![CloudFormation/EC2-访问模板中的 EC2 实例的 IP 地址?](https://linux22.com/image/582561/CloudFormation%2FEC2-%E8%AE%BF%E9%97%AE%E6%A8%A1%E6%9D%BF%E4%B8%AD%E7%9A%84%20EC2%20%E5%AE%9E%E4%BE%8B%E7%9A%84%20IP%20%E5%9C%B0%E5%9D%80%EF%BC%9F.png)
我正在尝试定义一个 Cassandra 节点集群,以及一些其他实例(一些中间件和应用服务器)。我希望能够将 Cassandra 节点的(内部)IP 地址添加到中间件的配置中,并将第一个 Cassandra 节点的 IP 添加到其他节点的配置中,作为种子节点。我可以完全从模板内部实现这一点吗?(在 AMI 中调用脚本是可以的,但集中配置或平台未提供的任何类型的远程数据库则不行)
谢谢! 安德拉斯
编辑:我忘了提到我还需要使用实例的 IP 来更新相关的安全组。
答案1
在对 AWS 文档进行一番挖掘之后,我发现你可以引用在同一模板中创建的资源的属性,只要它们 a) 在你的引用之前定义 b) 不指向正在创建的资源(没有循环依赖)
b) 意味着要找出 EC2 节点自己的 IP,我确实必须调用 ceejayoz 上面提到的 aws URL
这是我对 Cassandra 节点实例资源的定义。请注意,我在配置文件中放置了标记,以便能够安全地插入正确的值,但您始终可以恢复为简单地替换默认值(例如,将“initial_token: 0”替换为“initial_token: 123”)。
"Cas1" : {
"Type" : "AWS::EC2::Instance",
"Metadata" : {
"AWS::CloudFormation::Init" : {
"config" : {
"packages" : {
"yum" : {
"opscenter-free" : [],
"pyOpenSSL" : []
}
}
},
"services" : {
"sysvinit" : {
"cassandra" : {
"enabled" : "true",
"ensureRunning" : "true"
},
"opscenterd" : {
"enabled" : "true",
"ensureRunning" : "true"
}
}
}
}
},
"Properties" : {
"SecurityGroups" : [ { "Ref" : "CommonSecurityGroup" }, { "Ref" : "OpsCenterSecurityGroup" } ],
"KeyName" : { "Ref" : "KeyName" },
"InstanceType" : { "Ref" : "CassandraInstanceType" },
"ImageId" : { "Fn::FindInMap" : [ "AWSRegionArch2AMI", { "Ref" : "AWS::Region" },{ "Fn::FindInMap" : [ "AWSInstanceType2Arch", { "Ref" : "CassandraInstanceType" }, "Arch" ] } ] },
"UserData" : { "Fn::Base64" : { "Fn::Join" : ["", [
"#!/bin/bash -v\n",
"MY_IP=`(curl http://169.254.169.254/latest/meta-data/local-ipv4)`\n",
"sed -i 's/REPLACE_WITH_TOKEN/0/g' /etc/cassandra/conf/cassandra.yaml\n",
"sed -i 's/REPLACE_WITH_MY_IP/'$MY_IP'/g' /etc/cassandra/conf/cassandra.yaml\n",
"sed -i 's/REPLACE_WITH_SEED_IP/'$MY_IP'/g' /etc/cassandra/conf/cassandra.yaml\n",
"sed -i 's/REPLACE_WITH_MAX_HEAP_SIZE/8G/g' /etc/cassandra/conf/cassandra-env.sh\n",
"sed -i 's/REPLACE_WITH_HEAP_NEWSIZE/4G/g' /etc/cassandra/conf/cassandra-env.sh\n",
"yum update -y aws-cfn-bootstrap\n",
"/opt/aws/bin/cfn-init -s ", { "Ref" : "AWS::StackName" }, " -r Cas1 ",
" --access-key ", { "Ref" : "HostKeys" },
" --secret-key ", {"Fn::GetAtt": ["HostKeys", "SecretAccessKey"]},
" --region ", { "Ref" : "AWS::Region" }, " || error_exit 'Failed to run cfn-init'\n",
"sed -i 's/127.0.0.1/'$MY_IP'/g' /etc/opscenter/opscenterd.conf\n",
"sed -i 's/#passwd_file/passwd_file/g' /etc/opscenter/opscenterd.conf\n",
"echo 'xxx:xxx:admin' > /etc/opscenter/.passwd\n",
"rm -fR /var/lib/cassandra/data\n",
"rm -fR /var/lib/cassandra/commitlog\n",
"mkdir /var/lib/cassandra/data\n",
"mkdir /var/lib/cassandra/commitlog\n",
"chown -R cassandra:cassandra /var/lib/cassandra\n",
"service cassandra start\n",
"service opscenterd start\n"
]]}}
}
},
后续节点的配置相同,除了行
"sed -i 's/REPLACE_WITH_SEED_IP/'$MY_IP'/g' /etc/cassandra/conf/cassandra.yaml\n",
引用种子(第一个)节点的 IP 地址
"sed -i 's/REPLACE_WITH_SEED_IP/", { "Fn::GetAtt" : ["Cas1", "PrivateIp"] }, "/g' /etc/cassandra/conf/cassandra.yaml\n",
至于将实例 IP 添加到安全组,这似乎是不必要的,您只需创建一个组并向其中添加 Ingress 资源,并在其中引用该组作为源
"CommonSecurityGroup" : {
"Type" : "AWS::EC2::SecurityGroup",
"Properties" : {
"GroupDescription" : "Enables",
"SecurityGroupIngress" : [ {
"IpProtocol" : "tcp",
"FromPort" : "22",
"ToPort" : "22",
"CidrIp" : "0.0.0.0/0"
} ]
}
},
"OpsCenterSecurityGroup" : {
"Type" : "AWS::EC2::SecurityGroup",
"Properties" : {
"GroupDescription" : "Enables",
"SecurityGroupIngress" : [ {
"IpProtocol" : "tcp",
"FromPort" : "8888",
"ToPort" : "8888",
"CidrIp" : "0.0.0.0/0"
},
"SecurityGroupIngress" : [ {
"IpProtocol" : "tcp",
"FromPort" : "61620",
"ToPort" : "61621",
"SourceSecurityGroupName" : { "Ref": "CommonSecurityGroup" }
} ]
}
},
"CassandraThriftIngress" : {
"Type" : "AWS::EC2::SecurityGroupIngress",
"Properties" : {
"GroupName": { "Ref": "CommonSecurityGroup" },
"IpProtocol" : "tcp",
"FromPort" : "9160",
"ToPort" : "9160",
"SourceSecurityGroupName" : { "Ref": "CommonSecurityGroup" }
}
},
"CassandraData" : {
"Type" : "AWS::EC2::SecurityGroupIngress",
"Properties" : {
"GroupName": { "Ref": "CommonSecurityGroup" },
"IpProtocol" : "tcp",
"FromPort" : "7000",
"ToPort" : "7001",
"SourceSecurityGroupName" : { "Ref": "CommonSecurityGroup" }
}
},
"CassandraJMX" : {
"Type" : "AWS::EC2::SecurityGroupIngress",
"Properties" : {
"GroupName": { "Ref": "CommonSecurityGroup" },
"IpProtocol" : "tcp",
"FromPort" : "7199",
"ToPort" : "7199",
"SourceSecurityGroupName" : { "Ref": "OpsCenterSecurityGroup" }
}
},
答案2
可以调用 AMI 中的脚本
如果是这样,您只需要 cURL 和 EC2 的内部元数据服务。从实例中:
curl http://169.254.169.254/latest/meta-data/local-ipv4
还有一大堆其他可用的元数据http://169.254.169.254/latest/meta-data/
——主机名、安全组、实例 ID 等。
答案3
是的,您可以完全在模板内完成此操作。下面是模板的“资源”部分,其中定义了三个实例:两个 Cassandra 实例和一个中间件实例。
第二个 Cassandra 实例接收第一个 Cassandra 实例的 IP 作为用户数据。中间件实例接收两个 Cassandra 实例的 IP,也将其作为用户数据。
两个 Cassandra 实例都添加到“cassandra-nodes”安全组中。我没有包含此定义,但在片段部分。您不需要手动将其 IP 添加到 SG,只需在描述实例时引用它即可。
"Resources" : {
"CassOneInstance" : {
"Type" : "AWS::EC2::Instance",
"Properties" : {
"ImageId" : "ami-123",
"InstanceType": "c1.medium",
"SecurityGroups" : [ "cassandra-nodes" ]
}
},
"CassTwoInstance" : {
"Type" : "AWS::EC2::Instance",
"Properties" : {
"ImageId" : "ami-123",
"InstanceType": "c1.medium",
"SecurityGroups" : [ "cassandra-nodes" ],
"UserData" : {
"Fn::Base64" : {
"Fn::Join" : [ ":", [
{ "Fn::GetAtt" : [ "CaseOneInstance", "PrivateIP" ] }
]
}
},
}
},
"MiddleWareInstance" : {
"Type" : "AWS::EC2::Instance",
"Properties" : {
"ImageId" : "ami-123",
"InstanceType": "c1.medium",
"UserData" : {
"Fn::Base64" : {
"Fn::Join" : [ ":", [
{ "Fn::GetAtt" : [ "CaseOneInstance", "PrivateIp" ] },
{ "Fn::GetAtt" : [ "CaseTwoInstance", "PrivateIp" ] }
]
}
},
}
}
}