better error messaging when failure to create api session DB

[nicks]

What you'd like to see

Repro steps:

Create a Dockerfile like this:

FROM docker/cagent

USER root
WORKDIR /app
COPY agent.yaml ./agent.yaml

USER cagent
ENTRYPOINT ["/cagent", "api", "./agent.yaml", "--listen", ":3001"]

Build and run the Dockerfile.

You'll get the following error:

architect-api-1  | failed to create session store: unable to open database file: out of memory (14)

Why you'd like to see it

I'd like to see a better error message about what, exactly, cagent was trying to do that failed. Like what database file was it creating?

It took me a while to figure out why this was failing, since I spent a bunch of time trying to free up memory 😂

The real problem was that the filesystem was readonly, and cagent was trying to create a sqllite database in a readonly location.

Workarounds?

The fix was to add --session-db to a location where cagent has write access.

Additional context

Any other info you consider useful can be included here

[rumpl]

That final error is odd…

It comes from the library we use for our sqlite database, we could either propose a fix upstream or try to make sure that the place where we put the database is writable