本章将详细介绍执行和调用Lambda函数的过程及其中涉及的步骤.
AWS执行取决于为AWS Lambda Function添加的配置详细信息.创建函数时，会有内存和时间分配，用于执行AWS Lambda函数.
借助配置详细信息，AWS Lambda可创建执行上下文.执行上下文是一个临时运行时环境，可以使用任何外部依赖项(如数据库连接，http端点，第三方库等)(如果有).
调用AWS Lambda函数时第一次或者如果更新lambda函数，由于执行上下文设置，添加的延迟很少.但是，与第一次调用相比，后续调用更快.如果在较短的时间内调用Lambda函数，AWS Lambda会再次尝试重用执行上下文.
执行上下文的重用具有以下含义和减号;
如果为执行Lambda完成了任何数据库连接，则保持连接以便重用.因此，Lambda代码必须首先检查连接 - 如果存在并重新使用;否则我们必须重新建立新连接.
执行上下文在/tmp 目录中保留500MB的磁盘空间.所需数据缓存在此目录中.您可以在代码中进行额外检查以查看数据是否存在.
如果回调或某些后台进程在Lambda函数为调用时，执行将在再次调用lambda函数时启动.如果你不需要这样的事情，请确保你的进程在函数执行完成后正确结束.
你应该使用执行上下文和存储在tmp目录中的数据.您必须在代码中添加必要的检查，以查看在创建新的数据之前是否存在所需的数据.这将节省执行期间的时间并使其更快.
我们可以使用 aws cli手动调用AWS 的.我们已经了解了如何使用 cli 创建和部署AWS Lambda.在这里，我们将首先使用 aws cli 创建一个函数并调用它.
您可以使用以下命令使用 aws cli :
命令
$ b创建AWS Lambda函数$ b
create-function --function-name <value> --runtime <value> --role <value> --handler <value> [--code <value>] [--description <value>] [--timeout <value>] [--memory-size <value>] [--environment <value>] [--kms-key-arn <value>] [--tags <value>] [--zip-file <value>] [--cli-input-json <value>]
带值的命令
aws lambda create-function --function-name "lambdainvoke" --runtime "nodejs8.10" --role "arn:aws:iam::625297745038:role/lambdaapipolicy" --handler "index.handler" --timeout 5 --memory-size 256 --zip-file "fileb://C:\nodeproject\index.zip"
输出如下所示 :
在AWS控制台中创建的功能如下所示 :
现在，您可以使用以下命令调用该函数:调用
--function-name <value> [--invocation-type <value>] [--log-type <value>] [--client-context <value>] [--payload <value>] [--qualifier <value>] outfile <value>
选项
- function-name : 指定要调用的函数的名称.
- 调用类型(字符串) : 默认情况下，invokation类型为 requestResponse则的.可用于invokation类型的值是 RequestResponse，Event 和 DryRun .
事件调用类型用于异步响应.
要验证Lambda函数时要使用DryRun无需执行它.
- log-type : 它将尾巴如果调用类型是RequestResponse.它给出了最后4KB base64编码的日志数据.可能的值为尾部和无.
- 客户端上下文&减号; 您可以传递客户端Lambda函数的具体细节. clientcontext必须是json格式和base64编码.最大文件大小为3583字节.
- 有效负载&减去; json格式输入到lambda函数.
- 限定符和减号; 您可以指定Lambda函数版本或别名.如果传递函数版本，则api将使用限定函数arn来调用Lambda函数.如果指定了别名，则api使用别名ARN来调用Lambda函数.
outfile : 这是保存内容的文件名.
带值的命令
aws lambda invoke --function-name "lambdainvoke" --log-type Tail C:\nodeproject\outputfile.txt
您可以使用payload选项以json格式向lambda函数发送虚拟事件，如下所示./p>
相关的AWS Lambda代码如下 :
exports.handler = async (event, callback) => {
console.log("Hello => "+ event.name);
console.log("Address =>"+ event.addr);
callback(null, 'Hello '+event.name +" and address is "+ event.addr);
};请注意，在代码中，我们有控制台 event.name 和 event.addr .现在，让我们在aws cli中使用payload选项来发送带有名称和地址的事件，如下所示 :
aws lambda invoke --function-name "lambdainvoke" --log-type Tail --payload file://C:\clioutput\input.txt C:\clioutput\outputfile.txt
Thenpayload将输入作为文件路径，其中json输入如图所示 :
{"name":"Roy Singh", "addr":"Mumbai"}相应的输出如下所示 :
输出存储在文件 C:\ clioutput \ output.txt 如下 :
"Hello Roy Singh and address is Mumbai"
您可以通过传递示例事件来测试AWS Lambda函数.本节提供了AWS Services的一些示例事件.您可以使用 invoke 命令在使用任何服务触发时测试输出.观察为相应的样本事件提供的代码低于 :
{
"Records": [{
"eventVersion": "2.0",
"eventTime": "1970-01-01T00:00:00.000Z",
"requestParameters": {
"SourceIPAddress": "127.0.0.1"
},
"s3": {
"configurationId": "testConfigRule",
"object": {
"eTag": "0123456789abcdef0123456789abcdef",
"sequencer": "0A1B2C3D4E5F678901",
"key": "HappyFace.jpg",
"size": 1024
},
"bucket": {
"arn": bucketarn,
"name": "Sourcebucket",
"ownerIdentity": {
"principalId": "EXAMPLE"
}
},
"s3SchemaVersion": "1.0"
},
"responseElements": {
"x-amz-id-2": "EXAMPLE123/5678abcdefghijklambdaisawesome/mnopqrstuvwxyzABCDEFGH",
"x-amz-request-id": "EXAMPLE123456789"
},
"awsRegion": "us-east-1",
"eventName": "ObjectCreated:Put",
"userIdentity": {
"principalId": "EXAMPLE"
},
"eventSource": "aws:s3"
}]
}从s3 put事件中获取文件的详细信息，您可以使用以下命令 :
event.Records [0] .s3.object.key//将显示名称文件
要获取存储桶名称，您可以使用以下命令 :
event.Records [0] .s3.bucket.name//将给出桶的名称.
要查看EventName ，您可以使用以下命令 :
event.Records [0] .eventName//将显示事件名
{
"Records": [{
"eventVersion": "2.0",
"eventTime": "1970-01-01T00:00:00.000Z",
"requestParameters": {
"SourceIPAddress": "127.0.0.1"
},
"s3": {
"configurationId": "testConfigRule",
"object": {
"sequencer": "0A1B2C3D4E5F678901",
"key": "HappyFace.jpg"
},
"bucket": {
"arn": bucketarn,
"name": "Sourcebucket",
"ownerIdentity": {
"principalId": "EXAMPLE"
}
},
"s3SchemaVersion": "1.0"
},
"responseElements": {
"x-amz-id-2": "EXAMPLE123/5678abcdefghijklambdaisawesome/mnopqrstuvwxyzABCDEFGH",
"x-amz-request-id": "EXAMPLE123456789"
},
"awsRegion": "us-east-1",
"eventName": "ObjectRemoved:Delete",
"userIdentity": {
"principalId": "EXAMPLE"
},
"eventSource": "aws:s3"
}]
}在DynamoDB表上进行更改时，Amazon DynamoDB可以是AWS Lambda上的事件.我们可以执行添加条目，更新和删除DynamodDB表中的记录等操作.
此处显示DynamoDB添加，插入和删除事件的示例事件 :
{
"Records": [{
"eventID": "1",
"eventVersion": "1.0",
"dynamodb": {
"Keys": {
"Id": {
"N": "101"
}
},
"NewImage": {
"Message": {
"S": "New item!"
},
"Id": {
"N": "101"
}
},
"StreamViewType": "NEW_AND_OLD_IMAGES",
"SequenceNumber": "111",
"SizeBytes": 26
},
"awsRegion": "us-west-2",
"eventName": "INSERT",
"eventSourceARN": eventSourcearn,
"eventSource": "aws:dynamodb"
},
{
"eventID": "2",
"eventVersion": "1.0",
"dynamodb": {
"OldImage": {
"Message": {
"S": "New item!"
},
"Id": {
"N": "101"
}
},
"SequenceNumber": "222",
"Keys": {
"Id": {
"N": "101"
}
},
"SizeBytes": 59,
"NewImage": {
"Message": {
"S": "This item has changed"
},
"Id": {
"N": "101"
}
},
"StreamViewType": "NEW_AND_OLD_IMAGES"
},
"awsRegion": "us-west-2",
"eventName": "MODIFY",
"eventSourceARN": Sourcearn,
"eventSource": "aws:dynamodb"
},
{
"eventID": "3",
"eventVersion": "1.0",
"dynamodb": {
"Keys": {
"Id": {
"N": "101"
}
},
"SizeBytes": 38,
"SequenceNumber": "333",
"OldImage": {
"Message": {
"S": "This item has changed"
},
"Id": {
"N": "101"
}
},
"StreamViewType": "NEW_AND_OLD_IMAGES"
}, "awsRegion": "us-west-2",
"eventName": "REMOVE",
"eventSourceARN": Sourcearn,
"eventSource": "aws:dynamodb"
}]
}AWS Lambda可以帮助您处理在简单通知中创建的通知服务(SNS).每当在SNS中发布消息时，可以使用SNS事件触发Lambda函数，该事件具有消息的详细信息.此消息可在Lambda函数内处理，并可根据要求进一步发送到其他服务.
输入消息后，SNS将触发Lambda函数.如果任何错误试图调用Lambda函数，SNS将重试最多三次调用lambda函数.
示例具有AWS Lambda函数中可用于执行进一步处理的所有详细信息的事件如下所示 :
{
"Records": [{
"EventVersion": "1.0",
"EventSubscriptionArn": eventsubscriptionarn,
"EventSource": "aws:sns",
"Sns": {
"SignatureVersion": "1",
"Timestamp": "1970-01-01T00:00:00.000Z",
"Signature": "EXAMPLE",
"SigningCertUrl": "EXAMPLE",
"MessageId": "95df01b4-ee98-5cb9-9903-4c221d41eb5e",
"Message": "Hello from SNS!",
"MessageAttributes": {
"Test": {
"Type": "String",
"Value": "TestString"
},
"TestBinary": {
"Type": "Binary",
"Value": "TestBinary"
}
},
"Type": "Notification",
"UnsubscribeUrl": "EXAMPLE",
"TopicArn": topicarn,
"Subject": "TestInvoke"
}
}]
}亚马逊简单邮件服务可用于发送邮件和接收邮件.收到消息后，可以在简单邮件服务上调用AWS Lambda函数.
SES事件的详细信息在AWS Lambda中使用时显示在下面 :
{
"Records": [{
"eventVersion": "1.0",
"ses": {
"mail": {
"commonHeaders": {
"from": [
"Jane Doe <janedoe@example.com>"
],
"to": [
"johndoe@Source.com"
],
"returnPath": "janedoe@example.com",
"messageId": "<0123456789Source.com>",
"date": "Wed, 7 Oct 2015 12:34:56 -0700",
"subject": "Test Subject"
},
"example": "janedoe@example.com",
"timestamp": "1970-01-01T00:00:00.000Z",
"destination": [
"johndoe@example.com"
],
"headers": [{
"name": "Return-Path",
"value": "<janedoe@example.com>"
},
{
"name": "Received",
"value": "from mailer.example.com (mailer.example.com [203.0.113.1]) by inbound-smtp.us-west-2.amazonaws.com with SMTP id o3vrnil0e2ic for johndoe@example.com; Wed, 07 Oct 2015 12:34:56 +0000 (UTC)"
},
{
"name": "DKIM-Signature",
"value": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=example.com; s=example; h=mime-version:from:date:message-id:subject:to:content-type; bh=jX3F0bCAI7sIbkHyy3mLYO28ieDQz2R0P8HwQkklFj4=; b=sQwJ+LMe9RjkesGu+vqU56asvMhrLRRYrWCbV"
},
{
"name": "MIME-Version",
"value": "1.0"
},
{
"name": "From",
"value": "Jane Doe <janedoe@example.com>"
},
{
"name": "Date",
"value": "Wed, 7 Oct 2015 12:34:56 -0700"
},
{
"name": "Message-ID",
"value": "<0123456789example.com>"
},
{
"name": "Subject",
"value": "Test Subject"
},
{
"name": "To",
"value": "johndoe@example.com"
},
{
"name": "Content-Type",
"value": "text/plain; charset=UTF-8"
}],
"headersTruncated": false,
"messageId": "o3vrnil0e2ic28tr"
},
"receipt": {
"recipients": [
"johndoe@example.com"
],
"timestamp": "1970-01-01T00:00:00.000Z",
"spamVerdict": {
"status": "PASS"
},
"dkimVerdict": {
"status": "PASS"
},
"processingTimeMillis": 574,
"action": {
"type": "Lambda",
"invocationType": "Event",
"functionArn": "arn:aws:lambda:us-west-2:012345678912:function:example"
},
"spfVerdict": {
"status": "PASS"
},
"virusVerdict": {
"status": "PASS"
}
}
},
"eventexample": "aws:ses"
}]
}可以使用 CloudWatch Logs从Amazon CloudWatch Logs触发AWS Lambda订阅的. CloudWatch Logs订阅包含有关日志的数据实时数据，可以在AWS Lambda内部进行处理和分析，也可以用于加载到其他系统.
{
"awslogs": {
"data": "H4sIAAAAAAAAAHWPwQqCQBCGX0Xm7EFtK+smZBEUgXoLCdMhFtKV3akI8d0bLYmibvPPN3wz00CJxmQnTO41whwW
QRIctmEcB6sQbFC3CjW3XW8kxpOpP+OC22d1Wml1qZkQGtoMsScxaczKN3plG8zlaHIta5KqWsozoTYw3/djzwhpL
wivWFGHGpAFe7DL68JlBUk+l7KSN7tCOEJ4M3/qOI49vMHj+zCKdlFqLaU2ZHV2a4Ct/an0/ivdX8oYc1UVX860fQ
DQiMdxRQEAAA=="
}
}可以在https url上调用AWS Lambda函数。 IT可以在GET，POST，PUT上完成。 调用https url时，也会触发AWS Lambda函数，并且可以在AWS Lambda中使用get / post传递给https的数据，以用于在DynamoDB中插入或发送邮件等。
{
"path": "/test/hello",
"headers": {
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
"Accept-Encoding": "gzip, deflate, lzma, sdch, br",
"Accept-Language": "en-US,en;q=0.8",
"CloudFront-Forwarded-Proto": "https",
"CloudFront-Is-Desktop-Viewer": "true",
"CloudFront-Is-Mobile-Viewer": "false",
"CloudFront-Is-SmartTV-Viewer": "false",
"CloudFront-Is-Tablet-Viewer": "false",
"CloudFront-Viewer-Country": "US",
"Host": "wt6mne2s9k.execute-api.us-west-2.amazonaws.com",
"Upgrade-Insecure-Requests": "1",
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",
"Via": "1.1 fb7cca60f0ecd82ce07790c9c5eef16c.cloudfront.net (CloudFront)",
"X-Amz-Cf-Id": "nBsWBOrSHMgnaROZJK1wGCZ9PcRcSpq_oSXZNQwQ10OTZL4cimZo3g==",
"X-Forwarded-For": "192.168.100.1, 192.168.1.1",
"X-Forwarded-Port": "443",
"X-Forwarded-Proto": "https"
},
"pathParameters": {
"proxy": "hello"
},
"requestContext": {
"accountId": "123456789012",
"reexampleId": "us4z18",
"stage": "test",
"requestId": "41b45ea3-70b5-11e6-b7bd-69b5aaebc7d9",
"identity": {
"cognitoIdentityPoolId": "",
"accountId": "",
"cognitoIdentityId": "",
"caller": "",
"apiKey": "",
"exampleIp": "192.168.100.1",
"cognitoAuthenticationType": "",
"cognitoAuthenticationProvider": "",
"userArn": "",
"userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",
"user": ""
},
"reexamplePath": "/{proxy+}",
"httpMethod": "GET",
"apiId": "wt6mne2s9k"
},
"reexample": "/{proxy+}",
"httpMethod": "GET",
"queryStringParameters": {
"name": "me"
},
"stageVariables": {
"stageVarName": "stageVarValue"
}
}{
"statusCode": 200,
"headers": {
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
"Accept-Encoding": "gzip, deflate, lzma, sdch, br",
"Accept-Language": "en-US,en;q=0.8",
"CloudFront-Forwarded-Proto": "https",
"CloudFront-Is-Desktop-Viewer": "true",
"CloudFront-Is-Mobile-Viewer": "false",
"CloudFront-Is-SmartTV-Viewer": "false",
"CloudFront-Is-Tablet-Viewer": "false",
"CloudFront-Viewer-Country": "US",
"Host": "wt6mne2s9k.execute-api.us-west-2.amazonaws.com",
"Upgrade-Insecure-Requests": "1",
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",
"Via": "1.1 fb7cca60f0ecd82ce07790c9c5eef16c.cloudfront.net (CloudFront)",
"X-Amz-Cf-Id": "nBsWBOrSHMgnaROZJK1wGCZ9PcRcSpq_oSXZNQwQ10OTZL4cimZo3g==",
"X-Forwarded-For": "192.168.100.1, 192.168.1.1",
"X-Forwarded-Port": "443",
"X-Forwarded-Proto": "https"
},
"body": "Hello World"
}
