学习笔记
1. 装置要求
在开始之前，Dcoker Swarm 集群部署 机器须要满足以下几个条件：
- 虚构了3台机器，操作系统：Linux version 3.10.0-1127.el7.x86_64
- 硬件配置：CPU(s)-2；3GB或更多RAM;硬盘20G左右；
- 3台机器形成一个集群，机器之前网络互通；
- 集群能够拜访外网，用于拉取镜像
- 禁用swap分区
2. Swarm 的工作模式
2.1 集群调度图原理
swarm 集群由治理节点（manager）和工作节点（work node）形成。
2.2 Swarm集群调用架构图
docker 集群之间通过近程API实现通信（Remote API）
3. 环境筹备
- master节点 ： 192.168.11.99
- node1节点 ：192.168.11.131
- node2节点 ：192.168.11.130
## 1. 敞开防火墙$ systemctl stop firewalld### 敞开防火墙主动启动$ systemctl disable firewalld## 2. 敞开selinux### 2.1 批改配置文件永恒敞开selinux【重启失效】$ vi /etc/sysconfig/selinuxSELINUX=enforcing### 2.2 长期敞开selinux$ setenforce 0## 3. 别离设置设置主机名：$ hostnamectl set-hostname swarm-master$ hostnamectl set-hostname swarm-node1$ hostnamectl set-hostname swarm-node2### 3.1 查看hostname$ hostname## 4. 配置hosts文件$ cat >> /etc/hosts << EOF192.168.11.99 swarm-master192.168.11.130 swarm-node1192.168.11.131 swarm-node2EOF## 5. 安裝docker$ yum -y install docker### 5.1 docker服务启动$ systemctl enable docker && systemctl start docker4.创立Swarm并增加节点
# Swarm-master 虚拟机操作## 1. 创立Swarm集群(记录token)[root@localhost vagrant]# docker swarm init --advertise-addr 192.168.11.99 Swarm initialized: current node (6jir7f507ur05lrhtc2xq8plt) is now a manager. To add a worker to this swarm, run the following command: # 这就是增加节点的形式(要保留初始化后token，因为在节点退出时要应用token作为通信的密钥) docker swarm join --token SWMTKN-1-30sw7z3qrh3gs0pi5fmllypw0c5dxrnpzf2uwd5nldcifzzroh-0l4pkovtgy708qs5pn5v8rzsk 192.168.11.99:2377 To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions. ## 2. 查看集群的相干信息[root@localhost vagrant]# docker info | grep swarm WARNING: You're not using the default seccomp profile WARNING: bridge-nf-call-ip6tables is disabled Name: swarm-master### 2.1 查看节点信息[root@localhost vagrant]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 6jir7f507ur05lrhtc2xq8plt * swarm-master Ready Active Leader # Swarm-node 虚拟机## 3. 退出的集群### 3.1 Swarm-node1 节点退出到集群[root@localhost vagrant]# docker swarm join --token SWMTKN-1-30sw7z3qrh3gs0pi5fmllypw0c5dxrnpzf2uwd5nldcifzzroh-0l4pkovtgy708qs5pn5v8rzsk 192.168.11.99:2377 This node joined a swarm as a worker.### 3.2 Swarm-node2 节点退出到集群[root@localhost vagrant]# docker swarm join --token SWMTKN-1-30sw7z3qrh3gs0pi5fmllypw0c5dxrnpzf2uwd5nldcifzzroh-0l4pkovtgy708qs5pn5v8rzsk 192.168.11.99:2377 This node joined a swarm as a worker.## 4.查看集群节点状态[root@localhost vagrant]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 6jir7f507ur05lrhtc2xq8plt * swarm-master Ready Active Leader qt9ja2qbmq4n040y60g6xbdlz swarm-node2 Ready Active scnyaecep2d1eiccvubusykww swarm-node1 Ready Active5. Swarm 罕用操作
更改节点的availablity状态
swarm集群中node的availability状态能够为 active或者drain，其中：
active状态下，node能够承受来自manager节点的工作分派；
drain状态下，node节点会完结task，且不再承受来自manager节点的工作分派（也就是下线节点）
## 1.删除节点 [root@localhost vagrant]# docker node rm --force swarm-node1 swarm-node1 [root@localhost vagrant]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 6jir7f507ur05lrhtc2xq8plt * swarm-master Ready Active Leader qt9ja2qbmq4n040y60g6xbdlz swarm-node2 Ready Active ## 2. 更新状态[root@localhost vagrant]# docker node update --availability drain swarm-node1 swarm-node1 [root@localhost vagrant]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 6jir7f507ur05lrhtc2xq8plt * swarm-master Ready Active Leader 8nk8i2ekx8kykyzmaab475tnw swarm-node1 Ready Drain qt9ja2qbmq4n040y60g6xbdlz swarm-node2 Ready Active[root@localhost vagrant]# docker node update --availability active swarm-node1 swarm-node1 [root@localhost vagrant]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 6jir7f507ur05lrhtc2xq8plt * swarm-master Ready Active Leader 8nk8i2ekx8kykyzmaab475tnw swarm-node1 Ready Active qt9ja2qbmq4n040y60g6xbdlz swarm-node2 Ready Active6. Swarm 中部署服务（nginx）
Docker 1.12版本提供服务的Scaling、health check、滚动降级等性能，并提供了内置的dns、vip机制，实现service的服务发现和负载平衡能力
## 1. 部署服务### 1.1 创立网络[root@localhost vagrant]# docker network create -d overlay nginx_net lj3drxnqik170ta6fr7f4rq5i[root@localhost vagrant]# docker network ls | grep "nginx_net" lj3drxnqik17 nginx_net overlay swarm### 1.2 部署服务// 就创立了一个具备一个正本（--replicas 1 ）的nginx服务，应用镜像nginx[root@localhost vagrant]# docker service create --replicas 1 --network nginx_net --name my_nginx -p 80:80 nginx ufxp6pe02z3xggd73ni2jcxay ### 1.3 查看正在运行的服务列表[root@localhost vagrant]# docker service ls ID NAME MODE REPLICAS IMAGE ufxp6pe02z3x my_nginx replicated 1/1 nginx:latest ## 2. 查问Swarm中服务的信息[root@localhost vagrant]# docker service inspect --pretty my_nginx ID: ufxp6pe02z3xggd73ni2jcxay Name: my_nginx Service Mode: Replicated Replicas: 1 Placement: UpdateConfig: Parallelism: 1 On failure: pause Max failure ratio: 0 ContainerSpec: Image: nginx:latest@sha256:06e4235e95299b1d6d595c5ef4c41a9b12641f6683136c18394b858967cd1506 Resources: Networks: nginx_net Endpoint Mode: vip Ports: PublishedPort 80 Protocol = tcp TargetPort = 80## 3. 查看服务在哪个节点上；（在swarm-master节点）[root@localhost vagrant]# docker service ps my_nginx ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS t7o6f7hrjd9v my_nginx.1 nginx:latest swarm-master Running Running 6 minutes ago## 4. 在Swarm中动静扩大服务（scale）// 容器动静扩大到4个[root@localhost vagrant]# docker service scale my_nginx=4 my_nginx scaled to 4 [root@localhost vagrant]# docker service ps my_nginx ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS t7o6f7hrjd9v my_nginx.1 nginx:latest swarm-master Running Running 58 minutes ago ek7ckkc1g1b4 my_nginx.2 nginx:latest swarm-node2 Running Preparing 5 seconds ago jdl14u7a8or5 my_nginx.3 nginx:latest swarm-node1 Running Preparing 5 seconds ago 2vflrnohh6h8 my_nginx.4 nginx:latest swarm-node1 Running Preparing 5 seconds ago 7. Swarm 服务（nginx）--- 故障切換
如果一个节点宕机了（即该节点就会从swarm集群中被踢出），则Docker应该会将在该节点运行的容器，调度到其余节点，以满足指定数量的正本放弃运行状态。
# 查看服务所在节点[root@localhost vagrant]# docker service ps my_nginx ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS t7o6f7hrjd9v my_nginx.1 nginx:latest swarm-master Running Running 58 minutes ago ek7ckkc1g1b4 my_nginx.2 nginx:latest swarm-node2 Running Preparing 5 seconds ago jdl14u7a8or5 my_nginx.3 nginx:latest swarm-node1 Running Preparing 5 seconds ago 2vflrnohh6h8 my_nginx.4 nginx:latest swarm-node1 Running Preparing 5 seconds ago模仿其中一个节点机器关机了
# swarm-node1 节点敞开docker-service[root@localhost vagrant]# systemctl stop docker查看主节点信息
[root@localhost vagrant]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 6jir7f507ur05lrhtc2xq8plt * swarm-master Ready Active Leader 8nk8i2ekx8kykyzmaab475tnw swarm-node1 Down Active qt9ja2qbmq4n040y60g6xbdlz swarm-node2 Ready Active能够看到 swarm-node1 曾经敞开了
[root@localhost vagrant]# docker service ps my_nginx ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS t7o6f7hrjd9v my_nginx.1 nginx:latest swarm-master Running Running about an hour ago ek7ckkc1g1b4 my_nginx.2 nginx:latest swarm-node2 Running Running 19 minutes ago buaz7bbd2tjx my_nginx.3 nginx:latest swarm-node2 Running Running 2 minutes ago jdl14u7a8or5 \_ my_nginx.3 nginx:latest swarm-node1 Shutdown Running 2 minutes ago 5puac9f6ya0j my_nginx.4 nginx:latest swarm-node2 Running Running 2 minutes ago 2vflrnohh6h8 \_ my_nginx.4 nginx:latest swarm-node1 Shutdown Running 2 minutes ago咱们能够看到原来 swarm-node1 上的nginx 曾经敞开了，而且在其余节点上再创立了等量的 nginx 服务
当咱们从新复原 swarm-node1 节点的 docker 服务（模仿机器复原了）
[root@localhost vagrant]# docker service ps my_nginx ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS t7o6f7hrjd9v my_nginx.1 nginx:latest swarm-master Running Running about an hour ago ek7ckkc1g1b4 my_nginx.2 nginx:latest swarm-node2 Running Running 24 minutes ago buaz7bbd2tjx my_nginx.3 nginx:latest swarm-node2 Running Running 7 minutes ago jdl14u7a8or5 \_ my_nginx.3 nginx:latest swarm-node1 Shutdown Failed 2 minutes ago "No such container: my_nginx.3…" 5puac9f6ya0j my_nginx.4 nginx:latest swarm-node2 Running Running 7 minutes ago 2vflrnohh6h8 \_ my_nginx.4 nginx:latest swarm-node1 Shutdown Failed 2 minutes ago "No such container: my_nginx.4…" 调配到 swarm-node1 节点的并没复原
8. 多服务Swarm部署到集群
docker-compose 和 Swarm 联合实现对多服务进行编排
- nginx服务
- visualizer服务
- portainer服务
docker service部署的是单个服务，咱们能够应用docker stack进行多服务编排部署
创立 docker-compose.yml
version: "3"services: nginx: image: nginx ports: - 8888:80 deploy: mode: replicated replicas: 3 visualizer: image: dockersamples/visualizer ports: - "8080:8080" volumes: - "/var/run/docker.sock:/var/run/docker.sock" deploy: replicas: 1 placement: constraints: [node.role == manager] portainer: image: portainer/portainer ports: - "9000:9000" volumes: - "/var/run/docker.sock:/var/run/docker.sock" deploy: replicas: 1 placement: constraints: [node.role == manager]通过 docker-compose.yaml 部署服务
[root@localhost testswarm]# docker stack deploy -c docker-compose.yml deploy_deamon Creating network deploy_deamon_default Creating service deploy_deamon_visualizer Creating service deploy_deamon_portainer Creating service deploy_deamon_nginx # 查看状态[root@localhost testswarm]# docker service ls ID NAME MODE REPLICAS IMAGE il2vuomkg3by deploy_deamon_portainer replicated 1/1 portainer/portainer:latest sudtu6byntye deploy_deamon_visualizer replicated 1/1 dockersamples/visualizer:latest ywtzr8ssersf deploy_deamon_nginx replicated 3/3 nginx:latest