I'm working in a Go Lang REST API repo.
I'm wanting to build an endpoint that will take in a file (as part of the form-data, so I suppose I'll use request.FormFile('my-file-key')). This endpoint should also take in a body of a JSON model (which i suppose would be decoded with something like this:
var myData model.MyModel
json.NewDecoder(request.Body).Decode(&myData)
But I'm running into a lot of issues. Is it even possible to send both a body and a file in the form-data with a http request?
If I try to send both I get errors from FormFile saying that it can't find the file of the key name (but if I send the exact same request without a body, this error doesn't happen). I guessing it's having trouble decoding the request.
What you need is a multipart request. One part can be JSON data, and the other part the file data.
If you're using a Go client to prepare the request, you need to use the mime/multipart package to create a Writer, then use CreatePart to create the JSON part, then the file part, and submit the request to the server.
On the decoding side: since the body is JSON you cannot parse it as a form. You have to use a multipart.Reader to read from the body after you parse the headers. Again, from that reader you get a Part, and read the data from that part. You'll get two parts, one for the JSON data and one for the file data.
Related
I'm trying to download a firmware.bin file that is produced in a private Github repository. I have the code that is finding the right asset url to download the file and per Github instructions the accept header needs to be set to accept: application/octet-stream in order to get the binary file. I'm only getting JSON in response. If I run the same request through postman I'm getting a binary file as the body. I've tried downloading it using HTTPClient and I get the same JSON request. It seems the headers aren't being set as requested to tell Github to send the binary content as I'm just getting JSON. As for the ArduinoOTA abstraction, I can't see how to even try to set headers and in digging into the esp_https_ota functions and http_client functions there doesn't appear to be a way to set headers for any of these higher level abstractions because the http_config object has no place for headers as far as I can tell. I might file a feature request to allow for this, but am new to this programming area and want to check to see if I'm missing something first.
Code returns JSON, not binary. URL is github rest api url to the asset (works in postman)
HTTPClient http2;
http2.setAuthorization(githubname,githubpass);
http2.addHeader("Authorization","token MYTOKEN");
http2.addHeader("accept","application/octet-stream");
http2.begin( firmwareURL, GHAPI_CERT); //Specify the URL and certificate
With the ESP IDF HTTP client you can add headers to an initialized HTTP client using function esp_http_client_set_header().
esp_http_client_handle_t client = esp_http_client_init(&config);
esp_http_client_set_header(client, "HeaderKey", "HeaderValue");
err = esp_http_client_perform(client);
If using the HTTPS OTA API, you can register for a callback which gives you a handle to the underlying HTTP client. You can then do the exact same as in above example.
I am looking for a way to send a post request to a specific URI from PowerApps.
Basically I have a small audio file (webm) captured from the microphone and it's encoded using Base64. Now I have to send it to a server via post request and the encoded data should be put in the body of the request, since it is too big (for Nginx) to be put in the URL itself (?data=).
Can I achieve it in PowerApps?
Binary to encoded text (in PowerApps):
Set(BinaryAudioData_2, Substitute(JSON(Mic2.Audio,JSONFormat.IncludeBinaryData),"""",""));
Set(AudioFile, Mic2.Audio); Collect(Collection3, AudioFile);
You can trigger a Power Automate Flow from PowerApps, then Flow can target the specific URI. Read more
I am looking for an appropriate HTTP status code that tells the receiver that just the meta-data is being sent, not the complete data.
For example, say you do an HTTP GET:
GET /foo?meta_data_only=yes
the server won't look up the complete data, just send some metadata back about the endpoint, for example. Is there an HTTP status code for the response that can represent this? I would guess it's in the 200s or 300s somewhere?
Since your metadata is being returned in the headers, I would send a status code of 204 No Content.
https://httpstatuses.com/204
The server has successfully fulfilled the request and that there is no
additional content to send in the response payload body.
Metadata in
the response header fields refer to the target resource and its
selected representation after the requested action was applied.
This sounds exactly like what you’re looking for: a successful response that contains no body, and metadata in the headers that provide additional about the resource.
Another thing worth noting is that it’s common practice to use the HTTP verb HEAD when you only want metadata. HEAD is very similar to GET, except that it specifies that you do not want a body back. For example if you do a HEAD to an image url, you will get a 204 No Content response and some metadata about the file such as Content-Type, Content-Size, maybe ETag, but you won’t be sent all of the file data. A lot of web servers (such as Nginx) support this behavior out of the box for static files. I would recommend that you stop using your querystring parameter, and instead implement HEAD versions of your endpoints. That would make the intention even more clear and intuitive.
I'm developing a web page with a form which returns a PDF document based on the form data. Currently I use the HTTP response fields
Content-Type: application/pdf
Content-Disposition: attachment; filename="foo.pdf"
However, since the field Content-Disposition is non-standard and doesn't work in all browsers I'm looking for a different approach. Do I have to save the PDF document on the server? What is the modus operandi?
Edit: By "doesn't work in all browsers" I mean that with some browsers the filename is not set to foo.pdf. Dillo, for instance, just sets the default filename (in the download dialog) to the basename of the URL path (plus query string).
Do I have to save the PDF document on the server?
No. As far as the HTTP client is concerned it, the inner workings of the server are completely opaque to it. All it sees is a TCP stream of bytes from the server and how exactly that stream is produced doesn't matter as long as it matches the specified Content-Type.
Just send the PDF right after the HTTP headers and you're done with.
Update due to comment
So if you're wondering how to supply a filename without using a header field: Just augment the URL with it. I.e. something like
http://${DOMAIN}/${PDF_GENERATOR}/${DESIRED_FILENAME}
In the HTTP server add a rewrite rule to simply omit the filename part and redirect to just
http://${DOMAIN}/${PDF_GENERATOR}
The HTTP client does not see that, all it see is some URL ending with a "filename", that it can present the user as a default for saving.
We have an existing API where 3rd parties can push data. The API calls are authenticated with HMAC using the same scheme as described in Ruby's ApiAuth library which I use to verify signed requests. We now need to support multipart/form-data file uploads.
I'm attempting to write a bash script as an example API call using cURL. I already have one that works without file uploads (POST request with only JSON data) here.
The part I'm stuck on is generating the $content_md5 for the multipart request. I understand the content of a multipart request has content sections separated by the boundary string, as described here.
Problem 1: cURL generates it's own boundary string and appends it to my content-type header
Problem 2: Should I MD5 the entire request body with boundary strings and section headers included?
So basically, I need to be able to know what the boundary string is so that I can generate a string that looks like the content sections and boundaries described in the http multipart format, lines 7 through 23 so that I may MD5 it.
Is there a way to do this with only cURL? Is there a better way to construct such an HMAC signed multipart request?
I was hoping to do it with cURL to present as a generalized example to 3rd party devs that will integrate with our API so they can sign their requests in whatever language they're using.