容器实例可能不是真正的容器吗？

Question

我阅读了 AmazonECS documentation and also this 文章，其中对每个术语进行了基本解释，包括：

Container Instance — This is just an EC2 instance that is part of an ECS Cluster and has docker and the ecs-agent running on it.

感觉有点迷糊。我认为每个 task 都是一个 container，它在属于 ECS 集群的 EC2 instance 上运行。那么为什么 EC2 instance 会被这样调用呢？或者 EC2 instance 也是 container 而我错过了什么？

Answer 1

当你想到容器实例时，想到：

An EC2 instance configured to run containers (ECS tasks) by having the ECS agent and being part of an ECS cluster.

本质上，ECS 会跟踪与集群关联的 EC2 实例，包括有关它们的元数据。这意味着除了被跟踪为 EC2 实例外，它们还被跟踪为 "Container Instances"。如果您安装了 AWS CLI，请查看 aws ecs describe-container-instances 以查看有关容器实例的一些元数据。

$ aws ecs describe-container-instances --container-instance <container instance>
{
    "failures": [],
    "containerInstances": [
        {
            "status": "ACTIVE",
            "registeredAt": 1442818969.168,
            "registeredResources": [
                {
                    "integerValue": 2048,
                    "longValue": 0,
                    "type": "INTEGER",
                    "name": "CPU",
                    "doubleValue": 0.0
                },
                {
                    "integerValue": 1957,
                    "longValue": 0,
                    "type": "INTEGER",
                    "name": "MEMORY",
                    "doubleValue": 0.0
                },
                {
                    "name": "PORTS",
                    "longValue": 0,
                    "doubleValue": 0.0,
                    "stringSetValue": [
                        "22",
                        "2376",
                        "2375",
                        "51678",
                        "51679"
                    ],
                    "type": "STRINGSET",
                    "integerValue": 0
                },
                {
                    "name": "PORTS_UDP",
                    "longValue": 0,
                    "doubleValue": 0.0,
                    "stringSetValue": [],
                    "type": "STRINGSET",
                    "integerValue": 0
                }
            ],
            "ec2InstanceId": "i-98135490825890725",
            "agentConnected": true,
            "containerInstanceArn": "arn:aws:ecs:ca-central-1:23490141:container-instance/123984129047912347012340",
            "pendingTasksCount": 0,
            "remainingResources": [
                {
                    "integerValue": 1923,
                    "longValue": 0,
                    "type": "INTEGER",
                    "name": "CPU",
                    "doubleValue": 0.0
                },
                {
                    "integerValue": 1925,
                    "longValue": 0,
                    "type": "INTEGER",
                    "name": "MEMORY",
                    "doubleValue": 0.0
                },
                {
                    "name": "PORTS",
                    "longValue": 0,
                    "doubleValue": 0.0,
                    "stringSetValue": [
                        "22",
                        "2376",
                        "2375",
                        "51678",
                        "51679"
                    ],
                    "type": "STRINGSET",
                    "integerValue": 0
                },
                {
                    "name": "PORTS_UDP",
                    "longValue": 0,
                    "doubleValue": 0.0,
                    "stringSetValue": [],
                    "type": "STRINGSET",
                    "integerValue": 0
                }
            ],
            "version": 3197,
            "attributes": [
                {
                    "name": "com.amazonaws.ecs.capability.logging-driver.syslog"
                },
                {
                    "name": "ecs.ami-id",
                    "value": "ami-0f552e0a86f08b660"
                },
                {
                    "name": "com.amazonaws.ecs.capability.logging-driver.none"
                },
                {
                    "name": "com.amazonaws.ecs.capability.logging-driver.json-file"
                },
                {
                    "name": "ecs.capability.execution-role-awslogs"
                },
                {
                    "name": "ecs.vpc-id",
                    "value": "vpc-2309423409"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.17"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.18"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.19"
                },
                {
                    "name": "ecs.capability.docker-plugin.local"
                },
                {
                    "name": "ecs.capability.task-eni"
                },
                {
                    "name": "ecs.capability.task-cpu-mem-limit"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.30"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.31"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.32"
                },
                {
                    "name": "ecs.capability.execution-role-ecr-pull"
                },
                {
                    "name": "ecs.capability.container-health-check"
                },
                {
                    "name": "ecs.subnet-id",
                    "value": "subnet-13412345"
                },
                {
                    "name": "ecs.availability-zone",
                    "value": "us-east-1c"
                },
                {
                    "name": "ecs.instance-type",
                    "value": "t3.small"
                },
                {
                    "name": "com.amazonaws.ecs.capability.task-iam-role-network-host"
                },
                {
                    "name": "com.amazonaws.ecs.capability.logging-driver.awslogs"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.24"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.25"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.26"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.27"
                },
                {
                    "name": "com.amazonaws.ecs.capability.privileged-container"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.28"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.29"
                },
                {
                    "name": "ecs.cpu-architecture",
                    "value": "x86_64"
                },
                {
                    "name": "ecs.capability.cni-plugin-version",
                    "value": "93f43776-2018.10.0"
                },
                {
                    "name": "ecs.capability.secrets.ssm.environment-variables"
                },
                {
                    "name": "com.amazonaws.ecs.capability.ecr-auth"
                },
                {
                    "name": "ecs.capability.pid-ipc-namespace-sharing"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.20"
                },
                {
                    "name": "ecs.os-type",
                    "value": "linux"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.21"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.22"
                },
                {
                    "name": "com.amazonaws.ecs.capability.docker-remote-api.1.23"
                },
                {
                    "name": "com.amazonaws.ecs.capability.task-iam-role"
                },
                {
                    "name": "ecs.capability.private-registry-authentication.secretsmanager"
                }
            ],
            "versionInfo": {
                "agentVersion": "1.22.0",
                "agentHash": "26518174",
                "dockerVersion": "DockerVersion: 18.06.1-ce"
            },
            "runningTasksCount": 1,
            "attachments": []
        }
    ]
}

但是，不，ECS 容器实例不是 AFAIK，容器本身。它们是使用 ECS 配置为运行容器的虚拟服务器。

容器实例可能不是真正的容器吗？

Is it possible that a container instance isn't really a container?

amazon-ecs