end-point support

[amitu]

Status: In Progress

Tasks

• Basic actix web server with proxy endpoint
  • https://github.com/AbrarNitk/rust-web-services
• fpm::http::Request, fpm::http::Response
  • mapper from actix-web::HttpRequest, actix-web::HttpResponse
  • mapper from hyper::HttpRequest, hyper::HttpResponse
• Endpoint proxy in fpm
• forwarding in serve.rs
• Check If the endpoint is present in the sitemap or not
• endpoint for the main package
• Service endpoint in FPM.ftd in fpm.dependency section
  • end-point support for dependency #590
• Handle proxy pass for dependency packages
• dependency endpoint handling for http::processor
• redirect for dependency packages
  • redirect request if mount-point present #593
• X-FPM-* headers
• environment headers
• Provide support for both actix-web and hyper in fpm
• Proxy authentication

PR: #505
PR: #501
PR: #590
PR: #593
Next: #526
FPM Apps: FPM APPs: https://github.com/ftd-lang/fpm/discussions/599

19th Sep 2022

• Provide proxy support for actix-web
• fpm::http::Request, fpm::http::Response

16th Sep 2022

• Provide proxy support for actix-web
• fpm::http::Request, fpm::http::Response

12th Sep 2022

• On leave

9th Sep 2022

• Basic actix web server with proxy endpoint
  • https://github.com/AbrarNitk/rust-web-services

8th Sep 2022

• Working on hyper/actix web server with proxy endpoint.
• Provide support for both actix-web and hyper in fpm.

In first release we will no implement environment headers (some more thought is needed).

---

As app package and hosting we mentioned end-point:

-- fpm.package: amitu.com

-- fpm.dependency: abrark.com/analytics
theme: ganesh-salunke.com/analytics
end-point: https://<heroku-app-id>.herokuapps.com

Here we are added an attribute end-point.

Note: end-point is not a property of package, but of the unique deployment of the package. abrark.com/analytics could be deployed for amitu.com on one end-point and fifthtry.com on another.

URL Of An API

How does FPM discover what all links / APIs are available in abrark.com/analytics? We want to create link in header/footer etc to analytics related pages.

-- import: abrark.com/analytics

-- ftd.text: view site analytics
link: $analytics.links.home

Say tomorrow we want to use amitu.com/analytics instead:

-- fpm.dependency: amitu.com/analytics
implements: abrark.com/analytics
theme: ganesh-salunke.com/analytics
end-point: https://<heroku-app-id>.herokuapps.com

The Dockerfile for amitu.com/analytics would be used for hosting, but it would be assumed that it has the same links/APIs as abrark.com, so no other line in the package has to change other than the fpm.dependency lines shown above.

End-point Is For Proxying

When a dependency has end-point, any request to /-/<dependenc-package>/* is "proxy passed" to <end-point>/*. So for example in above case, any request coming to https://amitu.com/-/abrark.com/analytics/foo will be proxy passed by fpm to https://<heroku-app-id>.herokuapps.com/foo.

fpm will preserve http method, query params, headers, cookies etc to the endpoint, and whatever response fpm gets from the end-point we will return it back to browser.

In future we may implement caching.

Extra Arguments

If we are running some Django app on behalf of current package, we have to configure that Django app somehow. And ideally the configuration of that Django app should be in FPM.ftd of current package, so things are managed in more central way etc.

With that in mind, we will pass all the configuration specified in the dependency, like in our example we specified theme: ganesh-salunke.com/analytics. These arguments will be passed to end-point as header: X-FPM-theme: ganesh-salunke.com/analytics.

Security Sensitive Headers

This does not mean every configuration must be in FPM.ftd, some configurations are security sensitive, so they should not be in FPM.ftd file at all.

Some such configurations can be passed to fpm as environment variable. Say when we are deploying fpm package somewhere, in a totally different interfaces, the way Github or Heroku do it, the secrets added. These get passed to the fpm and ftd files as environment variable.

To forward some environment variable to end-point we can use the syntax:

-- fpm.package: amitu.com

-- fpm.dependency: abrark.com/analytics
config: theme=ganesh-salunke.com/analytics
config: foo=$ENV.FOO
config: bar=$ENV.BAR
end-point: https://<heroku-app-id>.herokuapps.com

Here we have read the environment variable named FOO using the $ENV.FOO and passed it to endpoint as foo, and the value of the environment variable will get passed as header X-FPM-FOO.

Can Main Package Use end-point?

-- fpm.package: amitu.com
end-point: https://<heroku-app-id>.herokuapps.com

Means any request to https://amitu.com/<foo> will be proxy passed to https://<heroku-app-id>.herokuapps.com/<foo>. This will only happen if <foo> is not handled by a document in the package (there is no foo.ftd nor foo/index.ftd, foo.md etc).

<foo> can not start with /-/.

[AbrarNitk]

Authentication for another Service

We will implement Authorization with Auth types, on priority, we can first implement API Key and Bearer Token, you can set another microservice auth key in the fpm environment.

[amitu]

@AbrarNitk: Add this to the todo.

[AbrarNitk]

How FPM Proxy Works with Services

In this example, we are using movie-db service, which is configured to fpm.

movie-db service

movie-db service exposes apis /api/add-movie and /api/get-movie/?id=<db-id>.
add movie API added movie in the service database and redirect to a browser with URL /movie/id=<db-id>.
get movie API return the movie details with the given id.

Flow: How Add Movie API Work

1. /add-movie/ which is served by fpm, renders ftd ui, where you can fill the details with Add Movie button.
2. On Click Add Movie browser will send the request to fpm, and then fpm will forward this request to movie-db
   service.
3. movie-db service will add the movie to the database and send a redirect to /movie/?id=<db-id> to fpm.
4. fpm will return this redirected response to the browser.
5. browser will send request to get movie details /movie/?id=<db-id> to fpm.
6. We will call microservice API /api/get-movie/?id=<db-id> using http processor from movie.ftd document to get data.
7. fpm will call this get movie API to get the data from movie-db service, while compiling FTD to HTML. This is
   what this http processor do.
8. This is how /movie/?id=<db-id> will show the added movie details.

[AbrarNitk]

TODO

endpoint with dependency package. We are only resolving endpoint from the main package.

-- fpm.dependency: abrark.com/analytics
theme: ganesh-salunke.com/analytics
foo: $ENV.FOO
endpoint: https://<heroku-app-id>.herokuapps.com

[AbrarNitk]

Package has to use package Urls

link example

-- ftd.code:
lang: ftd

/-- ftd.text: Hello World
link: /-/fifthtry.github.io/todos/add-todo/

Need to check in case of dynamic parameters

http-processor example

-- ftd.code:
lang: ftd

/-- todo list todos:
$processor$: http
method: get
url: /-/fifthtry.github.io/todos/api/todos/
;; url: https://kameri-service.herokuapp.com/api/sample/ 
;; This should also work

How will it work

• Get the end-point from using the package name from the request url, config.package.endpoint or dependency endpoint

object api call example, which should work

-- ftd.code:
lang: ftd

/-- object add-api:
function: http
method: post
url: /-/fifthtry.github.io/todos/api/add-todo/
title: title
status: selected-status
description: description

How will it Work

• Get the end-point from the package name, config.package.endpoint or dependency endpoint

For Document, both will work

• /-/fifthtry.github.io/todos/add-todo/
• /todos/add-todo/

For the endpoint urls mount-point will not work, these should have full package name in front of them.
A person who is writing kameri application does not know

• /-/fifthtry.github.io/todos/api/add-todo/ : This should work
• /todos/api/add-todo/ : This should work, Not supported

Let's say, If a request comes for the path /-/fifthtry.github.io/todos/add-todo/

1. check if present in the package sitemap or dynamic urls
2. if the above fails

• get the end-point from the current package or dependency package current package.