function metadataRequest()

in packages/opentelemetry-node/lib/detector-gcp.js [110:146]

• 32 lines of code
• 6 McCabe index (conditional complexity)

function metadataRequest(path) {
    const baseUrl = 'http://metadata.google.internal:80';
    const options = {
        method: 'GET',
        headers: {'Metadata-Flavor': 'Google'},
        signal: AbortSignal.timeout(1000),
    };
    return fetch(`${baseUrl}/computeMetadata/v1/${path}`, options)
        .then((res) => {
            // Validate status
            if (!(res.status >= 200 && res.status < 300)) {
                throw new Error(
                    `Invalid response from metadata service: invalid status code: ${res.status} text: ${res.statusText}`
                );
            }
            // Validation from gcp-metadata
            // https://github.com/googleapis/gcp-metadata/blob/d8a868e5f487dcc3dd4bfd2d59d8c331fcf2895b/src/index.ts#L177
            const headerVal = res.headers.get('metadata-flavor');
            if (res.headers.get('Metadata-Flavor') !== 'Google') {
                throw new Error(
                    `Invalid response from metadata service: incorrect 'Metadata-Flavor' header. Expected 'Google', got ${
                        headerVal || 'no header'
                    }`
                );
            }
            return res.text();
        })
        .then((txt) => {
            // ref: https://github.com/googleapis/gcp-metadata/blob/d8a868e5f487dcc3dd4bfd2d59d8c331fcf2895b/src/index.ts#L184
            try {
                return jsonBigint.parse(txt);
            } catch {
                // nothing
            }
            return txt;
        });
}