## This PR
Introduce flag sync capability to flagd as discussed at [1] and fixes
https://github.com/open-feature/flagd/issues/1230 .
**What's changed ?**
The change included with this PR introduces the gRPC sync contract [2].
This allows flagd to expose its store to in-process provider which
consumes gRPC flag stream.
**How to use ?**
flagd will start sync service on port `8015`. You can alter the default
sync port by providing desired port to the startup flag `syncPort`
(`--sync-port=8686`)
**Implementation details**
- Sync service startup is delayed to allow configured flag sources to
complete their initial loading (dealy is 5 seconds)
- Sync request's `selector` can be used to specify the specific flag
source. If unset, all flags will be sent
- A new stream response will be created whenever there are updates from
flag sources
[1] - https://github.com/open-feature/flagd/discussions/1153
[2] -
https://github.com/open-feature/flagd-schemas/blob/main/protobuf/flagd/sync/v1/sync.proto
---------
Signed-off-by: Kavindu Dodanduwa <kavindudodanduwa@gmail.com>
Signed-off-by: Kavindu Dodanduwa <Kavindu-Dodan@users.noreply.github.com>
Co-authored-by: Michael Beemer <beeme1mr@users.noreply.github.com>
Co-authored-by: Todd Baert <todd.baert@dynatrace.com>
Kavindu Dodanduwa