Simple Server

This is the backend for the Simple app to help track hypertensive patients across a population.

Table of Contents

• Development
• Documentation
• Deployment
• Contributing

Development

Caveat for Apple Silicon M1 macs

If you are installing on an M1 Mac, you should do all the below in Rosetta (ie arch returns i386 in a terminal). See here for how to create a Rosetta specific Terminal.

We have some rubygems that don't work under the native ARM architecture, so a fully ARM native setup does not work yet. For details you can follow this issue.

• Ruby 2.5.8
• PostgreSQL 10
• Redis
• Yarn

We have a bin/setup script that does most of the work of getting things setup, but you need a few things in place first. If you are on a Mac, install homebrew and then install rbenv, redis, and yarn:

brew install rbenv ruby-build redis yarn

To set up Ruby 2.5.8, see https://gorails.com/setup/osx/10.15-catalina

Then open Postgres.app and ensure you have a PostgreSQL 10 server initialized.

bin/setup

To set up the Simple server for local development, clone the git repository and run the setup script included:

$ git clone git@github.com:simpledotorg/simple-server.git
$ cd simple-server
$ bin/setup

If you encounter issues with this script, please open a new issue with details. Please include the entire log from bin/setup, as well as your computer / OS details.

Docker Compose

For quick development and testing, the server can be run locally using Docker Compose and the command:

docker-compose up

The Dockerfile and docker-compose.yml files replicate the steps detailed below for manual installation, including the running of ngrok for local android development.

Once the Docker Compose server is running, the logs should provide the ngrok URL. For example: SIMPLE_SERVER_HOST=91a705dde8c1.ngrok.io. This is the value that should be used when setting up the Android app as described in the section below.

Manual Setup

If the included bin/setup script fails for some reason, you can also manually set up the application step by step. You can do so as follows.

First, you need to install ruby. It is recommended to use rbenv to manage ruby versions. Note that we currently use Bundler version 1.17.3, so that is also hardcoded below.

gem install bundler -v 1.17.3
bundle _1.17.3_ install
rake yarn:install
rails db:setup

Developing with the Android app

To run simple-android app with the server running locally, you can use ngrok.

brew cask install ngrok
rails server
ngrok http 3000

The output of the ngrok command is HTTP and HTTPS URLs that can be used to access your local server. The HTTP URL cannot be used since HTTP traffic will not be supported by the emulator. Configure the following places with the HTTPS URL.

In the gradle.properties file in the simple-android repository,

qaManifestEndpoint=<HTTPS URL>

In the .env.development.local (you can create this file if it doesn't exist),

SIMPLE_SERVER_HOST=<HTTPS URL>
SIMPLE_SERVER_HOST_PROTOCOL=https

Workers

We use sidekiq to run async tasks. To run, first make sure that redis (>4) is installed:

brew install redis

# after installing ensure your redis version is >4
redis-server -v

Testing Email

We use Mailcatcher for testing email in development. Please use the following to set it up on your machine.

Note: Please don't add Mailcatcher to the Gemfile, as it causes conflicts.

gem install mailcatcher
mailcatcher

Now you should be able to see test emails at http://localhost:1080

Testing Web Views

When testing web views like the progress tab or help screens, you will need to authenticate yourself with specific request headers. You can run the following command to get a set of request headers for a user that you can attach to your requests.

$ bundle exec rails get_user_credentials

The command will output a set of request headers that you can attach to your requests using tools like Postman or ModHeader.

Attach the following request headers to your requests:
Authorization: Bearer 9b54814d4b422ee37dad46e7ebee673c59eed088c264e479880cbe7fb5ac1ce7
X-User-ID: 452b96c2-e0cf-49e7-ab73-c328acd3f1e5
X-Facility-ID: dcda7d9d-48f9-47d2-b1cc-93d90c94386e

Review Apps

Testing messages

Messages sent through Twilio are currently fixed to specific countries. To override this setting, go to the heroku console and add/update the DEFAULT_COUNTRY config variable on your review app to your desired country. The supported country codes are listed here.

# for US/Canada
DEFAULT_COUNTRY = US

# for UK
DEFAULT_COUNTRY = UK

Updating this config will automatically restart the review app and should allow one to receive messages in their appropriate ISD codes.

Configuration

The app uses a base development configuration using .env.development. To add or override any configurations during local development, create a .env.development.local file and add your necessary configurations there. If a configuration change is applicable to all dev environments, ensure that it is added to .env.development and checked into the codebase.

Running the application locally

Foreman can be used to run the application locally. First, install foreman.

$ gem install foreman

Then, run the following command to start the Rails and Sidekiq together.

$ foreman start -f Procfile.dev

Note: Foreman will also execute the whenever gem in trial mode. This will validate that the whenever configuration is valid, but will not actually schedule any cron jobs.

Alternatively, you can start these services locally without foreman by using the following commands individually.

• Rails: bundle exec rails server or bundle exec puma
• Sidekiq: bundle exec sidekiq

Running the tests

RAILS_ENV=test bundle exec rspec

Code

We use the standard gem as our default formatter and linter. To enable it directly in your editor, follow this.

To check all the offenses throughout the codebase:

$ bin/rails standard

To automatically fix all offenses,

$ bundle exec standardrb --fix

Note: Some files have been temporarily ignored under a .standard_todo.yml. As we fix these files, remove them from the yml file so that they can be picked up by standard again for future offenses. Refer to usage on how to generate todo files.

Note: Some files are permanently ignored under .standard.yml and do not require linting.

Generating seed data

To generate seed (fake patients) data, execute the following command from the project root

$ bin/rails db:seed_patients

To purge the generated patient data, run

$ bin/rails db:purge_users_data

You can also purge and re-seed by running:

$ bin/rails db:purge_and_reseed

Creating an admin user

Run the following command from the project root to create a new dashboard admin:

$ bin/rails 'create_admin_user[<name>,<email>,<password>]'

View Sandbox data in your local environment

1. Follow the steps in the "How to add an SSH key..." section here to add your SSH key to the deployment repo
2. Ask someone from the Simple team to add you as an admin to Sandbox
3. Create a password for your Sandbox account and use that to log into the Sandbox dashboard on https://api-sandbox.simple.org
4. Run ssh deploy@ec2-13-235-33-14.ap-south-1.compute.amazonaws.com to verify that your SSH access from step 1 was completed successfully.
5. Run bundle exec cap sandbox db:pull to sync Sandbox data with your local machine.
6. Use your Sandbox email and password to log into your local environment (http://localhost:3000).

Profiling

We use the vegeta utility to run performance benchmarks. The suite and additional instructions are here.

Documentation

API

API Documentation can be accessed at /api-docs on local server and hosted at https://api.simple.org/api-docs

To regenerate the Swagger API documentation, run the following command.

$ bundle exec rake docs

ADRs

Architecture decisions are captured in ADR format and are available in /doc/arch

Wiki

Guides, instructions and long-form maintenance documentation can go in /doc/wiki

ERD (Entity-Relationship Diagram)

These are not actively committed into the repository. But can be generated by running bundle exec erd

Deployment

Simple Server is deployed to several environments using a mixture of tools.

• Ansible: Server management and configuration is done using Ansible. See the deployment repository for more information.
• Capistrano: Application code is deployed to servers for a specific country and environment using Capistrano.
• SemaphoreCI: Continuous deployment

To make a deployment, run the release script.

bin/release

This will create a git release tag and automatically trigger a deployment to all non-production environments through Semaphore.

Once complete, trigger a manual deployment to production environments through the Semaphore CI dashboard.

Make sure you add your SSH keys as single sign-on so that cap doesn't get confused when there's more than 1 instance to deal with. You can do this simply by running ssh-add -K ~/.ssh/id_rsa.

Deployment to a specific environment

• We use Capistrano multi-config to do multi-country deploys.
• All cap commands are namespaced with the country name. For eg: bundle exec india:sandbox deploy.
• The available country names are listed under config/deploy. The subsequent envs, under the country directory, like config/deploy/india/sandbox.rb

Simple Server can be deployed to a specific environment of a specific country with the following command.

bundle exec cap <country_name>:<enviroment> deploy
# eg: bundle exec cap india:staging deploy
# or, bundle exec cap bangladesh:production deploy

Rake tasks can be run on the deployed server using Capistrano as well. For example,

bundle exec cap india:staging deploy:rake task=db:seed

Deployment Resources

The infrastructure setup including the ansible and terraform scripts are documented in the deployment repository.