From 81ebde88db65a71c31245d462adbf95c0deeb528 Mon Sep 17 00:00:00 2001
From: Jack Robison <jackrobison@lbry.io>
Date: Fri, 7 May 2021 12:42:52 -0400
Subject: [PATCH] resync ES search index on version bumps

-bump ES search index to version 1
---
 lbry/wallet/server/db/elasticsearch/search.py | 31 ++++++++++++++++++-
 lbry/wallet/server/db/elasticsearch/sync.py   |  9 +++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/lbry/wallet/server/db/elasticsearch/search.py b/lbry/wallet/server/db/elasticsearch/search.py
index e03d4cbec..6f9820e54 100644
--- a/lbry/wallet/server/db/elasticsearch/search.py
+++ b/lbry/wallet/server/db/elasticsearch/search.py
@@ -33,7 +33,15 @@ class StreamResolution(str):
         return LookupError(f'Could not find claim at "{url}".')
 
 
+class IndexVersionMismatch(Exception):
+    def __init__(self, got_version, expected_version):
+        self.got_version = got_version
+        self.expected_version = expected_version
+
+
 class SearchIndex:
+    VERSION = 1
+
     def __init__(self, index_prefix: str, search_timeout=3.0, elastic_host='localhost', elastic_port=9200):
         self.search_timeout = search_timeout
         self.sync_timeout = 600  # wont hit that 99% of the time, but can hit on a fresh import
@@ -48,6 +56,18 @@ class SearchIndex:
         self._elastic_host = elastic_host
         self._elastic_port = elastic_port
 
+    async def get_index_version(self) -> int:
+        try:
+            template = await self.sync_client.indices.get_template(self.index)
+            return template[self.index]['version']
+        except NotFoundError:
+            return 0
+
+    async def set_index_version(self, version):
+        await self.sync_client.indices.put_template(
+            self.index, body={'version': version, 'index_patterns': ['ignored']}, ignore=400
+        )
+
     async def start(self):
         if self.sync_client:
             return
@@ -61,8 +81,17 @@ class SearchIndex:
             except ConnectionError:
                 self.logger.warning("Failed to connect to Elasticsearch. Waiting for it!")
                 await asyncio.sleep(1)
+
         res = await self.sync_client.indices.create(self.index, INDEX_DEFAULT_SETTINGS, ignore=400)
-        return res.get('acknowledged', False)
+        acked = res.get('acknowledged', False)
+        if acked:
+            await self.set_index_version(self.VERSION)
+            return acked
+        index_version = await self.get_index_version()
+        if index_version != self.VERSION:
+            self.logger.error("es search index has an incompatible version: %s vs %s", index_version, self.VERSION)
+            raise IndexVersionMismatch(f"{index_version} vs {self.VERSION}")
+        return acked
 
     def stop(self):
         clients = [self.sync_client, self.search_client]
diff --git a/lbry/wallet/server/db/elasticsearch/sync.py b/lbry/wallet/server/db/elasticsearch/sync.py
index bc716021a..2ca7644f6 100644
--- a/lbry/wallet/server/db/elasticsearch/sync.py
+++ b/lbry/wallet/server/db/elasticsearch/sync.py
@@ -10,7 +10,7 @@ from elasticsearch import AsyncElasticsearch
 from elasticsearch.helpers import async_bulk
 from lbry.wallet.server.env import Env
 from lbry.wallet.server.coin import LBC
-from lbry.wallet.server.db.elasticsearch.search import extract_doc, SearchIndex
+from lbry.wallet.server.db.elasticsearch.search import extract_doc, SearchIndex, IndexVersionMismatch
 
 INDEX = 'claims'
 
@@ -63,8 +63,15 @@ async def consume(producer):
 async def make_es_index():
     env = Env(LBC)
     index = SearchIndex('', elastic_host=env.elastic_host, elastic_port=env.elastic_port)
+
     try:
         return await index.start()
+    except IndexVersionMismatch as err:
+        logging.info(
+            "dropping ES search index (version %s) for upgrade to version %s", err.got_version, err.expected_version
+        )
+        await index.delete_index()
+        return await index.start()
     finally:
         index.stop()