Resolved PHP 7.0.17 unable to resolve hostnames

[H9k]

Hi there! Since PHP7 plesk packages updated to 7.0.17, websites are no longer able to resolve hostnames.
Getting errors like these: cURL error 6: Could not resolve host: www.googleapis.com
Anyone else having this problem?

 

[H9k]

Nevermind, no idea where the problem came from, but it appears gone for now...

 

[UFHH01]

Hi H9k,

I assume that you are on Ubuntu and discovered a temporary update/upgrade issue for "libc-bin" and "libc6". Pls. see => https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/1674776 for further informations, regarding this ( temporary) bug.

 

[H9k]

Very interesting hint. Thanks! I was starting to thing I am crazy

 

[trialotto]

@Everyone,

The correct and patched version for Ubuntu 16.04.2 LTS would be 2.23-0ubuntu7 for libc-bin, libc6, libc6-dev and libc-i386.

Note that earlier versions of the libc* packages were partially patched, so it is not recommended to use lower versions than 2.23.

There are some common "do´s and don´ts" when applying the patched libc* packages, all depending on how one has identified the symptoms of libc* related problems.

The SYMPTOMS, caused by libc* related problems, are (amongst others)

- apt-get update related issues
- WordPress error messages, for instance:concerning RSS feeds (can be seen in the main page of the Dashboard)
- PHP related error messages (of many sorts)
- Curl related error messages
- Ping issues

and so on.

It has to be EMPHASIZED that there is NOT a PHP bug, a WP bug, a Curl bug or a networking issue (as suggested by ping related issues).

The root cause is simply an "incomplete" libc* package upgrade.

DO NOT mess with PHP or WordPress code and CERTAINLY DO NOT

- alter network or network interface settings, (and/or)
- add a nameserver to /etc/resolv.conf.

In order to complete the libc* package upgrade properly, we cannot rely on apt-get (it is not working properly), so do the following (in chronological order)

1) try a network service restart (note: I would not recommend this step, it can suffice, but starting with step 2 is better),

2) if step 1 does not work, simply REBOOT the server.

As a final remark, note that an excellent method to test for this libc* package related issue is the following:

- run the command: ping google.com (from the command line)

and if the result is "ping: unknown host google.com", then the libc* package related issue is present.

Hope the above helps a bit.

Regards.....