Move all files to _etc_based

uncloud_etcd_based/uncloud/hack/db.py

@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# 2020 Nico Schottelius (nico.schottelius at ungleich.ch)
+#
+# This file is part of uncloud.
+#
+# uncloud is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# uncloud is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with uncloud. If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+import etcd3
+import json
+import logging
+import datetime
+import re
+
+from functools import wraps
+from uncloud import UncloudException
+
+log = logging.getLogger(__name__)
+
+def db_logentry(message):
+    timestamp = datetime.datetime.now()
+    return {
+        "timestamp": str(timestamp),
+        "message": message
+    }
+
+
+def readable_errors(func):
+    @wraps(func)
+    def wrapper(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except etcd3.exceptions.ConnectionFailedError as e:
+            raise UncloudException('Cannot connect to etcd: is etcd running and reachable? {}'.format(e))
+        except etcd3.exceptions.ConnectionTimeoutError as e:
+            raise UncloudException('etcd connection timeout. {}'.format(e))
+
+    return wrapper
+
+
+class DB(object):
+    def __init__(self, config, prefix="/"):
+        self.config = config
+
+        # Root for everything
+        self.base_prefix= '/nicohack'
+
+        # Can be set from outside
+        self.prefix = prefix
+
+        try:
+            self.connect()
+        except FileNotFoundError as e:
+            raise UncloudException("Is the path to the etcd certs correct? {}".format(e))
+
+    @readable_errors
+    def connect(self):
+        self._db_clients = []
+        for endpoint in self.config.etcd_hosts:
+            client = etcd3.client(host=endpoint, **self.config.etcd_args)
+            self._db_clients.append(client)
+
+    def realkey(self, key):
+        return "{}{}/{}".format(self.base_prefix,
+                                self.prefix,
+                                key)
+
+    @readable_errors
+    def get(self, key, as_json=False, **kwargs):
+        value, _ = self._db_clients[0].get(self.realkey(key), **kwargs)
+
+        if as_json:
+            value = json.loads(value)
+
+        return value
+
+    @readable_errors
+    def get_prefix(self, key, as_json=False, **kwargs):
+        for value, meta in self._db_clients[0].get_prefix(self.realkey(key), **kwargs):
+            k = meta.key.decode("utf-8")
+            value = value.decode("utf-8")
+            if as_json:
+                value = json.loads(value)
+
+            yield (k, value)
+
+
+    @readable_errors
+    def set(self, key, value, as_json=False, **kwargs):
+        if as_json:
+            value = json.dumps(value)
+
+        log.debug("Setting {} = {}".format(self.realkey(key), value))
+        # FIXME: iterate over clients in case of failure ?
+        return self._db_clients[0].put(self.realkey(key), value, **kwargs)
+
+
+    @readable_errors
+    def list_and_filter(self, key, filter_key=None, filter_regexp=None):
+        for k,v in self.get_prefix(key, as_json=True):
+
+            if filter_key and filter_regexp:
+                if filter_key in v:
+                    if re.match(filter_regexp, v[filter_key]):
+                        yield v
+            else:
+                yield v
+
+
+    @readable_errors
+    def increment(self, key, **kwargs):
+        print(self.realkey(key))
+
+
+        print("prelock")
+        lock = self._db_clients[0].lock('/nicohack/foo')
+        print("prelockacq")
+        lock.acquire()
+        print("prelockrelease")
+        lock.release()
+
+        with self._db_clients[0].lock("/nicohack/mac/last_used_index") as lock:
+            print("in lock")
+            pass
+
+#        with self._db_clients[0].lock(self.realkey(key)) as lock:#            value = int(self.get(self.realkey(key), **kwargs))
+#            self.set(self.realkey(key), str(value + 1), **kwargs)
+
+
+if __name__ == '__main__':
+    endpoints = [ "https://etcd1.ungleich.ch:2379",
+                  "https://etcd2.ungleich.ch:2379",
+                  "https://etcd3.ungleich.ch:2379" ]
+
+    db = DB(url=endpoints)