Cannot load modules/mod_ssl.so into server: /etc/httpd/modules/mod_ssl.so: undefined symbol: ap_array_str_contains

Question

I am trying to run Apache on Amazon Linux with SSL for my website and I configured all ssl prerequisites. But when I start the Apache it throws the error saying:

Starting httpd: httpd: Syntax error on line 58 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf.modules.d/00-ssl.conf: Cannot load modules/mod_ssl.so into server: /etc/httpd/modules/mod_ssl.so: undefined symbol: ap_array_str_contains

conf.modules.d/00-ssl.conf file contains:

LoadModule ssl_module modules/mod_ssl.so

Apache httpd version:

Server version: Apache/2.4.12 (Amazon)

I installed mod_ssl using:

yum install mod24_ssl

I am not aware how to troubleshoot this; I am pretty new to apache.

Please help me if anyone would came across the similar issue?

Solution

My hunch would be that the SSL module has been compiled against a different version of Apache than the one trying to load it, given that version 2.4.12 of Apache was released in January 2015 and I can see reference to adding the function ap_array_str_contains() to server/util.c in the Apache source only in September 2015.

What does rpm -q mod24_ssl httpd(*) return? They should both realistically have the same version.

(*) Amazon Linux might name their Apache package slightly differently.

Comments

[Nagarjuna D N]

Thanks for your replay. Is there any possibility to upgrade Apache and install right version of mod24_ssl without affecting the application?

[Nagarjuna D N]

Output of "rpm -q mod24_ssl httpd*" mod24_ssl-2.4.18-1.64.amzn1.x86_64 package httpd* is not installed

[bodgit]

As suspected, you've somehow managed to install a newer version of mod_ssl for the version of Apache you have. You need to install/upgrade httpd (or that might be httpd24) so they're both version 2.4.18.

[Nagarjuna D N]

Yes, the issue is with Amazon Linux doesn't support mod24_ssl-2.4.12 right now. I just installed httpd24- 2.4.18 then it works. **$ yum --showduplicates list mod24_ssl | expand** Available Packages mod24_ssl.x86_64 1:2.4.18-1.64.amzn1 amzn-main **$ yum --showduplicates list httpd24 | expand** Installed Packages httpd24.x86_64 2.4.12-1.60.amzn1 @amzn-main Available Packages httpd24.x86_64 2.4.18-1.64.amzn1 amzn-main