create service|在swarm中部署服务

service create
swarm集群维护
- manager高可用
- 节点维护DRAIN

在swarm部署、管理、扩展、更新和删除服务。

service create

服务管理、部署需要在manager上发起。

用docker service create命令创建服务。

sudo docker service create --replicas 1 --name helloworld alpine ping docker.com

# --name: 服务名称helloworld
# --replicas: 运行实例1个
# 参数alpine ping docker.com，将服务定义为执行命令ping docker.com的Alpine Linux容器。

renuslhb2y8i0c16tr03kqn1p
overall progress: 1 out of 1 tasks
1/1: running   [==================================================>]
verify: Service converged

查看服务：

# 查看服务列表
docker service ls

ID             NAME         MODE         REPLICAS   IMAGE           PORTS
renuslhb2y8i   helloworld   replicated   1/1        alpine:latest

# 查看服务所在NODE
docker service ps helloworld
ID             NAME           IMAGE           NODE            DESIRED STATE   CURRENT STATE           ERROR     PORTS
j2cerfrndt10   helloworld.1   alpine:latest   swarm-manager   Running         Running 7 minutes ago

# 查看服务的详细信息
docker service inspect --pretty renuslhb2y8i
docker service inspect --pretty helloworld # 易于阅读格式输出
docker service inspect helloworld          # Json格式输出

ID:             renuslhb2y8i0c16tr03kqn1p
Name:           helloworld
Service Mode:   Replicated
 Replicas:      1
Placement:
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:         alpine:latest@sha256:51b67269f354137895d43f3b3d810bfacd3945438e94dc5ac55fdac340352f48
 Args:          ping docker.com
 Init:          false
Resources:
Endpoint Mode:  vip

docker容器操作

# 在对应NODE节点，用docker ps查看服务信息
docker ps
CONTAINER ID   IMAGE           COMMAND             CREATED         STATUS         PORTS     NAMES
356dc496222f   alpine:latest   "ping docker.com"   8 minutes ago   Up 8 minutes             helloworld.1.j2cerfrndt104opoip82ml7ww
# 进入容器、查看状态、查看日志
docker exec -it 356dc496222f /bin/sh
docker attach 356dc496222f
docker stats 356dc496222f
docker logs 356dc496222f
docker logs --since="2024-01-11" --tail=10 helloworld.1.j2cerfrndt104opoip82ml7ww

service scale

docker service scale helloworld=2

helloworld scaled to 2
overall progress: 2 out of 2 tasks
1/2: running   [==================================================>]
2/2: running   [==================================================>]
verify: Service converged

docker service ls
ID             NAME         MODE         REPLICAS   IMAGE           PORTS
renuslhb2y8i   helloworld   replicated   2/2        alpine:latest

docker service ps helloworld
ID             NAME           IMAGE           NODE            DESIRED STATE   CURRENT STATE                ERROR     PORTS
j2cerfrndt10   helloworld.1   alpine:latest   swarm-manager   Running         Running 25 minutes ago
yzkwbznot2ld   helloworld.2   alpine:latest   swarm-node1     Running         Running about a minute ago

service rm

docker service rm helloworld

service update

部署redis服务

docker service create --replicas 3 --name myredis --update-delay 10s redis:6.0-alpine

# --replicas 3，部署服务的数量
# --update-delay 10s，以10秒的更新延迟配置swarm，时间格式支持h、m、s，如：5m10s表示5分钟10秒
# --update-parllelism，更新时并行数量，默认一次只更新1个
# --name myredis，服务名称myredis
# redis:6.0-alpine，指定redis images版本

overall progress: 3 out of 3 tasks
1/3: running   [==================================================>]
2/3: running   [==================================================>]
3/3: running   [==================================================>]
verify: Service converged

docker service ls
ID             NAME      MODE         REPLICAS   IMAGE              PORTS
rvch2nxjqygi   myredis   replicated   3/3        redis:6.0-alpine

docker service ps myredis
ID             NAME        IMAGE              NODE            DESIRED STATE   CURRENT STATE           ERROR     PORTS
geok9gvw9rnf   myredis.1   redis:6.0-alpine   swarm-node1     Running         Running 2 minutes ago
iy7aly9fwsko   myredis.2   redis:6.0-alpine   swarm-node2     Running         Running 2 minutes ago
wwqtmfnq51gm   myredis.3   redis:6.0-alpine   swarm-manager   Running         Running 2 minutes ago

docker service inspect --pretty myredis

ID:             rvch2nxjqygim9ecpvtwotdzs
Name:           myredis
Service Mode:   Replicated
 Replicas:      3
Placement:
UpdateConfig:
 Parallelism:   1
 Delay:         10s
 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:         redis:6.0-alpine@sha256:3f62df0d21946090646f7eba8d8762139444f69e3cec5e345188ad2ecb62827f
 Init:          false
Resources:
Endpoint Mode:  vip

滚动更新redis版本

docker service update --image redis:6.0.20-alpine myredis

myredis
overall progress: 3 out of 3 tasks
1/3: running   [==================================================>]
2/3: running   [==================================================>]
3/3: running   [==================================================>]
verify: Service converged

更新调度过程：
1.停止第一个任务。
2.为停止的任务安排更新。
3.启动更新任务的容器。
4.根据更新任务返回状态：
	a.任务返回RUNNING，等待指定的延迟期，然后开始下一个任务。
	b.任务返回FAILED，暂停更新。

docker service ls
ID             NAME      MODE         REPLICAS   IMAGE                 PORTS
rvch2nxjqygi   myredis   replicated   3/3        redis:6.0.20-alpine

docker service ps myredis
ID             NAME            IMAGE                 NODE            DESIRED STATE   CURRENT STATE            ERROR     PORTS
p8ar47czvamy   myredis.1       redis:6.0.20-alpine   swarm-node1     Running         Running 2 minutes ago
geok9gvw9rnf    \_ myredis.1   redis:6.0-alpine      swarm-node1     Shutdown        Shutdown 2 minutes ago
0cpobbgygqio   myredis.2       redis:6.0.20-alpine   swarm-node2     Running         Running 2 minutes ago
iy7aly9fwsko    \_ myredis.2   redis:6.0-alpine      swarm-node2     Shutdown        Shutdown 2 minutes ago
md0byaxu9pic   myredis.3       redis:6.0.20-alpine   swarm-manager   Running         Running 2 minutes ago
wwqtmfnq51gm    \_ myredis.3   redis:6.0-alpine      swarm-manager   Shutdown        Shutdown 2 minutes ago

swarm集群维护

manager高可用

将swarm-node1、node2升有为manager，Manager status变成了Reachable。当leader故障时，通过选取可以产生一个新的leader。

docker node promote NODE [NODE...]
docker node update --role manager swarm-node2
Promote one or more nodes to manager in the swarm

docker node demote NODE [NODE...]
docker node update --role workerr swarm-node2
Demote one or more nodes from manager in the swarm

docker node promote swarm-node1 swarm-node2 # 升级
docker node demote swarm-node1              # 降级

docker node ls
ID                            HOSTNAME        STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
tonr5adn7buqjfqdx1kasmywy *   swarm-manager   Ready     Active         Leader           24.0.7
w4kwyvrmrazlto391br2q6iee     swarm-node1     Ready     Active         Reachable        24.0.7
2wwwkgepq5nz46tgiksbngwzo     swarm-node2     Ready     Active         Reachable        24.0.7

节点维护DRAIN

维护节点时，需要将节点可用性设置为DRAIN状态，Master会阻止此类节点接收新任务、停止节点上的任务，在具有ACTIVE状态的节点启动任务。

查看node和service现状

docker node ls
ID                            HOSTNAME        STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
tonr5adn7buqjfqdx1kasmywy *   swarm-manager   Ready     Active         Leader           24.0.7
w4kwyvrmrazlto391br2q6iee     swarm-node1     Ready     Active                          24.0.7
2wwwkgepq5nz46tgiksbngwzo     swarm-node2     Ready     Active                          24.0.7

docker service ps myredis
ID             NAME            IMAGE                 NODE            DESIRED STATE   CURRENT STATE             ERROR     PORTS
p8ar47czvamy   myredis.1       redis:6.0.20-alpine   swarm-node1     Running         Running 38 minutes ago
geok9gvw9rnf    \_ myredis.1   redis:6.0-alpine      swarm-node1     Shutdown        Shutdown 38 minutes ago
0cpobbgygqio   myredis.2       redis:6.0.20-alpine   swarm-node2     Running         Running 39 minutes ago
iy7aly9fwsko    \_ myredis.2   redis:6.0-alpine      swarm-node2     Shutdown        Shutdown 39 minutes ago
md0byaxu9pic   myredis.3       redis:6.0.20-alpine   swarm-manager   Running         Running 38 minutes ago
wwqtmfnq51gm    \_ myredis.3   redis:6.0-alpine      swarm-manager   Shutdown        Shutdown 38 minutes ago

将node2可用性设置为drain，再次查看状态

docker node update --availability drain swarm-node2
docker node ls
docker service ps myredis

ID                            HOSTNAME        STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
tonr5adn7buqjfqdx1kasmywy *   swarm-manager   Ready     Active         Leader           24.0.7
w4kwyvrmrazlto391br2q6iee     swarm-node1     Ready     Active                          24.0.7
2wwwkgepq5nz46tgiksbngwzo     swarm-node2     Ready     Drain                           24.0.7

ID             NAME            IMAGE                 NODE            DESIRED STATE   CURRENT STATE             ERROR     PORTS
p8ar47czvamy   myredis.1       redis:6.0.20-alpine   swarm-node1     Running         Running 42 minutes ago
geok9gvw9rnf    \_ myredis.1   redis:6.0-alpine      swarm-node1     Shutdown        Shutdown 42 minutes ago
1d7kebxldb29   myredis.2       redis:6.0.20-alpine   swarm-manager   Running         Running 46 seconds ago
0cpobbgygqio    \_ myredis.2   redis:6.0.20-alpine   swarm-node2     Shutdown        Shutdown 46 seconds ago
iy7aly9fwsko    \_ myredis.2   redis:6.0-alpine      swarm-node2     Shutdown        Shutdown 42 minutes ago
md0byaxu9pic   myredis.3       redis:6.0.20-alpine   swarm-manager   Running         Running 42 minutes ago
wwqtmfnq51gm    \_ myredis.3   redis:6.0-alpine      swarm-manager   Shutdown        Shutdown 42 minutes ago

启动节点可用性

docker node update --availability active swarm-node2