metropolis: first pass API for reconfiguring cluster
This implements management.ConfigureCluster. This API is based around
Protobuf FieldMasks, which is a new thing in the Metropolis codebase
(node config mutation is performed via optional fields).
Whether this is the right way to do this is to be discussed.
Alternatives considered are:
1. Always insert a full new config, providing the old one as a base. The
downside of that is the potential conflicts that will spring up the
moment we have systems regularly mutate independent parts of the
config. Additionally, this might lead to some odd behaviour when
dealing with clients that don't have support for newer versions of
the config proto.
2. Use optional fields, like in Node role code. However, this has the
downside of duplicating protos (one for the config state, one for the
mutation request). Plus, protobuf optionals are still somewhat
unusual.
3. Provide individual requests for mutating fields (like with Node
labels). This also results in a lot of boilerplate code.
4. Something akin to JSON Patch, but for protobufs, which doesn't seem
to exist.
Change-Id: I42e5eabd42076e947f4bc8399b843e0e1fd48548
Reviewed-on: https://review.monogon.dev/c/monogon/+/3591
Tested-by: Jenkins CI
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
diff --git a/metropolis/proto/api/BUILD.bazel b/metropolis/proto/api/BUILD.bazel
index f90885a..294dcb8 100644
--- a/metropolis/proto/api/BUILD.bazel
+++ b/metropolis/proto/api/BUILD.bazel
@@ -17,6 +17,7 @@
"//osbase/logtree/proto:proto_proto",
"//osbase/net/proto:net_proto_proto",
"@protobuf//:duration_proto",
+ "@protobuf//:field_mask_proto",
],
)