Avalanche Canada

[![dependencies] (https://david-dm.org/avalanche-canada/ac-web.png)](https://david-dm.org/)

Web app and RESTful API as used by Avalanche Canada
Contact admin@avalanche.ca for more details or to get invoved.

Technical Architecture

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!image of system diagram

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* aws-elastic beanstalk - is the deployment environment for ac-web. It creates and manages the ec2 servers, security groups, and load balanching for ac-web.
* ac-web is the node.js + express app which provides the /forecasts api and /observations api
* aws-elasticache (redis) supports /forecasts api and stores the forecast cache for node-webcache with the node-webcache-redis adapter. These facilities seed and update the forecasts from the legacy avalx server. They then provide the forecasts to ac-web quickly.
aws-dynamodb supports /observatons api and stores the mountain-info-network and mountain-info-network-qa DynamoDB tables. These tables store and serve the user contributed mountain information network submissions. DynamoDB can be easily and readily scaled by modifying the Provisioned Throughput Read and Write Capacity Units.*
* aws-s3 supports /observations api and stores the user images associated with user contributed mountain information network submissions. The event chain can be seen below.
!image /observations

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These are required to support functional aspects of the Avalanche Canada platform.
* Mapbox Provides the custom basemaps used in ac-web and ac-mobile
* Prismi.io Provides Content Management for ac-web client.
* Amazon Web Services Provides the infrastructure and components.
* Auth0 Provides the identity managment and authentication systems.
* Google Analytics Provides the analyics tracking in ac-web and ac-mobile.

#### saas services
These are used by the development team to provide efficiency.
* Github.com Provides the version management and service hooks for continuous deployment.
* Codeship.io Provides the continuous deployment by hooking into Github.com and automatically building to Elastic Beanstalk.
* Phonegap Provides the build methods to quickly build ac-mobile for Android and iOS.

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* Boilerplate scaffolded using Yeoman and the generator-angular-fullstack.
* AngularJS .
* Angular UI.
* Angular Bootstrap
* Font Awesome
* Grunt-based build system to ensure maximum productivity.
* Bower package management
* Compass
* SASS
* AC-COMPONENTS Re-Usable components developed by Avalanche Canada
* Leaflet Mobile Friendly Interactive Maps

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* NodeJS
* ExpressJS
* node-webcache
* node-webcache-redis

Prerequisites

The RESTful api uses a few external resource which need to be configured.

AWS Resources: which means you will need an AWS key/pair set in order to use these resource. There are a numbers of strategies to pass in credentials as described in the AWS NodeJS Configuration Guide.

Auth0:
In order to be able to parse the jwt on the server we need to configure the express-jwt middleware by passing in our Auth0 application client information.

Redis:
The application uses Redis as a caching layer. Redis need to be installed and running on localhost port 6379. The redis host is defined using environment variables.

#### Local Development
For development the recommended startegy is to use AWS profiles within the credentials file `~/.aws/credentials. For more details on how to configure the AWS CLI/SDK see: http://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html

``
[default]
aws_access_key_id = ...
aws_secret_access_key = ...

[avalanche-canada]
aws_access_key_id = ...
aws_secret_access_key = ...

``

For development add a .env file in the project root with the following contents:

`
$cat .env
AWS_PROFILE=avalanche-canada
SESSION_SECRET='mysecret'
AUTH0_CLIENT_ID='client-id'
AUTH0_CLIENT_SECRET='client-secret'
NO_CACHE_REFRESH=true
MINSUB_DYNAMODB_TABLE='mountain-info-network-qa'
HOTZONE_DYNAMODB_TABLE='hot-zone-qa'
AST_PROVIDER_TABLE='ast-provider-dev'
AST_COURSE_TABLE='ast-course-dev'
CLOUDINARY_AUTH='mykey'
`

The NO_CACHE_REFRESH environment variable controls wether the cache refreshes on a specified interval set in the application. For local and dev env its recommended to leave this to true.

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Install Node.js and Ruby then:

``sh
$ gem install compass
$ npm -g install grunt-cli karma bower
$ npm install
$ bower install
$ grunt serve
``

To run jslint to check javascript quality run:
``sh
grunt jshint
``

#### Configuring AWS environments

For production the best practice is to use an ec2 instance profiles and set the required permissions on it using policies.

``
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt1416283589000",
"Effect": "Allow",
"Action": [
"dynamodb:BatchGetItem",
"dynamodb:BatchWriteItem",
"dynamodb:DeleteItem",
"dynamodb:GetItem",
"dynamodb:ListTables",
"dynamodb:PutItem",
"dynamodb:Query",
"dynamodb:Scan",
"dynamodb:UpdateItem"
],
"Resource": [
"arn:aws:dynamodb:myregion:mytable"
]
},
{
"Sid": "Stmt1416283613000",
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:PutObjectAcl"
],
"Resource": [
"arn:aws:s3:::mybucket/*"
]
}
]
}
``
When using elastic beanstalk you can set the instance profile at environment creation using the console, cli or eb tool. You can also change the instance profile using the same tools at a later point.

The follwing environment variables also need to be set on the server:

``
SESSION_SECRET=mysessionsecret
AUTH0_CLIENT_ID=myauth0clientid
AUTH0_CLIENT_SECRET=myauth0clientsecret
REDIS_HOST='yourredishost'
NO_CACHE_REFRESH=true
MINSUB_DYNAMODB_TABLE='dynamotablename'
HOTZONE_DYNAMODB_TABLE='dynamotablename'
USE_PRERENDER=false
```