hashicorp
- Consul
- vault

hashicorp

Consul

https://github.com/hashicorp/consul
Consul provides several key features:

Service Discovery - Consul makes it simple for services to register themselves and to discover other services via a DNS or HTTP interface. External services such as SaaS providers can be registered as well.
Health Checking - Health Checking enables Consul to quickly alert operators about any issues in a cluster. The integration with service discovery prevents routing traffic to unhealthy hosts and enables service level circuit breakers.
Service Segmentation/Service Mesh - Consul Connect enables secure service-to-service communication with automatic TLS encryption and identity-based authorization. Applications can use sidecar proxies in a service mesh configuration to establish TLS connections for inbound and outbound connections without being aware of Connect at all.
Key/Value Storage - A flexible key/value store enables storing dynamic configuration, feature flagging, coordination, leader election and more. The simple HTTP API makes it easy to use anywhere.
Multi-Datacenter - Consul is built to be datacenter aware, and can support any number of regions without complex configuration.

fabio

Consul + fabio 实现自动服务发现、负载均衡

======    服务注册     =========         =========
  A服务      <------>       consul集群  ---->  健康的 A/不健康的 A 集群
======    健康检查     =========         =========
                                            ^
                                            | 加入/移出路由表
                                            |
                                     ========
                                      fabio 集群
                                     ========
                                             |
                                             | A服务   如果找到则成功路由，否则返回错误
                                             V
                                         http 请求

consul-template

https://github.com/hashicorp/consul-template

Consul-Template是基于Consul的自动替换配置文件的应用(nginx)
动态的配置系统可以分化为Etcd+Confd和Consul+Consul-Template两大阵营。Consul-Template的定位和Confd差不多，Confd的后端可以是Etcd或者Consul。

confd

https://github.com/kelseyhightower/confd

confd supports the following backends:
etcd
consul
vault
environment variables
file
redis
zookeeper
dynamodb
rancher
ssm (AWS Simple Systems Manager Parameter Store)

vault