Capgemini/Apollo

Handle scaling / replacing of nodes in conjunction with provisioning ansible / weave network addresses / config

Open

#355 opened on Jun 30, 2015

View on GitHub
 (2 comments) (0 reactions) (0 assignees)Python (725 stars) (109 forks)batch import
bughelp wantedthinking

Description

When adding nodes to the cluster we will run into problems with the way we assign the weave bridge address, and scaling. We need to think about the approach for this. Some options off the top of my head (but needs way more thought)

  • form a tigher integration with terraform to derive the values of the bridges / CIDR (possibly).
  • use a fact from the machine being provisioned which is dynamic / unique per host
  • use the backend service discovery (consul) to populate the values, where consul would hold the master state of the cluster at any point

We also need to handle if nodes are removed / replaced in the cluster, without screwing up the rest of the cluster configuration and breaking the weave network.

This is discussed over here - https://github.com/Capgemini/Apollo/pull/351#commitcomment-11938353 https://github.com/Capgemini/Apollo/pull/351 https://github.com/Capgemini/Apollo/pull/342

Contributor guide

Tech stack
pythondocker
Domain
infrastructuredevopscloud
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
5
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
unclear
Prerequisites
Apache Mesos basicsDocker containersWeave networkAnsible provisioning
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
15
Research direction
Investigate the linked PRs (#351, #342) and associated comments to understand the current network configuration and provisioning approach. Explore the three options: tighter Terraform integration, dynamic per host facts, or Consul based master state. Determine how node replacement and scaling can be handled without breaking the Weave network. Consider proposing a design document or prototype for further discussion.