Add envs for different sqlalchemy versions

Adjust tests to skip the sqlalchemy test if
sqlalchemy is not installed. Adjust examples
to fallback to a directory based backend if
the sqlalchemy does not load or is not available.

Include a updated tox.ini (generated from the
toxgen.py script) that includes the new venv
variations.

Change-Id: I7686f09901a9b65d7c81b4e037b5bffc24aa7ef7

1 files changed, 211 insertions, 0 deletions

diff --git a/tools/toxgen.py b/tools/toxgen.py
new file mode 100755
index 0000000..111ed9b
--- /dev/null
+++ b/tools/toxgen.py
@@ -0,0 +1,211 @@
+#!/usr/bin/env python
+
+# From: https://bitbucket.org/cdevienne/toxgen (pypi soon hopefully) and
+# modified slightly to work in python 2.6 and set some values that are not
+# being set.
+#
+# TODO(harlowja): remove me when toxgen is a pypi package.
+
+"""
+Produce a tox.ini file from a template config file.
+
+The template config file is a standard tox.ini file with additional sections.
+Theses sections will be combined to create new testenv: sections if they do
+not exists yet.
+"""
+
+import collections
+import itertools
+import optparse
+import os
+
+import six
+
+from six.moves import configparser
+
+try:
+    from collections import OrderedDict
+except ImportError:
+    from ordereddict import OrderedDict
+
+
+HEADER = '# DO NOT EDIT THIS FILE - it is machine generated from %(filename)s'
+SKIP_VENVS = frozenset(['venv'])
+
+parser = optparse.OptionParser(epilog=__doc__)
+parser.add_option('-i', '--input', dest='input',
+                  default='tox-tmpl.ini', metavar='FILE')
+parser.add_option('-o', '--output', dest='output',
+                  default='tox.ini', metavar='FILE')
+
+
+class AxisItem(object):
+    def __init__(self, axis, name, config):
+        self.axis = axis
+        self.isdefault = name[-1] == '*'
+        self.name = name[:-1] if self.isdefault else name
+        self.load(config)
+
+    def load(self, config):
+        sectionname = 'axis:%s:%s' % (self.axis.name, self.name)
+        if config.has_section(sectionname):
+            self.options = dict(config.items(sectionname))
+        else:
+            self.options = dict()
+
+        for name, value in self.axis.defaults.items():
+            if name not in self.options:
+                self.options[name] = value
+
+
+class Axis(object):
+    def __init__(self, name, config):
+        self.name = name
+        self.load(config)
+
+    def load(self, config):
+        self.items = dict()
+        values = config.get('axes', self.name).split(',')
+        if config.has_section('axis:%s' % self.name):
+            self.defaults = dict(
+                config.items('axis:%s' % self.name)
+            )
+        else:
+            self.defaults = {}
+        for value in values:
+            self.items[value.strip('*')] = AxisItem(self, value, config)
+
+
+def format_list(contents, max_len=80, sep=","):
+    lines = []
+    for line in contents:
+        if not lines:
+            lines.append(line + ",")
+        else:
+            last_len = len(lines[-1])
+            if last_len + len(line) >= max_len:
+                lines.append(str(line) + sep)
+            else:
+                lines[-1] = lines[-1] + str(line) + sep
+    return "\n".join(lines).rstrip(",")
+
+
+def render(incfg, filename, adjust_envlist=True):
+    test_envs = set()
+    for s in incfg.sections():
+        if s.startswith("testenv:"):
+            env = s[len("testenv:"):].strip()
+            if env in SKIP_VENVS or not env:
+                continue
+            test_envs.add(env)
+    test_envs = [s for s in test_envs if s]
+
+    try:
+        envlist = incfg.get("tox", 'envlist')
+        envlist = [e.strip() for e in envlist.split(",")]
+        envlist = set([e for e in envlist if e])
+    except (configparser.NoOptionError, configparser.NoSectionError):
+        envlist = set()
+    for e in test_envs:
+        if e not in envlist:
+            envlist.add(e)
+
+    if not incfg.has_section("tox"):
+        incfg.add_section("tox")
+    incfg.set("tox", "envlist",
+              format_list(list(sorted(envlist)), max_len=-1))
+
+    text = six.StringIO()
+    incfg.write(text)
+    contents = [
+        HEADER % {'filename': os.path.basename(filename)},
+        '',
+        # Remove how configparser uses tabs instead of spaces, madness...
+        text.getvalue().replace("\t", " " * 4),
+    ]
+    return "\n".join(contents)
+
+
+def compile_template(incfg):
+    axes = dict()
+
+    if incfg.has_section('axes'):
+        for axis in incfg.options('axes'):
+            axes[axis] = Axis(axis, incfg)
+
+    out = configparser.ConfigParser(dict_type=OrderedDict)
+    for section in incfg.sections():
+        if section == 'axes' or section.startswith('axis:'):
+            continue
+        out.add_section(section)
+        for name, value in incfg.items(section):
+            out.set(section, name, value)
+
+    items = [axis.items.keys() for axis in axes.values()]
+    for combination in itertools.product(*items):
+        options = {}
+
+        section_name = (
+            'testenv:' + '-'.join([item for item in combination if item])
+        )
+        section_alt_name = (
+            'testenv:' + '-'.join([
+                itemname
+                for axis, itemname in zip(axes.values(), combination)
+                if itemname and not axis.items[itemname].isdefault
+            ])
+        )
+        if section_alt_name == section_name:
+            section_alt_name = None
+
+        axes_items = [
+            '%s:%s' % (axis, itemname)
+            for axis, itemname in zip(axes, combination)
+        ]
+
+        for axis, itemname in zip(axes.values(), combination):
+            axis_options = axis.items[itemname].options
+            if 'constraints' in axis_options:
+                constraints = axis_options['constraints'].split('\n')
+                for c in constraints:
+                    if c.startswith('!') and c[1:] in axes_items:
+                        continue
+            for name, value in axis_options.items():
+                if name in options:
+                    options[name] += value
+                else:
+                    options[name] = value
+
+        constraints = options.pop('constraints', '').split('\n')
+        neg_constraints = [c[1:] for c in constraints if c and c[0] == '!']
+        if not set(neg_constraints).isdisjoint(axes_items):
+            continue
+
+        if not out.has_section(section_name):
+            out.add_section(section_name)
+
+        if (section_alt_name and not out.has_section(section_alt_name)):
+            out.add_section(section_alt_name)
+
+        for name, value in reversed(options.items()):
+            if not out.has_option(section_name, name):
+                out.set(section_name, name, value)
+            if section_alt_name and not out.has_option(section_alt_name, name):
+                out.set(section_alt_name, name, value)
+
+    return out
+
+
+def main():
+    options, args = parser.parse_args()
+    tmpl = configparser.ConfigParser()
+    with open(options.input, 'rb') as fh:
+        tmpl.readfp(fh, filename=options.input)
+    with open(options.output, 'wb') as outfile:
+        text = render(compile_template(tmpl), options.input)
+        outfile.write(text)
+
+
+if __name__ == '__main__':
+    main()
+