datadevil's questions

I'm trying to send requests to a docker image by using apache's proxy functionality. The request to the docker should look something like: https://127.0.0.1:8282/somepath/https://somedomain/someimage.jpg but it is being forwarded like https://127.0.0.1:8282/somepath/https:/somedomain/someimage.jpg (so missing one slash).

I think this is probably some default to prevent issues with directories accidentaly having double slashes, but can I somehow change some setting that makes it not do this? Or can I put it back using some rewrite regex magic?

I need a procmail recipe which stores the mail and forwards it to another address.

The following works fine:

:0c
! [email protected]

But..now I need to change the From: header in the mails that are being forwarded, and I know it can probably be done with formail but I failed to find any good examples on how to do that and still store the email

EDIT: solved it myself, see the answer below

I have a cronjob for rsync which runs every 2 minutes, but sometimes takes longer then 2 minutes. For that I wrote a simple locking system which checks, if file not found writes lockfile, takes action and deletes that lockfile.

Now if the script crashes or is killed for some reason that lockfile will linger on and cause problems.

What would be a good way of making sure the cron task is run again at some point? I have thought of checking the age of the lockfile and deleting it if older then a certain period, but there ought to be better more elegant solutions for this I'd think..

edited:

I now have implemented flock. I was a bit confused as to why the file always seems to exist, but I found this page that explains how it works, by storing the pid in the file information:

http://mattiasgeniar.be/2012/07/24/prevent-cronjobs-from-overlapping-in-linux/

I'm storing and forwarding (to google apps) emails using the following procmail recipe:

# set vars
USERNAME=local_username
LOCALPART=realemaillocalpart

:0
# Avoid email loops
* ! ^X-Loop: ${USERNAME}@domain\.nl
{
  :0c:   #Preserve a copy of the email
  ${DEFAULT}
  :0fwh  #Adjust some headers before forwarding
  | formail -A"X-Loop: ${USERNAME}@domain.nl" \
  # Forward the email
  :0
  !${LOCALPART}@apps.domain.nl
}

This works, but when I set up an 'out of office' message in gmail it returns the email to the forwarding system instead of to the original sender.

This probably has to do with the forwarding system adding or replacing a Return-path line and putting the local username and the servername in there.

My question is thus how can I prevent that from happening?

I have found a lot of examples for procmail to match on the From: header with wilcards, but I'd like to do an exact match, in order to prevent From:.*[email protected] matching both [email protected] and [email protected]

Is this possible, and if so, how?

I want to block access to some Samba shares from a certain machine, but somehow I can't get it to work: the machine can still access the shares, and I did restart and reload the samba daemon.

Here is a part of my configuration:

    security = share
    hosts allow = 127.0.0.1 192.168.1.0/24
    interfaces = 127.0.0.1 eth1 192.168.1.2
    bind interfaces only = yes
    hosts deny = 192.168.1.251
    encrypt passwords = yes
    guest ok = yes

The shares themselves look like this:

[examples]
    comment = Example
    path = /foo/bar
    read only = No
    guest ok = yes

What am I doing wrong here?

I'm using innobackupex to backup my databases like this:

usr/local/bin/innobackupex  --user=bkpuser --password='example' --rsync \
--no-timestamp /pathtobackup 2> /pathtobackup/innobackupex.log

Now this page says "However there are transactions which are incomplete, and others which have not been flushed to their datafiles. In other words the backup as-is would be similar to a datadir if your database crashed. Some additional transactions must still be applied.".

Is this true? I thought that at least the flushing part was not true, and I'm not sure about the transactions. My goal is to be able to restore my database of course like it never went down, so please advice.

I'm in doubt about how to scan my Linux system with Clamav: do I just scan the places where users can upload files (homedirs, their webroots) or do I scan the whole system?

The various sites I've read vary in opinion, some say you needn't scan the Linux-only parts, some say to not scan at all. The latter I've already discarded as I think it sensible to at least scan webroots for hosted viruses, but scanning the whole system is still something I am in doubt about.

I have read quite a lot of pages about the OOMKiller, including http://www.linuxatemyram.com/ , but I don't quite get still why a backup script I run would be killed if I look at my output of 'free -m':

             total       used       free     shared    buffers     cached
Mem:          8070       7968        102          0        293       6523
-/+ buffers/cache:       1151       6919
Swap:         1983          8       1975

Is this (Fedora 8) server doing something weird or am I misunderstanding something..?

This is the vmstat output of running the script, it is killed around 5/6 lines before the end:

procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
3  8   8312  40360  54592 6971548    0    0   716   204  669 1909 21 10  0 69  0
1  8   8312  40384  54592 6971616    0    0   752 10764  855 4284 37 24  1 37  0
2  9   8312  41068  54584 6970236    0    0   664  3752  896 3953 28 20  5 47  0
1  7   8312  40308  54588 6970180    0    0   484  2996  871 2058 21 10  9 59  0
1  8   8312  46228  54588 6963540    0    0   536 13372  531 2154 16 11  6 67  0
2  7   8312  44544  54600 6964004    0    0   340 18452  486 1726 24 14 21 41  0
3  7   8312  40056  54600 6968660    0    0   388 17136  591 1876 44 21  2 32  0
0  8   8312  40324  54612 6967248    0    0   388 14176  715 2146 32 18  1 50  0
2  9   8312  43464  54632 6964352    0    0   412 14080  788 4040 29 23  0 49  0
4  5   8312  41672  54688 6968836    0    0   260  9188  989 3258 63 32  0  4  0
2  6   8312  41376  54764 6969472    0    0   260  6244  587 2255 44 21  0 35  0
3  8   8312  42392  54740 6968180    0    0   228  5316  778 2869 24 17  0 60  0
1 19   8312  40568  54776 6957660    0    0   268  8844  467 3183 26 18  0 55  0
0  9   8312  43008  54788 6955548    0    0    20 19560  721 1036  4  3 17 75  0
1 10   8312  46232  54776 6951812    0    0    64 13608  675 1005 24  8  7 61  0
0  7   8312  47780  54776 6950692    0    0    40 14756  635  866 24 11 11 54  0
1  8   8312  43508  54796 6954844    0    0   128 33140  569 2676 29 19 12 39  0
3  7   8312  43976  54816 6954968    0    0    68 13168  854 2362 39 23  0 38  0
1  8   8312  43924  54824 6954784    0    0    84  9704  901 1866 11  6  0 82  0
3  7   8312  43872  54836 6954844    0    0    72 17812  882 1768 44 19  0 37  0
0  8   8312  43616  54836 6955068    0    0   172 15148  836 1247 36 11  0 53  0
0  9   8312  47708  54844 6950472    0    0    96 15020  556  938 22  5  0 72  0
1  8   8312  48608  54844 6950628    0    0   100  9304  637 1010 31 11  0 58  0
0  9   8312  48816  54844 6950764    0    0   120 15008  814 1192 35 12  0 53  0
4  7   8312  45604  54864 6949256    0    0    80  8604  654 1474  9  5  0 85  0
1  9   8312  41816  54892 6959464    0    0   188 11436  586 2206 26 13  0 61  0
1  9   8312  41584  54856 6956432    0    0    92  7364  763 1712 24 11 21 44  0
3  9   8312  41264  54844 6956360    0    0    88  4524  718 2172 27 16 12 46  0
2  9   8312  44600  54868 6953664    0    0   152  3960  630 2338 21 13 16 50  0
4  6   8312  40388  54860 6957156    0    0   156  4800  646 2789 29 16  6 49  0
4  6   8312  40756  54840 6956224    0    0   104 19644  399 2349 26 15  3 56  0
0  8   8312  40160  54896 6956332    0    0  1488 12436  822 2158 57 23  3 17  0

output of 'ulimit -a':

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 69632
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 69632
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

I have a backup script which I run in bash and after running it for a while it says 'killed'. I can't find anything in the messages log file, so what might it be that's killing my process?

I'm trying to write a shell script in busybox to check the filesize of a file. Having read that stat is more reliable then ls, I decided to use that, but somehow when using the following command:

stat -c %s filename

I get the following output: 559795. This goes for the following 2 files (shown using ls -la):

0 Jan 20 16:32 foo_empty
4 Jan 20 16:32 foo_not_empty

Anyone know what's happening there? I can just go back to using ls, but I'm not understanding what's happening here, and that's bothering me..

The manpage for usermod says this about locking a users account:

   -L, --lock
       Lock a user's password. This puts a ´!´ in front of the encrypted password, effectively disabling the password. You can´t use this option with -p or -U.

I have tried to use this to have a user only log in with the public key, but when I lock the account I get a password prompt. When I unlock the account again the public key works.

Edited: to make it clear: I want to be able to log in using the key still, and somehow locking the user gives me a password prompt when trying to use the key

I can't get iptables port forwarding to work. I think I have it set up correctly on the gateway, but I'm now doubting if the target machine might be the problem. If I set up forwarding from machine A on the Internet to machine C on the lan, with machine B being the gateway, would machine C's firewall then have to allow connections from the ip of B, or of A or..?

I'm trying to migrate from a situation with static ip addresses and a dhcp server on a router to one new dhcp server.

My idea was to add the current static ip addresses as static ip addresses in the dhcp server, so I can still manage them from that server, and to move the current dhcp leases to static ones as well, as these ip addresses are more or less used as static ones too, being referred to in hosts.allow etc on some machines for example.

I do however also still need dynamic addresses, and I'd like to know if I can for example define that my pool of dynamic addresses is from 192.168.1.2 to 192.168.1.200, but have some exlusions in that range for the static addresses.

What would my dhcpd.conf have to look like to achieve that, can I just define the pool and define seperate static addresses and will the dhcpd take those out of the pool automatically?

I can't test this setup as this is a live network with a working dhcp on a router already, that's why I have to ask it up front.

We have postfix on our development server, and I'd like it to be able to only send mail to our domain, not to other domains, preventing outside users from accidentally receiving mail from our development server.

I searched through the docs, tried several things but it's still sending to all domains...

apache segfaults when we have register_globals turned on with php 5.3. I know we should not do that, and we have it off now, but some of our very old code needs it. Anyone have any hints on what to try/look at to solve this?

thanks