envoyproxy/envoy

Enable dynamic configuration for "xds-grpc" cluster

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#10,059 opened on Feb 14, 2020

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area/xdsdesign proposalhelp wanted

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Description

Description: In Envoy with Istio scenario, the back end xDS server Pilot is configured through "envoy_bootstrap_v2.json" like this:

{
        "name": "xds-grpc",
        "type": "STATIC",
        "dns_lookup_family": "V4_ONLY",
        "connect_timeout": "{{ .connect_timeout }}",
        "lb_policy": "RANDOM",
        ...
        "hosts": {{ .pilot_grpc_address_group }},
        ...
}

However, this is a static address and can't not be changed any longer. If we want to migrate the Pilot address to another, the Envoy has to reboot to reload the new Pilot address. I'm wandering if there is any way to dynamically change this address. Maybe by enabling configure file watching and reloading is a good practice.

Contributor guide

Research direction
Explore Envoy's configuration reload mechanism and how to support dynamic updates for static clusters, specifically the xds grpc cluster. Investigate the use of xDS for dynamic bootstrap.
Tech stack
cpp
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C++EnvoyxDS
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35