Is it possible to add a header to a multipart form request (where I’m uploading a file)? My upload is failing because a bespoke request header is missing.
Also, is it possible to have a multipart request sent as one of the requests in a batch?
Yes, you can set custom headers like how you usually set them in single or batch requests. Here’s an example for both of your questions:
import http from "k6/http";
export default function () {
let payload = {
someFile: http.file("some file data, maybe via open()", "test.txt"),
someNonFileData: "whatever",
};
let params = {
headers: {
"my-special-header": "foo",
},
timeout: 2000,
};
let postResponse = http.post("https://httpbin.test.loadimpact.com/post", payload, params);
console.log(postResponse.body);
let batchResponses = http.batch([
["POST", "https://httpbin.test.loadimpact.com/post", payload, params],
["POST", "https://httpbin.test.loadimpact.com/post", payload, { headers: { "some-other-header": "bar" } }],
["GET", "https://httpbin.test.loadimpact.com/anything", null, params],
]);
console.log(batchResponses[1].body);
}
This would output something like this:
{
"args": {},
"data": "",
"files": {
"someFile": "some file data, maybe via open()"
},
"form": {
"someNonFileData": "whatever"
},
"headers": {
"Content-Length": "408",
"Content-Type": "multipart/form-data; boundary=551edbbd317cbea6471a55ab1a71e09b4a674629b90c9e8ec792c477b2d7",
"Host": "httpbin.test.loadimpact.com",
"My-Special-Header": "foo",
"User-Agent": "k6/0.26.0 (https://k6.io/)",
},
"json": null,
"url": "https://httpbin.test.loadimpact.com/post"
}
{
"args": {},
"data": "",
"files": {
"someFile": "some file data, maybe via open()"
},
"form": {
"someNonFileData": "whatever"
},
"headers": {
"Content-Length": "408",
"Content-Type": "multipart/form-data; boundary=f514b810aaeb5969fce380049a85f26cfa89ecd699733d337af6a5dad759",
"Host": "httpbin.test.loadimpact.com",
"Some-Other-Header": "bar",
"User-Agent": "k6/0.26.0 (https://k6.io/)",
},
"json": null,
"url": "https://httpbin.test.loadimpact.com/post"
}
1 Like
Hello!
I have related question here. I need to pass request body in a form like this:
------WebKitFormBoundarygBo5S1n4XIhu707h Content-Disposition: form-data; name="image"; filename="image.png" Content-Type: image/png PNG IHDR;.....some file data
In order to achieve that I’m tring to send request like this:
let binImage = open("./flag.png", "b");
let headers = {
"Authorization": "bearer " + user.token,
"clientid": "webapp"
}
var data = {
file: http.file(binImage, "flag.png", "image/png")
};
let res = http.post(URL, data, {headers: headers});
But as a result this kind of request is being sent:
–e6c19b95ce0975c1e8f83876bb81c534f1c89030ce54289cfac66657201c
Content-Disposition: form-data; name=“file”; filename=“flag.png”
Content-Type: image/png�PNG
IHDR…some file data
This causes me MulterError: Unexpected field error. My guess is that name field values in Content-Disposition differs from each other. I need name=“image”, but I get name=“file”. How can I pass the right value here and avoid such error?
Thank you
@AlexJioev, just change the key in data 
Something like this:
var data = {
// notice the "image" here instead of "file"
image: http.file(binImage, "image.png", "image/png")
};
let res = http.post(URL, data, {headers: headers});
2 Likes
OMG, that’s so obvious, and I spent like 1 hour trying to figure this out 
Thank you! 
I have a related question has well. If I have multiple urls that are the same with slightly different headers, how do I differentiate them in the batch requests. Take these for example
response = http.post(
"http://10.1.11.2:8000",
'{"size":0,"query":{"bool":{"must":[],"must_not":[],"filter":[]}},"aggregations":{"1__cfgroup":{"terms":{"field":"measure_name","size":10000,"order":{"_term":"asc"}},"aggregations":{}}}}',
{
headers: {
Host: "10.1.11.2:8000",
Connection: "keep-alive",
"User-Agent":
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147 Safari/537.36",
"content-type": "application/json",
Accept: "*/*",
Origin: "http://chart.com",
Referer: "http://chart.com",
"Accept-Encoding": "gzip, deflate",
"Accept-Language": "en-US,en;q=0.9",
"Content-Type": "application/json",
},
}
);
response = http.post(
"http://10.1.11.2:8000",
'{"size":0,"query":{"bool":{"must":[],"must_not":[],"filter":[]}},"aggregations":{"1__cfgroup":{"terms":{"field":"compliance_year","size":10000,"order":{"_term":"desc"}},"aggregations":{}}}}',
{
headers: {
Host: "10.1.11.2:8000",
Connection: "keep-alive",
"User-Agent":
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147 Safari/537.36",
"content-type": "application/json",
Accept: "*/*",
Origin: "http://chart.com",
Referer: "http://chart.com/",
"Accept-Encoding": "gzip, deflate",
"Accept-Language": "en-US,en;q=0.9",
"Content-Type": "application/json",
},
}
);
what would I add to a batch request like this to differentiate these urls.
export default function () {
group(' elasticsearch', function () {
group(':9200', function () {
let responses = http.batch([
['POST', 'http://10.1.11.2:8000'],
['POST', 'http://10.1.11.2:8000'],
@ralex7, I’m not sure I understand your question fully, but you can assign unique tags for every individual HTTP request in the http.batch() call, as shown in the examples here: batch( requests )
Would there be a way to use the ‘{“size”:0,“query”:{“bool”:{“must”:[],“must_not”:[],“filter”:[]}},“aggregations”:{“1__cfgroup”:{“terms”:{“field”:“measure_name”,“size”:10000,“order”:{“_term”:“asc”}},“aggregations”:{}}}}’, in my tags because that is the only difference in the urls.
The tags are a string to string map, technically you can put anything you want in there, though I’d advise you not to put the a JSON query inside one, but rather something shorter that summarizes it…
So if I have multiple of the same URL that only differs in the JSON query there is no way to put that in the batch requests?