1. 主旨介紹
使用mac和fusion vm兩臺主機搭建一個小的docker集羣, 採用docker swarm方式搭建. Swarm基本概念:
- manager:用來管理swarm服務
- node: docker enginer節點, 通過manager可以在node上操作, manager本身也是node
- worker: 非管理的node, 一般是實際部署和運行container的docker節點
目的是是探索使用swarm完成動態伸縮的可行性.
2. 操作步驟
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swarm init(vm中操作,因爲docker for mac有網絡問題 manager)
docker swarm init --advertise-addr 192.168.132.148 Swarm initialized: current node (b1uem2hg4y2ojnauvre3x2rdw) is now a manager. To add a worker to this swarm, run the following command: docker swarm join --token SWMTKN-1-1snrbxsenp4v1npcusox9l3n9jzsa4n8jbkvlhjc19e3z89c8a-7vfrbr1o1e1sr2g2r6f97xhne 192.168.132.148:2377 To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.初始化swarm之後可以使用docker node ls查看信息:
docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION b1uem2hg4y2ojnauvre3x2rdw * linuxkit-025000000001 Ready Active Leader 18.06.1-ce 18.06.1-ce -
join node(worker)
docker swarm join --token SWMTKN-1-3h1rzm2cdu6ms935f6kysy4rhzs54mqofnhr1thlwu0fiewqfq-9q6fwc7eqk70zwb1kwi2vdklj 192.168.132.148:2377 This node joined a swarm as a worker. -
deploy service 部署一個alpine容器, 運行ping命令視爲內部服務
docker service create --replicas 1 --name helloword alpine ping docker.com vyw5nezmiv37j3fk5kgu4231x overall progress: 1 out of 1 tasks 1/1: running [==================================================>]查看結果如下, 可以發現一個alpine被部署到worker節點(vm是manager機器名是unbuntu所以下面的linuxkit-xxxx是worker, 即mac server)
docker service ps helloword ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS ht9npghzzux9 helloword.1 alpine:latest linuxkit-025000000001 Running Running 4 minutes ago -
scale service 橫向擴展服務爲2個實例
docker service scale helloword=2 helloword scaled to 2 overall progress: 1 out of 2 tasks 1/2: running [==================================================>] overall progress: 2 out of 2 tasks 1/2: running [==================================================>] 2/2: running [==================================================>] verify: Service converged查看擴展的結果如下, 可以發現兩個實例被部署到worker和manager, 因爲worker不夠用, 所以使用了manager, 也可以設置manager只是管理, 不運行task
docker service ps helloword ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS ht9npghzzux9 helloword.1 alpine:latest linuxkit-025000000001 Running Running 5 minutes ago v0i6ghtx8eed helloword.2 alpine:latest ubuntu Running Running 26 seconds ago
3. 總結
使用swarm集羣可以優雅的進行docker部署和擴展, 結合docker-compose操作會更加方便, 如果增加了產線的流量監控+服務發現, 就可以實現產線環境的動態伸縮部署, 很棒!!
4. 問題和解答
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unavailable desc = all SubConns are in TransitentFailure
這個問題以爲manager是mac, docker for mac 因爲網絡的問題不能支持work去鏈接到mac docker swarm manager
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Error response from daemon: manager stopped: failed to listen on remote API address: listen tcp 10.0.1.34:2377: bind: cannot assign requested address
這是因爲指定了 --listen-addr和--advertise-addr ip一樣但是端口默認也是一直的, 去除listen-addr或者指定不同的端口即可
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結束swarm
在manager服務器運行: docker swarm leave --force, 這樣manager就變成inactive了, 可以重新操作執行init或者其他