Customize JRE used by Azure Functions

For Windows plan:

• Open Kudu: https://docs.microsoft.com/en-us/azure/azure-functions/functions-how-to-use-azure-function-app-settings#kudu
• Find the JRE you would like to use, which can be located at D:\Program Files\Java\
• Copy your JRE to a folder in d:\home. For example D:\home\MyJre
• Add AppSetting Key languageWorkers:java:defaultExecutablePath with value set to full path to your java.exe, for example d:\home\MyJre\bin\java.exe
• If your app is using consumption plan, you also need add following appsetting. Note: This will increase cold starts for java functions
  • App setting key WEBSITE_USE_PLACEHOLDER with value set to 0

For Linux plan:

• Please follow Manual version updates on linux