Pulp

I noticed this as part of the "browse a repository with a web browser" work (https://pulp.plan.io/issues/1512). We're responding with a content type of text/html:

[vagrant@dev ~]$ curl -v -k "https://dev.example.com/pulp/repos/zoo/gorilla-0.62-1.noarch.rpm"
*   Trying 127.0.0.1...
* Connected to dev.example.com (127.0.0.1) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* skipping SSL peer certificate verification
* ALPN, server accepted to use http/1.1
* SSL connection using TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
* Server certificate:
*       subject: E=root@dev,CN=dev,OU=SomeOrganizationalUnit,O=SomeOrganization,L=SomeCity,ST=SomeState,C=--
*       start date: Feb 01 14:00:37 2016 GMT
*       expire date: Jan 31 14:00:37 2017 GMT
*       common name: dev
*       issuer: E=root@dev,CN=dev,OU=SomeOrganizationalUnit,O=SomeOrganization,L=SomeCity,ST=SomeState,C=--
> GET /pulp/repos/zoo/gorilla-0.62-1.noarch.rpm HTTP/1.1
> Host: dev.example.com
> User-Agent: curl/7.43.0
> Accept: */*
> 
* skipping SSL peer certificate verification
* NSS: client certificate not found (nickname not specified)
* ALPN, server accepted to use http/1.1
* skipping SSL peer certificate verification
* ALPN, server accepted to use http/1.1
< HTTP/1.1 200 OK
< Date: Wed, 03 Feb 2016 19:01:14 GMT
< Server: Apache/2.4.18 (Fedora) OpenSSL/1.0.2f-fips mod_wsgi/4.4.8 Python/2.7.10
< Last-Modified: Tue, 02 Feb 2016 21:22:46 GMT
< ETag: "994-52ad01a568438"
< Content-Length: 2452
< Content-Type: text/html; charset=utf-8
< 

This, of course, makes the browser try its best to render an RPM as html (I snipped that from the above demo). Surprisingly, yum and company seem to handle this fine, but a browser doesn't. We need to (somehow) make sure the content type is set correctly. There may be a setting in mod_xsendfile. If not, we'll need to do it in the WSGI application.