On 2021-05-27 at 11:31:15 UTC-0400 (Thu, 27 May 2021 11:31:15 -0400)
<post...@ptld.com>
is rumored to have said:
enable_long_queue_ids = yes
New queue files are created with names such as 3Pt2mN2VXxznjll. These
are encoded in a 52-character alphabet that contains digits (0-9),
upper-case letters (B-Z) and lower-case letters (b-z). For safety
reasons the vowels (AEIOUaeiou) are excluded from the alphabet.
21 upper case + 21 lower case + 10 digits = 52 characters
The name format is: 6 or more characters for the time in seconds, 4
characters for the time in microseconds, the 'z'; the remainder is
the file inode number encoded in the first 51 characters of the
52-character alphabet.
Is the queue ID fixed length always 16 characters or is the last
section inode number dynamic in length?
The range of inode numbers is filesystem-specific. You cannot rely on it
being any particular scale.
Safe to assume the 11th character is always 'z'?
For as long as anyone now alive will live, yes. The "6 or more
characters" phrase is exceedingly optimistic about the lifetime of
Postfix.
It says vowels are excluded, then it says the the inode number is
encoded in the fist 51 of the alphabet.
Yes. The first 51 characters of the 52-character alphabet described
above, consisting of consonants and digits.
Does that mean 'a' and other vowels can appear in the last inode part
of the ID?
No. This is not a reference to The Latin Alphabet, but to the bespoke
alphabet defined for Postfix queue IDs.
Or is it safe to validate a queue ID by checking for vowels in any
part of the ID?
That should be safe, assuming that you are not trying to deal with the
older short form Postfix queue IDs, which are still the default and are
widely used. Or Sendmail queue IDs which are similar but different. So
if you're looking at Received headers in email you have a complex task
validating queue IDs.
Any other tips for parsing logs for queue ID?
Logs should be relatively straightforward, since you can count on the
queue IDs being in a fixed location in each line.
--
Bill Cole
b...@scconsult.com or billc...@apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Not Currently Available For Hire
