Panic when TLS CA file is missing

[claudiofahey]

Problem description

When using the client with TLS enabled, a missing TLS CA file results in the following panic.

thread '<unnamed>' panicked at 'should be valid path: Os { code: 2, kind: NotFound, message: "No such file or directory" }', pravega-client-rust-fa7c139c5174e088/0833868/config/src/lib.rs:128:49

There are two problems. First, the message is unclear what the problem is. Which file is missing? Is it a keycloak file, TLS file, or something else? Did I set the wrong env var?

Problem location

pravega-client-rust-fa7c139c5174e088/0833868/config/src/lib.rs:128

Suggestions for an improvement

1. The error message should identify the name of the file that is missing.
2. Since Pravega client is a library, this should should be returned as an error, not result in a panic. The application can panic if appropriate.