五十七、Docker Swarm-单节点service体验

创建service

• 使用docker service create [OPTIONS] IMAGE [COMMAND] [ARG...]创建

[root@localhost ~]# docker service create
"docker service create" requires at least 1 argument.
See 'docker service create --help'.

Usage:  docker service create [OPTIONS] IMAGE [COMMAND] [ARG...]

Create a new service
[root@localhost ~]# docker service create --help

Usage:  docker service create [OPTIONS] IMAGE [COMMAND] [ARG...]

Create a new service
...

• 例子

[root@localhost ~]# docker service create nginx:latest
ujf1xtef2e7xqleqrmh75b0mg
overall progress: 1 out of 1 tasks 
1/1: running   [==================================================>] 
verify: Service converged 
[root@localhost ~]# 
[root@localhost ~]# docker service ls
ID             NAME                    MODE         REPLICAS   IMAGE          PORTS
ujf1xtef2e7x   mystifying_cartwright   replicated   1/1        nginx:latest 

Note：这里输出的id是service的id而非container的id。service等同于container。

查看service信息

• docker service ls：查看所有的service基本信息
• docker service ps [SERVICE_ID]：查看具体某个service的信息

[root@localhost ~]# docker service ls
ID             NAME                    MODE         REPLICAS   IMAGE          PORTS
ujf1xtef2e7x   mystifying_cartwright   replicated   1/1        nginx:latest   
[root@localhost ~]# 
[root@localhost ~]# docker service ps uj
ID             NAME                      IMAGE          NODE                    DESIRED STATE   CURRENT STATE           ERROR     PORTS
nlj4so00wxz3   mystifying_cartwright.1   nginx:latest   localhost.localdomain   Running         Running 3 minutes ago 

• 查看容器信息发现容器id与service id确实不一样

[root@localhost ~]# docker container ls
CONTAINER ID   IMAGE          COMMAND                  CREATED         STATUS         PORTS     NAMES
49e36233b260   nginx:latest   "/docker-entrypoint.…"   5 minutes ago   Up 5 minutes   80/tcp    mystifying_cartwright.1.nlj4so00wxz3wo07lyktjzx3c

利用replicas复制多个容器

同一个服务启动多个容器

• docker service update [SERVICE_ID] --replicas [NUMBER]

[root@localhost ~]# docker service update uj --replicas 3
uj
overall progress: 3 out of 3 tasks
1/3: running   [==================================================>]
2/3: running   [==================================================>]
3/3: running   [==================================================>]
verify: Service converged
[root@localhost ~]#
[root@localhost ~]# docker service ls
ID             NAME                    MODE         REPLICAS   IMAGE          PORTS
ujf1xtef2e7x   mystifying_cartwright   replicated   3/3        nginx:latest
[root@localhost ~]# docker service ps uj
ID             NAME                      IMAGE          NODE                    DESIRED STATE   CURRENT STATE            ERROR     PORTS
nlj4so00wxz3   mystifying_cartwright.1   nginx:latest   localhost.localdomain   Running         Running 13 minutes ago
v7l8v247h2qo   mystifying_cartwright.2   nginx:latest   localhost.localdomain   Running         Running 45 seconds ago
xy85ftdwcpmp   mystifying_cartwright.3   nginx:latest   localhost.localdomain   Running         Running 45 seconds ago
[root@localhost ~]#
[root@localhost ~]# docker container ls
CONTAINER ID   IMAGE          COMMAND                  CREATED              STATUS              PORTS     NAMES
753076d85b2a   nginx:latest   "/docker-entrypoint.…"   About a minute ago   Up About a minute   80/tcp    mystifying_cartwright.2.v7l8v247h2qo3x06tk31syvbx
6cf61228c7a3   nginx:latest   "/docker-entrypoint.…"   About a minute ago   Up About a minute   80/tcp    mystifying_cartwright.3.xy85ftdwcpmpibb41h8kkjof6
49e36233b260   nginx:latest   "/docker-entrypoint.…"   13 minutes ago       Up 13 minutes       80/tcp    mystifying_cartwright.1.nlj4so00wxz3wo07lyktjzx3c
[root@localhost ~]#

swarm维护service的replicas

• 先删除掉service中的某个replica即删除一个容器，会发现swarm会自动开启另一个replica

[root@localhost ~]# docker container rm -f 753
753
[root@localhost ~]#
[root@localhost ~]# docker service ps uj
ID             NAME                          IMAGE          NODE                    DESIRED STATE   CURRENT STATE            ERROR                         PORTS
nlj4so00wxz3   mystifying_cartwright.1       nginx:latest   localhost.localdomain   Running         Running 16 minutes ago                           
p16tkh74v5om   mystifying_cartwright.2       nginx:latest   localhost.localdomain   Running         Running 11 seconds ago                           
v7l8v247h2qo    \_ mystifying_cartwright.2   nginx:latest   localhost.localdomain   Shutdown        Failed 17 seconds ago    "task: non-zero exit (137)"
xy85ftdwcpmp   mystifying_cartwright.3       nginx:latest   localhost.localdomain   Running         Running 4 minutes ago      

停止service

• docker service rm [SERVICE_ID]

[root@localhost ~]# docker service rm uj
uj
[root@localhost ~]# docker service ls
ID        NAME      MODE      REPLICAS   IMAGE     PORTS
[root@localhost ~]#