Runtime: System.Net.Http.CurlException HttpClient PostAsync

[erikpowa]

Environment

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04 LTS"

Curl version

curl 7.47.0 (x86_64-pc-linux-gnu) libcurl/7.47.0 GnuTLS/3.4.10 zlib/1.2.8 libidn/1.32 librtmp/2.3
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtmp rtsp smb smbs smtp smtps telnet tftp
Features: AsynchDNS IDN IPv6 Largefile GSS-API Kerberos SPNEGO NTLM NTLM_WB SSL libz TLS-SRP UnixSockets

Code

``` C#
var client = new HttpClient() {
BaseAddress = new Uri("http://example.com/")
};

var formContent = new FormUrlEncodedContent(new[]
{
new KeyValuePair("key", "val")
});

var response = await client.PostAsync("/some.php", formContent, CancellationToken.None);
```

Target

dotnet 1.0.0-preview1-002702
"System.Net.Http": "4.0.1-rc2-24027"

Exception

Unhandled Exception: System.AggregateException: One or more errors occurred. (An error occurred while sending the request.) ---> System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.Http.CurlException: _Failure when receiving data from the peer_
at System.Net.Http.CurlHandler.ThrowIfCURLEError(CURLcode error)
at System.Net.Http.CurlHandler.MultiAgent.FinishRequest(EasyRequest completedOperation, CURLcode messageResult)

Run Curl directly is working

curl -c cookies.txt -b cookies.txt -X POST --form "key=val" http://example.com/some.php -L

Can't get it working with dotnet, everything else just fine, except when I post FormUrlEncodedContent.
I tried different setup with HttpClientHandler, same exception.

Update!

Running with 1.0.0-preview2-003119 works fine.

[joshfree]

@ericeil can you take a look please?

[stephentoub]

@joshfree, you marked this as release notes. What's the note? Have we confirmed there's an issue? I tried the example and couldn't repro.

[joshfree]

@stephentoub, @ericeil is supposed to take a look and reproduce the issue.

[stephentoub]

@ericeil is supposed to take a look and reproduce the issue.

I understand, which is why I'm questioning the "release notes" tag.

[joshfree]

@stephentoub it's a war triage thing. This is a potential issue that won't block 1.0 from shipping but should be investigated and assuming it's valid should be added to the known issues list then moved to 1.1.

The other ~9 release notes bugs were investigated, doc'd, and closed yesterday; which may be why this one is standing out now. It should be resolved today as well.

[stephentoub]

Well, FWIW, I've not been able to repro this locally. I also put up the repro as a test in https://github.com/dotnet/corefx/issues/9414; it passed the test in all legs, and separately I submitted a private job on Ubuntu 16.04 to Jenkins, and it also passed the test. The error message "Failure when receiving data from the peer" is CURLE_RECV_ERROR, which typically means curl simply had trouble reading data from the network, and implies some kind of networking issue unrelated to the code consuming the libcurl library.

[erikpowa]

I just ran more PostAsync test, realized the remote got cloudflare on it. Running on Windows I get response but Ubuntu.. and because calling the curl from terminal is working (on Ubuntu), don't know how with .net doesn't. I'm currently digging more, maybe I'm missing something.

[joshfree]

Moving to 1.1 based on current information

[erikpowa]

I sent a cloned request (headers) to bypass cloudflare, but not working (still no problem on windows).
Noone ever ran into this issue?
I still can't figure it out if it's my-miss-coding / client-side / server-side failure / curl.

[stephentoub]

@erikpowa, in your repo you're connecting to example.com. I assume you're actually connecting to a different site? Is that something you can share with us?

[erikpowa]

@stephentoub Yes, different.
It would be better in private :)
[email protected]

[stephentoub]

Thanks, @erikpowa. @ericeil and I will get in touch with you offline.

[ericeil]

I was able to reproduce this on 1.0.0-preview1-002702. On more recent bits, this scenario seems to work. So it appears that this has already been fixed.

[BlasVilla]

Any progress on this bug? I encountered this in 1.1 (I thought this had been fixed by now). I can confirm that curl works but the HttpClient throws a CurlException and cannot find the host.

[stephentoub]

@BlasVilla, the issue should have been addressed for 1.1. If you're still having trouble, could you please open a new issue with the details of the failure you're encountering, what OS you're on, a repro, etc.? Thanks!

[xumingxiang]

我在centos6.8下也遇到这个问题，升级libcurl就行了。
centos6.8下自带的curl版本是7.19 ，版本过低
rpm -ivh http://mirror.city-fan.org/ftp/contrib/yum-repo/city-fan.org-release-1-13.rhel6.noarch.rpm
yum update libcurl
升级后的版本是libcurl-7.52

[flo8]

@BlasVilla Did you posted a new issue for this? We also encountered this bug in a console app with .Net Core 1.1 (netcoreapp1.1) in a standalone application running on Ubuntu 16.04.2 LTS (GNU/Linux 4.4.0-70-generic x86_64) the problem seems to happen randomly.

We get this error randomly when downloading a lot of files from Amazon S3 using AWSSDK.Core (3.3.8.2) and AWSSDK.S3 (3.3.5.7).

System.Net.Http.CurlException: Failure when receiving data from the peer
at System.Net.Http.CurlHandler.ThrowIfCURLEError(CURLcode error)
at System.Net.Http.CurlHandler.MultiAgent.FinishRequest(StrongToWeakReference`1 easyWrapper, CURLcode messageResult)

Here is the version of curl installed on our system:

curl 7.47.0 (x86_64-pc-linux-gnu) libcurl/7.47.0 GnuTLS/3.4.10 zlib/1.2.8 libidn/1.32 librtmp/2.3
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtmp rtsp smb smbs smtp smtps telnet tftp
Features: AsynchDNS IDN IPv6 Largefile GSS-API Kerberos SPNEGO NTLM NTLM_WB SSL libz TLS-SRP UnixSockets

Here is the code that seems to produce the error:
```
// Prepare S3 request
GetObjectRequest request = new GetObjectRequest();
request.Key = remoteFile;
request.BucketName = bucketName;

            // Download our file from S3
            Task<GetObjectResponse> response = client.GetObjectAsync(request);

            if (response.Result.ResponseStream != null)
            {
                using (MemoryStream memstream = new MemoryStream())
                {
                    // Get the stream
                    response.Result.ResponseStream.CopyTo(memstream);
                    byte[] bytes = memstream.ToArray();`

[hach-que]

EDIT: Scratch that, I'm going to do a bit more investigation as it might be another issue.

[KiarashS]

Also i have this problem in Linux(Mint) with requests from a Console Application to a Local Web Server.

[iAlexanderMoon]

I have also received: System.Net.Http.CurlException: Couldn't resolve host name
running my dockerized asp.netcore mvc application on a ubuntu 16.04 LTS host.

Where:

• the host COULD ping the dns name
• the container COULD ping the dns name
• the container COULD curl the request

The dns name was internal and I had specified 2 nameservers only one of which would resolve the internal dns name. After removing the secondary dns nameserver from my network interface on the HOST machine: /etc/network/interfaces (restart required). I confirmed the fix by re-enabling the secondary nameserver again and the issue returned.

Hope that helps someone in the future.

[galvesribeiro]

I'm having a similar issue with Azure SDK here https://github.com/Azure/azure-sdk-for-net/issues/3312

If I comment the code that download a blob from Azure Blob, the error doesn't happen. If I put it back, it fail with that curl exception... Any clues would be appreciated...

[stephentoub]

@galvesribeiro, do you have a standalone repro you can share? What OS? What version of .NET Core? Etc. A repro targeting HttpClient directly rather than going through pounds of layers above it would be best. :smile:

[Foroughi]

I get the same error while running this piece of code in a console app

 using (HttpClient client = new HttpClient())
            {               
                var result = client.GetAsync("https://2.ubookrdev.com").Result;                
                Console.Write(result.Content.ReadAsStringAsync().Result);    
            }  

OS: Ubuntu
Dotnet Version 1.1

FYI @stephentoub : using http://google.com as URL for GetAsync method works properly and also using http://google.com1 will return a not found exception which is correct.

UPDATE 1:

I've checked the other versions of dotnet core which all have the same issue, here is the list of them:

1.0.3
1.0.4
dotnet-dev-1.1.0-preview1-005051
dotnet-dev-2.0.0-preview1-005977

[patroza]

Same problem on WSL (Bash on Windows) with .NET Core 2.0.
I have an ASP.Net Core http server running in one bash, and try to connect with a Core console app in another bash, and get the error.

[patroza]

My workaround:

• Do not listen on http://+:port but on http://specific-ip:port.
• Connect to http://specific-ip:port from the client app.

[sunithathiyagarajan]

@patroza : Yes, as you said mentioning "IP Address : specific port" works !