Consul data cache plugin.

salt/cache/consul.py

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+# -*- coding: utf-8 -*-
+'''
+Data cache plugin for Consul key/value data store.
+This requires python-consul python package.
+
+.. versionadded:: 2016.11.2
+'''
+from __future__ import absolute_import
+import logging
+try:
+    import consul
+    HAS_CONSUL = True
+except ImportError:
+    HAS_CONSUL = False
+
+from salt.exceptions import SaltCacheError
+
+log = logging.getLogger(__name__)
+CONSUL = None
+
+
+# Define the module's virtual name
+__virtualname__ = 'consul'
+
+
+def __virtual__():
+    '''
+    Confirm this python-consul package is installed
+    '''
+    if not HAS_CONSUL:
+        return (False, "Please install python-consul package to use consul data cache driver")
+
+    global CONSUL
+    CONSUL = consul.Consul()
+
+    return __virtualname__
+
+
+def store(bank, key, data):
+    '''
+    Store a key value.
+    '''
+    c_key = '{0}/{1}'.format(bank, key)
+    try:
+        c_data = __context__['serial'].dumps(data)
+        CONSUL.kv.put(c_key, c_data)
+    except Exception as exc:
+        raise SaltCacheError(
+            'There was an error writing the key, {0}: {1}'.format(
+                c_key, exc
+            )
+        )
+
+
+def fetch(bank, key):
+    '''
+    Fetch a key value.
+    '''
+    c_key = '{0}/{1}'.format(bank, key)
+    try:
+        _, value = CONSUL.kv.get(c_key)
+        if value is None:
+            return value
+        return __context__['serial'].loads(value['Value'])
+    except Exception as exc:
+        raise SaltCacheError(
+            'There was an error reading the key, {0}: {1}'.format(
+                c_key, exc
+            )
+        )
+
+
+def flush(bank, key=None):
+    '''
+    Remove the key from the cache bank with all the key content.
+    '''
+    if key is None:
+        c_key = bank
+    else:
+        c_key = '{0}/{1}'.format(bank, key)
+    try:
+        return CONSUL.kv.delete(c_key, recurse=key is None)
+    except Exception as exc:
+        raise SaltCacheError(
+            'There was an error removing the key, {0}: {1}'.format(
+                c_key, exc
+            )
+        )
+
+
+def list(bank):
+    '''
+    Return an iterable object containing all entries stored in the specified bank.
+    '''
+    try:
+        _, keys = CONSUL.kv.get(bank + '/', keys=True, separator='/')
+    except Exception as exc:
+        raise SaltCacheError(
+            'There was an error getting the key "{0}": {1}'.format(
+                bank, exc
+            )
+        )
+    if keys is None:
+        keys = []
+    else:
+        # Any key could be a branch and a leaf at the same time in Consul
+        # so we have to return a list of unique names only.
+        out = set()
+        for key in keys:
+            out.add(key[len(bank) + 1:].rstrip('/'))
+        keys = list(out)
+    return keys
+
+
+def contains(bank, key):
+    '''
+    Checks if the specified bank contains the specified key.
+    '''
+    if key is None:
+        return True  # any key could be a branch and a leaf at the same time in Consul
+    else:
+        try:
+            c_key = '{0}/{1}'.format(bank, key)
+            _, value = CONSUL.kv.get(c_key)
+        except Exception as exc:
+            raise SaltCacheError(
+                'There was an error getting the key, {0}: {1}'.format(
+                    c_key, exc
+                )
+            )
+        return value is not None