AppEngine Tools

This is a simple project that allows you to manage an AppEngine application from the command line.


At the moment, you must build from sources to have a executable jar:

hg clone
mvn clean package


After building it, you can see the comand help with the --help flag:

$ java -jar target/appengine-cli.jar --help

App Engine Tools - CLI interface

Usage: appengine-cli COMMAND [OPTIONS]

Where COMMAND can be one of:
    console : starts an interactive shell session
    dump : export/import the local datastore

Remote API Console

You can then use the console command to connect to your local or production instance, and execute java commands into it.

$ java -jar target/appengine-cli.jar console --appid=myappid

Note: this is not a remote shell, like ssh. You're running code in your machine, delegating AppEngine RPCs to your production application Datastore. Read the AppEngine datastore documentation on Remote API form more details.

DevAppServer Datastore Dump Tool

You can also use the dump command, to export your local datastore as a Yaml backup, or to load it back again.

$ java -jar target/appengine-cli.jar dump > backup.yaml
$ java -jar target/appengine-cli.jar dump --load backup.yaml

Note: This tool will download all your datastore data using the RemoteAPI connection. This is not a backup tool! If your dataset is very small, you can do backups of it, but not ALL data is backed up: some property value types are not handled properly. To make restorable backups, use the Backup Tool from Datastore Admin console.

Fixtures for local development

One usefull aspect of the dump command is that it can be used to generate local fixtures and store a local state of your entities, in a human readable, reproducible and editable way.

The format of the Entity Yaml document is pretty simple:

--- !entity
key: [Profile, 1]
  activeProfile: true
  age: 27
  height: 1.87
  name: John Doe [Porshe, Camaro, Mustang]
  preferences.fruits: [Apple, Orange, Lemon]
  registrationDate: 2014-02-10T21:34:45.085Z
  system.mixedList: [public, 12, true, 2.0]
  system.mixedSet: !!set {2: null, 3: null, one: null}

There is a basic support for some custom types that has special meaning Strings are 500 byte limited character sequences, when stored in the Datastore, and are serialied as Yaml !!str scalars. Text values are stored with the custom tag !text:

--- !entity
key: [TextEntity, key-name]
  long-string: !text |-
    This is a long text string
  short-string: This is a simple short string

Shortblobs are !!binary (byte[]) yaml arrays when serialized, and Blob objects are tagged with !blob:

--- !entity
key: [ComplextBlobs, blob-holder-1]
  long-blob: !blob |-
  short-blob: !!binary |-