RStudio App Engine

App Engine is a managed compute service that recently started to support Docker environments that can run any code. This is a demo of deploying RStudio.

App Engine offers benefits such as auto scaling that turns off the instance when you are not using it. It reboots upon request of the application URL.

This builds on top of the persistent RStudio image developed for googleComputeEngineR, with which you can configure persistent GitHub/SSH keys and backups on Cloud Storage.

Pricing

Pricing is here. Flexible doesn't do a free tier yet, and the minimum is 1 instance running 24/7

A rough guide is $1.26 per 24hours per core, $0.17 per 24hours per GB of RAM.

Running a 1 core instance with 2GB of ram per day will be $1.60 for 24hours, or $0.07 an hour, $48 a month. This is more expensive than running an equivalent GCE instance, so this solution is only worth looking at if you have more users.

Launch

1. If you haven't got one already, set up a Google Cloud Storage bucket that will contain the R session backup data
2. Clone this repo
3. The authentication service email will be the default App Engine project one: e.g. your-project@appspot.gserviceaccount.com - give this at least Cloud Storage access to the bucket from step 1
4. Change this line in the Renviron.site to the bucket from step 1

GCS_SESSION_BUCKET="your bucket"

5. [Optional] In the Dockerfile, add your default username that you use on other RStudio backups by altering your_username and your_password in the below. If you don't do this, you will be saving files under /home/rstudio username.

## add your default user and password
RUN useradd --create-home --shell /bin/bash your_username && \
    echo your_username:your_password | chpasswd

6. In the same directory run:

gcloud app deploy --project your-project

It takes a while (10mins +)

7. Once ready, log in at https://your-project.appspot.com with username rstudio and password rstudio, or the credentials you set in step 5.
8. Configure Identity Aware Proxy https://console.cloud.google.com/iam-admin/iap for the App Engine project URL. How-to guide. This will add a Google OAuth2 login over the RStudio login page (much more secure)

You shuld now be able to log in and access all the files you saved under /home/your_user on the Cloud Service. When first logging in, it should load any SSH and GitHub configurations, and when you create a new RStudio Project with the same name as one already saved, it should download any missing files.

The server will turn off after some time of inactivity. See this link for more details.

Configuration

The app.yaml configures how the RStudio instance performs:

runtime: custom
env: flex
automatic_scaling:
  min_num_instances: 1
  max_num_instances: 1
  
resources:
  cpu: 2
  memory_gb: 4

The Dockerfile downloads a prepared RStudio instance with tools to persist data, and rserver.conf puts RStudio on port 8080 as required by App Engine, which will then route traffic onto normal web ports 80. It then adds any environment arguments saved in Renviron.site - minimum it needs GCS_SESSION_BUCKET but you can add other stuff such as other API keys, defaults etc. here.

Authentication

Identity Aware Proxy https://console.cloud.google.com/iam-admin/iap for the App Engine. How-to guide.

The instance uses this to add a Google OAuth2 proxy login over the top of the normal RStudio login, you can configure access

After Google Auth, you can log into RStudio using the default rstudio / rstudio login.

scaling config

The RStudio session disconnects on default scaling settings, as only one session is allowed per RStudio Server connection and appengine defaults to 2 https://cloud.google.com/appengine/docs/standard/python/how-instances-are-managed

Configure app.yaml to get around this:

app.yaml configuration

See how to config the app.yaml here

Set to only 1 per instance with 30min timeout via:

automatic_scaling:
  min_num_instances: 1
  max_num_instances: 1

If you want the instance to run all the time, replace basic scaling with manual scaling - but this is not worth doing as its much more expensive than running a GCE instance.

manual_scaling:
  instances: 1

Flexible containers do not support basic_scaling

Instance size

You can set the size of the instance via the resources config.

e.g.

resources:
  cpu: 2
  memory_gb: 2

reference

https://cloudyr.github.io/googleComputeEngineR/articles/persistent-rstudio.html

https://support.rstudio.com/hc/en-us/articles/200552316-Configuring-the-Server

https://github.com/rocker-org/rocker/blob/master/rstudio/testing/Dockerfile

https://cloud.google.com/appengine/docs/standard/python/an-overview-of-app-engine

debug

gcloud app --project [PROJECT-ID] instances enable-debug