Re: [opensuse-packaging] RFC: Namespacing group and usernames

On 02/28/2014 03:12 PM, Darin Perusich wrote:

On Fri, Feb 28, 2014 at 5:32 AM, Bernhard Voelker wrote:

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What are examples of possible collisions? I mean which of the following are subject to collisions on a typical system?

$ cut -d: -f1 /etc/passwd | head -n -2 | paste -s -d ' ' at avahi bin colord daemon dnsmasq ftp games gdm lp mail man messagebus news nobody nscd ntop ntp obsrun polkitd postfix pulse root rtkit sshd statd svn tftp usbmux uucp vboxadd wwwrun

The "problem" with this example is you're only looking at local accounts and not including environments which use external naming services such as NIS/NIS+, LDAP, AD, etc, which may has hundreds or thousands of accounts and groups. In these environments collisions happen regardless of how much to try to limit scoop of user/group lookups.

I *do* live in such a heterogeneous environment, including e.g. Solaris. I wouldn't expect any other OSes to follow such a convention, and therefore there not much gain for a user who wants to have an account like 'lp'. Even worse - while today a user 'wwwrun' may exist on other UNIXoide OSs and everybody is familiar with it, "_wwwrun" won't.

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Second, this will be inconsistent anyway because I don't think that anyone will want to rename e.g. 'root' to '_root' (for which someone already proposed an exemption list).

Third, some daemon user names today are already too long (>8) for tools like ps(1) ...

useradd(8) limits users names to 32 chars, see the CAVEATS section, however that is a local limit and if you're using an external name service longer user names are valid. I just created an LDAP user w/a username of 72 char's which was completely valid, not that I'm saying you'd want to do that. The LOGIN_NAME_MAX, getconf LOGIN_NAME_MAX, on my SLES/openSUSE systems is 256, and POSIX 2.9.2, _POSIX_LOGIN_NAME_MAX, sets that value to 9 chars.

That's right, yet IMO that's not an argument for artificially enlarging user names. Again: what was the starting point of the discussion, i.e. the problem? User "wwwrun" vs. "apache" as mentioned in the other thread? Well, that doesn't have much to do with collisions with normal user names, does it? Have a nice day, Berny -- To unsubscribe, e-mail: opensuse-packaging+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-packaging+owner@opensuse.org