Micro Platform

The micro platform is a complete runtime for building and managing microservices at scale. Where micro provides the fundamental building blocks and core essentials, the platform goes a step further and addresses every requirement for large scale distributed system deployments. Monitoring, distributed tracing, authentication, dynamic configuration, label based routing, etc, etc.

This repository provides a unified entry point for running the individual platform services.

Use the go-platform client to leverage the platform.

Platform Services

Platform Web Dashboards

Additional Services

There are a few other services that we support as part of the go-platform but haven't written backend services for. These are still vital for a microservice platform and we may build services for them later but there are very strong systems in the OSS world for them.

Go-platform Features

What's it even good for?

The Micro platform is useful for where you want to build a reliable globally distributed systems platform at scale. You would be in good company by doing so, with the likes of Google, Facebook, Amazon, Twitter, Uber, Hailo, etc, etc.

How does it work?

The go-platform is a client side interface for the fundamentals of a microservice platform. Each package connects to a platform service which handles that feature. Everything is an interface and pluggable which means you can choose how to architect your platform. Micro however provides a "platform" implementation backed by it's own services by default.

Each package can be used independently or integrated using go-micro client and handler wrappers.

Auth

Auth addresses authentication and authorization of services and users. The default implementation is Oauth2 with an additional policy engine coming soon. This is the best way to authenticate users and service to service calls using a centralised authority. Security is a first class citizen in a microservice platform.

Config

Config implements an interface for dynamic configuration. The config can be hierarchically loaded and merged from multiple sources e.g file, url, config service. It can and should also be namespaced so that environment specific config is loaded when running in dev, staging or production. The config interface is useful for business level configuration required by your services. It can be reloaded without needing to restart a service.

DB (experimental)

The DB interface is an experiment CRUD interface to simplify database access and management. The amount of CRUD boilerplate written and rewritten in a microservice world is immense. By offloading this to a backend service and using RPC, we eliminate much of that and speed up development. The platform implementation includes pluggable backends such as mysql, cassandra, elasticsearch and utilises the registry to lookup which nodes databases are assigned to.

This is purely experimental at this point based on some ideas from how Google, Facebook and Twitte do database management internally.

Discovery

Discovery provides a high level service discovery interface on top of the go-micro registry. It utilises the watcher to locally cache service records and also heartbeats to a discovery service. It's akin to the Netflix Eureka 2.0 architecture whereby we split the read and write layers of discovery into separate services.

Event

The event package provides a way to send platform events and essentially create an event stream and record of all that's happening in your microservice environment. On the backend an event service aggregates the records and allows you to subscribe to a specific set of events. An event driven architecture is a powerful concept in a microservice environment and must be addressed adequately. At scale it's essential for correlating events within a distributed system e.g provisioning of new services, change of dynamic config, logouts for customers, tracking notifications, alerts.

KV

KV represents a simple distributed key-value interface. It's useful for sharing small fast access bits of data amonst instances of a service. We provide three implementations currently. Memcached, redis and a consistently hashed in distributed in memory system.

Log

Log provides a structured logging interface which allows log messages to be tagged with key-value pairs. The default output plugin is file which allows many centralised logging systems to be used such as the ELK stack.

Monitor

The monitor provides a way to publish Status, Stats and Healtchecks to a monitoring service. Healthchecks are user defined checks that may be critical to a service e.g can access database, can sync from s3, etc. Monitoring in a distributed system is fundamentally different from the classic LAMP stack. In the old ways pings and tcp checks were regarded as enough, in a distributed system we require much more fine grained metrics and a monitoring service which can make sense of what failure means in this world.

Metrics

Metrics is an interface for instrumentation. We regard metrics as a superior form of observability in a distributed system over logging. Instrumentation is a great way to graph historic and realtime data which can be correlated and immediately understood. The metrics interface provides a way to create counters, gauges and histograms. We currently implement the statsd interface and offload to telegraf which provides an augmented statsd interface with labels.

Router

The router builds on the registry and selector to provide rate limiting, circuit breaking and global service load balancing. It implements the selector interface. Stats are recorded for every request and periodically published. A centralised routing service aggregates these metrics from all services in the environment and makes decisions about how to route requests. The routing service is not a proxy. Proxies are a weak form of load balancing, we prefer smart clients which retrieve a list of nodes from the router and make direct connections, this means if the routing service dies or misbehaves, clients can continue to make request independently.

Sync

Sync is an interface for distributed synchronisation. This provides an easy way to do leadership election and locking to serialise access to a resource. We expect there to be multiple copies of a service running to provide fault tolerance and scalability but it makes it much harder to deal with transactions or serialising access. The sync package provides a way to regain some of these semantics.

Trace

Trace is a client side interface for distributed tracing e.g dapper, zipkin, appdash. In a microservice world, a single request may fan out to 20-30 services. Failure may be non deterministic and difficult to track. Distributed tracing is a way of tracking the lifetime of a request. The interface utilises client and server wrappers to simplify using tracing.

Usage

$ platform
NAME:
   platform - A microservices platform

USAGE:
   platform [global options] command [command options] [arguments...]

VERSION:
   latest

COMMANDS:
   auth     Auth commands
   config   Config commands
   discovery    Discovery commands
   db       DB commands
   event    Event commands
   monitor  Monitor commands
   router   Router commands
   trace    Trace commands
   help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --server_name                                Name of the server. go.micro.srv.example [$MICRO_SERVER_NAME]
   --server_version                                 Version of the server. 1.1.0 [$MICRO_SERVER_VERSION]
   --server_id                                  Id of the server. Auto-generated if not specified [$MICRO_SERVER_ID]
   --server_address                                 Bind address for the server. 127.0.0.1:8080 [$MICRO_SERVER_ADDRESS]
   --server_advertise                               Used instead of the server_address when registering with discovery. 127.0.0.1:8080 [$MICRO_SERVER_ADVERTISE]
   --server_metadata [--server_metadata option --server_metadata option]    A list of key-value pairs defining metadata. version=1.0.0 [$MICRO_SERVER_METADATA]
   --broker                                     Broker for pub/sub. http, nats, rabbitmq [$MICRO_BROKER]
   --broker_address                                 Comma-separated list of broker addresses [$MICRO_BROKER_ADDRESS]
   --registry                                   Registry for discovery. memory, consul, etcd, kubernetes [$MICRO_REGISTRY]
   --registry_address                               Comma-separated list of registry addresses [$MICRO_REGISTRY_ADDRESS]
   --selector                                   Selector used to pick nodes for querying. random, roundrobin, blacklist [$MICRO_SELECTOR]
   --transport                                  Transport mechanism used; http, rabbitmq, nats [$MICRO_TRANSPORT]
   --transport_address                              Comma-separated list of transport addresses [$MICRO_TRANSPORT_ADDRESS]
   --database_url                               The database URL e.g root@tcp(127.0.0.1:3306)/database [$MICRO_DATABASE_URL]
   --register_ttl "0"                               Register TTL in seconds [$MICRO_REGISTER_TTL]
   --register_interval "0"                          Register interval in seconds [$MICRO_REGISTER_INTERVAL]
   --html_dir                                   The html directory for a web app [$MICRO_HTML_DIR]
   --help, -h                                   show help

Running a platform service

The platform consists of a number of services. They can be run in the following way. For example config srv.

$ platform --registry_address=192.168.99.100 --database_url="root@tcp(127.0.0.1:3306)/config" config srv
2016/03/15 21:04:26 Listening on [::]:62017
2016/03/15 21:04:26 Broker Listening on [::]:62018
2016/03/15 21:04:26 Registering node: go.micro.srv.config-803dcb2a-eaf1-11e5-806f-68a86d0d36b6

Running a platform web service

The platform web services are a visual frontend for the service backends. They can be run in the following way.

$ platform --registry_address=192.168.99.100 --html_dir=/path/to/trace-web/templates trace web
Listening on [::]:60576

Roadmap

• Micro {API, Web, CLI, SideCar} added with platform enhancements e.g auth, routing, etc
• Web services for each platform service
• CLI shortcuts for the platform
• Provisioning and dependency management