func getRegionalXdsEndpoint()

in agent/envoy_bootstrap/envoy_bootstrap.go [283:320]
34 lines of code
10 McCabe index (conditional complexity)

func getRegionalXdsEndpoint(region string, envoyCLIInst EnvoyCLI) (*string, error) {
	xdsEndpoint := env.Get("APPMESH_XDS_ENDPOINT")
	if xdsEndpoint != "" {
		return &xdsEndpoint, nil
	}
	preview, err := env.Truthy("APPMESH_PREVIEW")
	if err != nil {
		return nil, err
	}
	dualstack, err := env.Truthy("APPMESH_DUALSTACK_ENDPOINT")
	if err != nil {
		return nil, err
	}
	var useFips bool
	if fips, err := isFipsCompatible(region, envoyCLIInst); err != nil {
		return nil, err
	} else {
		// TODO: In GovCloud regions the AppMesh FIPS xDS endpoint does not contain the suffix `-fips`.
		// In future if AppMesh adds endpoints with suffx '-fips' in GovCloud regions then get rid of
		// this below logic and directly use the variable `fips`.
		useFips = fips && !strings.HasPrefix(region, "us-gov-")
	}

	if preview && useFips {
		v := fmt.Sprintf("appmesh-preview-envoy-management-fips.%s.%s:443", region, getXdsDomain(region, dualstack))
		return &v, nil
	}
	if preview {
		v := fmt.Sprintf("appmesh-preview-envoy-management.%s.%s:443", region, getXdsDomain(region, dualstack))
		return &v, nil
	}
	if useFips {
		v := fmt.Sprintf("appmesh-envoy-management-fips.%s.%s:443", region, getXdsDomain(region, dualstack))
		return &v, nil
	}
	v := fmt.Sprintf("appmesh-envoy-management.%s.%s:443", region, getXdsDomain(region, dualstack))
	return &v, nil
}