Difference between revisions of "User talk:Haoqili"

Revision as of 14:05, 29 June 2009

Bugs I've encountered and fixed (started loggin since Jun 24th).

• When trying to kinit username

ERROR: kinit: Cannot contact any KDC for realm [your realm fqdn] while getting initial credentials

SOLUTION: make sure KDC is running. /usr/local/sbin/krb5kdc

SOLUTION: 1. check log file. I looked in /var/log/auth.log. The bottom of it says: Cannot create reply cache file /var/tmp/krb5kdc_rcache: File exits. 2. sudo rm /var/tmp/krb5kdc_rcache.

• Can't start krb5kdc and in auth.log it says:

ERROR: Address already in use - Cannot bind server socket to port [#] address [IP address]

SOLUTION: 1. see if it is true that port [#] is in use by netstat -nap | grep [#] (I also did pgrep -x krb5kdc). 2. kill the process: pkill -x krb5kdc. note the "-x" is for matching exactly the process "krb5kdc".

Tips. Useful little things to know

Python

• p = Popen('blah', stdin=PIPE, stdout=PIPE, stderr=PIPE)

(out, err) = p.communicate('inputThing\n') <-- don't forget the return "\n" at the end!

• When you're doing a bunch of p=Popen('shell command') be careful because Popen starts a new branch so the next Popen might start without the previous one having completed. To fix this problem, put in:

if int(p.wait()) != 0: #meaning that it's not executed

print "error message"

exit

• Two ways to display outputs after Popen( a command that has to get into something, in my case, getting into kadmin.local) 06262009

Way 1:

p = Popen(['commannd', 'all', 'in', 'one', 'line'], stdin=PIPE, stdout=PIPE, stderr=PIPE) #e.g. ['kadmin.local', '-q', 'listprincs']

if int(p.wait()) != 0:

print p.stdout.readlines()

Way 2:

p = Popen(['command', 'front', 'chunk'], stdin=PIPE, stdout=PIPE, stderr=PIPE) #e.g. ['kadmin.local']

(out, err) = p.communicate('rest of command') #e.g. 'listprincs'

print out