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append a ssh public key to a remote machines keys file

// What the title says :-)

cat .ssh/id_dsa.pub | ssh user@domain.tld 'cat >> .ssh/authorized_keys'

some nix commands (from MT)

Common SSH commands for (dv) 2.0 - (dv) 3.0 Servers [ *'d items work on (ss) also ]

=========================================================================================|
This is a list of Common commands that can be run from root / SSH access.


I. Basic Commands

A. Retrieve Plesk Admin Password

cat /etc/psa/.psa.shadow

B. Change Directory (cd) *


cd /path/to/directory/

C. Listing Files/SubFolders (ls) *

ls -alh (files and subfolders listed with perms in human-readable sizes)

D. Checking Processes

ps -a top -c (process viewer - Ctrl+C to exit)

ps -auxf (process list)

E. Start/Stop Services

/etc/init.d/<service> start|stop|restart|status ("/etc/init.d/httpd stop" stops apache)

F. Check Bean Counters (hard and soft limits, failcounts, etc.)

cat /proc/user_beancounters




II. File System Commands (df & du are (dv)-only commands)

A. Check Total Disk Usage

df (gives physical disk usage report with % used)

B. List Files/Folders +Sizes (du)

du (lists all filesizes. takes a LONG time, dont run this)

1. du -sh * (lists all the subfolders/sizes in a dir)

C. Remove/Delete Files (rm /path/to/filename.htm) -DANGER- always verify *

1. rm -vf (force-deletes file. Dont run unless you know EXACTLY what you're doing)

2. rm -vrf (force deletes folder and all subfolders and files)

D. Copy Files (cp) *

cp filename.abc /new/path/filename.abc.123

E. Move Files (mv) *

mv filename.abc /new/path/filename.abc.123

F. Create Empty File (touch) *

touch filename.123



III. File Permissions and Ownership (dv)+(ss)

A. Change Permissions of files (chmod) *

chmod 000 filename.abc (defaults are usually 755 for folders, 644 for files)

1. Numbers correspond to users. 1st=Owner; 2nd=Group; 3rd=Other

(-rwxrwxwrx = 777, -rwxr-xr-x = 755, -rw-r--r-- = 644, etc.)

7 = Read + Write + Execute
6 = Read + Write
5 = Read + Execute
4 = Read
3 = Write + Execute
2 = Write
1 = Execute
0 = All access denied

B. Change Ownership of files (chmown) *

chown user:group filename.abc (you can see user and group w/ ls -alh)

Anytime a user creates a file, the Ownership of the file matches that user. In Plesk,
every domain that has hosting has a different user. So if you are copying files from
one domain to another, you must remember to change ownership.



IV. Checking Log Files (dv)

Log files can tell you alot about whats going on on a (dv). You can use the command:
'tail -n 100' before the logfile name to list the last 100 entries of the logfile.
Here are some of the most common:

A. Main Error Log

/var/log/messages

B. Apache Error Log

1. /var/log/httpd/error_log (main)

2. /home/httpd/vhosts/domain.com/statistics/logs/error_log (per-domain)
(May also be: /var/www/vhosts on newer dvs)

C. MySQL Logs

/var/log/mysqld.log

D. Mail Logs

/user/local/psa/var/log/maillog


**Common issues to look out for in log files**

-The main error log will not always give you all the information you want for a svc.
You may see alot of failed SSH and FTP connections, that is generally normal.

-Keep an eye out for MaxClients errors in the Apache logs if a customer is complaining
of Apache dying alot. You can check the internal KB for raising MaxClients settings.

-If a customer does not set up Log Rotation for a domain under Plesk, then Log Files
will build up and may take up alot of unneeded space. You can usually delete old log
files in Plesk, and change the Log Rotation to Daily instead of by size.

-MailLogs can show you if a customer is spamming, or if mail is coming in or out.

-MySQL Logs should be able to show you general MySQL errors such as bad connections,
or corrupted tables. Check the Int. KB for the 'myisamchk -r' repair table command.



V. Advanced Commands

A. Find. You can do alot with find. for now lets find all files over 10MB.

find . -size '+10000k' -exec ls -Shl {} ;

B. Grep. Another handy tool to get specific information

cat file | grep blah (only lists the information where the word blah is found)

C. Less/More

less filename.abc (displays the content of a file. arrows to scroll, 'q' to quit.)
more == same thing basically.

You can use the '| more' command to scroll through something page or line at a time.
'tail -n 1000 /var/log/httpd/error_log | more'

D. VI. Vi is a basic text editor. Careful what keys you hit while in vi.

vi /path/to/filename.abc

i = INSERT mode. Hit 'i' when you are ready to type in some junk.
leave INSERT mode by hitting the 'Esc' key.

:q = Quit without saving. (Make sure your not in INSERT mode)

:wq = Write file and Quit (Save).

Generate DSA Keys

// generates SSH DSA keys in ~/.ssh/

ssh-keygen -d

ssh tunnel

Quick syntax example for ssh tunelling.
ssh -l username -L 4444:alpha.hostname.com:80 dmz.hostname.com

Running Mutt w/Maildirs (not IMAP) on TxD servers via ssh

I modified Pteron's muttrc file to use my local Maildir rather than login via IMAP.

This is A) Faster/better since it cuts out the bother of an imap connection to localhost and accesses your mail directly, B) It actually works (the imap method always failed on a segfault for me at least), C) You gotta like not having to store your username/password in the clear since there's no imap login to perform D) More responsive than webmail for quick email checks, and works even when webmail doesn't.

To use, change the realname line and save with filename ".muttrc"; upload this to your home directory, then login via ssh and type "mutt".

# For TextDrive accounts (running mutt on the server)

set mbox_type=Maildir
set folder="~/Maildir/"
set spoolfile="~/Maildir/"
set mask="!^\\.[^.]"
set record="+.Sent"
set postponed="+.Drafts"

set realname="Yourname"

mailboxes `\
echo -n "+ "; \
for file in ~/Maildir/.*; do \
  box=$(basename $file); \
  if [ ! $box = '.' -a ! $box = '..' -a ! $box = '.customflags' \
      -a ! $box = '.subscriptions' ]; then \
    echo -n "+$box "; \
  fi; \
done`

macro index c "<change-folder>?<toggle-mailboxes>" "open a different folder"
macro pager c "<change-folder>?<toggle-mailboxes>" "open a different folder"

set allow_8bit  # Don't do any Quoted-Printable encoding on 8-bit data!
set copy=yes    # Ask me if I want to save a copy of my outgoing messages.
set delete=yes
set noaskcc
set nomark_old
set reverse_alias
set reverse_name
set reply_to
set attribution="On %d, %n wrote:"
set envelope_from
set noconfirmappend
set print=ask-no
set print_cmd="echo Nix printi printi!"
set nosave_empty
set sort=threads
set read_inc=10
set write_inc=10
set noprompt_after
set status_format="%r %v [%?M?%M/?%m] %?n?%n new, ?%?p?%p postponed, ?%?t?%t +tagged, ?%?d?%d delet ed, ?(%h:%f) %?b?%b more to go.?%> %r"

#set alias_file="~/.aliases"
set quote_regexp="^([A-Za-z ]+>|[]>:|}-][]>:|}-]*)"
set include
set hdr_format="%4C %Z %{%b %d} %-15.15n (%4l) %s"
set nomove
set tilde
set noautoedit
set pager_context=1
set pager_stop
set pipe_decode
set postponed="+postponed"
set to_chars="b .c>"

set fast_reply

color header brightcyan black .
color header yellow black Subject:
color body brightyellow black [_a-z\.\$A-Z0-9-]+@[a-zA-Z0-9\./\-]+
color body yellow black (http|ftp)://[_a-zA-Z0-9\./~\-]+
color quoted green black
color signature brightblue black
color attachment yellow black
color tree red black
color indicator black cyan
color status yellow blue
color tilde blue black

bind pager 'w' previous-page
bind pager 'j' next-line
bind pager 'k' previous-line
bind index '#' tag-entry
bind index '{' previous-thread
bind index '}' next-thread

# Headers to ignore
ignore *
unignore date from to cc subject x-mailer resent-from reply-to

Bash script to export ssh public key to a remote server

This isn't a brilliant script, but it sure can be a time saver. When I add a public key by hand I end up doing a lot more commands.

#!/bin/bash

## USAGE: add_to_server.sh remote_server

## This script will add your ssh dsa public key to remote_server's authorized_keys list, 
## assuming that everything is in it's default location

set -v 				# verbose output
username="USERNAME"		# CHANGE ME!!!!
remote_server=$1		# assigns the first commandline argument to $remote_server


## Pipe the public key to ssh, then remotely touch the file to make sure it will be there, and concat to the end of it.
## Might work without the touch?
cat ~/.ssh/id_dsa.pub | ssh ${username}@${remote_server} "touch ~/.ssh/authorized_keys && cat - >> ~/.ssh/authorized_keys"

exit 0

Remote file editing using emacs + ssh

Get TRAMP (Transparent Remote file Access, Multiple Protocol) :
http://savannah.gnu.org/projects/tramp/


Install it :
cd ~/.emacs.d/
tar -xvzf /your/download/folder/tramp-2.X.X.tar.gz
ln -s tramp-2.X.X tramp
cd tramp
./configure --with-contrib
make
sudo make install


Configure your emacs to use it :
1. Add the following in your .emacs
;; Remote file editing via ssh
(add-to-list 'load-path "~/.emacs.d/tramp/lisp/")
(require 'tramp)
(setq tramp-default-method "ssh")

2. Launch your emacs
3. C-x C-f /user@your.host.com:/path/to/file

Warning :
Seems it doesn't work if no password is required to login to host (using public key for example). But not sure at all...

Enable svn+ssh remote logins

Installing Subversion for local use is general an easy install, but allowing remote access to your svn repository over SSH can be problomatic dependent upon your OS and the means taken to install.

For Darwinports and Fink on OS X the install location has to be added to users $PATHs, but there are extra steps outlined here for use of the svn+ssh means of access:

http://subversion.tigris.org/faq.html#ssh-svnserve-location

A much easier alternate is to sym link the svn binaries to a place on the default PATH (used by the SSH login):

#For Darwinports
ln -s /opt/local/bin/sv* /usr/bin/

#For Fink
ln -s /sw/bin/sv* /usr/bin/


This links all the binaries at once.

Accessing CVS on a remote server through SSH

If the repository is on a remote server and you have SSH access, then just set CVS_RSH and CVSROOT.

For example, in bash:

export CVS_RSH="ssh"
export CVSROOT=":ext:me@someserver:/path/to/repository"


In combination with ssh-agent, this works nicely.

Mute Remote Macintosh

Sometimes I am in bed and too lazy to get out to mute my G5. I can just grab my iBook, SSH into the G5 and run the following command:

osascript -e 'set volume output muted true'


brilliant!