Fix nil panic in UpdateCache when listapisresponse is empty (#211)

[rohanmishra29]

Fixes #211

Problem

When the CloudStack management server returns an empty listapisresponse (i.e., {"listapisresponse":{}}), the sync command panics with:
panic: interface conversion: interface {} is nil, not []interface {}
This happens in config/cache.go at the type assertion response["api"].([]interface{}) when response["api"] is nil.

Fix

Added a nil check for response["api"] before the type assertion. If the API list is empty, the function now returns nil with a clear error message instead of panicking.

Testing

Built successfully with go build ./.... The nil check prevents the panic when an empty listapisresponse is received.

[borisstoyanov]

@rohanmishra29 thanks for this fix, I'll include it in the milestone

[Copilot]

🟡 Changes recommended

The new early-return path can still produce confusing CLI output and may wipe existing in-memory caches before validation, so the error handling should be adjusted to be safe and consistent.

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Pull request overview

This PR addresses a crash in CloudMonkey’s API discovery/cache update path when the CloudStack listApis response contains an empty listapisresponse (missing the api field), by adding a guard before the []interface{} type assertion.

Changes:

• Add a nil check for response["api"] in Config.UpdateCache to prevent a panic on empty listapisresponse.
• Print an error message and return early when the API list is missing.

File summaries

File	Description
config/cache.go	Adds a guard in UpdateCache to avoid panicking when listApis returns an empty response payload.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 1
• Review effort level: Lite

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