danielmerriott danielmerriott - 3 months ago 18
PHP Question

How to trace where php5-fpm umask settings are coming from on ubuntu

I'd really appreciate any help in tracking down and diagnosing an umask issue on Ubuntu:

I'm running

php5-fpm
with Apache via
proxy_fcgi
. The process is running with a umask of 0022 (confirmed by having PHP send the results of
umask()
into a file [the result is '18' == 0022]). I'd like to change this to 0002, but can't track down where the umask is coming from.

Apache is set with umask 0002, and as a test, if I disable
proxy_fcgi
and run my test above, I get a file with u+g having rw access (and the file contents confirm the umask as '2' == 0002).

If I
sudo -iu fpmuser
and run
umask
the results are 0002.

System info:


  • PHP: 5.5.3-1ubuntu2.1

  • Apache: 2.4.6

  • Ubuntu: 13.10

  • PHP-PFM is listing using TCP ports (as Unix ports aren't yet working/support)



So far I've tried the following (each followed by a system restart and a retest):


  • adding
    umask 0002
    to the start of
    /etc/init.d/php5-fpm

  • adding
    --umask 0002
    into the
    start-stop-daemon
    calls in
    /etc/init.d/php5-fpm

  • adding
    umask 0002
    to
    .profile
    in the home of the
    fpm
    user



Something is clearly adjusting the umask of the php-fpm process - so, how can I begin tracing what is forcing the umask 0022 onto the php-fpm process?

EDIT (1):


  • adjusting the system wide umask via
    /etc/login.defs
    (see How to set system wide umask?) affects the umask elsewhere (e.g. comannds via
    sudo
    now have a umask of 0002), but still php-fpm creates files with a umask of 0022. Note that I verified that
    session optional pam_umask.so
    was also present in
    /etc/pam.d/common-session-noninteractive
    and I tested umasks of 002 and 0002.



EDIT (2):


  • I have been able to replicate the issue using
    nginx
    and
    php5-fpm
    (using unix sockets set to listen mode '0666').

  • I would love to trace where the umask is coming from but I'd settle for some way to force it to what I want.

  • I should add that the first test was done on an Amazon Ubuntu 13.10 image. My tests in 'edit 2' where completed using a copy of the Ubuntu13.10 server ISO setup from scratch in a virtual machine. All installations were completed via apt-get rather than by downloading the source and building.



EDIT (3):


  • I have confirmed I can manipulate the umask manually by either of the following (verified by checking the permissions on the test file created):

    a. In a shell, set a umask then run
    /usr/sbin/php-fpm
    from the shell

    b. In a shell, run the following with whatever umask value I like:

    start-stop-daemon --start --quiet --umask 0002 --pidfile /var/run/php5-fpm.pid --exec /usr/sbin/php5-fpm -- --daemonize --fpm-config /etc/php5/fpm/php-fpm.conf

  • However this exact same command in the
    /etc/init.d/php5-fpm
    file fails to adjust the umask when running
    sudo service php5-fpm stop; sudo service php5-fpm start
    or at reboot.


Answer

Not a solution for generically tracing where umask settings are coming from on ubuntu (the only way I've found so far is the good old hard work approach of replicating the issue, attempting to isolate it to a script or a function, then stepping back through each script/function that is called recursively) but a solution to the php5-fpm umask issue. I've found a lot of hits on google, stackoverflow, and elsewhere for the problem, but so far no solution. Hopefully this is useful for people.

Edit /etc/init/php-fpm.conf to include the line umask 0002 (or whatever umask you wish). My version of the file now looks like this:

# php5-fpm - The PHP FastCGI Process Manager

description "The PHP FastCGI Process Manager"
author "Ondřej Surý <ondrej@debian.org>"

start on runlevel [2345]
stop on runlevel [016]

### my edit - change umask setting
umask 0002

pre-start exec /usr/lib/php5/php5-fpm-checkconf

respawn
exec /usr/sbin/php5-fpm --nodaemonize --fpm-config /etc/php5/fpm/php-fpm.conf

Explanation

Having traced through the service command which launches php5-fpm at startup, it runs some checks (line 118 on my copy) for /etc/init/${SERVICE}.conf, along with verifying initctl is present and can report it's version. If these tests are passed then upstart is used which in the case of php5-fpm uses the /etc/init/php-fpm.conf file.

The ubuntu upstart site gives pretty clear instructions. In particular you can check out the upstart cookbook for the specifics you need.

As best I can work out that means that therefore the 'service' command was never actually running the start-stop-daemon … commands found in /etc/init.d/php5-fpm which is why my previous edits were having no effect. Instead it passes off to upstart (actually initctl) when you use something like service php5-fpm start, etc.