Add Etcd v3 protocol support via api gRPC-gateway (#1162)

mirror of https://github.com/outbackdingo/patroni.git synced 2026-08-25 14:53:37 +00:00

The only python-etcd3 client working directly via gRPC still supports only a single endpoint, which is not very nice for high-availability.

Since Patroni is already using a heavily hacked version of python-etcd with smart retries and auto-discovery out-of-the-box, I decided to enhance the existing code with limited support of v3 protocol via gRPC-gateway.

Unfortunately, watches via gRPC-gateway requires us to open and keep the second connection to the etcd.

Known limitations:
* The very minimal supported version is 3.0.4. On earlier versions transactions don't work due to bugs in grpc-gateway. Without transactions we can't do atomic operations, i.e. leader locks.
* Watches work only starting from 3.1.0
* Authentication works only starting from 3.3.0
* gRPC-gateway does not support authentication using TLS Common Name. This is because gRPC-proxy terminates TLS from its client so all the clients share a cert of the proxy: https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/authentication.md#using-tls-common-name

This commit is contained in:

Alexander Kukushkin

2020-07-31 14:33:40 +02:00

committed by

GitHub

parent b3c69b5fb2

commit 3341c898ff

20 changed files with 1271 additions and 125 deletions

									
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				@@ -14,7 +14,7 @@ ARG PGDATA

				ARG LC_ALL

				ARG LANG

				ENV ETCDVERSION=2.3.8 CONFDVERSION=0.16.0

				ENV ETCDVERSION=3.3.13 CONFDVERSION=0.16.0

				RUN set -ex \

				    && export DEBIAN_FRONTEND=noninteractive \