Is it possible to add custom netlify functions

[loweisz]

Hey there 👋

I'm trying to deploy my svelte kit app to netlify, which seems to be working perfectly, when using the adapter.

However, I also wanted to deploy a custom function of mine and I noticed that this function is never deployed to netlify. Only the function called render.

I also noticed that when I add my custom function to the specified functions directory and then run npm run build, my custom function is removed from the functions folder and only the render function is still there.

I'm wondering am I missing something here or is it currently not possible to add a custom function to netlify when using the adapter ?

Thanks in advance 🙇‍♂️

[benmccann]

Can you just create a SvelteKit endpoint?

This may also be somewhat a duplicate of #930 where existing Netlify config is overwritten

[asgerb]

Maybe I can chime in as I've been bitten by this as well.

Perhaps it's due to my lack of understanding the intricacies of SvelteKit, vite, or node more specifically, but I wasn't able to figure out how to use a Svelte endpoint since I needed to use puppeteer and the require syntax wasn't working (to my understanding it's due to it being node syntax and not esm). This might be due to vite though, more than SvelteKit...

Apologies for the fuzzy details, I could spin up the app and provide a more detailed summary if that's helpful?

[benmccann]

@asgerb your issue seems unrelated to this ticket and would probably be best handled on Discord

[loweisz]

@benmccann Sorry for the late response.

Yes with SvelteKit endpoints it works perfectly, thanks for the tip.
However, I would still say it might be a confusing behavior when trying to use netlify functions directly.
But I could solve my use case without 👍

[ClaytonFarr]

@benmccann I think this is still a real issue and need.

There is unique Netlify functionality that doesn't seem accessible via SvelteKit endpoints yet.

Two examples I'm currently encountering are -

1. Not able to take advantage of specially named functions that trigger on events (https://docs.netlify.com/functions/trigger-on-events)
2. Not able to access user context information from Netlify authentication product 'Identity'; this is needed to be able to perform admin actions (https://docs.netlify.com/functions/functions-and-identity)

I'm not sure if / when it'll make sense for SvelteKit to afford this ability via endpoints (esp if #2 is unique to Netlify only).

But, being able to create and include additional serverless functions in the build somehow (e.g. copying files from an aliased directory into the 'build/functions' directory) should make this work.

Without it, I'm finding myself running in circles trying to implement a full auth solution using Netlify.

If there's a way to work around this in the short, that'd be great to know.

Thanks.

[benmccann]

Interesting. I wonder if perhaps the Netlify adapter should copy context.clientContext into SvelteKit's locals

[ClaytonFarr]

That'd a big help for issue #2 above.

Being able to also add specially named function files would be very nice too. I'm not sure if Netlify can catch these as function names bundled in SKs 'render' function. It doesn't seem like it.

[ClaytonFarr]

Looking forward to this hopefully being achievable natively in the Netlify adapter.

For others who stumble into this need and issue in the meantime, this workaround may be helpful -

https://discord.com/channels/457912077277855764/819723698415599626/846467065196052510

[splatte]

My usecase is similar to @ClaytonFarr's as I want to prevent protected admin pages from rendering unless the user is logged in. I am using patch-package to make this small change to the netlify-adapter https://gist.github.com/splatte/8d57ba18d5f0643119e242beb424a3c3 which lets me access user context information in SvelteKit's handle function:

  netlifyContext: {
    custom: {
      netlify: 'eyJpZGVudGl0eSI6eyJ1cmwiOiJxxxxxxxxxxxxxxxxxIQWlPakUyTWpJeU5UvY29'
    },
    identity: {
      url: 'https://abcdfdfdfdfd.netlify.app/.netlify/identity',
      token: 'eyJhbGciOiJIxxxxxxxxxxxxxxxkpQqdV0bDJVgq562Ac'
    },
    user: { /* only populated when Authorization: Bearer <token> is present in request */ }
  },

However, https://docs.netlify.com/functions/functions-and-identity/ states that "The user object is present if the function request has an Authorization: Bearer header with a valid JWT from the Identity instance. In this case the object will contain the decoded claims." so the header does not seem to be present when accessing the page via the browser. The browser sends the token via the nf_jwt cookie which doesn't get decoded by netlify automatically.

I hope I am on the right track here, but how do I get netlify to decode the claims automatically when the user accesses a protected page like /admin/secret-page?

[ClaytonFarr]

@splatte Nice. I wasn't aware of using an approach like patch-package in the interim; I'll have to try that.

Regarding passing the token as an authorization header, you can parse your cookie in the hooks.js to use it in your function call.

Hooks.js will receive all cookies automatically on each request. You can then parse the JWT and attach it to the request.locals object (including httpOnly cookies) to have it available to the request, to or attach any of the decoded JWT claims to the session.

Here is some example code from a current project -
https://gist.github.com/ClaytonFarr/d4555f396179b0375652285abe43d37e

1. within hooks.js you'll see the parsing of the cookie token and attaching it to request.locals.token
2. within updateEmail.js you'll see this request.locals.token value being grabbed and passed to a helper method for Netlify Identity (I ended up recreating the GoTrue-JS methods in the auth-api.js file to be able to access an Identity instance directly in serverless functions.)
3. within the helper method in auth-api.js you'll see this token being attached as an authorization bearer token in the final call.

For cases where you also need an identity admin token from clientContext, you'd either leverage your patch to get this data out of a normal SvelteKit endpoint (if I understand it correctly) – or create a custom serverless function and call this function as a mid-step to get the admin token before hitting the final Netlify Identity endpoint.

[splatte]

awesome, thanks a lot for this great input @ClaytonFarr! I have a lot to go through :)

[swyxio]

@ClaytonFarr i might be able to help... are you able to provide a small sample repo with what you're trying to do?