前言
本文主要讲如何把drone部署到k8s集群当中，本身drone这种基于容 器的pipeline方式，和k8s是相当契合的。这样的好处有：
- k8s集群守护drone-server 和drone-agent。
- 可以利用rpc特性，根据agent负载压力来动态调整agent的数量。当然即使不动态调整，我们手动调整一下复制集的数目也是相当简单的。
- 部署到k8s集群以后，可以利用k8s已有的日志系统和监控系统。
其实在接下来的文章系列中，我们会不断侧重于k8s相关。依旧是直接先上yaml文件，先来一个直观的感受。
相关yaml文件
ConfigMap在此处可以理解为drone应用的配置文件。这里有关于server和agent一系列设置。不过在k8s中大家需要注意的是：更新configmap以后，对于挂载该configmap的应用，配置内容并不能立即生效，大约需要10s。
apiVersion: v1
kind: ConfigMap
metadata:
name: drone-config
namespace: devops
data:
#######################
# Drone Server Config #
####################### # server host name
server.host: drone.xxx.com
# start the server in debug mode
server.debug: "false" # open user registration
server.open: "true" # database driver, defaul as sqlite3
server.database.driver: sqlite3
# database driver configuration string
server.database.datasource: drone.sqlite
# remote parameters (Gogs)
server.remote.gogs: "true"
server.remote.gogs.url: "http://gogs.xxx.com"
server.remote.gogs.private.mode: "true" ######################
# Drone Agent Config #
######################
agent.debug: "false"
agent.debug.pretty: "false"
agent.max.procs: "1"
agent.healthcheck: "true"
Secret文件，主要是存放一些秘钥之类的。不过这里也是有坑的，这个secret用于server和angent通信，设置不对就会构建项目一直处于pending状态。切记k8s中，secret需要base64。
echo -n "yourpassword" | base64
eW91cnBhc3N3b3Jk
apiVersion: v1 kind: Secret metadata: name: drone-secrets namespace: devops data: server.secret: eW91cnBhc3N3b3Jk
接下来就是drone-server的Deployment和Service和Ingress。此处为了简单，用了sqlite数据库，真正生产环境建议用mysql或是pgsql。即使用sqlite，也应该挂载到ceph中，保证数据的安全。这里直接hostpath。k8s中，应该做到存储和计算的分离。
apiVersion: extensions/v1beta1 kind: Deployment metadata: name: drone-server namespace: devops spec: replicas: 1 template: metadata: labels: app: drone-server spec: nodeSelector: net-type: external containers: - image: drone/drone:latest imagePullPolicy: Always name: drone-server ports: - containerPort: 8000 protocol: TCP - containerPort: 9000 protocol: TCP volumeMounts: # Persist our configs in an SQLite DB in here - name: drone-server-sqlite-db mountPath: /var/lib/drone resources: requests: cpu: 40m memory: 32Mi env: - name: DRONE_HOST valueFrom: configMapKeyRef: name: drone-config key: server.host - name: DRONE_OPEN valueFrom: configMapKeyRef: name: drone-config key: server.open - name: DRONE_DATABASE_DRIVER valueFrom: configMapKeyRef: name: drone-config key: server.database.driver - name: DRONE_DATABASE_DATASOURCE valueFrom: configMapKeyRef: name: drone-config key: server.database.datasource - name: DRONE_SECRET valueFrom: secretKeyRef: name: drone-secrets key: server.secret - name: DRONE_GOGS valueFrom: configMapKeyRef: name: drone-config key: server.remote.gogs - name: DRONE_GOGS_URL valueFrom: configMapKeyRef: name: drone-config key: server.remote.gogs.url - name: DRONE_GOGS_PRIVATE_MODE valueFrom: configMapKeyRef: name: drone-config key: server.remote.gogs.private.mode - name: DRONE_DEBUG valueFrom: configMapKeyRef: name: drone-config key: server.debug volumes: - name: drone-server-sqlite-db hostPath: path: /var/lib/drone
apiVersion: v1 kind: Service metadata: name: drone-service namespace: devops spec: ports: - name: http protocol: TCP port: 80 targetPort: 8000 - name: grpc protocol: TCP port: 9000 targetPort: 9000 selector: app: drone-server
apiVersion: extensions/v1beta1 kind: Ingress metadata: name: drone-ingress namespace: devops spec: rules: - host: drone.xxx.com http: paths: - backend: serviceName: drone-service servicePort: 80 path: /
下面就是agent的部署文件了，replicas: 1 该项可以设置agent的数量，扩容起来特别方便。server和agent通过grpc的方式进行通信，主要端口是9000。
apiVersion: extensions/v1beta1 kind: Deployment metadata: name: drone-agent namespace: devops spec: replicas: 1 template: metadata: labels: app: drone-agent spec: nodeSelector: net-type: external containers: - image: drone/agent:latest imagePullPolicy: Always name: drone-agent volumeMounts: # Enables Docker in Docker - name: docker-socket mountPath: /var/run/docker.sock resources: requests: cpu: 100m memory: 64Mi livenessProbe: httpGet: path: /healthz port: 3000 initialDelaySeconds: 3 periodSeconds: 3 env: - name: DRONE_SERVER value: drone-service:9000 # issue: https://github.com/drone/drone/issues/2048 - name: DOCKER_API_VERSION value: "1.24" - name: DRONE_SECRET valueFrom: secretKeyRef: name: drone-secrets key: server.secret volumes: - name: docker-socket hostPath: path: /var/run/docker.sock
所有都部署到devops命名空间下，这个namespace已经建好了。当然如果没有的话，需要提前创建。
效果图
![9baa5eeebecf40e1194d629b1eff6cb77a268e9c]()
总结
项目github地址，这里有该系列的所有文件。
本文转自中文社区-k8s与CICD--将drone部署到kubernetes中，实现agent动态收缩
