I try to fetch HTTP content with cURL, but I only get an empty body in the reply:
[root#www ~]# curl -v http://www.existingdomain.com/
* About to connect() to www.existingdomain.com port 80 (#0)
* Trying 95.211.256.257... connected
* Connected to www.existingdomain.com (95.211.256.257) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.21.0 (x86_64-redhat-linux-gnu) libcurl/7.21.0 NSS/3.12.8.0 zlib/1.2.5 libidn/1.18 libssh2/1.2.4
> Host: www.existingdomain.com
> Accept: */*
>
< HTTP/1.1 200 OK
< Server: nginx/0.8.53
< Date: Sat, 28 May 2011 15:56:23 GMT
< Content-Type: text/html
< Transfer-Encoding: chunked
< Connection: keep-alive
< Vary: Accept-Encoding
< X-Powered-By: PHP/5.3.3-0.dotdeb.1
<
* Connection #0 to host www.existingdomain.com left intact
* Closing connection #0
If I change the URL to another domain, like www.google.com, I get the content.
How can this be possible? And how to fetch content?
The server is free to send to the client whatever he likes, including nothing. While this is not exactly nice, there's little the client can do about this. You could
check the server logs to see if there is some problem which makes him so calm (given the server is under your control) or
try another client to see if the server does not like to talk to curl. You can then configure curl to mimic a regular web browser, if that helps
Related
This cURL command works how it should:
curl -i -v http://localhost:81/hallo
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 81 (#0)
> GET /hallo HTTP/1.1
> Host: localhost:81
> User-Agent: curl/7.55.1
> Accept: */*
>
1 -1 0* Connection #0 to host localhost left intact
Now I tried to do the same http-request in my go-service like this:
request, err := http.NewRequest("GET", "http://localhost:81/" + url.QueryEscape("Hallo"), nil)
client := &http.Client{}
resp, err := client.Do(request)
If I run the go code (I tried it with a test) it only produces this error: I only get the error net/http: HTTP/1.x transport connection broken: malformed HTTP status code "-1".
(I initially tried http.Get(myurl). this produces the same http Request. the current code was generated by https://mholt.github.io/curl-to-go/ )
Can anyone help me to understand why this two request produce different results?
Sample request and response to a really server:
[#xxxx ~]# curl -v -i 10.103.118.178:40000/ready
* About to connect() to 10.103.118.178 port 40000 (#0)
* Trying 10.103.118.178...
* Connected to 10.103.118.178 (10.103.118.178) port 40000 (#0)
> GET /ready HTTP/1.1
> User-Agent: curl/7.29.0
> Host: 10.103.118.178:40000
> Accept: */*
>
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< date: Fri, 25 Dec 2020 01:43:05 GMT
date: Fri, 25 Dec 2020 01:43:05 GMT
< content-length: 2
content-length: 2
< content-type: text/plain; charset=utf-8
content-type: text/plain; charset=utf-8
<
* Connection #0 to host 10.103.118.178 left intact
ok
You use -i to tell curl to include headers in the output. However, I cannot see any valid HTTP response header in your curl output. So probably your server is malfunctioning and did not make a valid HTTP response. So the Go program correctly reports about this, that it cannot interpret it as a valid HTTP header. (It tried to interpret it as an HTTP response header, but in where a status code should appear, it found -1 which is not a valid HTTP response code)
We observe that if we reload the nginx configuration the in-flight HTTP 1.1 requests complete successfully but without Connection:close which cause clients to attempt to re-use a closed connection. The behaviour can be reproduced easily by doing a curl with two requests where during the first request we reload the nginx configuration by HUP signal.
curl -v -H "Host: foo.bar.host" "http://proxy1:4080/do-it-takes-time-and-reload-is-called" "http://proxy1:4080/do-it"
* Connected to proxy1 (xx.xxx.xxx.xxx) port 4080 (#0)
>GET /do-it-takes-time-and-reload-is-called HTTP/1.1
> Host: foo.bar.host
> User-Agent: curl/7.54.0
> Accept: */*
< HTTP/1.1 200 OK
< Server: nginx/1....
< Date: ..
< Content-Type: application/json;charset=utf-8
< Content-Length: 160
< Connection: keep-alive
< Vary: Accept-Encoding
< Keep-Alive: timeout=10, max=360
* Connection #0 to host proxy left intact
{ "foo":"bar"}
While this long lived request was in-fight we did a kill -HUP to reload the configuration but notice how the response says Connection:keep-alive so curl attempts to re-use the connection but server don't want any of that so the request is rejected (RST)
* Found bundle for host proxy1 0x7f96e980f510 [can pipeline]
* Re-using existing connection! (#0) with host proxy1
* Connected to proxy1 (xx.xxx.xxx.xxx) port 4080 (#0)
> GET /do-it HTTP/1.1
> Host: foo.bar.host
> User-Agent: curl/7.54.0
> Accept: */*
>
* Connection died, retrying a fresh connect
* Closing connection 0
* Issue another request to this URL: ..
So is there a way to make nginx end the conversation politely with a Connection:close in the event of a configuration reload?
I have downloaded the official consul image and I am running it behin an nginx load balancer.
When I send any http request using curl for ex
curl my-consul-http-endpoint:8500/v1/catalog/nodes I get the following back
* Trying 172.29.225.62...
* Connected to my-consul-http-endpoint.com (172.29.225.62) port 80 (#0)
> GET /v1/session/list HTTP/1.1
> Host: my-consul-http-endoint
> User-Agent: curl/7.43.0
> Accept: */*
>
< HTTP/1.1 502 Bad Gateway
< Server: nginx
< Date: Tue, 19 Jul 2016 15:32:55 GMT
< Content-Type: text/html
< Content-Length: 18633
< Connection: keep-alive
< ETag: "56f72a9b-48c9"
Connection #0 to host my-consul-http-endpoint left intact
What does the response suggest? Did I get connected to the consul server? Did the server return an error and inturn the nginx load balancer returned a 502?
Deploy the consul client and connect to it with http://localhost:8500
Im using both the chrome REST API console and Postman to send a post request to my server (running nginx and symfony2)
Its a very simple request, just simply posting to a URL with an empty body. If this request runs from another server via a HTTP request, it will register as POST. Trying to POST from the api consoles registers as GET in my nginx access logs and returns a 405 Method not allowed.
If I use curl I initially get a 301 Moved Permanently, so I have to use -L to follow redirects. Im not sure if this is standard Symfony or if it is effecting the request.
I've found some problems with the curl request, but am unsure how to resolve them.
$ curl -v -L -d "1EepG1a63X" xxx.io/api/convert_mov/
* Trying xx.76.9.82...
* Connected to xxx.io (xx.76.9.82) port 80 (#0)
> POST /api/convert_mov/ HTTP/1.1
> Host: xxx.io
> User-Agent: curl/7.43.0
> Accept: */*
> Content-Length: 10
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 10 out of 10 bytes
< HTTP/1.1 301 Moved Permanently
< Server: nginx/1.6.2
< Date: Tue, 15 Sep 2015 09:00:43 GMT
< Content-Type: text/html
< Content-Length: 184
< Connection: keep-alive
< Location: https://xxx.io/api/convert_mov/
<
* Ignoring the response-body
* Connection #0 to host xxx.io left intact
* Issue another request to this URL: 'https://xxx.io/api/convert_mov/'
* Switch from POST to GET
* Found bundle for host xxx.io: 0x7fcad9c14e70
* Trying xx.76.9.82...
* Connected to xxx.io (xx.76.9.82) port 443 (#1)
* TLS 1.2 connection using TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
* Server certificate: xxx.io
* Server certificate: DigiCert SHA2 Secure Server CA
* Server certificate: DigiCert Global Root CA
> GET /api/convert_mov/ HTTP/1.1
> Host: xxx.io
> User-Agent: curl/7.43.0
> Accept: */*
>
< HTTP/1.1 404 Not Found
< Server: nginx/1.6.2
< Content-Type: text/html; charset=UTF-8
< Transfer-Encoding: chunked
< Connection: keep-alive
< X-Powered-By: PHP/5.5.25
< Cache-Control: no-cache
< Date: Tue, 15 Sep 2015 09:00:43 GMT
If you look closer, you will see your request is with HTTP. Then your server sends a redirect to your HTTPS site. And a 301 redirect does not preserve the request method. You MUST issue all your requests correctly against HTTPS.
I'm building a simple ServiceStack app and intending to host it on AzureWebSites. That's working fine. I need CORS to make the app work. In IIS Express and IIS 7.5 locally, this works fine - but not on Azure or AppHarbor.
The actual AJAX GET and POST requests work fine, the problem is the pre-flight OPTIONS checks return an empty response; no headers, nothing.
The code is on GitHub. You can see in the git commit history some things I've tried.
I've enabled Failed Request Logging- but that doesn't help. I'm not getting a 400+ series error code - I'm getting no response at all.
EDIT: Thanks to #paaschpa I've started looking at the problem from different machines. Added one more response from a Linux machine. It shows that cURL is getting back something odd (see below) causing it to output debugging as per this SO question:
Why is cURL returning "additional stuff not fine"?
When I test Azure from my Rackspace Linux machine, I get this:
kyleh#media:~$ curl -X curl -X OPTIONS -H "Origin: http://www.example.com" -H "Access-Control-Request-Method: POST" -H "Access-Control-Request-Headers: X-Requested-With" --verbose http://sstodo.azurewebsites.net/items
* About to connect() to sstodo.azurewebsites.net port 80 (#0)
* Trying 23.101.118.145...
* connected
* Connected to sstodo.azurewebsites.net (23.101.118.145) port 80 (#0)
> OPTIONS /items HTTP/1.1
> User-Agent: curl/7.21.0 (x86_64-pc-linux-gnu) libcurl/7.26.0 OpenSSL/1.0.1e zlib/1.2.3.4 libidn/1.25 libssh2/1.4.2 librtmp/2.3
> Host: sstodo.azurewebsites.net
> Accept: */*
> Origin: http://www.example.com
> Access-Control-Request-Method: POST
> Access-Control-Request-Headers: X-Requested-With
>
* additional stuff not fine transfer.c:1037: 0 0
* additional stuff not fine transfer.c:1037: 0 0
* additional stuff not fine transfer.c:1037: 0 0
* HTTP 1.1 or later with persistent connection, pipelining supported
< HTTP/1.1 200 OK
< Cache-Control: private
< Content-Length: 0
< Vary: Accept
< Server: Microsoft-IIS/8.0
< X-Powered-By: ServiceStack/4.036 Win32NT/.NET
< Access-Control-Allow-Origin: *
< Access-Control-Allow-Methods: GET, POST, PUT, DELETE, PATCH, OPTIONS
< Access-Control-Allow-Headers: Content-Type
< X-AspNet-Version: 4.0.30319
< X-Powered-By: ASP.NET
< Set-Cookie: ARRAffinity=f1d67e2939c9eab291aa7a92c2c5cffe872dc89340409c771374fbf6bc961bd3;Path=/;Domain=sstodo.azurewebsites.net
< Date: Sun, 01 Feb 2015 02:57:55 GMT
<
* Connection #0 to host sstodo.azurewebsites.net left intact
* Closing connection #0
When I test the site locally, the result looks right. Here's the local result (VS / IIS Express):
curl -X OPTIONS
-H "Origin: http://www.example.com"
-H "Access-Control-Request-Method: POST"
-H "Access-Control-Request-Headers: X-Requested-With"
--verbose http://localhost:1061/items
* timeout on name lookup is not supported
* About to connect() to localhost port 1061 (#0)
* Trying 127.0.0.1...
* connected
* Connected to localhost (127.0.0.1) port 1061 (#0)
> OPTIONS /items HTTP/1.1
> User-Agent: curl/7.26.0
> Host: localhost:1061
> Accept: */*
> Origin: http://www.example.com
> Access-Control-Request-Method: POST
> Access-Control-Request-Headers: X-Requested-With
>
< HTTP/1.1 200 OK
< Cache-Control: private
< Vary: Accept
< Server: Microsoft-IIS/8.0
< X-Powered-By: ServiceStack/4.036 Win32NT/.NET
< Access-Control-Allow-Origin: *
< Access-Control-Allow-Methods: GET, POST, PUT, DELETE, PATCH, OPTIONS
< Access-Control-Allow-Headers: Content-Type
< X-AspNet-Version: 4.0.30319
< X-SourceFiles: =?UTF-8?B?QzpccHJvamVjdHNcc2VydmljZXN0YWNrLXRvZG8tYmFja2VuZFxUb0RvQmFja2VuZFxUb0RvQmFja2VuZFxpdGVtcw==?=
< X-Powered-By: ASP.NET
< Date: Thu, 22 Jan 2015 23:51:29 GMT
< Content-Length: 0
<
* Connection #0 to host localhost left intact
* Closing connection #0
Here's the result in IIS7.5 locally:
curl -H "Origin: http://www.example.com" -H "Access-Control-Request-Method: P
OST" -H "Access-Control-Request-Headers: X-Requested-With" -X OPTIONS --verbose
http://localhost/sstodo/items
* timeout on name lookup is not supported
* About to connect() to localhost port 80 (#0)
* Trying 127.0.0.1...
* connected
* Connected to localhost (127.0.0.1) port 80 (#0)
> OPTIONS /sstodo/items HTTP/1.1
> User-Agent: curl/7.26.0
> Host: localhost
> Accept: */*
> Origin: http://www.example.com
> Access-Control-Request-Method: POST
> Access-Control-Request-Headers: X-Requested-With
>
< HTTP/1.1 200 OK
< Cache-Control: private
< Vary: Accept
< Server: Microsoft-IIS/7.5
< X-Powered-By: ServiceStack/4.036 Win32NT/.NET
< Access-Control-Allow-Origin: *
< Access-Control-Allow-Methods: GET, POST, PUT, DELETE, PATCH, OPTIONS
< Access-Control-Allow-Headers: Content-Type
< X-AspNet-Version: 4.0.30319
< X-Powered-By: ASP.NET
< Date: Sat, 24 Jan 2015 02:44:55 GMT
< Content-Length: 0
<
* Connection #0 to host localhost left intact
* Closing connection #0
When I run the test against AzureWebSites (and AppHarbor) it does not.
curl -X OPTIONS
-H "Origin: http://www.example.com"
-H "Access-Control-Request-Method: POST"
-H "Access-Control-Request-Headers: X-Requested-With"
--verbose http://sstodo.azurewebsites.net/items
* timeout on name lookup is not supported
* About to connect() to sstodo.azurewebsites.net port 80 (#0)
* Trying 23.101.118.145...
* connected
* Connected to sstodo.azurewebsites.net (23.101.118.145) port 80 (#0)
> OPTIONS /items HTTP/1.1
> User-Agent: curl/7.26.0
> Host: sstodo.azurewebsites.net
> Accept: */*
> Origin: http://www.example.com
> Access-Control-Request-Method: POST
> Access-Control-Request-Headers: X-Requested-With
>
* Empty reply from server
* Connection #0 to host sstodo.azurewebsites.net left intact
curl: (52) Empty reply from server
* Closing connection #0
Here's AppHarbor:
curl -X OPTIONS
-H "Origin: http://www.example.com"
-H "Access-Control-Request-Method: POST"
-H "Access-Control-Request-Headers: X-Requested-With"
--verbose http://sstodo.apphb.com/items
* timeout on name lookup is not supported
* About to connect() to sstodo.apphb.com port 80 (#0)
* Trying 50.17.211.206...
* connected
* Connected to sstodo.apphb.com (50.17.211.206) port 80 (#0)
> OPTIONS /items HTTP/1.1
> User-Agent: curl/7.26.0
> Host: sstodo.apphb.com
> Accept: */*
> Origin: http://www.example.com
> Access-Control-Request-Method: POST
> Access-Control-Request-Headers: X-Requested-With
>
* Empty reply from server
* Connection #0 to host sstodo.apphb.com left intact
curl: (52) Empty reply from server
* Closing connection #0
I'm at a bit of a loss for direction. In my mental model, I should be able to repro the issue on my local environment. All the documentation I see for Azure and AppHarbor both indicate that they're not blocking the OPTIONS calls, but that doesn't appear to be the case.
I don't care so much about how the site works in cURL of course.
I'm betting you ran into the same issue I did; the "Web Security" module in the Cisco VPN client running on your OS X laptop was intercepting your HTTP requests and silently dropping OPTIONS requests made as part of the CORS preflight. What a great "feature" for this VPN software. It even does this when you're not using the VPN.
Switching to https fixes this because the proxy is not able to read your requests and so not able to drop OPTIONS.
More info about this problem here: http://www.bennadel.com/blog/2559-cisco-anyconnect-vpn-client-may-block-cors-ajax-options-requests.htm
You can uninstall the web security module with:
sudo /opt/cisco/anyconnect/bin/websecurity_uninstall.sh
Well...not sure this helps but I have a 'works from my machine' for you. Screenshot below...
If you fixed your own issue, I'd be curious to see the fix.
In the end, what worked was switching to HTTPS.
I can't say that I understand why, but using HTTPS always resolves the issue.