redis migrate script (#388)

Author: tonicmuroq

scripts/redis_as_broker.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import argparse
+import sys
+
+import etcd3
+import redis
+
+
+def migrate(root, etcd_client, redis_client, dry_run):
+    range_start = root
+    range_end = etcd3.utils.increment_last_byte(
+        etcd3.utils.to_bytes(range_start)
+    )
+
+    while True:
+        range_request = etcd3.etcdrpc.RangeRequest()
+        range_request.key = etcd3.utils.to_bytes(range_start)
+        range_request.keys_only = False
+        range_request.range_end = etcd3.utils.to_bytes(range_end)
+        range_request.sort_order = etcd3.etcdrpc.RangeRequest.ASCEND
+        range_request.sort_target = etcd3.etcdrpc.RangeRequest.KEY
+        range_request.serializable = True
+        range_request.limit = 1000
+
+        resp = etcd_client.kvstub.Range(
+            range_request,
+            etcd_client.timeout,
+            credentials=etcd_client.call_credentials,
+            metadata=etcd_client.metadata,
+        )
+
+        for kv in resp.kvs:
+            key = kv.key.decode('utf-8')
+            value = kv.value.decode('utf-8')
+
+            if dry_run:
+                print('will set %s to %s' % (key, value))
+                continue
+
+            redis_client.set(key, value)
+            print('key %s is set to %s' % (key, value))
+
+        if not resp.more:
+            break
+
+        range_start = etcd3.utils.increment_last_byte(kv.key)
+
+
+def getargs():
+    ap = argparse.ArgumentParser()
+    ap.add_argument('--source', dest='source_root_prefix', help='source root prefix', default='/eru')
+    ap.add_argument('--etcd-host', default='127.0.0.1')
+    ap.add_argument('--etcd-port', type=int, default=2379)
+    ap.add_argument('--redis-host', default='127.0.0.1')
+    ap.add_argument('--redis-port', type=int, default=6379)
+    ap.add_argument('--redis-db', type=int, default=0)
+    ap.add_argument('--dry-run', dest='dry_run', action='store_true', help='dry run, will not actually migrate')
+    return ap.parse_args()
+
+
+def main():
+    args = getargs()
+
+    etcd_client = etcd3.client(host=args.etcd_host, port=args.etcd_port)
+    redis_client = redis.StrictRedis(host=args.redis_host, port=args.redis_port, db=args.redis_db)
+    migrate(args.source_root_prefix, etcd_client, redis_client, args.dry_run)
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())