gunzip / io-functions-backend

IO App backend

This repository contains the code of the backend used by the mobile applications of the IO project.

Table of content

• What is this?
• How to run the application
  • Dependencies
  • Installation steps
  • Containers description
  • Environment variables
  • Logs
  • SPID user management
• Redis Database
  • Data Structure
• Mobile App compatibility
• How to contribute
  • Dependencies
  • Starting steps
  • Generate the API client
• Troubleshooting

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What is this?

This is the backend that supports the io-app mobile application.

This project is part of the Italian Digital Citizenship initiative, see the main repository for further information.

Authentication process

The io-app application will authenticate to the backend in two steps:

1. an initial user initiated SPID authentication process (SAML2 based) that identifies the user and, on success, triggers the creation of a new authentication session (associated to a session token)
2. subsequent requests to the backend will be authenticated via a bearer session token

User authentication

When a client (the mobile app or a browser) wants to login with the backend it will call the /login endpoint with the IDP entityID as parameter in the query string. The backend will then builds an authorization URL and performs a redirect to the chosen IDP. The authentication process will continue to the IDP website. If the authentication process ends with success the IDP will redirect the client to an HTML page with a form that will auto-post itself to the /assertionConsumerService endpoint with a SAMLResponse as an hidden field. The backend will parse and validate the SAMLResponse to extract all the user attributes (fiscal code, first name, last name, email), then it will generates an unique alphanumeric string as token and saves an User object to the SessionStorage service using the token as key. Finally the backend will redirect the client to the value of the environment variable CLIENT_REDIRECTION_URL with the token in the query string. The client must saves the token and use it in all API request.

The code that manage this flow are in the spid-passport package (more info here), and in the src/strategies/spidStrategy.ts and src/controllers/authenticationController.ts files.

Token authentication

All API requests sent by the client to the backend must have an Authorization: Bearer header with the value of the token obtained from the SPID authentication process. The token is used to retrieve the User object from the SessionStorage service.

The code that manage this flow are in the src/strategies/bearerSessionTokenStrategy.ts file.

How to run the application

Dependencies

• Docker and Docker Compose

To fully simulate the SPID authentication process we use the images provided by the spid-testenv2 project.

A Linux/macOS environment is required at the moment.

Installation steps

1. clone the project in a folder called io-backend

2. go to the project's folder

3. run scripts/build-tools.sh to build the tools Docker image

4. run scripts/yarn.sh to install backend dependencies

5. run scripts/generate-proxy-api-models.sh to generate the models defined in api_proxy.yaml and api_notifications.yaml

6. run scripts/build.sh to compile the Typescript files

7. run scripts/generate-test-certs-task.sh to create SAML (SPID) certificates

8. run docker-compose up -d to start the containers

9. edit your /etc/hosts file by adding:

   127.0.0.1    spid-testenv2
   127.0.0.1    io-backend
   

10. copy .env.example to .env and fill the variables with your values

11. point your browser to https://io-backend/metadata and copy the source of the page to a new testenv2/conf/sp_metadata.xml file

12. run docker-compose up -d to restart the containers

13. point your browser to https://io-backend

If you are using Docker with a Docker Machine replace 127.0.0.1 with the IP of the Docker Machine (More details here).

Container description

• backend: the backend Node application that serves the web and mobile applications
• spid-testenv2: the test IDP server

App backend is reachable at https://io-backend
IDP is reachable at https://spid-testenv2:8088 \

Environment variables

Those are all Environment variables needed by the application:

Variable name	Description	type
API_KEY	The key used to authenticate to the API backend	string
API_URL	The API backend URL	string
CLIENT_REDIRECTION_URL	The path where the user will be redirected after a successful SPID login	string
CLIENT_ERROR_REDIRECTION_URL	The path where the user will be redirected when en error occurs during SPID login	string
PORT	The HTTP port the Express server is listening to	int
REDIS_URL	The URL of a Redis instance	string
TOKEN_DURATION_IN_SECONDS	The number of seconds a session token is considered valid	int
SAML_CALLBACK_URL	The absolute URL of the assertion consumer service endpoint	string
SAML_ISSUER	The issuer id for this Service Provider	string
SAML_ATTRIBUTE_CONSUMING_SERVICE_INDEX	The index in the attribute consumer list	int
PRE_SHARED_KEY	The key shared with the API backend to authenticate the webhook notifications	string
ALLOW_NOTIFY_IP_SOURCE_RANGE	The range in CIDR form of allowed IPs for the webhook notifications	string
AZURE_NH_HUB_NAME	The hub name configured in the Azure Notification HUB	string
AZURE_NH_ENDPOINT	The endpoint URL configured in the Azure Notification HUB	string
ALLOW_PAGOPA_IP_SOURCE_RANGE	The range in CIDR form of allowed IPs for the PagoPA API	string
AUTHENTICATION_BASE_PATH	The root path for the authentication endpoints	string
API_BASE_PATH	The root path for the api endpoints	string
PAGOPA_API_URL	The url for the PagoPA api endpoints	string
PAGOPA_API_URL_TEST	The url for the PagoPA api endpoints in test mode	string
PAGOPA_BASE_PATH	The root path for the PagoPA endpoints	string
SPID_AUTOLOGIN	The user used in the autologin feature, omit this to disable autologin	string
IDP_METADATA_URL	Url to download IDP metadata from	string
IDP_METADATA_REFRESH_INTERVAL_SECONDS	The number of seconds when the IDPs Metadata are refreshed	int
CACHE_MAX_AGE_SECONDS	The value in seconds for duration of in-memory api cache	int
APICACHE_DEBUG	When is true enable the apicache debug mode	boolean
ALLOW_MULTIPLE_SESSIONS	When is true allow multiple sessions for an user (default false)	boolean

Logs

Application logs are saved into the logs folder.

SPID user management

The setup procedure adds some test users to the test IDP server, the full list could be retrieved in testenv2/conf/users.json. To add more users simply add more items to this file and restart the spid-testenv2 container.

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API Monitoring

Is possible link the API to AppInsignts service by setting the ENV variable APPINSIGHTS_INSTRUMENTATIONKEY. Stats of API CPU and RAM usage, API call execution time, success or failure of API calls are collected. Realtime data collection is enabled.

Redis Database

Data Structure

Redis Database stores data required only by application side functionalities. Below a table with an example of data for an hypothetical user with fiscal code MRARSS80A01H501T and with session token HexToken.

Key	Value	type	expire in
SESSION-HexToken	a JSON representing the user object	User	TOKEN_DURATION_IN_SECONDS
WALLET-WalletHexToken	"SESSION-HexToken"	String	TOKEN_DURATION_IN_SECONDS
SESSIONINFO-HexToken	a JSON representing the SessionInfo object	SessionInfo	TOKEN_DURATION_IN_SECONDS
USERSESSIONS-MRARSS80A01H501T	a Set of SessionInfo Keys	Set<SessionInfoKey>	never

Mobile App compatibility

Backend

To handle Backend compatibility with several Mobile App versions, the oldest mobile app version supported by the backend is stored into the property min_app_version inside the package.json. This value is provided to the app through the /info API. If the mobile app version is lower an upgrade is required.

PagoPa

To handle the mobile app compatibility with the latest implementation of PagoPA APIs, the backend exposes through the /info API a property called min_app_version_pagopa defined into package.json file. If the mobile app version is lower of this value, all the functions that require PagoPa are disabled to avoid compatibility issues.

How to contribute

Dependencies

• nodenv
• YARN
• Docker (optional)

A Linux/macOS environment is required at the moment.

Starting steps

• use nodenv to run the correct version of Nodejs as specified in app/.node-version
• run Jest tests directly or with scripts/test.sh

In general follow the Node Best Practices.

Generate SAML (SPID) certs (development)

The backend implements a SAML Service Provider - for authenticating the clients it needs a certificate that you can generate with the following command (you need to have openssl available in your path):

$ yarn generate:test-certs

Generate SAML (SPID) certs (production)

For production, the SPID certificate must be generated with the following command:

$ openssl req -x509 -nodes -sha256 -days 365 -newkey rsa:4096 -keyout key.pem -out cert.pem

Then, the key and the certificate must be stored in the Kubernetes secrets:

$ kubectl create secret generic spid-cert --from-file=./cert.pem --from-file=./key.pem

Architecture decision records

In a world of evolutionary architecture, it's important to record certain design decisions for the benefit of future team members as well as for external oversight. Architecture Decision Records is a technique for capturing important architectural decisions along with their context and consequences. We store these details in source control, along with code, as then they can provide a record that remains in sync with the code itself.

We use ADRs to track architectural decisions of this initiative.

This repository is configured for Nat Pryce's adr-tools.

Here's the decisions we taken so far:

ADR	Title	PR (discussion)
1	Record architecture decisions
2	Backend runs on Docker on local environments
3	Use OpenAPI to defined the API specs
4	Use a dependency injection container
5	Use a GUID as Installation ID
6	Backend is deployed on more than one instance

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Troubleshooting

I installed on my mac but seems that https://io-backend:80 is not working (ping io-backend return a host error)

Check out /etc/hosts Remember that in some cases you need to use your docker-machine ip (get it from >docker-machine ip) instead of localhost.

I followed all the steps but when i go to https://io-backend it shows me the same as https://io-backend:8080

This problem seems to be dependent on how Docker for Mac (doesn't) manage well the /etc/hosts file. If you install Docker Toolbox it works fine (and can coexist) (Read more at https://medium.com/@itseranga/set-hosts-in-docker-for-mac-2029276fd448)

License