Docker Swarm
一. 架构
Dokcer swarm主要有两部分组成：一个奇数的manger 节点 的a raft consensus group，和一组工作结点，工作结点之间使用的是流言网络协议 ，也叫做控制层面。下图对架构的阐述：
每个管理节点在它本地的raft存储都有swarm状态的所有信息，它们的通信方式使用的是同步的一种方式。
工作节点之间由于扩容的原因，使用是异步通信方式
二. 创建 Docker Swarm
1. swarm的初始化
xiodi@c720131:~$ sudo docker swarm init
Swarm initialized: current node (6h6a4hf307jil12pa891siaib) is now a manager.To add a worker to this swarm, run the following command:
docker swarm join --token SWMTKN-1-08odkkfd4mui46wvxlehv0y5klis7z30q28mrp7pnw89y4a11y-0rvkmr0tikgulqjgl8h2g6xtw 192.168.20.131:2377
To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.
2. 列出swarm的节点
xiodi@c720131:~$ sudo docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
6h6a4hf307jil12pa891siaib * c720131.xiodi.cn Ready Active Leader 18.05.0-ce
3. 检查节点的详细信息
xiodi@c720131:~$ sudo docker node inspect 6h6a4hf307jil12pa891siaib
[
{
"ID": "6h6a4hf307jil12pa891siaib",
"Version": {
"Index": 9
},
"CreatedAt": "2018-06-06T07:09:41.581326206Z",
"UpdatedAt": "2018-06-06T07:09:42.09767829Z",
"Spec": {
"Labels": {},
"Role": "manager",
"Availability": "active"
},
"Description": {
"Hostname": "c720131.xiodi.cn",
"Platform": {
"Architecture": "x86_64",
"OS": "linux"
},
"Resources": {
"NanoCPUs": 2000000000,
"MemoryBytes": 4143411200
},
"Engine": {
"EngineVersion": "18.05.0-ce",
"Plugins": [
{
"Type": "Log",
"Name": "awslogs"
},
{
"Type": "Log",
"Name": "fluentd"
},
{
"Type": "Log",
"Name": "gcplogs"
},
{
"Type": "Log",
"Name": "gelf"
},
{
"Type": "Log",
"Name": "journald"
},
{
"Type": "Log",
"Name": "json-file"
},
{
"Type": "Log",
"Name": "logentries"
},
{
"Type": "Log",
"Name": "splunk"
},
{
"Type": "Log",
"Name": "syslog"
},
{
"Type": "Network",
"Name": "bridge"
},
{
"Type": "Network",
"Name": "host"
},
{
"Type": "Network",
"Name": "macvlan"
},
{
"Type": "Network",
"Name": "null"
},
{
"Type": "Network",
"Name": "overlay"
},
{
"Type": "Volume",
"Name": "local"
}
]
},
"TLSInfo": {
"TrustRoot": "-----BEGIN CERTIFICATE-----\nMIIBajCCARCgAwIBAgIUWWC4eyklvnLS5Jg/voHIkWorxCIwCgYIKoZIzj0EAwIw\nEzERMA8GA1UEAxMIc3dhcm0tY2EwHhcNMTgwNjA2MDcwNTAwWhcNMzgwNjAxMDcw\nNTAwWjATMREwDwYDVQQDEwhzd2FybS1jYTBZMBMGByqGSM49AgEGCCqGSM49AwEH\nA0IABO8UDtnIWogbHOVgdV2Gq7dqlrmGxiS9t2S53bciCJEcSZEARRdq2qEfGI3N\nDFksU70gOhMPTzYwyyqWUGlnZzCjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMB\nAf8EBTADAQH/MB0GA1UdDgQWBBQqIjWQ8OWpVx6ZKXrEyaV4OuaoQTAKBggqhkjO\nPQQDAgNIADBFAiA2OiJMd2OwuXFH4uQixic7TvCLRaemuLnkR4MXKdhJKAIhAP+Y\nf6FL0wZw/NVDRw3Z6lNDl9Wayv5lHwC6V36C9DpP\n-----END CERTIFICATE-----\n",
"CertIssuerSubject": "MBMxETAPBgNVBAMTCHN3YXJtLWNh",
"CertIssuerPublicKey": "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE7xQO2chaiBsc5WB1XYart2qWuYbGJL23ZLndtyIIkRxJkQBFF2raoR8Yjc0MWSxTvSA6Ew9PNjDLKpZQaWdnMA=="
}
},
"Status": {
"State": "ready",
"Addr": "192.168.20.131"
},
"ManagerStatus": {
"Leader": true,
"Reachability": "reachable",
"Addr": "192.168.20.131:2377"
}
}
]
三. 使用swarm创建单个服务
（1）创建一个stack文件
version: "3.5"
services:
whoami:
image: training/whoami:latest
networks:
- test-net
ports:
- 81:8000
deploy:
replicas: 6
update_config:
parallelism: 2
delay: 10s
labels:
app: sample-app
environment: prod-southnetworks:
test-net:
driver: overlay
2. 进行部署stack
xiodi@c720131:~/docker$ sudo docker stack deploy -c stack.yaml sample-stack
[sudo] password for xiodi:
Creating network sample-stack_test-net
Creating service sample-stack_whoami
3. 查看部署的stack
xiodi@c720131:~/docker$ sudo docker stack ls
NAME SERVICES
sample-stack 1
4. 查看部署的服务
xiodi@c720131:~/docker$ sudo docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
t98tjpn7xpby sample-stack_whoami replicated 6/6 training/whoami:latest *:81->8000/tcp
5. 检查服务和它的任务
xiodi@c720131:~/docker$ sudo docker service ps sample-stack_whoami
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
ib67sdpbu7xc sample-stack_whoami.1 training/whoami:latest ubuntu Running Running 3 minutes ago
3qhfu2lj4qis sample-stack_whoami.2 training/whoami:latest c720131.xiodi.cn Running Running 3 minutes ago
xdrxww29h2wi sample-stack_whoami.3 training/whoami:latest c720132.xiodi.cn Running Running 3 minutes ago
mtyc6cw65qu0 sample-stack_whoami.4 training/whoami:latest ubuntu Running Running 3 minutes ago
x8gtlzrqwm3j sample-stack_whoami.5 training/whoami:latest c720131.xiodi.cn Running Running 3 minutes ago
vfq7gksylhom sample-stack_whoami.6 training/whoami:latest c720132.xiodi.cn Running Running 3 minutes ago
6. 列出在该节点运行的容器
xiodi@c720131:~/docker$ sudo docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0cafe15b204c training/whoami:latest "/app/http" 5 minutes ago Up 5 minutes 8000/tcp sample-stack_whoami.2.3qhfu2lj4qisgk5akkskzqnop
42b4d5626c58 training/whoami:latest "/app/http" 5 minutes ago Up 5 minutes 8000/tcp sample-stack_whoami.5.x8gtlzrqwm3juduzonczhima1
stack---service---任务--和容器对应关系如下图：
7. 获取服务的详细信息
xiodi@c720131:~/docker$ sudo docker service inspect sample-stack_whoami
[
{
"ID": "t98tjpn7xpbyryk7ikbtucwut",
"Version": {
"Index": 25
},
"CreatedAt": "2018-06-06T07:29:03.797319458Z",
"UpdatedAt": "2018-06-06T07:29:03.802084194Z",
"Spec": {
"Name": "sample-stack_whoami",
"Labels": {
"app": "sample-app",
"com.docker.stack.image": "training/whoami:latest",
"com.docker.stack.namespace": "sample-stack",
"environment": "prod-south"
},
"TaskTemplate": {
"ContainerSpec": {
"Image": "training/whoami:latest@sha256:4d54f5ea6d2c562ae96add2792e8d71a56b7613cbc4e7b8e20a4e4d3085bbaff",
"Labels": {
"com.docker.stack.namespace": "sample-stack"
},
"Privileges": {
"CredentialSpec": null,
"SELinuxContext": null
},
"StopGracePeriod": 10000000000,
"DNSConfig": {},
"Isolation": "default"
},
"Resources": {},
"RestartPolicy": {
"Condition": "any",
"Delay": 5000000000,
"MaxAttempts": 0
},
"Placement": {
"Platforms": [
{
"Architecture": "amd64",
"OS": "linux"
}
]
},
"Networks": [
{
"Target": "ojgp9mdhz2xaorsxca0g64zv2",
"Aliases": [
"whoami"
]
}
],
"ForceUpdate": 0,
"Runtime": "container"
},
"Mode": {
"Replicated": {
"Replicas": 6
}
},
"UpdateConfig": {
"Parallelism": 2,
"Delay": 10000000000,
"FailureAction": "pause",
"Monitor": 5000000000,
"MaxFailureRatio": 0,
"Order": "stop-first"
},
"RollbackConfig": {
"Parallelism": 1,
"FailureAction": "pause",
"Monitor": 5000000000,
"MaxFailureRatio": 0,
"Order": "stop-first"
},
"EndpointSpec": {
"Mode": "vip",
"Ports": [
{
"Protocol": "tcp",
"TargetPort": 8000,
"PublishedPort": 81,
"PublishMode": "ingress"
}
]
}
},
"Endpoint": {
"Spec": {
"Mode": "vip",
"Ports": [
{
"Protocol": "tcp",
"TargetPort": 8000,
"PublishedPort": 81,
"PublishMode": "ingress"
}
]
},
"Ports": [
{
"Protocol": "tcp",
"TargetPort": 8000,
"PublishedPort": 81,
"PublishMode": "ingress"
}
],
"VirtualIPs": [
{
"NetworkID": "1ov2xqk3ws0017wq9x1eo9sv3",
"Addr": "10.255.0.5/16"
},
{
"NetworkID": "ojgp9mdhz2xaorsxca0g64zv2",
"Addr": "10.0.0.5/24"
}
]
}
}
]
8. 获取服务的日志信息
xiodi@c720131:~/docker$ sudo docker service logs sample-stack_whoami
sample-stack_whoami.2.3qhfu2lj4qis@c720131.xiodi.cn | Listening on :8000
sample-stack_whoami.5.x8gtlzrqwm3j@c720131.xiodi.cn | Listening on :8000
sample-stack_whoami.3.xdrxww29h2wi@c720132.xiodi.cn | Listening on :8000
sample-stack_whoami.6.vfq7gksylhom@c720132.xiodi.cn | Listening on :8000
sample-stack_whoami.4.mtyc6cw65qu0@ubuntu | Listening on :8000
sample-stack_whoami.1.ib67sdpbu7xc@ubuntu | Listening on :8000
9. 协调至满意状态（在某个容器由于某原因不能提供服务时，swarm会自动修复这种状态）
（1）在此删除其中一个实列。
xiodi@c720131:~$ sudo docker container rm -f sample-stack_whoami.2.3qhfu2lj4qisgk5akkskzqnop
sample-stack_whoami.2.3qhfu2lj4qisgk5akkskzqnop
10. 从第9步可以看到，docker-swarm是可以自动恢复的。
11. 接下来演示一下停止掉一个worker节点，看会怎么样。
![M945SRM4WG1FT6S5H]H49BW](https://images2018.cnblogs.com/blog/1416119/201806/1416119-20180606164235425-1388853720.png "M945SRM4WG1FT6S5H]H49BW")
从上图可以看到，我们停止一个worker节点后，仍然能够自动恢复。
12. 删除服务或者stack.
xiodi@c720131:~$ sudo docker stack rm sample-stack
Removing service sample-stack_whoami
Removing network sample-stack_test-net
四. 使用Docker swarm部署多个服务stack.
1. stack文件内容如下
xiodi@c720131:~/docker$ cat pet-stack.yaml
version: "3.5"
services：
web:
image: fundamentalsofdocker/ch08-web:1.0
networks:
- pets-net
ports:
- 3000:3000
deploy:
replicas: 3
db:
image: fundamentalsofdocker/ch08-db:1.0
networks:
- pets-net
volumes:
- pets-data:/var/lib/postgresql/datavolumes:
pets-data:networks:
pets-net:
driver: overlay
2. 部署服务应用
xiodi@c720131:~/docker$ sudo docker stack deploy -c pet-stack.yaml pets
Creating network pets_pets-net
Creating service pets_db
Creating service pets_web
3. 在pets stack列出所有的任务
xiodi@c720131:~/docker$ sudo docker stack ps pets
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
99uuyw2m5fbc pets_web.1 fundamentalsofdocker/ch08-web:1.0 c720132.xiodi.cn Running Running about a minute ago
8key67a3aaai pets_db.1 fundamentalsofdocker/ch08-db:1.0 c720131.xiodi.cn Running Running about a minute ago
nkogzxahoxhq pets_web.2 fundamentalsofdocker/ch08-web:1.0 ubuntu Running Running about a minute ago
6230n44cvt04 pets_web.3 fundamentalsofdocker/ch08-web:1.0 c720131.xiodi.cn Running Running about a minute ago
4. 请求本机的3000端口，校验部署的服务
