@instana/core
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Core library for Instana's Node.js packages
328 lines (308 loc) • 15.5 kB
JavaScript
/*
* (c) Copyright IBM Corp. 2021
* (c) Copyright Instana Inc. and contributors 2019
*/
;
/**
* Used in http server instrumentation, the headers are already lower cased in the data we receive. This method is less
* expensive than getExtraHeadersCaseInsensitive/getExtraHeadersFromOptions.
*
* @param {import('http').IncomingMessage} message the request object to inspect for headers
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} an object literal with the captured headers or undefined if no headers matched the
* extraHttpHeadersToCapture list
*/
exports.getExtraHeadersFromMessage = function getExtraHeadersFromMessage(message, extraHttpHeadersToCapture) {
return exports.getExtraHeadersFromNormalizedObjectLiteral(message.headers, extraHttpHeadersToCapture);
};
/**
* Used in http2 server instrumentation (and indirectly in http1 server instrumentation), the headers are already lower
* cased in the data we receive. This method is less expensive than
* getExtraHeadersCaseInsensitive/getExtraHeadersFromOptions.
*
* @param {Object.<string, string | string[]>} headers an object literal that represents the headers of an HTTP message;
* this method expects that the keys have already been normalized to lower case
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} an object literal with the captured headers or undefined if no headers matched the
* extraHttpHeadersToCapture list
*/
exports.getExtraHeadersFromNormalizedObjectLiteral = function getExtraHeadersFromNormalizedObjectLiteral(
headers,
extraHttpHeadersToCapture
) {
if (!extraHttpHeadersToCapture || extraHttpHeadersToCapture.length === 0) {
return undefined;
}
let extraHeadersFound = false;
const /** @type Object.<string, string> */ extraHeaders = {};
for (let i = 0; i < extraHttpHeadersToCapture.length; i++) {
const key = extraHttpHeadersToCapture[i];
const value = headers[key];
if (Array.isArray(value)) {
// If the client has set the same header multiple times, Node.js has already normalized
// this to a single string ("value 1, value 2, ..."). However, the type definitions in Node.js core declare
// interface IncomingHttpHeaders extends NodeJS.Dict<string | string[]>, so technically string array values
// are allowed and we should be able to handle them.
extraHeaders[key] = value.join(', ');
extraHeadersFound = true;
} else if (value) {
extraHeaders[key] = value;
extraHeadersFound = true;
}
}
if (!extraHeadersFound) {
return undefined;
}
return extraHeaders;
};
/**
* Used in native fetch instrumentation; the headers are already normalized to a
* Headers object (https://developer.mozilla.org/en-US/docs/Web/API/Headers) and the header names are normalized
* to lower case.
*
* @param {import('node-fetch').Headers} headers a Fetch API Headers object
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} an object literal with the captured headers or undefined if no headers matched the
* extraHttpHeadersToCapture list
*/
exports.getExtraHeadersFromFetchHeaders = function getExtraHeadersFromFetchHeaders(headers, extraHttpHeadersToCapture) {
if (!extraHttpHeadersToCapture || extraHttpHeadersToCapture.length === 0) {
return undefined;
}
let extraHeadersFound = false;
const /** @type Object.<string, string> */ extraHeaders = {};
for (let i = 0; i < extraHttpHeadersToCapture.length; i++) {
const key = extraHttpHeadersToCapture[i];
if (headers.has(key)) {
// If the client has set the same header multiple times, Node.js has already normalized
// this to "value 1, value 2, ..."
extraHeaders[key] = headers.get(key);
extraHeadersFound = true;
}
}
if (!extraHeadersFound) {
return undefined;
}
return extraHeaders;
};
/**
* Used in http client instrumentation, the headers can appear in any lower case/upper case combination there. This is
* slightly more expensive than getExtraHeadersFromMessage.
*
* @param {import ('http').RequestOptions} options the options object passed to http.request/http.get
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} an object literal with the captured headers or undefined if no headers matched the
* extraHttpHeadersToCapture list
*/
exports.getExtraHeadersFromOptions = function getExtraHeadersFromOptions(options, extraHttpHeadersToCapture) {
if (!options) {
return undefined;
}
return exports.getExtraHeadersCaseInsensitive(options.headers, extraHttpHeadersToCapture);
};
/**
* Used in http2 (and indirectly http 1.x client) instrumentation, the headers can appear in any lower case/upper case
* combination there. This is slightly more expensive than getExtraHeadersFromNormalizedObjectLiteral.
*
* @param {Object.<string | number, number | string | string[]>} headers an object literal that represents the headers
* of an HTTP request; in contrast to getExtraHeadersFromNormalizedObjectLiteral this method expects does not expect the
* keys to have been normalized to lower case
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} an object literal with the captured headers or undefined if no headers matched the
* extraHttpHeadersToCapture list
*/
exports.getExtraHeadersCaseInsensitive = function getExtraHeadersCaseInsensitive(headers, extraHttpHeadersToCapture) {
if (!extraHttpHeadersToCapture || extraHttpHeadersToCapture.length === 0 || !headers || typeof headers !== 'object') {
return undefined;
}
const keys = Object.keys(headers).map(key => ({
orig: key,
low: key.toLowerCase()
}));
let extraHeadersFound = false;
const /** @type Object.<string, string> */ extraHeaders = {};
for (let i = 0; i < extraHttpHeadersToCapture.length; i++) {
const keyToCapture = extraHttpHeadersToCapture[i];
for (let j = 0; j < keys.length; j++) {
if (keys[j].low === keyToCapture) {
extraHeaders[keys[j].low] = Array.isArray(headers[keys[j].orig])
? headers[keys[j].orig].join(', ')
: headers[keys[j].orig];
extraHeadersFound = true;
}
}
}
if (!extraHeadersFound) {
return undefined;
}
return extraHeaders;
};
/**
* This is used to merge HTTP response headers with HTTP request headers that have been captured earlier in the request
* lifecycle (in the http server instrumentation), or to merge additional headers from multiple sources (in the http
* client instrumentation).
*
* @param {Object.<string, string> | undefined} headersAlreadyCapturedIfAny an object literal representing the headers
* that have already been captured earlier
* @param {import('http').ServerResponse|import('http').ClientRequest} message the object to inspect for additional
* headers; this object is assumed to have a `getHeader` method that retrieves headers in a case-insensitive fashion.
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} a new object literal with the merged captured headers, or the parameter
* `headersAlreadyCapturedIfAny` unmodified if no new headers were found
*/
exports.mergeExtraHeadersFromServerResponseOrClientRequest =
function mergeExtraHeadersFromServerResponseOrClientRequest(
headersAlreadyCapturedIfAny,
message,
extraHttpHeadersToCapture
) {
return mergeExtraHeaders(headersAlreadyCapturedIfAny, extraHttpHeadersToCapture, key => message.getHeader(key));
};
/**
* This is used to merge HTTP response headers with HTTP request headers that have been captured earlier in the request
* lifecycle (in the http client instrumentation).
*
* @param {Object.<string, string> | undefined} headersAlreadyCapturedIfAny an object literal representing the headers
* that have already been captured earlier
* @param {import('http').IncomingMessage} incomingMessage the response object to inspect for headers; this method
* assumes that this object has a `headers` property which is an object literal where header names have been normalized
* to lower case
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} a new object literal with the merged captured headers, or the parameter
* `headersAlreadyCapturedIfAny` unmodified if no new headers were found
*/
exports.mergeExtraHeadersFromIncomingMessage = function mergeExtraHeadersFromIncomingMessage(
headersAlreadyCapturedIfAny,
incomingMessage,
extraHttpHeadersToCapture
) {
return exports.mergeExtraHeadersFromNormalizedObjectLiteral(
headersAlreadyCapturedIfAny,
incomingMessage.headers,
extraHttpHeadersToCapture
);
};
/**
* This is used to merge HTTP response headers with HTTP request headers that have been captured earlier in the request
* lifecycle (in the http 2 client instrumentation and implicitly in the http client instrumentation).
*
* @param {Object.<string, string> | undefined} headersAlreadyCapturedIfAny an object literal representing the headers
* that have already been captured earlier
* @param {Object.<string, string | string[]>} headers an object literal that represents the headers of an HTTP message;
* this method expects that the keys have already been normalized to lower case
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} a new object literal with the merged captured headers, or the parameter
* `headersAlreadyCapturedIfAny` unmodified if no new headers were found
*/
exports.mergeExtraHeadersFromNormalizedObjectLiteral = function mergeExtraHeadersFromNormalizedObjectLiteral(
headersAlreadyCapturedIfAny,
headers,
extraHttpHeadersToCapture
) {
if (!headers) {
return headersAlreadyCapturedIfAny;
}
return mergeExtraHeaders(headersAlreadyCapturedIfAny, extraHttpHeadersToCapture, key => headers[key]);
};
/**
* This is used to merge HTTP response headers provided in the form of a Fetch API Headers object
* (https://developer.mozilla.org/en-US/docs/Web/API/Headers) with HTTP request headers that have been captured earlier
* in the request lifecycle (in the native fetch instrumentation).
*
* @param {Object.<string, string> | undefined} headersAlreadyCapturedIfAny an object literal representing the headers
* that have already been captured earlier
* @param {import('node-fetch').Headers} headers a Fetch API Headers object
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} a new object literal with the merged captured headers, or the parameter
* `headersAlreadyCapturedIfAny` unmodified if no new headers were found
*/
exports.mergeExtraHeadersFromFetchHeaders = function mergeExtraHeadersFromFetchHeaders(
headersAlreadyCapturedIfAny,
headers,
extraHttpHeadersToCapture
) {
if (!extraHttpHeadersToCapture || extraHttpHeadersToCapture.length === 0 || !headers) {
return headersAlreadyCapturedIfAny;
}
return mergeExtraHeaders(headersAlreadyCapturedIfAny, extraHttpHeadersToCapture, keyToCapture =>
headers.get(keyToCapture)
);
};
/**
* This is used to merge HTTP response headers with HTTP request headers that have been captured earlier in the request
* lifecycle (in the http 2 server instrumentation). This method can handle object literals in which the keys have not
* been normalized to lower case yet. It is slightly more expensive than mergeExtraHeadersFromNormalizedObjectLiteral.
*
* @param {Object.<string, string> | undefined} headersAlreadyCapturedIfAny an object literal representing the headers
* that have already been captured earlier
* @param {Object.<string, string | string[]>} headers an object literal that represents the headers of an HTTP message;
* in contrast to mergeExtraHeadersFromNormalizedObjectLiteral this method does _not_ expect that the keys have already
* been normalized to lower case
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @returns {Object | undefined} a new object literal with the merged captured headers, or the parameter
* `headersAlreadyCapturedIfAny` unmodified if no new headers were found
*/
exports.mergeExtraHeadersCaseInsensitive = function mergeExtraHeadersCaseInsensitive(
headersAlreadyCapturedIfAny,
headers,
extraHttpHeadersToCapture
) {
if (!extraHttpHeadersToCapture || extraHttpHeadersToCapture.length === 0 || !headers) {
return headersAlreadyCapturedIfAny;
}
const keys = Object.keys(headers).map(key => ({
orig: key,
low: key.toLowerCase()
}));
return mergeExtraHeaders(headersAlreadyCapturedIfAny, extraHttpHeadersToCapture, keyToCapture => {
for (let j = 0; j < keys.length; j++) {
if (keys[j].low === keyToCapture) {
return headers[keys[j].orig];
}
}
return null;
});
};
/**
* This is used to merge HTTP response headers with HTTP request headers that have been captured earlier in the request
* lifecycle, or headers from multiple sources. It is used under the hood by all mergeExtraHeaders... methods.
*
* @param {Object.<string, string> | undefined} headersAlreadyCapturedIfAny an object literal representing the headers
* that have already been captured earlier
* @param {Array<string>} extraHttpHeadersToCapture the configured list of headers that need to be captured
* @param {(key: string) => string | string[] | number | undefined} getHeader a function that takes a header name (from
* the extraHttpHeadersToCapture list) and returns the header value from the HTTP request/response (or undefined, if the
* header does not exist)
* @returns {Object | undefined} a new object literal with the merged captured headers, or the parameter
* `headersAlreadyCapturedIfAny` unmodified if no new headers were found
*/
function mergeExtraHeaders(headersAlreadyCapturedIfAny, extraHttpHeadersToCapture, getHeader) {
if (!extraHttpHeadersToCapture || extraHttpHeadersToCapture.length === 0) {
return headersAlreadyCapturedIfAny;
}
let /** @type Object.<string, string> */ additionalHeaders = {};
let additionalHeadersFound = false;
for (let i = 0; i < extraHttpHeadersToCapture.length; i++) {
const key = extraHttpHeadersToCapture[i];
const value = getHeader(key);
if (Array.isArray(value)) {
additionalHeaders[key] = value.join(', ');
additionalHeadersFound = true;
} else if (typeof value === 'number') {
additionalHeaders[key] = String(value);
additionalHeadersFound = true;
} else if (value) {
additionalHeaders[key] = value;
additionalHeadersFound = true;
}
}
if (!additionalHeadersFound) {
additionalHeaders = undefined;
}
if (headersAlreadyCapturedIfAny && additionalHeaders) {
return Object.assign(headersAlreadyCapturedIfAny, additionalHeaders);
} else if (additionalHeaders) {
return additionalHeaders;
}
return headersAlreadyCapturedIfAny;
}