Sample Azure Functions with Timer trigger and SendGrid output binding for Java

function.json

{
    "bindings": [
      {
        "type": "timerTrigger",
        "name": "keepAliveTrigger",
        "direction": "in",
        "schedule": "0 * * * * *"
      },
      {
        "type": "sendGrid",
        "name": "$return",
        "direction": "out",
        "apiKey": "SendGridAttribute.ApiKey"
      }
    ]
}

Functions.java

package com.functions;

import java.time.*;
import com.microsoft.azure.functions.annotation.*;
import com.microsoft.azure.functions.*;

/**
 * Azure Functions with HTTP Trigger.
 */
public class Function {
    @FunctionName("keepAlive")
    public void keepAlive(
            @TimerTrigger(name = "keepAliveTrigger", schedule = "0 * * * * *") String timerInfo,
            final ExecutionContext context,
            @SendGridOutput(
                name = "email", dataType = "String", apiKey = "SendGridAttribute.ApiKey", to = "<to mail address>", from = "<from mail address>",
                subject= "Sending with SendGrid", text = "Hello from Azure Functions"
                ) OutputBinding<String> email
            )
    {
        String name = "test";

        final String emailBody = "{\"personalizations\":" +
                                    "[{\"to\":[{\"email\":\"<to mail address>\"}]," +
                                    "\"subject\":\"Sending with SendGrid\"}]," +
                                    "\"from\":{\"email\":\"<from mail address>\"}," +
                                    "\"content\":[{\"type\":\"text/plain\",\"value\": \"Hello" + name + "\"}]}";

        email.setValue(emailBody);
        context.getLogger().info("Java Timer trigger function executed at: " + LocalDateTime.now());
    }
}

host.json

{
  "version": "2.0",
  "extensionBundle": {
      "id": "Microsoft.Azure.Functions.ExtensionBundle",
      "version": "[1.*, 2.0.0)"
  }
}

local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "",
    "FUNCTIONS_WORKER_RUNTIME": "java",
    "SendGridAttribute.ApiKey": "<SendGrid ApiKey>"
  }
}

概要

• Azure Functionsで定期的にメールを送信するサンプルプログラムです(for Java)
• triggerをTimer、output bindingをSendGridにしています
• 環境はubuntu1904

事前に

• Azure Functions Core Toolsをインストール
  • https://docs.microsoft.com/ja-jp/azure/azure-functions/functions-run-local
• Azuriteをインストール
  • https://github.com/azure/azurite
• SendGridのApiKeyを取得しておく
  • https://docs.microsoft.com/ja-jp/azure/sendgrid-dotnet-how-to-send-email

プロジェクト作成

• 公式サイトを参考にプロジェクト作成する
  • https://docs.microsoft.com/ja-jp/azure/azure-functions/functions-create-first-java-maven

$ mvn archetype:generate \
>     -DarchetypeGroupId=com.microsoft.azure \
>     -DarchetypeArtifactId=azure-functions-archetype
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------< org.apache.maven:standalone-pom >-------------------
[INFO] Building Maven Stub Project (No POM) 1
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] >>> maven-archetype-plugin:3.1.1:generate (default-cli) > generate-sources @ standalone-pom >>>
[INFO]
[INFO] <<< maven-archetype-plugin:3.1.1:generate (default-cli) < generate-sources @ standalone-pom <<<
[INFO]
[INFO]
[INFO] --- maven-archetype-plugin:3.1.1:generate (default-cli) @ standalone-pom ---
[INFO] Generating project in Interactive mode
[INFO] Archetype [com.microsoft.azure:azure-functions-archetype:1.23] found in catalog remote
Define value for property 'groupId' (should match expression '[A-Za-z0-9_\-\.]+'): com.functions
[INFO] Using property: groupId = com.functions
Define value for property 'artifactId' (should match expression '[A-Za-z0-9_\-\.]+'): example-function-timer-sendgrid
[INFO] Using property: artifactId = example-function-timer-sendgrid
Define value for property 'version' 1.0-SNAPSHOT: :
Define value for property 'package' com.functions: :
Define value for property 'appName' example-function-timer-sendgrid-20190803135456210: : example-function-timer-sendgrid
Define value for property 'appRegion' westus: : japaneast
Define value for property 'resourceGroup' java-functions-group: : example-function
Confirm properties configuration:
groupId: com.functions
groupId: com.functions
artifactId: example-function-timer-sendgrid
artifactId: example-function-timer-sendgrid
version: 1.0-SNAPSHOT
package: com.functions
appName: example-function-timer-sendgrid
appRegion: japaneast
resourceGroup: example-function
 Y: :
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Archetype: azure-functions-archetype:1.23
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: groupId, Value: com.functions
[INFO] Parameter: artifactId, Value: example-function-timer-sendgrid
[INFO] Parameter: version, Value: 1.0-SNAPSHOT
[INFO] Parameter: package, Value: com.functions
[INFO] Parameter: packageInPathFormat, Value: com/functions
[INFO] Parameter: appName, Value: example-function-timer-sendgrid
[INFO] Parameter: resourceGroup, Value: example-function
[INFO] Parameter: package, Value: com.functions
[INFO] Parameter: version, Value: 1.0-SNAPSHOT
[INFO] Parameter: groupId, Value: com.functions
[INFO] Parameter: appRegion, Value: japaneast
[INFO] Parameter: artifactId, Value: example-function-timer-sendgrid
[INFO] Project created from Archetype in dir: /home/tsaeki/Develop/example-function-timer-sendgrid
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  19:10 min
[INFO] Finished at: 2019-08-03T14:12:59+09:00
[INFO] ------------------------------------------------------------------------

• 各ファイルを設定する

ファイル名	説明
Function.java	メインプログラム
function.json	bindingsの設定
host.json
local.settings.json	ローカル環境の設定値. SendGrid ApiKeyを設定

• build and run

# 事前にazuriteを実行しておく
$ azurite

# 実行
$ mvn clean package 
$ mvn azure-functions:run

# 1分おきにメールが届くことを確認

参考

• https://docs.microsoft.com/ja-jp/azure/azure-functions/functions-create-first-java-maven
• https://docs.microsoft.com/ja-jp/azure/azure-functions/functions-triggers-bindings
• https://docs.microsoft.com/ja-jp/azure/azure-functions/functions-bindings-timer
• https://docs.microsoft.com/ja-jp/azure/azure-functions/functions-bindings-sendgrid
• https://docs.microsoft.com/ja-jp/azure/azure-functions/functions-run-local
• https://github.com/azure/azurite
• https://docs.microsoft.com/ja-jp/azure/sendgrid-dotnet-how-to-send-email