Add a copy of the nginx builder module

sysadmin/nginx/config/builder/plugins.py

@@ -0,0 +1,99 @@
+from .baseplugins import Plugin
+from ..api import KeyValueOption, EmptyBlock
+
+from abc import ABCMeta, abstractproperty
+from enum import Enum, unique
+import six
+
+
+class _ValEnum(Enum):
+    """Enum that yields its value on stringification"""
+    def __str__(self):
+        return str(self.value)
+
+
+@unique
+class CacheUseStale(_ValEnum):
+    """
+    enum for possible options to be passed to *_use_stale. enum for safety
+    (preventing invalid options) as well as documentation and reuse
+    """
+
+    error = 'error'
+    timeout = 'timeout'
+    invalid_header = 'invalid_header'
+    updating = 'updating'
+    http_500 = 'http_500'
+    http_503 = 'http_503'
+    http_403 = 'http_403'
+    http_404 = 'http_404'
+    off = 'off'
+
+
+@six.add_metaclass(ABCMeta)
+class CacheRoutePlugin(Plugin):
+    """
+    Route caching superclass
+
+    All caching plugins can inherit off of this, by setting a `cache_prefix` property
+    that gets prepended to each nginx directive that gets set. This automatically sets
+    the top-level cache directives that need to be set, and when called off of a route,
+    it turns caching on for that route for the duration specified in the arguments
+    """
+
+    invalid = ()
+    valid_cfg_parents = ('location',)
+
+    @abstractproperty
+    def cache_prefix(self):
+        pass
+
+    def _set_cache_option(self, opt, val):
+        cp = "{cache_prefix}_".format(cache_prefix=self.cache_prefix)
+        if opt not in self.invalid and val:
+            self.config_builder.top.options[cp + opt] = val
+
+    def cache_route(self, cache_key='$request_uri', ignore_headers=None,
+                    cache_min_uses=1, cache_bypass='$nocache',
+                    cache_use_stale=CacheUseStale.off, cache_valid=None,
+                    cache_convert_head=None):
+        cp = "{cache_prefix}_".format(cache_prefix=self.cache_prefix)
+
+        # set the options directly on the route now
+        self.add_child(EmptyBlock(
+            *tuple(KeyValueOption(cp + 'cache_valid', value='{k} {v}'.format(k=k, v=v))
+                   for (k, v) in cache_valid.items())
+        ))
+
+        # XXX: check if these are set the first time
+        # add options to top
+        self._set_cache_option('cache_key', cache_key)
+        self._set_cache_option('cache_min_uses', cache_min_uses)
+        self._set_cache_option('cache_bypass', cache_bypass)
+        self._set_cache_option('cache_use_stale', cache_use_stale)
+        self._set_cache_option('cache_convert_head', cache_convert_head)
+
+        if 'add_header' not in self.config_builder.top.options:
+            self.config_builder.top.options['add_header'] = []
+        self.config_builder.top.options['add_header'].extend(['X-Cache-Status', '$upstream_cache_status'])
+
+        return self
+
+
+class UWSGICacheRoutePlugin(CacheRoutePlugin):
+    name = 'cache uwsgi route'
+    cache_prefix = 'uwsgi'
+    invalid = ('cache_convert_head',)
+
+    @property
+    def exported_methods(self):
+        return {'cache_uwsgi_route': self.cache_route}
+
+
+class ProxyCacheRoutePlugin(CacheRoutePlugin):
+    name = 'cache proxy route'
+    cache_prefix = 'proxy'
+
+    @property
+    def exported_methods(self):
+        return {'cache_proxy_route': self.cache_route}