Istio

An open platform to connect, manage, and secure microservices.

• Introduction
• Istio authors
• Repositories
• Issue management
• Community and support

In addition, here are some other docs you may wish to read:

• Istio Working Groups - how we partition work in the project
• Contribution Guidelines - explains the process for contributing to the Istio code base
• Reviewing and Merging Pull Requests - explains the process we use to review code changes
• Istio Developer's Guide - explains how to setup and use an Istio development environment
• Project Conventions - describes the conventions we use within the code base
• Creating Fast and Lean Code - performance-oriented advice and guidelines for the code base

Introduction

Istio is an open platform for providing a uniform way to integrate
microservices, manage traffic flow across microservices, enforce policies
and aggregate telemetry data. Istio's control plane provides an abstraction
layer over the underlying cluster management platform, such as Kubernetes,
Mesos, etc.

Visit istio.io for in-depth information about using Istio.

Istio is composed of these components:

• Envoy - Sidecar proxies per microservice to handle ingress/egress traffic
  between services in the cluster and from a service to external
  services. The proxies form a secure microservice mesh providing a rich
  set of functions like discovery, rich layer-7 routing, circuit breakers,
  policy enforcement and telemetry recording/reporting
  functions.

  Note: The service mesh is not an overlay network. It
  simplifies and enhances how microservices in an application talk to each
  other over the network provided by the underlying platform.

• Mixer - Central component that is leveraged by the proxies and microservices
  to enforce policies such as ACLs, rate limits, quotas, authentication, request
  tracing and telemetry collection.

• Pilot - A component responsible for configuring the
  proxies at runtime.

• CA - A component responsible for cert issuance and rotation.

• Broker - A component implementing the open service broker API for Istio-based services. (Under development)

Istio currently supports Kubernetes, Consul, and Eureka-based environments. We plan support for additional platforms such as
Cloud Foundry, and Mesos in the near future.

Istio authors

Istio is an open source project with an active development community. The project was started
by teams from Google and IBM, in partnership with the Envoy team at Lyft.

Repositories

The Istio project is divided across a few GitHub repositories.

• istio/istio. This is the main repo that you are
  currently looking at. It hosts Istio's core components and also
  the sample programs and the various documents that govern the Istio open source
  project. It includes:

  • security. This directory contains security related code,
    including CA (Cert Authority), node agent, etc.
  • pilot. This directory
    contains platform-specific code to populate the
    abstract service model, dynamically reconfigure the proxies
    when the application topology changes, as well as translate
    routing rules into proxy specific configuration. The
    istioctl command line utility is also available in
    this directory.
  • mixer. This directory
    contains code to enforce various policies for traffic passing through the
    proxies, and collect telemetry data from proxies and services. There
    are plugins for interfacing with various cloud platforms, policy
    management services, and monitoring services.
  • broker. This directory
    contains code for Istio's implementation of the Open Service Broker API.

• istio/api. This repository defines
  component-level APIs and common configuration formats for the Istio platform.

• istio/mixerclient. Client libraries
  for Mixer's API.

• istio/proxy. The Istio proxy contains
  extensions to the Envoy proxy (in the form of
  Envoy filters), that allow the proxy to delegate policy enforcement
  decisions to Mixer.

Issue management

We use GitHub combined with ZenHub to track all of our bugs and feature requests. Each issue we track has a variety of metadata:

• Epic. An epic represents a feature area for Istio as a whole. Epics are fairly broad in scope and are basically product-level things.
  Each issue is ultimately part of an epic.

• Milestone. Each issue is assigned a milestone. This is 0.1, 0.2, 0.3, or 'Nebulous Future'. The milestone indicates when we
  think the issue should get addressed.

• Priority/Pipeline. Each issue has a priority which is represented by the Pipeline field within GitHub. Priority can be one of
  P0, P1, P2, or >P2. The priority indicates how important it is to address the issue within the milestone. P0 says that the
  milestone cannot be considered achieved if the issue isn't resolved.

We don't annotate issues with Releases; Milestones are used instead. We don't use GitHub projects at all, that
support is disabled for our organization.

Community and support

There are several communication channels available to get
support for Istio or to participate in its evolution.