Easegress

What is Easegress
Features
User Cases
Getting Started
Documentation
Roadmap
Community
License
原文链接

What is Easegress

Easegress is a Cloud Native traffic orchestration system designed for:

High Availability: Built-in Raft consensus & leader election provides 99.99% availability.
Traffic Orchestration: Simple orchestration of various filters for each traffic pipeline.
High Performance: Lightweight and essential features speed up the performance.
Observability: There are many meaningful statistics periodically in a readable way.
Extensibility: It’s easy to develop your own filter or controller with high-level programming language.
Integration: The simple interfaces make it easy to integrate with other systems, such as Kubernetes Ingress, EaseMesh sidecar, Workflow, etc.

The architecture of Easegress:

Features

Service Management
- Multiple protocols:
  - HTTP/1.1
  - HTTP/2
  - HTTP/3(QUIC)
  - MQTT
- Rich Routing Rules: exact path, path prefix, regular expression of the path, method, headers.
- Resilience&Fault Tolerance
  - Circuit breaker: temporarily blocks possible failures.
  - Rate limiter: limits the rate of incoming requests.
  - Retryer: repeats failed executions.
  - Time limiter: limits the duration of execution.
- Deployment Management
  - Blue-green Strategy: switches traffic at one time.
  - Canary Strategy: schedules traffic slightly.
- API Management
  - API Aggregation: aggregates results of multiple APIs.
  - API Orchestration: orchestrates the flow of APIs.
- Security
  - IP Filter: Limits access to IP addresses.
  - Static HTTPS: static certificate files.
  - API Signature: supports HMAC verification.
  - JWT Verification: verifies JWT Token.
  - OAuth2: validates OAuth/2 requests.
  - Let’s Encrypt: automatically manage certificate files.
- Pipeline-Filter Mechanism
  - Chain of Responsibility Pattern: orchestrates filters chain.
  - Filter Management: makes it easy to develop new filters.
- Service Mesh
  - Mesh Master: is the control plane to manage the lifecycle of mesh services.
  - Mesh Sidecar: is the data plane as the endpoint to do traffic interception and routing.
  - Mesh Ingress Controller: is the mesh-specific ingress controller to route external traffic to mesh services.Notes: This feature is leveraged by EaseMesh
- Third-Part Integration
  - FaaS integrates with the serverless platform Knative.
  - Service Discovery integrates with Eureka, Consul, Etcd, and Zookeeper.
  - Ingress Controller integrates with Kubernetes as an ingress controller.
Extensibility
- WebAssembly executes user developed WebAssembly code.
High Performance and Availability
- Adaption: adapts request, response in the handling chain.
- Validation: headers validation, OAuth2, JWT, and HMAC verification.
- Load Balance: round-robin, random, weighted random, ip hash, header hash.
- Cache: for the backend servers.
- Compression: compresses body for the response.
- Hot-Update: updates both config and binary of Easegress in place without losing connections.
Operation
- Easy to Integrate: command line(egctl), MegaEase Portal, HTTP clients such as curl, postman, etc.
- Distributed Tracing
  - Built-in Open Zipkin
  - Open Tracing for vendor-neutral APIs
- Observability
  - Node: role(leader, writer, reader), health or not, last heartbeat time, and so on
  - Traffic: in multi-dimension: server and backend.
    - Throughput: total and error statistics of request count, TPS/m1, m5, m15, and error percent, etc.
    - Latency: p25, p50, p75, p95, p98, p99, p999.
    - Data Size: request and response size.
    - Status Codes: HTTP status codes.
    - TopN: sorted by aggregated APIs(only in server dimension).
      User Cases
      The following examples show how to use Easegress for different scenarios.
API Aggregator - Aggregating many APIs into a single API.
Distributed Tracing - How to do APM tracing - Zipkin.
FaaS - Supporting Knative FaaS integration
Flash Sale - How to do high concurrent promotion sales with Easegress
Kubernetes Ingress Controller - How to integrated with Kubernetes as ingress controller
LoadBalancer - A number of strategy of load balancing
MQTTProxy - An Example to MQTT proxy with Kafka backend.
Performance - Performance optimization - compression, caching etc.
Pipeline - How to orchestrate HTTP filters for requests/responses handling
Resilience and Fault Tolerance - Circuit Breaker, Rate Lmiter, Retryer, Time limiter, etc. (Porting from Java resilience4j)
Security - How to do authenication by Header, JWT, HMAC, OAuth2, etc.
Service Proxy - Supporting the Microservice registries - Zookeeper, Eureka, Consul, Nacos, etc.
WebAssembly - Using AssemblyScript to extend the Easegress
Workflow - An Example to make a workflow for a number of APIs.

For full list, see Cookbook.

Getting Started

The basic common usage of Easegress is to quickly set up proxy for the backend servers. We split it into multiple simple steps to illustrate the essential concepts and operations.

Setting up Easegress

We can download the latest or history binaries from the release page. For example, we can install Easegress v1.0.0 for Linux amd64 platform with command:

$ mkdir easegress
$ wget https://github.com/megaease/easegress/releases/download/v1.0.0/easegress-v1.0.0-linux-amd64.tar.gz
$ tar zxvf easegress-v1.0.0-linux-amd64.tar.gz -C easegress && cd easegress

or if we can install Easegress from source code:

$ git clone https://github.com/megaease/easegress && cd easegress
$ make

Then we can add the binary directory to the PATH and execute the server:

$ export PATH=${PATH}:$(pwd)/bin/
$ easegress-server
2021-05-17T16:45:38.185+08:00    INFO    cluster/config.go:84    etcd config: init-cluster:eg-default-name=http://localhost:2380 cluster-state:new force-new-cluster:false
2021-05-17T16:45:38.185+08:00    INFO    cluster/cluster.go:379    client is ready
2021-05-17T16:45:39.189+08:00    INFO    cluster/cluster.go:590    server is ready
2021-05-17T16:45:39.21+08:00    INFO    cluster/cluster.go:451    lease is ready
2021-05-17T16:45:39.231+08:00    INFO    cluster/cluster.go:187    cluster is ready
2021-05-17T16:45:39.253+08:00    INFO    supervisor/supervisor.go:180    create system controller StatusSyncController
2021-05-17T16:45:39.253+08:00    INFO    cluster/cluster.go:496    session is ready
2021-05-17T16:45:39.253+08:00    INFO    api/api.go:96    api server running in localhost:2381
2021-05-17T16:45:44.235+08:00    INFO    cluster/member.go:210    self ID changed from 0 to 689e371e88f78b6a
2021-05-17T16:45:44.236+08:00    INFO    cluster/member.go:137    store clusterMembers: eg-default-name(689e371e88f78b6a)=http://localhost:2380
2021-05-17T16:45:44.236+08:00    INFO    cluster/member.go:138    store knownMembers  : eg-default-name(689e371e88f78b6a)=http://localhost:2380

The default target of Makefile is to compile two binary into the directory bin/. bin/easegress-server is the server-side binary, bin/egctl is the client-side binary. We could add it to the $PATH for simplifying the following commands.

We could run easegress-server without specifying any arguments, which launch itself by opening default ports 2379, 2380, 2381. Of course, we can change them in the config file or command arguments that are explained well in easegress-server --help.

$ egctl member list
- options:
    name: eg-default-name
    labels: {}
    cluster-name: eg-cluster-default-name
    cluster-role: writer
    cluster-request-timeout: 10s
    cluster-listen-client-urls:
    - http://127.0.0.1:2379
    cluster-listen-peer-urls:
    - http://127.0.0.1:2380
    cluster-advertise-client-urls:
    - http://127.0.0.1:2379
    cluster-initial-advertise-peer-urls:
    - http://127.0.0.1:2380
    cluster-join-urls: []
    api-addr: localhost:2381
    debug: false
    home-dir: ./
    data-dir: data
    wal-dir: ""
    log-dir: log
    member-dir: member
    cpu-profile-file: ""
    memory-profile-file: ""
  lastHeartbeatTime: "2021-05-05T15:43:27+08:00"
  etcd:
    id: a30c34bf7ec77546
    startTime: "2021-05-05T15:42:37+08:00"
    state: Leader

After launched successfully, we could check the status of the one-node cluster. It shows the static options and dynamic status of heartbeat and etcd.

Create an HTTPServer and Pipeline

Now let’s create an HTTPServer listening on port 10080 to handle the HTTP traffic.

$ echo '
kind: HTTPServer
name: server-demo
port: 10080
keepAlive: true
https: false
rules:
  - paths:
    - pathPrefix: /pipeline
      backend: pipeline-demo' | egctl object create

The rules of routers above mean that it will lead the traffic with the prefix /pipeline to the pipeline pipeline-demo, which will be created below. If we curl it before created, it will return 503.

$ echo '
name: pipeline-demo
kind: HTTPPipeline
flow:
  - filter: proxy
filters:
  - name: proxy
    kind: Proxy
    mainPool:
      servers:
      - url: http://127.0.0.1:9095
      - url: http://127.0.0.1:9096
      - url: http://127.0.0.1:9097
      loadBalance:
        policy: roundRobin' | egctl object create

The pipeline means it will do proxy for 3 backend endpoints in load balance policy roundRobin.

Test

Now you can use some HTTP clients such as curl to test the feature:

$ curl -v http://127.0.0.1:10080/pipeline

If you are not set up some applications to handle the 9095, 9096, and 9097 in the localhost, it will return 503 too. We prepare a simple service to let us test handily, the example shows:

$ go run example/backend-service/mirror/mirror.go & # Running in background
$ curl http://127.0.0.1:10080/pipeline -d 'Hello, Easegress'
Your Request
===============
Method: POST
URL   : /pipeline
Header: map[Accept:[*/*] Accept-Encoding:[gzip] Content-Type:[application/x-www-form-urlencoded] User-Agent:[curl/7.64.1]]
Body  : Hello, Easegress

More Filters

Now we want to add more features to the pipeline, then we could add kinds of filters to the pipeline. For example, we want validation and request adaptation for the pipeline-demo.

$ cat pipeline-demo.yaml
name: pipeline-demo
kind: HTTPPipeline
flow:
  - filter: validator
    jumpIf: { invalid: END }
  - filter: requestAdaptor
  - filter: proxy
filters:
  - name: validator
    kind: Validator
    headers:
      Content-Type:
        values:
        - application/json
  - name: requestAdaptor
    kind: RequestAdaptor
    header:
      set:
        X-Adapt-Key: goodplan
  - name: proxy
    kind: Proxy
    mainPool:
      servers:
      - url: http://127.0.0.1:9095
      - url: http://127.0.0.1:9096
      - url: http://127.0.0.1:9097
      loadBalance:
        policy: roundRobin
$ egctl object update -f pipeline-demo.yaml

After updating the pipeline, the original curl -v http://127.0.0.1:10080/pipeline will get 400 because of the validating. So we changed it to satisfy the limitation:

$ curl http://127.0.0.1:10080/pipeline -H 'Content-Type: application/json' -d '{"message": "Hello, Easegress"}'
Your Request
===============
Method: POST
URL   : /pipeline
Header: map[Accept:[*/*] Accept-Encoding:[gzip] Content-Type:[application/json] User-Agent:[curl/7.64.1] X-Adapt-Key:[goodplan]]
Body  : {"message": "Hello, Easegress"}

We can also see Easegress send one more header X-Adapt-Key: goodplan to the mirror service.

Documentation

See reference and developer guide for more information.

Roadmap

See Easegress Roadmap for details.

Community

Join Slack Workspace for requirement, issue and development.
MegaEase on Twitter

License

Easegress is under the Apache 2.0 license. See the LICENSE file for details.

原文链接

https://github.com/megaease/easegress/blob/main/README.md