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<p class="MsoNormal"><span style="font-size:14.0pt">The script does have a shebang line and it runs fine from the command line.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">It also work it I run “pdns_server –daemon=no”
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">I checked, and the VM does have SELinux, which was set to permissive mode by default. I disabled SELinux and rebooted. It didn’t help.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">Thanks for the suggestion, though. I didn’t know to check for that.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:14.0pt">-- <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:14.0pt">Dan Campbell</span><span style="font-size:14.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">Brian Candler <b.candler@pobox.com><br>
<b>Date: </b>Thursday, January 21, 2021 at 2:07 PM<br>
<b>To: </b>"Dan Campbell - dan@us.ibm.com" <dan@us.ibm.com>, "pdns-users@mailman.powerdns.com" <pdns-users@mailman.powerdns.com><br>
<b>Subject: </b>[EXTERNAL] Re: [Pdns-users] Pipebackend can't run backend<o:p></o:p></span></p>
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<p class="MsoNormal">On 21/01/2021 20:48, Dan Campbell - dan--- via Pdns-users wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:14.0pt">I just installed the Authoritative server 4.4.0 on a CentOS 8 virtual machine and I’m trying to get a simple pipebackend running.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:14.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:14.0pt">The backend is a python script that runs from the command line, but pdns_server fails to start and give the following error:<br>
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<br>
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<span style="font-size:14.0pt">[PIPEBackend] Unable to launch, fatal argument error: Command '/home/webapps/dns/bin/backend.py' cannot be executed: Permission></span><o:p></o:p></p>
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<span style="font-size:14.0pt">Caught an exception instantiating a backend: Command '/home/webapps/dns/bin/backend.py' cannot be executed: Permission denied</span><o:p></o:p></p>
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<span style="font-size:14.0pt">Cleaning up</span><o:p></o:p></p>
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<span style="font-size:14.0pt">Distributor caught fatal exception: Command '/home/webapps/dns/bin/backend.py' cannot be executed: Permission denied</span><o:p></o:p></p>
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<span style="font-size:14.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:14.0pt">The permissions on the script and all directories in the path are 755 …</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:14.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:14.0pt">Any ideas about why pdns_server (running under the pdns id) does not have permissions to run a program with 755 permissions?</span><o:p></o:p></p>
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<p>If it has a shebang line and you can run it directly from the command line by typing "/home/webapps/dns/bin/backend.py", then my guess is that it's an SELinux or AppArmor thing.<o:p></o:p></p>
<p>Being CentOS then it would be SELinux. Try switching SELinux into permissive mode and see if that makes it work. If it does, have fun tweaking SELinux policies :-)<o:p></o:p></p>
<p>HTH,<o:p></o:p></p>
<p>Brian.<o:p></o:p></p>
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