AppEngine に Ktor アプリをデプロイする

1. Google Cloud SDK をインストールする

https://cloud.google.com/sdk/docs/install

2. 認証 & プロジェクト選択

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1. > gcloud init  

> gcloud init

3. Ktor アプリを作る

IntelliJ IDEA に Ktor plugin を入れて、New Project wizard から Ktor プロジェクトを作る

4. AppEngine の設定を追加する

build.gradle.kts

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1. ...  
2.   
3. plugins {  
4.     ...  
5.     // ↓ 追加  
6.     id("com.google.cloud.tools.appengine") version "2.2.0"  
7.     // ↓ 追加  
8.     war  
9. }  
10.   
11. ...  
12.   
13. dependencies {  
14.     ...  
15.   
16.     // ↓ 追加  
17.     implementation("io.ktor:ktor-server-servlet:$ktor_version")  
18.     // ↓ 追加  
19.     compileOnly("com.google.appengine:appengine:$appengine_version")  
20. }  
21.   
22. // ↓ 追加  
23. appengine {  
24.     deploy {  
25.         projectId = "GCLOUD_CONFIG"  
26.         version = "GCLOUD_CONFIG"  
27.     }  
28. }  
29.   
30. // ↓ 追加  
31. tasks.named("run") {  
32.     dependsOn(":appengineRun")  
33. }  

... plugins { ... // ↓ 追加 id("com.google.cloud.tools.appengine") version "2.2.0" // ↓ 追加 war } ... dependencies { ... // ↓ 追加 implementation("io.ktor:ktor-server-servlet:$ktor_version") // ↓ 追加 compileOnly("com.google.appengine:appengine:$appengine_version") } // ↓ 追加 appengine { deploy { projectId = "GCLOUD_CONFIG" version = "GCLOUD_CONFIG" } } // ↓ 追加 tasks.named("run") { dependsOn(":appengineRun") } settings.gradle.kts

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1. ...  
2.   
3. // https://stackoverflow.com/questions/48502220/how-to-configure-appengine-gradle-plugin-using-kotlin-dsl/48510049#48510049  
4. // ↓ 追加  
5. pluginManagement {  
6.     repositories {  
7.         gradlePluginPortal()  
8.         google()  
9.     }  
10.     resolutionStrategy {  
11.         eachPlugin {  
12.             if (requested.id.id == "com.google.cloud.tools.appengine") {  
13.                 useModule("com.google.cloud.tools:appengine-gradle-plugin:${requested.version}")  
14.             }  
15.         }  
16.     }  
17. }  

... // https://stackoverflow.com/questions/48502220/how-to-configure-appengine-gradle-plugin-using-kotlin-dsl/48510049#48510049 // ↓ 追加 pluginManagement { repositories { gradlePluginPortal() google() } resolutionStrategy { eachPlugin { if (requested.id.id == "com.google.cloud.tools.appengine") { useModule("com.google.cloud.tools:appengine-gradle-plugin:${requested.version}") } } } } src/main/webapp/WEB-INF/web.xml

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1. <?xml version="1.0" encoding="ISO-8859-1" ?>  
2. <web-app xmlns="http://java.sun.com/xml/ns/javaee"  
3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
4.          xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"  
5.          version="3.0">  
6.     <!-- path to application.conf file, required -->  
7.     <!-- note that this file is always loaded as an absolute path from the classpath -->  
8.     <context-param>  
9.         <param-name>io.ktor.ktor.config</param-name>  
10.         <param-value>application.conf</param-value>  
11.     </context-param>  
12.   
13.     <servlet>  
14.         <display-name>KtorServlet</display-name>  
15.         <servlet-name>KtorServlet</servlet-name>  
16.         <servlet-class>io.ktor.server.servlet.ServletApplicationEngine</servlet-class>  
17.   
18.         <!-- required! -->  
19.         <async-supported>true</async-supported>  
20.   
21.         <!-- 100mb max file upload, optional -->  
22.         <multipart-config>  
23.             <max-file-size>304857600</max-file-size>  
24.             <max-request-size>304857600</max-request-size>  
25.             <file-size-threshold>0</file-size-threshold>  
26.         </multipart-config>  
27.     </servlet>  
28.   
29.     <servlet-mapping>  
30.         <servlet-name>KtorServlet</servlet-name>  
31.         <url-pattern>/</url-pattern>  
32.     </servlet-mapping>  
33.   
34. </web-app>  

<?xml version="1.0" encoding="ISO-8859-1" ?> <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <!-- path to application.conf file, required --> <!-- note that this file is always loaded as an absolute path from the classpath --> <context-param> <param-name>io.ktor.ktor.config</param-name> <param-value>application.conf</param-value> </context-param> <servlet> <display-name>KtorServlet</display-name> <servlet-name>KtorServlet</servlet-name> <servlet-class>io.ktor.server.servlet.ServletApplicationEngine</servlet-class> <!-- required! --> <async-supported>true</async-supported> <!-- 100mb max file upload, optional --> <multipart-config> <max-file-size>304857600</max-file-size> <max-request-size>304857600</max-request-size> <file-size-threshold>0</file-size-threshold> </multipart-config> </servlet> <servlet-mapping> <servlet-name>KtorServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app> src/main/webapp/WEB-INF/appengine-web.xml

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1. <?xml version="1.0" encoding="utf-8"?>  
2. <appengine-web-app xmlns="http://appengine.google.com/ns/1.0">  
3.     <threadsafe>true</threadsafe>  
4.     <runtime>java8</runtime>  
5. </appengine-web-app>  

<?xml version="1.0" encoding="utf-8"?> <appengine-web-app xmlns="http://appengine.google.com/ns/1.0"> <threadsafe>true</threadsafe> <runtime>java8</runtime> </appengine-web-app>

5. ローカルで実行する

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1. > ./gradlew appengineRun  
2.     
3. // 止めるとき  
4. > ./gradlew appengineStop  

> ./gradlew appengineRun // 止めるとき > ./gradlew appengineStop

6. デプロイする

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1. > ./gradlew appengineDeploy  

> ./gradlew appengineDeploy


参考

• Run a Kotlin Ktor app on App Engine standard environment （注 Groovy なのとちょっと内容が古いです。（2021/3/9現在））
• https://ktor.io/docs/war.html （web.xml の設定)
• https://ktor.io/docs/google-app-engine.html
• https://github.com/ktorio/ktor-documentation/tree/main/codeSnippets/snippets/google-appengine-standard