gcloud: how to download the app via cli

I am coming to Google App Engine after two years, I see that they have made lots of improvements and added tons of features. But sadly, their documentation sometimes leaves much to be desired.

I used to download my code of the uploaded version with the appcfg.pyusing the following command.

appcfg.py download_app -A <app_id> -V <version> <output-dir>

But of course now that they have culminated everything in the gcloud shell where appcfg.py is not accessible.

However, the following method helped me to download the deployed code:

1. Go the console and in to the Google App Engine.

2. Select the project you want to work with.

3. Once the project's dashboard opens, Click on the top right to open the built in console window.

   

4. Which should load the cloud shell at the bottom, now if you check appcfg.py is available to you to use in this VM.

   

5. Hence, use appcfg.py download_app -A <app_id> -V <version> <output-dir> to download the code.

6. Now once you have the code in the desired folder, in order to download it on your local machine - You can open the docker code editor

   

7. Now here I assumed if I rightclicked and exported the desired folder it would work,

   

   but instead it gave me the following error message.

   {"Error":"'concurrency' must be a number but it is [object Undefined]","Message":"'concurrency' must be a number but it is [object Undefined]"}
   

8. So, I thought maybe it would play along nicely if the the folder was an archive. Go back to the cloud shell and using whatever utility you fancy make an archive of the folder

   zip -r mycode.zip mycode
   

9. Go to the docker code editor, export and download.

   

Now. Of course there might many more ways do it (hopefully) but this is what made sense to me after returning to Google App Engine after 2 years.

Currently, the best way to do this is to pull the files out of Docker.

Put instance into self-managed mode, so that you can ssh into it:

$ gcloud preview app modules set-managed-by default --version 1 --self

Find the name of the instance:

$ gcloud compute instances list | grep gae-default-1

Copy it out of the Docker container, change the permissions, and copy it back to your local machine:

$ gcloud compute ssh --zone=us-central1-f gae-default-1-1234 'sudo docker cp gaeapp:/app /tmp'
$ gcloud compute ssh --zone=us-central1-f gae-default-1-1234 "chown -R $USER /tmp/app"
$ gcloud compute copy-files --zone=us-central1-f gae-default-1-1234:/tmp/app /tmp/
$ ls /tmp/app
Dockerfile
[...]

IMHO, the best option today (Aug 2018) is:

Under the main menu, under Products, go to Tools -> Cloud Build -> Build history.

There, click the ID of the build you want.

Then, in the opened window (Build details), click the source link, the download of your compressed code begins.

As simple as that.

HTH.