docker - ECS Agent启动Docker容器未完成。手动启动成功

Question

我遵循了ECS Getting Started tutorial，但是ECS代理无法启动容器。当我在同一实例上手动启动镜像时，它可以正常启动。

该图像是一个Spring Boot Web应用程序，在/上具有单个端点，该端点返回字符串“Hello world !!”。该容器在本地运行良好，并且在我创建的CentOS EC2实例上也运行良好。当我在CentOS EC2实例上运行docker镜像时，该端点可公开使用。

ECS实例具有由向导创建的安全组，并已打开端口80。我添加了用于SSH访问的端口22。

当我通过SSH进入ECS实例以查看我的容器的Docker日志时，它似乎在入口点执行期间挂起。

以下是挂起实例的Docker日志:

[ec2-user@ip-10-0-0-156 ~]$ docker logs --tail 100 107d4cf04dd8

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.4.2.RELEASE)

2016-11-25 17:36:22.505  INFO 1 --- [           main] ecstest.Application                      : Starting Application on 107d4cf04dd8 with PID 1 (/ecstest-1.0-SNAPSHOT.jar started by root in /)
2016-11-25 17:36:22.546  INFO 1 --- [           main] ecstest.Application                      : No active profile set, falling back to default profiles: default
2016-11-25 17:36:23.059  INFO 1 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@6d21714c: startup date [Fri Nov 25 17:36:23 UTC 2016]; root of context hierarchy
2016-11-25 17:36:30.972  INFO 1 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2016-11-25 17:36:31.014  INFO 1 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2016-11-25 17:36:31.016  INFO 1 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.6
2016-11-25 17:36:31.464  INFO 1 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2016-11-25 17:36:31.464  INFO 1 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 8458 ms

最初，我的容器镜像中似乎有一个应用程序错误，但是当我停止docker进程并手动运行相同的镜像时，输出就如预期的那样，并且可以按预期从实异常(exception)部到达端点。

[ec2-user@ip-10-0-1-124 ~]$ docker stop -t 1 4d2401d7db93 && docker run -p 80:8080 -d ############.dkr.ecr.us-west-2.amazonaws.com/ecstest
4d2401d7db93
db8cffa89995401d9314d7d70e954f09c7fde972a5e6a423615827d8c47b9d10
[ec2-user@ip-10-0-1-124 ~]$ docker ps
CONTAINER ID        IMAGE                                                  COMMAND                  CREATED             STATUS              PORTS                  NAMES
db8cffa89995        ############.dkr.ecr.us-west-2.amazonaws.com/ecstest   "java -jar ecstest-1."   10 seconds ago      Up 9 seconds        0.0.0.0:80->8080/tcp   small_gates
85bd18480c99        amazon/amazon-ecs-agent:latest                         "/agent"                 11 minutes ago      Up 11 minutes                              ecs-agent
[ec2-user@ip-10-0-1-124 ~]$ docker logs --tail 1000 db8cffa89995

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.4.2.RELEASE)

2016-11-25 18:06:57.960  INFO 1 --- [           main] ecstest.Application                      : Starting Application on db8cffa89995 with PID 1 (/ecstest-1.0-SNAPSHOT.jar started by root in /)
2016-11-25 18:06:58.004  INFO 1 --- [           main] ecstest.Application                      : No active profile set, falling back to default profiles: default
2016-11-25 18:06:58.578  INFO 1 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@6d21714c: startup date [Fri Nov 25 18:06:58 UTC 2016]; root of context hierarchy
2016-11-25 18:07:05.784  INFO 1 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2016-11-25 18:07:05.866  INFO 1 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2016-11-25 18:07:05.876  INFO 1 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.6
2016-11-25 18:07:06.283  INFO 1 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2016-11-25 18:07:06.283  INFO 1 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 7753 ms
2016-11-25 18:07:07.026  INFO 1 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2016-11-25 18:07:07.031  INFO 1 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2016-11-25 18:07:07.031  INFO 1 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2016-11-25 18:07:07.032  INFO 1 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2016-11-25 18:07:07.033  INFO 1 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2016-11-25 18:07:08.432  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@6d21714c: startup date [Fri Nov 25 18:06:58 UTC 2016]; root of context hierarchy
2016-11-25 18:07:08.786  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[],methods=[GET]}" onto public java.lang.String ecstest.Application.get()
2016-11-25 18:07:08.800  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2016-11-25 18:07:08.801  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2016-11-25 18:07:09.036  INFO 1 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-11-25 18:07:09.036  INFO 1 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-11-25 18:07:09.204  INFO 1 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-11-25 18:07:09.893  INFO 1 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2016-11-25 18:07:10.201  INFO 1 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2016-11-25 18:07:10.216  INFO 1 --- [           main] ecstest.Application                      : Started Application in 14.385 seconds (JVM running for 16.522)

为什么ECS代理无法启动我的应用程序？

任务定义JSON

{
  "attributes": null,
  "requiresAttributes": [
    {
      "value": null,
      "name": "com.amazonaws.ecs.capability.ecr-auth",
      "targetId": null,
      "targetType": null
    }
  ],
  "taskDefinitionArn": "arn:aws:ecs:us-west-2:############:task-definition/DcTaskDefinition:4",
  "networkMode": "bridge",
  "status": "ACTIVE",
  "revision": 4,
  "taskRoleArn": null,
  "containerDefinitions": [
    {
      "volumesFrom": [],
      "memory": 128,
      "extraHosts": null,
      "dnsServers": null,
      "disableNetworking": null,
      "dnsSearchDomains": null,
      "portMappings": [
        {
          "hostPort": 80,
          "containerPort": 8080,
          "protocol": "tcp"
        }
      ],
      "hostname": null,
      "essential": true,
      "entryPoint": null,
      "mountPoints": [],
      "name": "DcContainer",
      "ulimits": null,
      "dockerSecurityOptions": null,
      "environment": [],
      "links": null,
      "workingDirectory": null,
      "readonlyRootFilesystem": null,
      "image": "############.dkr.ecr.us-west-2.amazonaws.com/ecstest:latest",
      "command": null,
      "user": null,
      "dockerLabels": null,
      "logConfiguration": null,
      "cpu": 0,
      "privileged": null,
      "memoryReservation": null
    }
  ],
  "placementConstraints": [],
  "volumes": [],
  "family": "DcTaskDefinition"
}

Answer 1

任务定义JSON中的memory键在容器上施加了硬盘限制。当容器试图超过该限制时，Docker守护程序应该将其杀死。
我不确定这是否会导致您的容器“卡住”，但是这是我所见的ECS运行时容器如何运行以及命令行中如何运行之间的唯一重要区别。
因此，我将尝试将memory的值至少设置为300，或者改用memoryReservation键，该键强加了软内存限制。

可以在official ECS documentation中找到有关硬内存限制和软内存限制之间差异的更多信息。