The init context (aka "init code") is code in the global context that has access to a few functions not accessible during main script execution (aka "VU context" or "VU code"). For a more detailed description see Running k6.
|open( filePath, [mode] )||Opens a file and reads all the contents into memory.|
The k6 module contains k6-specific functionality.
|check(val, sets, [tags])||Runs one or more checks on a value and generates a pass/fail result but does not throw errors or otherwise interrupt execution upon failure.|
|fail([err])||Throws an error, failing and aborting the current VU script iteration immediately.|
|group(name, fn)||Runs code inside a group. Used to organize results in a test.|
|randomSeed(int)||Set seed to get a reproducible pseudorandom number using |
|sleep(t)||Suspends VU execution for the specified duration.|
The k6/crypto module provides common hashing functionality available in the GoLang crypto package.
|createHash(algorithm)||Create a Hasher object, allowing the user to add data to hash multiple times, and extract hash digests along the way.|
|createHMAC(algorithm, secret)||Create an HMAC hashing object, allowing the user to add data to hash multiple times, and extract hash digests along the way.|
|hmac(algorithm, secret, data, outputEncoding)||Use HMAC to sign an input string.|
|md4(input, outputEncoding)||Use MD4 to hash an input string.|
|md5(input, outputEncoding)||Use MD5 to hash an input string.|
|randomBytes(int)||Return an array with a number of cryptographically random bytes.|
|ripemd160(input, outputEncoding)||Use RIPEMD-160 to hash an input string.|
|sha1(input, outputEncoding)||Use SHA-1 to hash an input string.|
|sha256(input, outputEncoding)||Use SHA-256 to hash an input string.|
|sha384(input, outputEncoding)||Use SHA-384 to hash an input string.|
|sha512(input, outputEncoding)||Use SHA-512 to hash an input string.|
|sha512_224(input, outputEncoding)||Use SHA-512/224 to hash an input string.|
|sha512_256(input, outputEncoding)||Use SHA-512/256 to hash an input string.|
The k6/http module contains functionality for performing HTTP transactions.
|batch( requests )||Issue multiple HTTP requests in parallel (like e.g. browsers tend to do).|
|cookieJar()||Get active HTTP Cookie jar.|
|del( url, [body], [params] )||Issue an HTTP DELETE request.|
|file( data, [filename], [contentType] )||Create a file object that is used for building multi-part requests.|
|get( url, [params] )||Issue an HTTP GET request.|
|options( url, [body], [params] )||Issue an HTTP GET request.|
|patch( url, [body], [params] )||Issue an HTTP PATCH request.|
|post( url, [body], [params] )||Issue an HTTP POST request.|
|put( url, [body], [params] )||Issue an HTTP PUT request.|
|request( method, url, [body], [params] )||Issue any type of HTTP request.|
|CookieJar||Used for storing cookies, set by the server and/or added by the client.|
|FileData||Used for wrapping data representing a file when doing multipart requests (file uploads).|
|Params||Used for setting various HTTP request-specific parameters such as headers, cookies, etc.|
|Response||Returned by the http.* methods that generate HTTP requests.|
The metrics module provides functionality to create custom metrics of various types. All metrics (both the built-in metrics and the custom ones) have a type. There are four different metrics types, and they are:
All values added to a custom metric can optionally be tagged which can be useful when analysing the test results.
|Counter||A metric that cumulatively sums added values.|
|Gauge||A metric that stores the min, max and last values added to it.|
|Rate||A metric that tracks the percentage of added values that are non-zero.|
|Trend||A metric that allows for calculating statistics on the added values (min, max, average and percentiles).|
|connect( url, params, callback )||Create a WebSocket connection, and provides a Socket client to interact with the service. The method blocks the test finalization until the connection is closed.|
|Socket||WebSocket client used to interact with a WS connection.|
|Socket.close()||Close the WebSocket connection.|
|Socket.on(event, callback)||Set up an event listener on the connection for any of the following events:|
|Socket.ping()||Send a ping.|
|Socket.setInterval(callback, interval)||Call a function repeatedly at certain intervals, while the connection is open.|
|Socket.setTimeout(callback, period)||Call a function with a delay, if the connection is open.|
Error codes, introduced in k6 0.24.0, are unique numbers that can be used to identify and handle different application and network errors more easily. For the moment, these error codes are applicable only for errors that happen during HTTP requests, but they will be reused and extended to support other protocols in future k6 releases.
When an error occurs, its code is determined and returned as both the
error_code field of the
http.Response object, and also attached as the
error_code tag to any metrics associated with that request. Additionally, for more details, the
error metric tag and
http.Response field will still contain the actual string error message.
Error codes for different errors are as distinct as possible, but for easier handling and grouping, codes in different error categories are also grouped in broad ranges. The current error code ranges are:
- 1000-1099 - General errors
- 1100-1199 - DNS errors
- 1200-1299 - TCP errors
- 1300-1399 - TLS errors
- 1400-1499 - HTTP 4xx errors
- 1500-1599 - HTTP 5xx errors
- 1600-1699 - HTTP/2 specific errors
The following specific error codes are currently defined:
- 1000: A generic error that isn't any of the ones listed below.
- 1010: A non-TCP network error - this is a place holder there is no error currently known to trigger it.
- 1100: A generic DNS error that isn't any of the ones listed below.
- 1101: No IP for the provided host was found.
- 1110: Blacklisted IP was resolved or a connection to such was tried to be established.
- 1200: A generic TCP error that isn't any of the ones listed below.
- 1201: A "broken pipe" on write - the other side has likely closed the connection.
- 1202: An unknown TCP error - We got an error that we don't recognize but it is from the operating system and has
errnoset on it. The message in
errorincludes the operation(write,read) and the errno, the OS, and the original message of the error.
- 1210: General TCP dial error.
- 1211: Dial timeout error - the timeout for the dial was reached.
- 1212: Dial connection refused - the connection was refused by the other party on dial.
- 1220: Reset by peer - the connection was reset by the other party, most likely a server.
- 1300: General TLS error
- 1310: Unknown authority - the certificate issuer is unknown.
- 1311: The certificate doesn't match the hostname.
- 1400 to 1499: error codes that correspond to the HTTP 4xx status codes for client errors
- 1500 to 1599: error codes that correspond to the HTTP 5xx status codes for server errors
- 1600: A generic HTTP/2 error that isn't any of the ones listed below.
- 1610: A general HTTP/2 GoAway error.
- 1611 to 1629: HTTP/2 GoAway errors with the value of the specific HTTP/2 error code added to 1611.
- 1630: A general HTTP/2 stream error.
- 1631 to 1649: HTTP/2 stream errors with the value of the specific HTTP/2 error code added to 1631.
- 1650: A general HTTP/2 connection error.
- 1651 to 1669: HTTP/2 connection errors with the value of the specific HTTP/2 error code added to 1651.