[WIP] Fix crash in Nakama due to missing IP cache configuration

[Copilot]

Fix Nakama crash when IP cache is not configured

• Analyze the issue and understand the root cause
• Modify evr_pipeline.go to handle missing IP cache providers gracefully
• Ensure ipInfoCache is always initialized (even with no providers)
• Add warning logs instead of fatal errors
• Create tests to verify the fix
• Verify the changes work correctly
• Format code with gofmt
• Address code review feedback

Summary

Fixed potential crash when Redis is not configured by:

• Adding warning log when Redis client is not configured
• Adding warning log when no IP providers are configured
• Making it explicit that server can run without IP cache
• Created comprehensive tests for IP cache with no providers
• Fixed bug where IPAPI_API_KEY was checked instead of IPQS_API_KEY

The IP cache now gracefully handles missing providers:

• Get() returns nil (no error) when no providers configured
• IsVPN() returns false (safe default) when no providers configured
• All code paths verified to handle nil ipInfo correctly

Original prompt

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This section details on the original issue you should resolve

<issue_title>Nakama crashes if IP cache is not configured in server/evr_pipeline.go</issue_title>
<issue_description>### Summary
Nakama crashes when an IP cache is not configured. This occurs in server/evr_pipeline.go. The crash is due to the lack of handling for a nil or missing IPInfoProvider configuration, leading to a fatal error when initializing the IP info cache.

Steps to Reproduce

1. Run Nakama without configuring an IP cache (no Redis client, no IPAPI/IPQS keys).
2. Application crashes on startup.

Error Location

The problematic code is in server/evr_pipeline.go:

	var providers []IPInfoProvider
	if redisClient != nil {
		if vars["IPAPI_API_KEY"] != "" {
			ipqsClient, err := NewIPQSClient(logger, metrics, redisClient, vars["IPQS_API_KEY"])
			if err != nil {
				logger.Fatal("Failed to create IPQS client", zap.Error(err))
			}
			providers = append(providers, ipqsClient)
		}

		ipapiClient, err := NewIPAPIClient(logger, metrics, redisClient)
		if err != nil {
			logger.Fatal("Failed to create IPAPI client", zap.Error(err))
		}
		providers = append(providers, ipapiClient)
	}
	ipInfoCache, err = NewIPInfoCache(logger, metrics, providers...)
	if err != nil {
		logger.Fatal("Failed to create IP info cache", zap.Error(err))
	}

Proposed Fix

Add logic to handle the case where no providers are configured (e.g., redisClient is nil), so Nakama does not crash. This could involve initializing an empty provider slice or logging a warning instead of calling logger.Fatal.

Version

Please specify the Nakama version where this occurs.

Additional Context

• File: server/evr_pipeline.go
• The crash occurs at startup if no IP cache provider is set.

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Labels: bug, crash
Issue Type: Bug</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Nakama crashes if IP cache is not configured in server/evr_pipeline.go #85

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