General

Info and docs

Services and Versions

Can have multiple versions of multiple services (AKA modules)

Default service served at https://<project id>.appspot.com/
Other services: https://<service name>-dot-<project id>.appspot.com/
Specific versions: https://<version>-dot-<service name>-dot-<project id>.appspot.com/

Microservices with app engine: https://cloud.google.com/appengine/docs/standard/python/microservices-on-app-engine –> gradle modules == services?? https://github.com/GoogleCloudPlatform/appengine-modules-sample-java

Environment Options

Standard

https://cloud.google.com/appengine/docs/standard/

Languages:

Python 2.7
Java 7, 8
PHP 5.5
Go 1.6
Standard environment has google.appengine APIs (not available in the flexible environment) for typical service requirements like the Google CLoud Datastore, though you can use the Google Cloud client libraries instead for increased portability.
Sandboxed (no local file system access, only whitelisted binary libraries)
Stateless lightweight HTTP services

Flexible

https://cloud.google.com/appengine/docs/flexible/

Any language

The Flexible Environment allows SSH access, allows disk writes, and supports third-party binaries (also allows stack customization and background processes).

No google.appengine APIs available, use the Google Cloud client libraries instead.

Additional Features

Task queues
Scheduled tasks
Blobstore
Memcache
Search
Logs

Pricing

TODO https://cloud.google.com/appengine/pricing

Environment Configuration

Standard environment can be configured with the appengine-web.xml configuration file: https://cloud.google.com/appengine/docs/standard/java/config/appref

<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
  <module>service-1</module>
  <threadsafe>true</threadsafe>
</appengine-web-app>

If there is an appengine-web.xml file in project, then this is used to configure and deploy to the standard environment. TODO at least IntelliJ ignores app.yaml… might be IDE configuration issue though. And is this an IntelliJ-only construct??? To deploy to the flexible environment, you need to remove the appengine-web.xml file and create an app.yaml file instead with env set to flex.

Minimal app.yaml in root directory of a java project:

Flexible

runtime: java
env: flex
service: service-1
# threadsafe: true
# automatic_scaling:
#   min_num_instances: 2
#   max_num_instances: 20
#   cpu_utilization:
#   target_utilization: 0.5

Standard

runtime: java7
env: standard
service: service-1
# threadsafe: true
# instance_class: F1
# inbound_services:
#   - warmup
handlers:
  - url: /
    script: unused
  - url: '/.*/'
    script: unused
  - url: '/_ah/.*'
    script: unused
  - url: ".*\\.jsp"
    script: unused
# automatic_scaling:
#   min_idle_instances: automatic
#   max_idle_instances: automatic
#   min_pending_latency: automatic
#   max_pending_latency: automatic

For standard environment, change env value to standard. If service is left out, then the app will be deployed as the default service. Apparently the handlers section is not necessary for flex environment. Commented out bits are default values assigned by GCP.

TODO image of result, point out different env. for different versions

Deploying

IntelliJ

If Google App Engine Flexible framework is not autodetected, right-click on project -> Add Framework Support and check “Google App Engine Flexible” TODO cannot see it there though!
File > Settings > Build, Execution, Deployment > Clouds -> Add new deployment profile by clicking +
File -> Project Structure -> Facets -> Google App Engine Flexible -> Configure path to app.yaml or generate a new app.yaml
File -> Project Structure -> Artifacts -> + -> Web Application: Archive -> for ‘'
https://stackoverflow.com/questions/43073707/how-to-get-intellij-java-project-on-google-app-engine-flex
https://cloud.google.com/tools/intellij/docs/deploy-flex
https://cloudplatform.googleblog.com/2016/08/never-leave-your-Java-IDE-with-Google-Cloud-Tools-for-IntelliJ-plugin.html
https://www.jetbrains.com/help/idea/getting-started-with-google-app-engine.html

TODO Unable to change deployment mode to

Using the gcloud CLI tool

https://cloud.google.com/appengine/docs/flexible/python/testing-and-deploying-your-app

gcloud app deploy [--no-promote] app.yaml

gcloud help app deploy

TODO possible to use appengine-web.xml instead of app.yaml from cli?

Samples & Tutorials

Tutorial in Cloud Console using Cloud Shell

Java: git clone https://github.com/GoogleCloudPlatform/appengine-try-java.git

mvn appengine:run mvn appengine:deploy

Quickstarts

Using the GCP Client library

See tutorials for supported languages on GitHub.

TODO Using the app engine features (any available outside app engine, like task queues etc?)

Tasks https://cloud.google.com/appengine/docs/standard/python/taskqueue/push/creating-handlers