Refactor libpod python varlink bindings

- More pythonic
- Leverage context managers to help with socket leaks
- Add system unittest's
- Add image unittest's
- Add container unittest's
- Add models for system, containers and images, and their collections
- Add helper functions for datetime parsing/formatting
- GetInfo() implemented
- Add support for setuptools
- Update documentation
- Support for Python 3.4-3.6

Signed-off-by: Jhon Honce <jhonce@redhat.com>

Closes: #748
Approved by: baude

1 files changed, 96 insertions, 0 deletions

diff --git a/contrib/python/podman/libs/__init__.py b/contrib/python/podman/libs/__init__.py
new file mode 100644
index 000000000..ab8fb94a8
--- /dev/null
+++ b/contrib/python/podman/libs/__init__.py
@@ -0,0 +1,96 @@
+"""Support files for podman API implementation."""
+import datetime
+import re
+import threading
+
+__all__ = [
+    'cached_property',
+    'datetime_parse',
+    'datetime_format',
+]
+
+
+class cached_property(object):
+    """cached_property() - computed once per instance, cached as attribute.
+
+    Maybe this will make a future version of python.
+    """
+
+    def __init__(self, func):
+        """Construct context manager."""
+        self.func = func
+        self.__doc__ = func.__doc__
+        self.lock = threading.RLock()
+
+    def __get__(self, instance, cls=None):
+        """Retrieve previous value, or call func()."""
+        if instance is None:
+            return self
+
+        attrname = self.func.__name__
+        try:
+            cache = instance.__dict__
+        except AttributeError:  # objects with __slots__ have no __dict__
+            msg = ("No '__dict__' attribute on {}"
+                   " instance to cache {} property.").format(
+                       repr(type(instance).__name__), repr(attrname))
+            raise TypeError(msg) from None
+
+        with self.lock:
+            # check if another thread filled cache while we awaited lock
+            if attrname not in cache:
+                cache[attrname] = self.func(instance)
+        return cache[attrname]
+
+
+def datetime_parse(string):
+    """Convert timestamp to datetime.
+
+    Because date/time parsing in python is still pedantically stupid,
+    we rip the input string apart throwing out the stop characters etc;
+    then rebuild a string strptime() can parse. Igit!
+
+    - Python >3.7 will address colons in the UTC offset.
+    - There is no ETA on microseconds > 6 digits.
+    - And giving an offset and timezone name...
+
+    # match: 2018-05-08T14:12:53.797795191-07:00
+    # match: 2018-05-08T18:24:52.753227-07:00
+    # match: 2018-05-08 14:12:53.797795191 -0700 MST
+    # match: 2018-05-09T10:45:57.576002  (python isoformat())
+
+    Some people, when confronted with a problem, think “I know,
+    I'll use regular expressions.”  Now they have two problems.
+      -- Jamie Zawinski
+    """
+    ts = re.compile(r'^(\d+)-(\d+)-(\d+)'
+                    r'[ T]?(\d+):(\d+):(\d+).(\d+)'
+                    r' *([-+][\d:]{4,5})? *')
+
+    x = ts.match(string)
+    if x is None:
+        raise ValueError('Unable to parse {}'.format(string))
+
+    # converting everything to int() not worth the readablity hit
+    igit_proof = '{}T{}.{}{}'.format(
+        '-'.join(x.group(1, 2, 3)),
+        ':'.join(x.group(4, 5, 6)),
+        x.group(7)[0:6],
+        x.group(8).replace(':', '') if x.group(8) else '',
+    )
+
+    format = '%Y-%m-%dT%H:%M:%S.%f'
+    if x.group(8):
+        format += '%z'
+    return datetime.datetime.strptime(igit_proof, format)
+
+
+def datetime_format(dt):
+    """Format datetime in consistent style."""
+    if isinstance(dt, str):
+        return datetime_parse(dt).isoformat()
+    elif isinstance(dt, datetime.datetime):
+        return dt.isoformat()
+    else:
+        raise ValueError('Unable to format {}. Type {} not supported.'.format(
+            dt, type(dt)))