README.md updated

Author: Sylvain Maucourt

README.md

@@ -1,48 +1,59 @@
 # Herow SDK Backend
 
-[HSB is the SDK backside API](https://github.com/herowio/herow-sdk-backend) helping us to save the world.
+## Table of contents
 
-It includes several api interacting with [SDK iOS](https://github.com/herowio/herow-sdk-ios) and [SDK Android](https://github.com/herowio/herow-sdk-android).
+* [General info](#general-info)
+* [Technologies](#technologies)
+* [Setup](#setup)
 
-![let's go save the world](https://media.giphy.com/media/26BRxBeok96wnAwpy/source.gif)
+## General info
 
-## How to test it?
+[This project is the HEROW's SDK backside API](https://github.com/herowio/herow-sdk-backend).
 
-`node` is also needed, we use `v15.14.0` but should work with lower version.
+It includes API needed to interact with [SDK iOS](https://github.com/herowio/herow-sdk-ios) and [SDK Android](https://github.com/herowio/herow-sdk-android).
+
+You can deploy it on AppEngine, Heroku, Kubernetes or on premise.
+
+## Technologies
+
+Project is created with:
+
+- Node _(v15.14.0 - but should work with lower version)_
+- Redis 1+
+- Kafka 0.10+
+
+## Setup
 
 ```
 $> brew install node
 ```
 
-After that, install dependencies and run tests
+Clone the project
 
 ```
-$> npm install
-$> npm test
+$> git clone [email protected]:herowio/herow-sdk-backend.git
+$> cd herow-sdk-backend
 ```
 
-## How to contribute?
-
-`docker-compose` sets up a Redis and a Kafka instances.
-
-Under macOS, edit `docker-compose.yml` and update `KAFKA_ADVERTISED_HOST_NAME` by setting your local IP. _(localhost should work under Linux)_
+Deploy Redis and Kafka via docker
 
 ```
-$> docker-compose up
-$> docker-compose -f docker-compose.yml.arm64 up # for Apple M1
+$> docker-compose up # for x86
+$> docker-compose -f docker-compose.yml.arm64 up # for M1
 ```
 
-and…
+After that, install dependencies and run it 
 
 ```
+$> npm install
 $> npm start
 ```
 
-# Redis interactions
+## Redis interactions
 
-We massively use Redis as database. You have to set a `REDIS_URL` env var to interact with. _(the default value is: redis://127.0.0.1)_
+We massively use Redis as database. You have to set a `REDIS_URL` env var to interact with. _(default value: redis://127.0.0.1)_
 
-## identity key
+### Identity key
 
 This key allows to match an SDK instance to a `client`. You can create any client as needed. **You should create a dedicated key for SDK Android and SDK iOS by client and by version**. By this way, you could "stop" easily a specific sdk for a given client.
 
@@ -57,8 +68,11 @@ We need 4+1 informations :
 | username | a dedicated account allowing to use the app | appdemo |
 | password | a dedicated password | rtFGHG6$ |
 
+
 The 5th element is a salt used to hash those informations:
 
+![](https://media.giphy.com/media/l0EoBVexxvaP88SSQ/giphy.gif)
+
 `sha256(TOKEN_SALT, client_id@client_secret@username@password)`
 
 `TOKEN_SALT` env var is used to override salt key _(default is set to secret)_.
@@ -77,30 +91,32 @@ undefined
 'd52066c26e3803659e5d1a4b75cdbaab2b26474f371eb17c7e582be67fdca0df'
 ```
 
-## token key
+## Token key
 
-Every time an SDK generates a token, it is stored with key `token:<token>` and associated with `client`'s identifier (see above). This key is storing during `TOKEN_EXPIRATION` env var _(default is set to 10800 seconds -> 3 hours)_.
+After successful authentification, `token` is stored by using key `token:<token>` and associated with the `client`'s identifier _(see above)_. This key is storing during `TOKEN_EXPIRATION` env var _(default is set to 10800 seconds -> 3 hours)_.
 
-## device key
+## Device key
 
 The SDK configuration _(IDFA, customId, optin)_ is stored on key `device:<deviceId>` during `USER_INFO_EXPIRATION` env var _(default is set to 2592000 seconds -> 30 days)_.
 
+SDK updates those information every day. Meaning that a quiet user is forgotten after 30 days, to prevent privacy.
+
 ## last-modified-cache key
 
 The SDK regularly pulls its configuration.
-When cache seems oudated, we can use the key `last-modified-cache:<client>` to order a cache refresh.
+When cache seems outdated, we use the key `last-modified-cache:<client>` to order a cache refresh.
 
 `last-modified-cache:<client>` contains timestamp in milliseconds of the last cache update. SDK will decide if it have to refresh it.
 
-## campaigns key
+## Campaigns key
 
 `campaigns:<client>` contains an array of campaigns associated to a given client. If this key is modified, we also should upgrade `last-modified-cache:<client>`.
 
-## zones key
+## Zones key
 
-`zones:<client>:<geohash>` contains an array of "zones" dedicated to a client and to a specific area. [Geohash](https://fr.wikipedia.org/wiki/Geohash) is a 4 digits geocoding code used to parcel the world on 20kmx20km squares. If this key is modified, we also should upgrade `last-modified-cache:<client>`.
+`zones:<client>:<geohash>` contains an array of "zones" dedicated to a client and to a specific area. [Geohash](https://fr.wikipedia.org/wiki/Geohash) is a 4 digits geocoding code used to parcel the world on 20x20 km squares. If this key is modified, we also should upgrade `last-modified-cache:<client>`.
 
-## pois key
+## Pois key
 
 `pois:<geohash>` contains a array of "pois" for a given area. Content is shared with every client.
 
@@ -505,4 +521,4 @@ Sent when a notification is opened _(click on it)_.
         "techno_hash": "1qnn4irqfmghs"
     }
 }
-```
+```