perfSONAR User Q&A and Other Discussion

[Andrew Lake <>]

Hi,

I did some testing on my own and I think its just an artifact of how running the httpd syntax check interacts with the weird way we setup mod_wsgi to work with python 2.7. It doesn't appear to be preventing anything from running that should be. In practice there is actually a python virtualenv running python 2.7 that gets pointed at, when running with -t it doesn't appear to initialize that the same way it does when you actually start the server hence the error. The good news this is fixed in the forthcoming perfSONAR version as we reshuffled the python27-mod_wsgi setup on CentOS 6 to avoid headaches like this. 

Thanks,

Andy 

On January 4, 2017 at 4:01:52 PM, Wussler, Doug () wrote:

Thanks for the replies.  Based on what Mark said, I attempted to restart apache and there was no problem.  I suspect this issue has been there for some time.  However, I cannot recall ever adding or removing repos, or installing any packages.  Looking in my /etc/httpd/modules directory I see that “mod_wsgi.so” (and “mod_auth-shadow.so”) has a date from 2014 while all other modules have a date of Nov 2016.  Looking in /usr/lib64 I see “libpython2.6.so.1.0” but no “libpython2.7.so.1.0”.  There is nothing at all in /usr/local/lib64. 

yum repolist:

repo id                                                                    repo name                                                                                                          status

Internet2                                                                  Internet2 RPM Repository - software.internet2.edu - main                                                              286

Internet2-web100_kernel                                                    Internet2 Web100 Kernel RPM Repository - software.internet2.edu - main                                                166

base                                                                       CentOS-6 - Base                                                                                                     6,696

dell-system-update_dependent                                               dell-system-update_dependent                                                                                           62

dell-system-update_independent                                             dell-system-update_independent                                                                                        566

epel                                                                       Extra Packages for Enterprise Linux 6 - x86_64                                                                     12,207

extras                                                                     CentOS-6 - Extras                                                                                                      62

updates                                                                    CentOS-6 - Updates                                                                                                    712

repolist: 20,757

yum info python27-mod_wsgi:

Installed Packages

Name        : python27-mod_wsgi

Arch        : x86_64

Version     : 3.2

Release     : 3.el6

Size        : 177 k

Repo        : installed

From repo   : anaconda-CentOS-201508042137.x86_64

Summary     : A WSGI interface for Python web applications in Apache

URL         : http://modwsgi.org

License     : ASL 2.0

From: Mark Maciolek <>
Date: Wednesday, January 4, 2017 at 3:51 PM
To: 'Andrew Lake' <>, Default User Name <>, "" <>
Subject: RE: [perfsonar-user] mod_wsgi.conf

Hi,

 

CentOS release 6.8 (Final)

 

Same issue and yum info says it came from Internet2

 

Installed Packages

Name        : python27-mod_wsgi

Arch        : x86_64

Version     : 3.2

Release     : 3.el6

Size        : 177 k

Repo        : installed

From repo   : Internet2

Summary     : A WSGI interface for Python web applications in Apache

URL         : http://modwsgi.org

License     : ASL 2.0

Description : The mod_wsgi adapter is an Apache module that provides a WSGI compliant

            : interface for hosting Python based web applications within Apache. The

            : adapter is written completely in C code against the Apache C runtime and

            : for hosting WSGI applications within Apache has a lower overhead than using

            : existing WSGI adapters for mod_python or CGI.

 

Have not noticed any issues with server or with restarting apache.

 

mark

 

From: [] On Behalf Of Andrew Lake
Sent: Wednesday, January 4, 2017 3:39 PM
To: Wussler, Doug <>;
Subject: Re: [perfsonar-user] mod_wsgi.conf

 

Hi,

 

If you run "yum repolist” do you have the SCL repo installed (will probably be named something like centos-sclo)? You may have grabbed a version of python27-mod_wsgi that causes some problems for perfSONAR. You can also check with “yum info python27-mod_wsgi”. If the repo is Internet2 you are in good shape, otherwise you may have a bad version. I’d imagine the problem would appear sooner, though maybe apache hasn’t been restarted in awhile so it just rearing its head now. If it is indeed because it grabbed the SCL version I can help you get it back on the right one.

 

Thanks,

Andy

 

 

 

On January 4, 2017 at 3:09:48 PM, Wussler, Doug () wrote:

We are running three 3.5.1 servers that were originally installed from a CentOS 6 ISO.  These servers auto-update and I don’t need to touch them except to reboot when  a new kernel comes out, which I did prior to Christmas.

 

Today, before editing the HTTPD config to implement stricter SSL ciphers I ran “httpd –t” and got this:

 

httpd: Syntax error on line 239 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf.d/wsgi.conf: Cannot load /etc/httpd/modules/mod_wsgi.so into server: libpython2.7.so.1.0: cannot open shared object file: No such file or directory

 

I checked my other two servers and got the same thing.  I checked the YUM history and I see it picked up a couple of updates after my reboot:

 

ID     | Login user               | Date and time    | Action(s)      | Altered

-------------------------------------------------------------------------------

   129 | root <root>              | 2017-01-04 04:16 | Update         |   50   

   128 | root <root>              | 2016-12-22 03:54 | Update         |    4   

 

 

Is it possible that something got corrupted in one of these recent updates?

 

 

Doug Wussler

850.645.4201

Application Developer/Designer – Core Network Team

Information Technology Services

RK Shaw Building

644 W. Call Street

Tallahassee, FL  32304