PHP5 - Fails to resolve hostnames when not in interactive mode

Question

I'm working with an OS X 10.6 Server running Apache2 / PHP5 and having a problem with PHP not resolving hostnames when 'fopen()' tries to retrieve a file from a remote server. When run in interactive mode on the command line 'fopen()' works perfectly. However, when run through the web it will always fail with the error:

failed to open stream: php_network_getaddresses: getaddrinfo failed: nodename nor servname provided, or not known

I'm at a loss in finding the source of this problem: 'fopen()' works on the web when given an IP address instead of a hostname; 'gethostbyname()' also fails when run on the web (it doesn't error, it just returns whatever hostname it was given to resolve) but also works fine when run in interactive mode. The only exception seems to be 'dns_get_record()' which works fine when run on the web or in interactive mode.

I've been trying to find DNS problems on the server but dig, nslookup, and ping all work and "scutil -r" says the remote server is reachable with the current DNS settings. Any ideas on where the problem might be?

Answer 1

Try to recompile PHP with '--disable-ipv6' option. Then, apachectl stop & start (not 'apachectl restart'). I've got the same error message on Mac OS 10.6.4 + manually compiled PHP5.3.3 + Apache2.2.16.

Answer 2

You must set properly the allow_url_fopen value of your php.ini.

http://ar.php.net/manual/en/filesystem.configuration.php#ini.allow-url-fopen

Consider the CLI uses a different php.ini that the webserver (I assume you are using Apache).

Another option may be you are not including libnss_dns

Try adding to your httpd configuration (correct path as needed for you system):

LoadFile /lib/libnss_dns.so