Error in converting sdl to metadata - Hasura


September 2023

The idea of the article is to help you fix the simple error of Hasura Migrations. There are many Github issues that have solved this, but all the Google searches I performed to fix this did not result in any Github Issue links. Maybe its a comment of the decline in search quality of Google Search. This problem existed in our deployment at Medblocks for a year before I figured it out.

The problem

Hasura migration fails when using the CLI to migrate - this usually occurs in production. The same bunch of SQL files that work on local does not seem to be working in production. We used a Kubernetes Service job to run the migrations and it constantly kept failing with the following error:

error in converting sdl to metadata: fork/exec /root/.hasura/cli-ext/v2.32.1/cli-ext-886403857/cli-ext: no such file or directory:

The end of the error message says no such file or directory but after verifying I found that the migration files existed. My migration command used to be

hasura deploy --endpoint http://<my-deployment-url>

then I changed it to

ls -a && hasura deploy --endpoint http://<my-deployment-url>

It logged all the files I knew were there, but still the error persisted.

The solution

Then I built the container locally and SSH'd into it. Then tried to run the migrations from inside it and voila the same error popped up again.

error in converting sdl to metadata: fork/exec /root/.hasura/cli-ext/v2.32.1/cli-ext-886403857/cli-ext: no such file or directory:

So now we know it was because of the docker container I'm using. I was using docker node:20-alpine image, then I changed it to node:20-slim and the migrations worked.

TLDR: Change your docker image from alpine to a non-alpine version. If youre on a serverless platform facing this error then try and get an env as close to Debian as possible

What is different is Alpine that caused this ? We know alpine is a stripped down version of an OS that supposed to be super light to run, and it is. Alpine Linux site. Im not a systems engineer so I Google'd for this specifically and found the issue.

  2. - This one relates to running migrations on Heroku. Turns out even the Heroku build env strips out a few essential binaries.

A fast summary for people like me is that Hasura CLI is distributed as a binary, its written in Go. It depends on a few OS specific libraries which are absent in alpine version of Docker Images. The other

Hope this helps your case! Thanks for reading!

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