"panic: assignment to entry in nil map" when using custom metrics as of 0.5.0

[9numbernine9]

I'm submitting a ...

• bug report
• feature request

What is the current behavior?

When using custom metrics, a Go stack trace is generated:

github.com/iamseth/oracledb_exporter/collector.(*Exporter).checkIfMetricsChanged(0xc000290000)
    /go/src/oracledb_exporter/collector/collector.go:353 +0x3e5
<snip>
panic: assignment to entry in nil map

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem

Specfying a CUSTOM_METRICS environment variable that points to a file with any custom metrics inside of it will do the trick.

What is the expected behavior?

Custom metrics behave as they did previously in 0.4.4.

What is the motivation / use case for changing the behavior?

Using custom metrics. 😄

Please tell us about your environment:

Version: 0.5.0

NOTES

This appears to be a result of commit d0fbef9 . Previously the hashMap was being initialized in main.go but since the refactoring this initialization step isn't being performed anywhere in collector.go, resulting in an attempt to index into an unitialized map.

[schmikei]

Thanks for finding this! Looking into this, I'm sorry for the inconvenience.

[schmikei]

I've created #323 to resolve this, I strongly think it should work, but would you mind giving it a try to ensure it satisfies your bug report?

[gabguy]

@schmikei Can you please make a new release with this fix. Cannot use docker pull to get a valid container for version 0.5.0 with your fix atm.

[9numbernine9]

@schmikei Sorry for not reporting back sooner but I can confirm that the latest release fixes the issue that I originally reported. Thank you for looking into it! 👍