development.md

# Development

The main role for this repo is provide Single-Sign-On. The architecture to make
this happen has a lot of moving components. A quick overview:

 - Hydra: Hydra is an Identity Provider, or IdP for short. It means connected
   applications connect to Hydra to start a session with a user. Hydra provides
   the application with the username and other roles/claims for the application. 
   This is done using the OIDC protocol. Hydra is developed by Ory and has
   security as one of their top priorities. Also it is fully OpenSource.

 - Login application: If hydra hits a new session/user, it has to know if this
   user has access. To do so, the user has to login. Hydra does not support
   this, so it will redirect to a login application. This is developed by the
   Stackspin team (Greenhost) and part of this repository. It is a Python Flask
   application. 
   Because the security decisions made by kratos (see below), a lot of the 
   interaction is done in the web-browser, rather then server-side. 
   This means the login application has an UI component which relies heavily on 
   JavaScript. As this is a relatively small application, it is based on
   traditional Bootstrap + Jquery. This elements the requirement for yet an
   other build environment.

 - Kratos: This is Identity Manager and contains all the user profiles and
   secrets (passwords). Kratos is designed to work mostly between UI (browser)
   and kratos directly, over a public API endpoint without an extra server side
   component/application. So authentication, form-validation etc, are all handled
   by Kratos. Kratos only provides an API and not UI itself.
   Kratos provides a Admin API, which is only used from the server-side flask
   app to create/delete users.

 - Postgres: All three components need to store data. This is done in a postgres
   database server. There is once instance, with three databases. As all
   databases are very small this will not lead to resource limitation problems.

## Prerequisites

The current login panel is not yet installed available in released  versions 
of Stackspin. However, this does not prevent us from developing already on the
login panel. Experience with `helm` and `kubernetes` is expected when you follow
this manual.

On your provisioning machine, make sure to checkout:

`git@open.greenhost.net:stackspin/single-sign-on.git`

Be sure to check out the latest main branch. Or select a more modern branch if you
want to test / install (optional) improvements of login panel.

Once this is all fetched, installation can be done with the following steps:

1. Create an overwrite ConfigMap file:

   For local development, we have to configure the endpoint of the application to
   be pointing to our development system. In this example, we use `localhost` on
   http.

   Because of CORS and strict configuration, all needs to end up on the same
   system. With modern browser, it even have to run on the same port (at least with
   firefox). As we want to mimic the real life setup as much as possible as,
   we will do this by running a local proxy. In production this will be handled by
   kubernetes ingress configuration.

   First we will tell kratos and hydra where to find the right endpoints. An
   overview of all relevant end-points:

   The endpoints used by the browser are (public accessible)

   - `localhost/api` -> kratos public API
   - `localhost/login` -> login flask app

   The endpoint used by the login app/API are:
   - `localhost:8000` -> kratos Admin API (only local accessible)
   - `localhost/api`  -> kratos Public API
   - `localhost:4445` -> hydra Admin API (only local accessible)
   - `localhost:5432` -> PostgreSQL

   To reflect those public endpoints in your cluster, we have to override the 
   default URLs in the cluster. We do this with a ConfigMap.

   It is essential SMTP/e-mail is working during development, so an example 
   is included on how to override those if SMTP is not working on your 
   cluster. Otherwise those lines are irrelevant.

   Create a file with the following content:

```
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: stackspin-single-sign-on-override
data:
  values.yaml: |
    kratos:
      kratos:
        config:
          courier:
            smtp:
             # Kratos enforces the use of STARTTLS. Be sure your SMTP provider
             # supports that (if not, it is time to switch providers)
             #
             # Uncomment and correct below lines if e-mail is not working in your
             # cluster
             # connection_uri: smtp://user@password@smtp.example.com:25/
             # from_address: stackspin-admin@example.com

          # For development, we forward all to our local server (or your dev server
          # if that is remote)
          serve:
            public:
              base_url: http://localhost/api/

          selfservice:
            default_browser_return_url: http://localhost/login/login

            flows:
              recovery:
                ui_url: http://localhost/login/recovery

              login:
                ui_url: http://localhost/login/login

              settings:
                ui_url: http://localhost/login/settings

              registration:
                ui_url: http://localhost/login/registration

    hydra:
      hydra:
        config:
          urls:
            # For development we redirect to localhost (or your dev server)
            login: http://localhost/login/auth
            consent: http://localhost/login/consent
            logout: http://localhost/login/logout
```

2. Apply the ConfigMap to your cluster:
 
   ```
   kubectl apply -n stackspin -f stackspin-single-sign-on-override.yaml
   ```

3. Tell flux to reconcile the configuration

   Normally flux will do this on some interval. We will tell flux to apply
   the override immediately.

   ```
   flux reconcile kustomization core
   flux reconcile helmrelease -n stackspin single-sign-on
   ```

## Development

1. Setup port redirects

To be able to work on the Login panel, we have to configure our development
system to access all the remote services and endpoints.

A helper script is available in this directory to setup and redirect the
relevant ports locally. It will open ports 8000, 8080, 4445, 5432 to get access
to all APIs:

```
cd project_root/login
./set-ssh-tunnel.sh "stackspin.example.com"
```

(the tunnel goes to the kubernetes node, so *not* to your provisioning machine,
 it will uses SSH port forwarding to map ports, as a result you will also have
 SSH session to your kubernetes node. Do not close this session, as closing the
 session will close the forwarded ports as well)

2. Configure a local proxy

Because of strict CORS headers, we have to map the public kratos API and login
app which we will run locally, with a local proxy.

This can be done with any proxy server, for example with NGINX. Be sure you have
NGINX installed and listening on port 80 locally (`sudo apt-get install nginx`)
should be enough. 

Now configure NGINX with this configuration in `/etc/nginx/sites-enabled/default`

```

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    root /var/www/html;

    index index.html;

    server_name _;

    location / {
        # First attempt to serve request as file, then
        # as directory, then fall back to displaying a 404.
        try_files $uri $uri/ =404;
    }

    # Flask app
    location /login/ {
        proxy_pass http://127.0.0.1:5000/;
        proxy_redirect     default;
        proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
    }

    # Kratos Public
    location /api/  {
        proxy_pass http://127.0.0.1:8080/;
        proxy_redirect     default;
        proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
    }
}
```

Reload your NGINX:

```
sudo systemctl reload nginx.service
```

3. Run FLASK app

Now it is time to start the flask app. Please make sure you are using python 3 in your environment. And install the required dependencies:

```
cd projectroot/login
pip3 install -r requirements.txt
```

Then verify if you are happy with the settings in the `source_env` file:

```
cat source_env

export FLASK_RUN_HOST=0.0.0.0
export FLASK_RUN_PORT=5000
export HYDRA_ADMIN_URL=http://localhost:4445
export KRATOS_PUBLIC_URL=http://localhost/api
export KRATOS_ADMIN_URL=http://localhost:8000
export PUBLIC_URL=http://localhost/login

export DATABASE_URL="postgresql://stackspin:stackspin@localhost/stackspin"
export APP_SETTINGS="config.DevelopmentConfig"
```

Normally you only need to change the database password if you did not use the
default.

Assuming you did not populate the database yet, run this to populate it:

```
. source_env
flask db upgrade
```

If that all looks fine, it is time to add you first user:

```
flask user create myemail@example.com
```

And now it is time to start the app:

```
./run.sh
```

If this starts smoothly, you should be ready to go.

## Test you setup

Hydra and kratos are now configured to redirect to localhost when they receive a
request. So to test the setup, you can go to one of your applications (for
example nextcloud), what we expect when you click the login button is the
following:

- Nextcloud redirect to Hydra (on sso.example.com)
- Hydra does not have a session, so ask to authorize on: http://localhost/login/auth
- Kratos does not have a session, so the login panel will ask to login on:
  http://localhost/login/login
- You do not have a password setup yet, so you click "recover account", which
  should bring you to: http://localhost/login/recovery
- You enter your email address and request a reset token. Check you e-mail. The
  email should contain a link to http://localhost/api/self-service/recovery/..
- The link logs you in in kratos and ask you to setup a password. Complete this
  step and you account is ready.

We started the flow with trying to reach nextcloud. Because we
did a password recovery in between, this information is lost. If you go again to
nextcloud manually, you should now be logged in automatically.

If you retry this, but now with a password (for example in a privacy window or
by removing you cookies), you should be redirected automatically after login.