(dirname)
+        failures.fail_entity("unit-xyz")
+
+        self.assertTrue(os.path.exists(dirname))
+
+    def test_fail_entity_one(self):
+        """Failures,fail_entity() writes an initial entry to disk."""
+        failures = Failures(self.dirname)
+        failures.fail_entity("unit-abc")
+        with open(failures.filename) as file:
+            data = file.read()
+
+        self.assertEqual(data, "unit-abc\n")
+
+    def test_fail_entity_multiple(self):
+        """Failures.fail_entity() correctly writes multiple entries to disk."""
+        failures = Failures(self.dirname)
+        failures.fail_entity("unit-abc")
+        failures.fail_entity("unit-xyz")
+
+        with open(failures.filename) as file:
+            data = file.read()
+        entities = set(tag for tag in data.splitlines() if tag)
+        self.assertEqual(entities, failures.entities)
+        self.assertTrue(data.endswith("\n"))
+
+    def test_clear_exists(self):
+        """Failures.clear() deletes the failures file if it exists."""
+        failures = Failures(self.dirname)
+        failures.fail_entity("unit-abc")
+        self.assertTrue(os.path.exists(failures.filename))
+        failures.clear()
+
+        self.assertFalse(os.path.exists(failures.filename))
+        self.assertEqual(failures.entities, set())
+
+    def test_clear_not_exists(self):
+        """Failures.clear() does nothing if the failures file is missing."""
+        failures = Failures(self.dirname)
+        self.assertFalse(os.path.exists(failures.filename))
+        failures.clear()
+
+        self.assertFalse(os.path.exists(failures.filename))
 
=== modified file 'python/fakejuju/tests/test_fakejuju.py'
--- python/fakejuju/tests/test_fakejuju.py	2016-10-13 18:25:28 +0000
+++ python/fakejuju/tests/test_fakejuju.py	2016-10-17 15:55:46 +0000
@@ -1,8 +1,13 @@
 # Copyright 2016 Canonical Limited.  All rights reserved.
 
+import os
 import unittest
 
-from fakejuju.fakejuju import get_filename, set_envvars
+from txjuju import _juju1, _juju2
+from txjuju._utils import Executable
+
+from fakejuju.failures import Failures
+from fakejuju.fakejuju import get_filename, set_envvars, FakeJuju
 
 
 class GetFilenameTests(unittest.TestCase):
@@ -115,3 +120,150 @@
             "FAKE_JUJU_FAILURES": "",
             "FAKE_JUJU_LOGS_DIR": "",
             })
+
+
+class FakeJujuTests(unittest.TestCase):
+
+    def test_from_version_full(self):
+        """FakeJuju.from_version() works correctly when given all args."""
+        juju = FakeJuju.from_version(
+            "1.25.6", "/a/juju/home", "/logs/dir", "/failures/dir", "/bin/dir")
+
+        self.assertEqual(juju.filename, "/bin/dir/fake-juju-1.25.6")
+        self.assertEqual(juju.version, "1.25.6")
+        self.assertEqual(juju.cfgdir, "/a/juju/home")
+        self.assertEqual(juju.logsdir, "/logs/dir")
+        self.assertEqual(juju.failures.filename, "/failures/dir/juju-failures")
+
+    def test_from_version_minimal(self):
+        """FakeJuju.from_version() works correctly when given minimal args."""
+        juju = FakeJuju.from_version("1.25.6", "/my/juju/home")
+
+        self.assertEqual(juju.filename, "/usr/bin/fake-juju-1.25.6")
+        self.assertEqual(juju.version, "1.25.6")
+        self.assertEqual(juju.cfgdir, "/my/juju/home")
+        self.assertEqual(juju.logsdir, "/my/juju/home")
+        self.assertEqual(juju.failures.filename, "/my/juju/home/juju-failures")
+
+    def test_full(self):
+        """FakeJuju() works correctly when given all args."""
+        cfgdir = "/my/juju/home"
+        failures = Failures(cfgdir)
+        juju = FakeJuju("/fake-juju", "1.25.6", cfgdir, "/some/logs", failures)
+
+        self.assertEqual(juju.filename, "/fake-juju")
+        self.assertEqual(juju.version, "1.25.6")
+        self.assertEqual(juju.cfgdir, cfgdir)
+        self.assertEqual(juju.logsdir, "/some/logs")
+        self.assertIs(juju.failures, failures)
+
+    def test_minimal(self):
+        """FakeJuju() works correctly when given minimal args."""
+        juju = FakeJuju("/fake-juju", "1.25.6", "/my/juju/home")
+
+        self.assertEqual(juju.filename, "/fake-juju")
+        self.assertEqual(juju.version, "1.25.6")
+        self.assertEqual(juju.cfgdir, "/my/juju/home")
+        self.assertEqual(juju.logsdir, "/my/juju/home")
+        self.assertEqual(juju.failures.filename, "/my/juju/home/juju-failures")
+
+    def test_conversions(self):
+        """FakeJuju() doesn't convert the type of any value."""
+        juju_str = FakeJuju(
+            "/fake-juju", "1.25.6", "/x", "/y", Failures("/..."))
+        juju_unicode = FakeJuju(
+            u"/fake-juju", u"1.25.6", u"/x", u"/y", Failures(u"/..."))
+
+        for name in ('filename version cfgdir logsdir'.split()):
+            self.assertIsInstance(getattr(juju_str, name), str)
+            self.assertIsInstance(getattr(juju_unicode, name), unicode)
+
+    def test_missing_filename(self):
+        """FakeJuju() fails if filename is None or empty."""
+        with self.assertRaises(ValueError):
+            FakeJuju(None, "1.25.6", "/my/juju/home")
+        with self.assertRaises(ValueError):
+            FakeJuju("", "1.25.6", "/my/juju/home")
+
+    def test_missing_version(self):
+        """FakeJuju() fails if version is None or empty."""
+        with self.assertRaises(ValueError):
+            FakeJuju("/fake-juju", None, "/my/juju/home")
+        with self.assertRaises(ValueError):
+            FakeJuju("/fake-juju", "", "/my/juju/home")
+
+    def test_missing_cfgdir(self):
+        """FakeJuju() fails if cfgdir is None or empty."""
+        with self.assertRaises(ValueError):
+            FakeJuju("/fake-juju", "1.25.6", None)
+        with self.assertRaises(ValueError):
+            FakeJuju("/fake-juju", "1.25.6", "")
+
+    def test_logfile(self):
+        """FakeJuju.logfile returns the path to the fake-juju log file."""
+        juju = FakeJuju("/fake-juju", "1.25.6", "/x", "/some/logs")
+
+        self.assertEqual(juju.logfile, "/some/logs/fake-juju.log")
+
+    def test_infofile(self):
+        """FakeJuju.logfile returns the path to the fake-juju info file."""
+        juju = FakeJuju("/fake-juju", "1.25.6", "/x")
+
+        self.assertEqual(juju.infofile, "/x/fakejuju")
+
+    def test_fifo(self):
+        """FakeJuju.logfile returns the path to the fake-juju fifo."""
+        juju = FakeJuju("/fake-juju", "1.25.6", "/x")
+
+        self.assertEqual(juju.fifo, "/x/fifo")
+
+    def test_cacertfile(self):
+        """FakeJuju.cacertfile returns the path to the Juju API cert."""
+        juju = FakeJuju("/fake-juju", "1.25.6", "/x")
+
+        self.assertEqual(juju.cacertfile, "/x/cert.ca")
+
+    def test_cli_full(self):
+        """FakeJuju.cli() works correctly when given all args."""
+        juju = FakeJuju("/fake-juju", "1.25.6", "/x")
+        cli = juju.cli({"SPAM": "eggs"})
+
+        self.assertEqual(
+            cli._exe,
+            Executable("/fake-juju", {
+                "SPAM": "eggs",
+                "FAKE_JUJU_FAILURES": "/x/juju-failures",
+                "FAKE_JUJU_LOGS_DIR": "/x",
+                "JUJU_HOME": "/x",
+                }),
+            )
+
+    def test_cli_minimal(self):
+        """FakeJuju.cli() works correctly when given minimal args."""
+        juju = FakeJuju("/fake-juju", "1.25.6", "/x")
+        cli = juju.cli()
+
+        self.assertEqual(
+            cli._exe,
+            Executable("/fake-juju", dict(os.environ, **{
+                "FAKE_JUJU_FAILURES": "/x/juju-failures",
+                "FAKE_JUJU_LOGS_DIR": "/x",
+                "JUJU_HOME": "/x",
+                })),
+            )
+
+    def test_cli_juju1(self):
+        """FakeJuju.cli() works correctly for Juju 1.x."""
+        juju = FakeJuju.from_version("1.25.6", "/x")
+        cli = juju.cli()
+
+        self.assertEqual(cli._exe.envvars["JUJU_HOME"], "/x")
+        self.assertIsInstance(cli._juju, _juju1.CLIHooks)
+
+    def test_cli_juju2(self):
+        """FakeJuju.cli() works correctly for Juju 2.x."""
+        juju = FakeJuju.from_version("2.0.0", "/x")
+        cli = juju.cli()
+
+        self.assertEqual(cli._exe.envvars["JUJU_DATA"], "/x")
+        self.assertIsInstance(cli._juju, _juju2.CLIHooks)