部署service到swarm集群，指定task运行的节点？（节点自定义标签）

如标题所示，如何将service中task，指定运行在具有某个特殊的节点上，比如，存储特别大，有GPU的？

 

方法，非常的简单。

 

1、节点增加标签

 

首先，给特殊的主机增加label

 

[root@nccztsjb-node-01 ~]# docker node ls
ID                            HOSTNAME           STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
gxfkhuc95br6ltkhorpw1q4tq *   nccztsjb-node-01   Ready     Active         Reachable        20.10.17
8zjicf39fk28jn106symk1g5e     nccztsjb-node-02   Ready     Active                          20.10.17
7d59usghrgq05k0yh4lbykw5v     nccztsjb-node-04   Ready     Active         Reachable        20.10.17
wnd24l698iruhhp1xw0y3iyig     nccztsjb-node-05   Ready     Active         Leader           20.10.17
[root@nccztsjb-node-01 ~]# docker node update --label-add store=large nccztsjb-node-04
nccztsjb-node-04
[root@nccztsjb-node-01 ~]# 

 

2、部署service

 

此时，具有特殊资源的节点，已经增加好了标签，接下来，就是关键点了，部署service

 

通过--constraint参数指定具体约束条件

 

docker service create \
  --name redis \
  --constraint node.labels.store==large \
  172.20.58.152/middleware/redis:3.0.6  

 

部署过程

[root@nccztsjb-node-01 ~]# docker service create \

> --name redis \

> --constraint node.labels.store==large \

> 172.20.58.152/middleware/redis:3.0.6

u2a9nm7byfnxv3t7lofgsc321

overall progress: 1 out of 1 tasks

1/1: running [==================================================>]

verify: Service converged

 

 

查看task的运行状态

 

[root@nccztsjb-node-01 ~]# docker service ps redis
ID             NAME      IMAGE                                  NODE               DESIRED STATE   CURRENT STATE            ERROR     PORTS
rzwlggf8i37r   redis.1   172.20.58.152/middleware/redis:3.0.6   nccztsjb-node-04   Running         Running 42 seconds ago             
[root@nccztsjb-node-01 ~]# 
[root@nccztsjb-node-01 ~]# docker service inspect redis --pretty

ID:        u2a9nm7byfnxv3t7lofgsc321
Name:        redis
Service Mode:    Replicated
 Replicas:    1
Placement:
 Constraints:    [node.labels.store==large]
UpdateConfig:
 Parallelism:    1
 On failure:    pause
 Monitoring Period: 5s
 Max failure ratio: 0
 Update order:      stop-first
RollbackConfig:
 Parallelism:    1
 On failure:    pause
 Monitoring Period: 5s
 Max failure ratio: 0
 Rollback order:    stop-first
ContainerSpec:
 Image:        172.20.58.152/middleware/redis:3.0.6@sha256:d161fc7de1183ed220e28cf5e4cc50f1b535d580f2c3503c0b4ae4f2d63c1b1f
 Init:        false
Resources:
Endpoint Mode:    vip

[root@nccztsjb-node-01 ~]# 

 

Placement:

Constraints: [node.labels.store==large] # 执行部署的限制条件。

 

OK，这样task就运行到这个节点了。

 

那别停，如果是多个副本呢？

 

[root@nccztsjb-node-01 ~]# docker service scale redis=2
redis scaled to 2
overall progress: 2 out of 2 tasks 
1/2: running   [==================================================>] 
2/2: running   [==================================================>] 
verify: Service converged 
[root@nccztsjb-node-01 ~]# 

 

毫无疑问，多个副本，都是运行在这一个节点上的，因为，只有一个节点，有这样的标签

 

[root@nccztsjb-node-01 ~]# docker service ps redis
ID             NAME      IMAGE                                  NODE               DESIRED STATE   CURRENT STATE            ERROR     PORTS
rzwlggf8i37r   redis.1   172.20.58.152/middleware/redis:3.0.6   nccztsjb-node-04   Running         Running 3 minutes ago              
shonptv3fcae   redis.2   172.20.58.152/middleware/redis:3.0.6   nccztsjb-node-04   Running         Running 18 seconds ago             
[root@nccztsjb-node-01 ~]# 

 

到这里应该结束了吧，没有，后面还会介绍到，其他的约束该怎么做？

 

比如：

• 根据主机名
• 根据主机的操作系统
• 根据主机平台
• 根据主机的ID
• 根据的CPU架构

 

这些，后面的文章中，我们会讲到······