Executing custom binaries like aria2c
in the runtime are not supported in Cloud Functions.
You can find a hacky solution here: Can you call out to FFMPEG in a Firebase Cloud Function This involves having a statically linked binary (so you might need to recompile aria2c
as I'm assuming it won't be statically linked by default and it'll rely on more system packages like libc, libxxxx...) and bundling this library to your function deployment fackage.
You should really consider using Cloud Run for this use case. Cloud Run gives you the flexibility of creating your own container image that can include the binaries and libraries you want.
You can find a tutorial that bundles custom binaries on Cloud Run here: https://cloud.google.com/run/docs/tutorials/system-packages