基于k8s的私有微服务方案落地

微服务

• 微服务架构，将应用程序构建为独立的组件，并将每个应用程序进程作为一项服务运行
• 这些服务使用轻量级 API 通过明确定义的接口进行通信
• 由于它们是独立运行的，因此可以针对各项服务进行更新、部署和扩展，以满足对应用程序特定功能的需求

背景

• 传统的物理部署，运维起来相对繁琐，且环境难以维护
• 单容器部署，难以保证并发性能
• 容器集群化+自动扩容，可以解决上面两个问题，但是最少会有一个容器运行，对资源会有一定浪费
• 容器集群化+自动扩容+微服务，解决了资源成本问题，在我们需要时按需启动容器

方案fission落地serverless

• 项目地址

快速

• 100msec冷启动
• Fission 维护着一个“暖”容器池，每个容器都包含一个小的动态加载器。当一个函数第一次被调用时，即“冷启动”，一个正在运行的容器被选择并加载该函数。这个池是使 Fission 快速的原因：冷启动延迟通常约为 100 毫秒
• 函数即服务

基于Kubernetes

• 基本所有的运行都以k8s运行

多语言

• Fission 目前支持 NodeJS、Python、Ruby、Go、PHP、Bash 和任何 Linux 可执行文件

安装serverless集群服务

请确保你已经部署了k8s集群，集群的部署请参考

安装

• 拉取部署文件

# 下载1.13.1版本的yaml
[ ~ ] wget https://github.com/fission/fission/releases/download/1.13.1/fission-all-1.13.1.yaml 

• 修改pvc

apiVersion: v1
kind: PersistentVolume
metadata:
  name: fission-storage-pvc
  labels:
    type: local
spec:
  capacity:
    storage: 10Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  storageClassName: manual
  # 存储根据实际情况修改
  hostPath:
    path: "/home/g5/lijiacai/fission/data"

---
# Source: fission-all/templates/pvc.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: fission-storage-pvc
  labels:
    app: fission-storage
    chart: "fission-all-1.13.1"
    release: "fission-1-13-1"
spec:
  storageClassName: manual
  volumeName: fission-storage-pvc
  accessModes:
    - "ReadWriteOnce"
  resources:
    requests:
      storage: "8Gi"
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: fission-alertmanager
  labels:
    type: local
spec:
  capacity:
    storage: 3Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  storageClassName: manual
  # 存储根据实际情况修改
  hostPath:
    path: "/home/g5/lijiacai/fission/alertmanager"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  labels:
    component: "alertmanager"
    app: prometheus
    release: fission-1-13-1
    chart: prometheus-13.2.1
    heritage: Helm
  name: fission-1-13-1-prometheus-alertmanager
  namespace: fission
spec:
  storageClassName: manual
  volumeName: fission-alertmanager
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: "2Gi"
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: fission-prometheus-server
  labels:
    type: local
spec:
  capacity:
    storage: 10Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  storageClassName: manual
  # 存储根据实际情况修改
  hostPath:
    path: "/home/g5/lijiacai/fission/prometheusserver"
---
# Source: fission-all/charts/prometheus/templates/server/pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  labels:
    component: "server"
    app: prometheus
    release: fission-1-13-1
    chart: prometheus-13.2.1
    heritage: Helm
  name: fission-1-13-1-prometheus-server
  namespace: fission
spec:
  storageClassName: manual
  volumeName: fission-prometheus-server
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: "8Gi"

• 部署

[ ~ ]# kubectl apply -f .

fission客户端安装

[ ~ ]# curl -Lo fission https://github.com/fission/fission/releases/download/1.13.1/fission-1.13.1-darwin-amd64
[ ~ ]# chmod +x fission && sudo mv fission /usr/local/bin/
[ ~ ]# fisson version
client:
  fission/core:
    BuildDate: "2021-06-21T10:38:48Z"
    GitCommit: d06ad04341377bec6b8c905a440956b7d659d8fb
    Version: 1.13.1
server:
  fission/core:
    BuildDate: "2021-06-21T09:13:11Z"
    GitCommit: 401cbd597b63f5646e3e4be7df38870fdd617485
    Version: 1.13.1

部署效果

初体验微服务（文档）

ENVIRONMENT	IMAGE
NodeJS (Alpine)	fission/node-env
NodeJS (Debian)	fission/node-env-debian
Python 3	fission/python-env
Python 2.7	fission/python-env-27
Go	fission/go-env
Ruby	fission/ruby-env
Binary (for executables or scripts)	fission/binary-env
.NET	fission/dotnet-env
.NET 2.0	fission/dotnet20-env
Perl	fission/perl-env
PHP 7	fission/php-env

hello体验(单文件)

• 创建一个运行环境

# 新建一个环境，镜像使用官方内置的python镜像
[ ~ ]# fission environment create --name python --image fission/python-env 
# fission/python-env 可以根据需求自定义镜像

• 编写运行函数hello.py

def main():
    return "Hello, world!"

• 创建一个函数

# --env python为上一步骤中创建的环境
[ ~ ]# fission function create --name hello --env python --code hello.py 

• 函数测试

[ ~ ]# fission function test --name hello
Hello, world!

• 暴露http接口

[ ~ ]# fission route create --url /hello --function hello --method GET
[ ~ ]# kubectl get svc router -n fission
NAME     TYPE           CLUSTER-IP    EXTERNAL-IP   PORT(S)        AGE
router   LoadBalancer   10.43.50.10                 80:31188/TCP   43h
[ ~ ]# curl http://localhost:31188/hello
hello, world!

hello world体验（多文件）

• 创建一个运行环境

# --builder 允许以包的形式创建函数，并支持编译，安装依赖
[ ~ ]# fission env create --name pythonbuilder --image fission/python-env --builder fission/python-builder --mincpu 40 --maxcpu 80 --minmemory 64 --maxmemory 128 --poolsize 4 
# --mincpu 40 --maxcpu 80 --minmemory 64 --maxmemory 128 --poolsize 4  扩容参数

• 编写运行函数pkg/world.py

def world():
    return "world"

• 编写运行函数pkg/hello.py

from world import world
def main():
    return "Hello " + world()

• 打包代码

[ ~ ]# zip -jr demo-src-pkg.zip pkg/

• 代码包上传至fission库

[ ~ ]# fission package create --sourcearchive demo-src-pkg.zip --env pythonbuilder
Package 'demo-src-pkg-zip-hnwm' created
[ ~ ]# fission package info --name demo-src-pkg-zip-hnwm
Name:        demo-src-pkg-zip-hnwm
Environment: pythonbuilder
Status:      succeeded
Build Logs:
+ '[' -f /packages/demo-src-pkg-zip-hnwm-fxg0n4/requirements.txt ]
+ cp -r /packages/demo-src-pkg-zip-hnwm-fxg0n4 /packages/demo-src-pkg-zip-hnwm-fxg0n4-6j7zf7

• 创建函数

[ ~ ]# fission fn create --name theyourszero --pkg demo-src-pkg-zip-hnwm --entrypoint "hello.main" --executortype poolmgr
# --executortype poolmgr 有容器缓冲池，访问延迟较低
# --executortype newdeploy 延迟较高，冷启动问题比较明显，但是资源成本控制了

• 创建http

[ ~ ]# fission route create --url /theyourszero --function theyourszero --method GET

• 压测
  • 压测前
    
  • 压测

[ ~ ]# hey -c 250 -n 10000 http://127.0.0.1:31188/theyourszero
Summary:
  Total:        7.8584 secs
  Slowest:      4.1861 secs
  Fastest:      0.0678 secs
  Average:      0.1953 secs
  Requests/sec: 1272.5231
  
  Total data:   40000 bytes
  Size/request: 4 bytes

Response time histogram:
  0.068 [1]     |
  0.480 [9749]  |■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  0.891 [0]     |
  1.303 [0]     |
  1.715 [0]     |
  2.127 [0]     |
  2.539 [0]     |
  2.951 [0]     |
  3.362 [0]     |
  3.774 [0]     |
  4.186 [250]   |■


Latency distribution:
  10% in 0.0882 secs
  25% in 0.0898 secs
  50% in 0.0939 secs
  75% in 0.0984 secs
  90% in 0.1063 secs
  95% in 0.1078 secs
  99% in 4.1340 secs

Details (average, fastest, slowest):
  DNS+dialup:   0.0012 secs, 0.0678 secs, 4.1861 secs
  DNS-lookup:   0.0000 secs, 0.0000 secs, 0.0000 secs
  req write:    0.0000 secs, 0.0000 secs, 0.0076 secs
  resp wait:    0.1939 secs, 0.0677 secs, 4.1264 secs
  resp read:    0.0000 secs, 0.0000 secs, 0.0052 secs

Status code distribution:
  [200] 10000 responses

- 压测后

fission-function展示

原理剖析请参考