在swarm集群中部署service时，如何使用私有镜像仓库中的镜像？

最近在部署service到swarm集群的时候，出现了下列的报错：

 

[root@nccztsjb-node-01 ~]# docker service create \
>   --name=nginx \
>   --publish published=8080,target=80 \
>   172.20.58.152/middleware/nginx:1.21.4  
image 172.20.58.152/middleware/nginx:1.21.4 could not be accessed on a registry to record
its digest. Each node will access 172.20.58.152/middleware/nginx:1.21.4 independently,
possibly leading to different nodes running different
versions of the image.

hr3vb5wdzkzhewbc62f06nenr
overall progress: 0 out of 1 tasks 
1/1: No such image: 172.20.58.152/middleware/nginx:1.21.4 

 

 

看到报错信息，才恍然大悟，原来，这个镜像是在私有的、内部搭建的仓库中的。

 

也就是说，拉取镜像是需要认证的，或者，在拉取镜像之前，需要登录仓库

 

解决的方法，也是非常的简单的

 

首先，登录到这个仓库中（在manager节点操作）

 

[root@nccztsjb-node-01 ~]# docker login  172.20.58.152
Username: admin
Password: 
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store

Login Succeeded
[root@nccztsjb-node-01 ~]# 

 

 

然后，部署service的时候加上认证参数  --with-registry-auth （在manager节点）

 

docker service create \
  --name=nginx \
  --with-registry-auth \
  --publish published=8080,target=80 \
  172.20.58.152/middleware/nginx:1.21.4  

 

 

[root@nccztsjb-node-01 ~]# docker service create \
>   --name=nginx \
>   --with-registry-auth \
>   --publish published=8080,target=80 \
>   172.20.58.152/middleware/nginx:1.21.4  
qi8fxxrdrbxlidenqxyd7ywx4
overall progress: 1 out of 1 tasks 
1/1: running   [==================================================>] 
verify: Service converged 
[root@nccztsjb-node-01 ~]# docker service ls
ID             NAME         MODE         REPLICAS   IMAGE                                   PORTS
qi8fxxrdrbxl   nginx        replicated   1/1        172.20.58.152/middleware/nginx:1.21.4   *:8080->80/tcp
hz926ckhmkd9   redis        replicated   1/1        172.20.58.152/middleware/redis:3.0.6    
pzcsua3xuur9   test-commd   replicated   1/1        172.20.58.152/baseimage/alpine:latest   
[root@nccztsjb-node-01 ~]# docker service ps nginx
ID             NAME      IMAGE                                   NODE               DESIRED STATE   CURRENT STATE            ERROR     PORTS
j0ltlwxwcsnw   nginx.1   172.20.58.152/middleware/nginx:1.21.4   nccztsjb-node-04   Running         Running 14 seconds ago             
[root@nccztsjb-node-01 ~]# 
[root@nccztsjb-node-01 ~]# 

 

 

有没有发现，是在nccztsjb-node-01上，即manager节点上做的登录，但是，现在的task实际上运行nccztsjb-node-04这个节点上的。

 

也就是说，所有的集群中的节点，都是可以获取这个认证的信息的！

 

原理：会将manager节点本地客户端的登录tokenc传送到swarm集群中service运行的节点。使用这个token信息，节点可以登录到私有仓库，然后拉取镜像

 

所以，关键步骤：

 

• manger节点登录私有仓库(使用用户名和密码)
• 部署service指定认证参数--with-registry-auth