Deployed on Vercel as Next.js /api/graphql route leads to a 500: Error: No mesh config file was found

[schmidsi]

Hello there

I try to use graphql-mesh as part of a Next.js app and deploy it to Vercel. It works fine locally, but on Vercel the following error shows in the server-log if I try to navigate to https://nfts.vercel.app/api/graphql:

2021-06-11T15:35:53.330Z	3c2d5545-7a4f-457e-bedb-27e0bbfdb72b	ERROR	Error: No mesh config file was found in "/var/task"!
    at findAndParseConfig (/var/task/node_modules/@graphql-mesh/config/index.cjs.js:425:15)
    at async createApolloServer (/var/task/.next/server/pages/api/graphql.js:34:22)
    at async graphql (/var/task/.next/server/pages/api/graphql.js:52:24)
    at async apiResolver (/var/task/node_modules/next/dist/next-server/server/api-utils.js:8:1)
    at async Server.handleApiRequest (/var/task/node_modules/next/dist/next-server/server/next-server.js:66:462)
    at async Object.fn (/var/task/node_modules/next/dist/next-server/server/next-server.js:58:580)
    at async Router.execute (/var/task/node_modules/next/dist/next-server/server/router.js:25:67)
    at async Server.run (/var/task/node_modules/next/dist/next-server/server/next-server.js:68:1042)
    at async Server.handleRequest (/var/task/node_modules/next/dist/next-server/server/next-server.js:32:504)
    at async Server.<anonymous> (/var/task/___next_launcher.js:31:9)

I assume this is because .meshrc.yaml is not part of the build, so findAndParseConfig does not find it. But I had also not luck directly calling processConfig. Any ideas?

https://github.com/schmidsi/nft-browser/blob/main/pages/api/graphql.ts

[schmidsi]

Update: I also tried to deploy the example to Vercel. It has the same effect: https://graphql-mesh-mu.vercel.app/api/graphql

Next steps would be to try to include .yaml files into the build somehow.

[schmidsi]

Another approach would be to inline the config like on this blogpost: https://dev.to/stephengfriend/hasura-graphql-mesh-3-5i5

[schmidsi]

It seems that it is a general issue of Vercel/Next. More specific: Server-less functions (see: vercel/next.js#8251). So the question is probably more: Is it possible to set graphql-mesh up in a way that it does not depend on Node's fs. That would also enable in-browser support.

[schmidsi]

I found a solution by myself 💪

Although it is a bit hacky. The trick is:

• Use mesh.config.js instead of .meshrc.yaml to add it to the build
• Circumvent runtime module resolution by providing an importFn to processConfig

[Urigo]

thank you for the update @schmidsi !
Do you think this is something we should document?
Or maybe change?

[schmidsi]

I can add an example and write something into the cookbook if that helps. Although my personal feeling is that my solution is hacky and it could be done better if we change the config loading a bit:

• Remove the strict dependency on cosmiconfig and generally the dependency on fs and any other non-isomorphic dependencies. It is great if someone wants to run graphql-mesh standalone. But it can stand in the way for other usecases like this server-less approach or in-browser meshing.
• One option would be to move the "preimports" to mesh.config.js. I tried that, but it is not possible because the config is validated according to a JSON-schema. Maybe it's possible to loosen this schema validation a bit to support js modules? I generally like the config approach from next.js a bit more, because it is config-as-code.

I think this raises a strategically question: Is the primary use-case of Graphql-mesh to be run as a standalone server/service and should be configuration-over-code? If yes: I'm happy to document my learnings as a recipe in the docs and add/extend an example. If no and it wants to become more flexible, code-over-configuration, and the SDK-approach is more important, than it should switch more into a next.js style of configuration in my opinion.