部署服务 · Docker 学习

# 部署服务我们使用 `docker service` 命令来管理 `Swarm` 集群中的服务，该命令只能在管理节点运行。 ## 新建服务现在我们在上一节创建的 `Swarm` 集群中运行一个名为 `nginx` 服务。 ```bash $ docker service create --replicas 3 -p 80:80 --name nginx nginx:1.13.7-alpine ``` 现在我们使用浏览器，输入任意节点 IP ，即可看到 nginx 默认页面。 ## 查看服务使用 `docker service ls` 来查看当前 `Swarm` 集群运行的服务。 ```bash $ docker service ls ID NAME MODE REPLICAS IMAGE PORTS kc57xffvhul5 nginx replicated 3/3 nginx:1.13.7-alpine *:80->80/tcp ``` 使用 `docker service ps` 来查看某个服务的详情。 ```bash $ docker service ps nginx ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS pjfzd39buzlt nginx.1 nginx:1.13.7-alpine swarm2 Running Running about a minute ago hy9eeivdxlaa nginx.2 nginx:1.13.7-alpine swarm1 Running Running about a minute ago 36wmpiv7gmfo nginx.3 nginx:1.13.7-alpine swarm3 Running Running about a minute ago ``` 使用 `docker service logs` 来查看某个服务的日志。 ```bash $ docker service logs nginx nginx.3.36wmpiv7gmfo@swarm3 | 10.255.0.4 - - [25/Nov/2017:02:10:30 +0000] "GET / HTTP/1.1" 200 612 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:58.0) Gecko/20100101 Firefox/58.0" "-" nginx.3.36wmpiv7gmfo@swarm3 | 10.255.0.4 - - [25/Nov/2017:02:10:30 +0000] "GET /favicon.ico HTTP/1.1" 404 169 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:58.0) Gecko/20100101 Firefox/58.0" "-" nginx.3.36wmpiv7gmfo@swarm3 | 2017/11/25 02:10:30 [error] 5#5: *1 open() "/usr/share/nginx/html/favicon.ico" failed (2: No such file or directory), client: 10.255.0.4, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "192.168.99.102" nginx.1.pjfzd39buzlt@swarm2 | 10.255.0.2 - - [25/Nov/2017:02:10:26 +0000] "GET / HTTP/1.1" 200 612 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:58.0) Gecko/20100101 Firefox/58.0" "-" nginx.1.pjfzd39buzlt@swarm2 | 10.255.0.2 - - [25/Nov/2017:02:10:27 +0000] "GET /favicon.ico HTTP/1.1" 404 169 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:58.0) Gecko/20100101 Firefox/58.0" "-" nginx.1.pjfzd39buzlt@swarm2 | 2017/11/25 02:10:27 [error] 5#5: *1 open() "/usr/share/nginx/html/favicon.ico" failed (2: No such file or directory), client: 10.255.0.2, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "192.168.99.101" ``` ## 服务伸缩我们可以使用 `docker service scale` 对一个服务运行的容器数量进行伸缩。当业务处于高峰期时，我们需要扩展服务运行的容器数量。 ```bash $ docker service scale nginx=5 ``` 当业务平稳时，我们需要减少服务运行的容器数量。 ```bash $ docker service scale nginx=2 ``` ## 删除服务使用 `docker service rm` 来从 `Swarm` 集群移除某个服务。 ```bash $ docker service rm nginx ```