I m using dispatch-nio library to make several Http request calls. But I cannot find an example how to handle callback responses through nio library.
And also I am unable to handle exceptions thrown by nio.Http call. Could anyone please post an example or an url where we can find some information of it.
So far I achieved:
val http = new nio.Http
withShutdown(http) {
val host = :/("http://example.org") /"api"
val withParams = host <<? Map(
"page" -> "1"
)
val future = http(withParams as_str)
while (!future.isSet) {
println("Waiting for results...")
Thread.sleep(15000)
}
future.apply()
}
}
How to set headers and onComplete? any example please
Thanks in advance.
Related
Stuck on this problem where I received this error everytime making POST request to my actix-web server.
CORS header 'Access-Control-Allow-Origin' missing
my javascript (VueJs running on localhost:3000) :
let data = //some json data
let xhr = new XMLHttpRequest();
xhr.open("POST", "http://localhost:8080/abc");
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onload = () => {
console.log(xhr.responseText);
}
xhr.send(JSON.stringify(data));
My Actix_Web server (running on localhost:8080) :
#[actix_web::main]
async fn main() {
HttpServer::new(move || {
let cors = Cors::default()
.allowed_origin("http://localhost:3000/")
.allowed_methods(vec!["GET", "POST"])
.allowed_header(actix_web::http::header::ACCEPT)
.allowed_header(actix_web::http::header::CONTENT_TYPE)
.max_age(3600);
App::new()
.wrap(cors)
.service(myfunc)
})
.bind(("0.0.0.0", 8080))
.unwrap()
.run()
.await
.unwrap();
}
my cargo.toml dependencies
[dependencies]
actix-web = "4"
actix-cors = "0.6.1"
...
Got any idea?
Okay, so I've done some testing. If you're writing a public API, you probably want to allow all origins. For that you may use the following code:
HttpServer::new(|| {
let cors = Cors::default().allow_any_origin().send_wildcard();
App::new().wrap(cors).service(greet)
})
If you're not writing a public API... well, I'm not sure what they want you to do. I've not figured out how to tell the library to send that header. I guess I will look at the code.
UPDATE:
So funny story, this is how you allow specific origins:
let cors = Cors::default()
.allowed_origin("localhost:3000")
.allowed_origin("localhost:2020");
BUT, and oh boy, is that but juicy. The Access-Control-Allow-Origin response header is only set when there is a Origin request header. That header is normally added by the browser in certain cases 1. So I did that (using the Developer tools in the browser). What did I get? "Origin is not allowed to make this request". I set my origin header to localhost:3000. Turns out, the arctix library simply discards that header if no protocol was provided... (e.g. http://) (I assume it discards it, if it deems its format invalid). That internally results in the header being the string "null". Which is, checks notes, not in the list of allowed origins.
And now the grand finale:
Your origin header needs to be set to (by either you or the browser): "http://localhost:3000".
Your configuration needs to include: .allowed_origin("http://localhost:3000").
After doing that, the server will happily echo back your origin header in the Access-Control-Allow-Origin header. And it will only send that one.
I've no idea if any of that is what the standard specifies (or not). I encourage you to read through it, and if it doesn't comply, please open an issue on GitHub. I would do it myself, but I'm done with programming for today.
Cheers!
Using gRPC bindings from https://github.com/gkkachi/firestore-grpc I was able to puzzle together something that is seemingly working but does not receive any content:
Creating the request:
let req = ListenRequest {
database: format!("projects/{}/databases/(default)", project_id),
labels: HashMap::new(),
target_change: Some(TargetChange::AddTarget(Target {
// "Rust" in hex: https://github.com/googleapis/python-firestore/issues/51
target_id: 0x52757374,
once: false,
target_type: Some(TargetType::Documents(DocumentsTarget {
documents: vec![users_collection],
})),
resume_type: None,
})),
};
Sending it:
let mut req = Request::new(stream::iter(vec![req]));
let metadata = req.metadata_mut();
metadata.insert(
"google-cloud-resource-prefix",
MetadataValue::from_str(&db).unwrap(),
);
println!("sending request");
let res = get_client(&token).await?.listen(req).await?;
let mut res = res.into_inner();
while let Some(msg) = res.next().await {
println!("getting response");
dbg!(msg);
}
(full code in this repo).
The request can be made but the stream does not contain any actual content. The only hint I get from the debug logs is
[2021-10-27T14:54:39Z DEBUG h2::codec::framed_write] send frame=GoAway { error_code: NO_ERROR, last_stream_id: StreamId(0) }
[2021-10-27T14:54:39Z DEBUG h2::proto::connection] Connection::poll; connection error error=GoAway(b"", NO_ERROR, Library)
Any idea what is missing?
The crucial thing I was missing as pointed out in the rust users forum was that the request stream was immediately ending which caused the connection to close. The send frame=GoAway was actually send by the client (facepalm).
To keep the connection open and receive responses we can keep the input stream pending: Request::new(stream::iter(vec![req]).chain(stream::pending())). There will be a better way to set things up and keep control over subsequent input requests but this is enough to fix the example.
For example we have setup like this:
user -> api gateway -> (specific endpoint) varnish -> backend service
If backend returns response 500 {"message":"error"} I want to patch this response and return 200 "[]" instead.
Is it possible to do something like this using varnish or some other proxy?
It is definitely possible to intercept backend errors, and convert them into regular responses.
A very simplistic example is the following:
sub vcl_backend_error {
set beresp.http.Content-Type = "application/json";
set beresp.status = 200;
set beresp.body = "[]";
return(deliver);
}
sub vcl_backend_response {
if(beresp.status == 500) {
return(error(200,"OK"));
}
}
Whenever your backend would fail, and return an HTTP/503 error, we will send a HTTP/200 response with [] output.
This output template for backend errors is also triggered when the backend does reply, but with a HTTP/500 error.
In real world scenarios, I would a some conditional logic in vcl_backend_error to only return the JSON output template when specific criteria are matched. For example: a certain URL pattern was matched.
I would advise the same in vcl_backend_response: maybe you don't want to convert all HTTP/500 errors into regular HTTP/200 responses. Maybe you also want to add conditional logic.
I am writing a http proxy which needs to call DumpRequest. For some reason, the client does not offer "Host" header while the server needs it. I then do this:
if req.Header.Get("host") == "" {
req.Header.Set("Host", "www.domain.com:80")
}
data, _ := httputil.DumpRequest(req, true)
conn.Write(data)
The problem is after I set "host", data still does not has it. I digged into source code of DumpRequest, found this:
var reqWriteExcludeHeaderDump = map[string]bool{
"Host": true, // not in Header map anyway
"Transfer-Encoding": true,
"Trailer": true,
}
Why is Host "not in Header map anyway"?
Short answer
I guess you should use Header.Add() instead of Header.Set()
I didn't try it. So if my answer is wrong, be free to figure it out.
Reference
From source code , It said that.
It replaces any existing values associated with key
But in you case, you don't have that K existing. So it behaves as we expected.
If you use Set() method, it's cool.
DumpRequest should not be used to implement a proxy - see doc:
It should only be used by servers to debug client requests. The returned
representation is an approximation only ...
If you are trying to change the origin host value of the request while it goes through your proxy, you do not need to change the header of host. You can do the following:
if req.Host == "" {
req.Host = "www.domain.com"
}
data, _ := httputil.DumpRequest(req, true)
conn.Write(data)
Playground
https://play.golang.org/p/f-qaZRC0RMO
Using python requests session I can connect to JIRA and retrieve issue information ...
session = requests.Session()
headers = {"Authorization": "Basic %s" % bas64_val}
session.post(jira_rest_url, headers=headers)
jira = session.get(jira_srch_issue_url + select_fields)
# select_fields = the fields I want from the issue
Now I'm trying to post a payload via the JIRA API, using a fixed issue url e.g. "https://my_jira_server.com:1234/rest/api/latest/issue/KEY-9876"
Which should be a case of the following, given: https://developer.atlassian.com/jiradev/jira-apis/about-the-jira-rest-apis/jira-rest-api-tutorials/jira-rest-api-example-edit-issues
payload = { "update": {
"fixVersions": [ {"set": "release-2.139.0"} ]
}}
posted = session.post(jira_task_url, data=payload)
# returns <Response [405]>
# jira_task_url = https://my_jira_server.com:1234/rest/api/latest/issue/KEY-9876
But this doesn't appear to work! Looking into the http 405 response, suggests that my payload is not properly formatted! Which notably, is the not easiest thing to diagnose.
What am I doing wrong here? Any help on this would be much appreciated.
Please note, I am not looking to use the python jira module, I am using requests.session to manage several sessions for different systems i.e. JIRA, TeamCity, etc..
Found the solution! I had two problems:
1) The actual syntax structure should have been:
fix_version = { "update": { "fixVersions": [ {"set" : [{ "name" : "release-2.139.0" }]}]
2) To ensure the payload is actually presented as JSON, use json.dumps() which takes an object and produces a string (see here) AND set 'content-type' to 'application/json':
payload = json.dumps(fix_version)
app_json = { 'content-type': 'application/json' }
session.put(https://.../rest/api/latest/issue/KEY-9876, headers=app_json, data=payload)
Rather than trying to define the JSON manually!