sysadmin-utils
This repository contains a small collection of scripts that might be useful to sysadmins. I put it together myself to centralise the small tools that I find useful, and it seems to be popular.
I used to solicit the inclusion of new tools, but have slowly come to realize that "less is more". I love the idea of sysadmins, developers, and other people building up their own toolkits, but also find that people submit things that I just don't understand the appeal of.
It makes sense that personal-tools are very personal, but it does mean rejection is almost always the default behaviour and that makes me feel bad.
Instead of adding things here consider this repository a small collection of things that I use, and if you want to take some/all of utilities into your own use then please do so. If not then I would strongly encourage you to consider what tools would make your daily-life more useful and then collect them, document them, and publish them yourself.
In short the value here is the idea of collecting your commonmost utilities and making them easy to install and update from one central-source. Not the specific tools themselves.
There is a replacement repository which is still open, and which new additions can be made more freely:
- https://github.com/skx/sysbox
ago
Show how long ago a file/directory was modified in a human-readable fashion.
Example:
$ ./ago /etc/passwd
/etc/passwd 15 weeks ago
Alternatives:
stat
andls
both show ages, but not in a human-readable fashion.
chronic
Run a command, hiding STDOUT and STDERR if it completes successfully.
Example:
./chronic cp /etc/passwd /tmp/not/found
This is designed to be used for cron-jobs, where output is generally ignored in the case of success.
This was written by Joey Hess and is part of moreutils.
cidr2ip
Given a set of CIDR ranges output the individual IPs in the range(s).
Example:
$ ./cidr2ip 192.168.0.0/24
192.168.0.0
192.168.0.1
192.168.0.2
192.168.0.3
192.168.0.4
..
collapse
Remove extraneous whitespace from lines, and remove empty-lines entirely.
Example:
$ echo -e "Test1\n f \n\nTest2\n\n\n\n" | ./collapse
Test1
f
Test2
Alternatives:
tr
- …
dupes
Report on duplicate files, via a SHA1 hash of the contents, recursively.
Example:
$ dupes
./.git/logs/HEAD
./.git/logs/refs/heads/master
./.git/refs/heads/master
./.git/refs/remotes/origin/master
Alternatives:
empty-dir
Indicate, via return code, whether a given directory is empty or not.
Example:
if empty-dir /etc; then echo "We're broken" ; fi
expand-ipv6
Expand an abbreviated/compressed IPv6 address to the full-form.
Example:
./expand-ipv6 fe80::1 2001:41c8:10b:103::111
fe80:0000:0000:0000:0000:0000:0001
2001:41c8:010b:0103:0000:0000:0111
Alternatives:
sipcalc
- …
graphite_send
A simple script to send a consistent set of metrics & values to a remote graphite instance.
The metrics may be extended via small "plugins", which are nothing more than shell/perl/ruby/python scripts in a particular directory.
Example:
graphite_send -v
NOTE Some metrics will only be sent if the invoking user is root.
Alternatives
ipaddr
Get IP addresses easily, either all IPs, all those which are IPv4/IPv6, or those for a device. Designed primarily for scripting.
Example:
$ ./ips -4
lo 127.0.0.1
eth0 80.68.84.102
eth0 80.68.84.104
Or to see all IPv6 addreses on eth0:
$ ipaddr -6 -d eth0
eth0 2001:41c8:10b:102::10
eth0 fe80::216:3eff:fe08:16a4
NOTE Requires compilation via make build
.
Alternatives:
ip -[46] addr show
ifconfig -a
maybe
In a similar vein to true
and false
the maybe
command exits with
a status code of zero or one, depending on a random number.
It can be useful in scripts which need to test-failures, or which benefit from randomness:
Example:
maybe && echo "I pass"
maybe || echo "I fail"
multi-ping
Ping a host, regardless of whether it is an IPv6 or IPv4 host.
Example:
$ multi-ping steve.org.uk
Host steve.org.uk - 80.68.85.46 alive
Host steve.org.uk - 2001:41c8:125:46:0:0:0:10 alive
As a convenience you may also specify URIs as arguments, for example:
$ multi-ping http://steve.org.uk/foo/bar
Host steve.org.uk - 80.68.85.46 alive
Host steve.org.uk - 2001:41c8:125:46:0:0:0:10 alive
Requirements:
- The
Net::DNS
perl module. - The
ping
+ping6
binaries.
mysql-slave-check
If the current host is a MySQL slave this script will test that the slave replication is still working.
Replication is regarded as being OK if the following three conditions are true:
- The output of "SHOW SLAVE STATUS" includes: SlaveIORunning: Yes
- The output of "SHOW SLAVE STATUS" includes: SlaveSQLRuning: Yes
- The slave is less than 24 hours behind the master.
Example:
# ./mysql-slave-check
The replication appears to show an error:
..
Master_Host: da-db1
Master_User: slave
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000124
Read_Master_Log_Pos: 65667
Relay_Log_File: relay-log.001139
Relay_Log_Pos: 27251
Relay_Master_Log_File: mysql-bin.000124
Slave_IO_Running: No
Slave_SQL_Running: No
..
The script exits silently if all is well, unless you add "--verbose
":
# ./mysql-slave-check -v
The slave is running, successfully.
Replication lag: 0 seconds
Requirements:
- There must be a file /etc/mysql/debian.cnf with valid "user=" and "password=" lines.
pyhttpd
A simple Python HTTP server, which has been updated to allow it to bind to arbitrary IP addresses, specifically to allow you to bind to localhost.
Example:
$ ./pyhttpd 127.0.0.1:8080
Serving HTTP on 127.0.0.1 port 8080 ...
or
$ ./pyhttpd 8080
Serving HTTP on 0.0.0.0 port 8080 ...
randpass
Generate a single random password via /dev/urandom
.
Example:
$ ./randpass
cT3j7Zp6
$ ./randpass -n 10
ulHrNvYLaa
$ ./randpass -n 20 -f
oe[d7+e.{Uw=L'RO~[]{
(Adding "-f" uses the full alphabet of possible symbols, otherwise only alpha-numeric values are shown. "-n" sets the length of the generated password.)
Existing alternatives:
- apg
- gpw
- pwgen
- …
since
Show the new output since previously reading a file. This is useful for keeping track of logfile updates.
Example:
$ ./since /var/log/messages >/dev/null
$ logger "testing the log"
$ ./since /var/log/messages
Apr 20 11:24:37 precious skx: testing the log
Existing alternatives:
- logtail
ssh-auth-types
Show the authentication types presented by a remote SSH server.
Example:
$ ./ssh-auth-types precious
publickey password
$ ./ssh-auth-types ssh.example.com
publickey
ssh-test
Test whether ssh
connections to a list of hosts will succeed, by testing
each in order.
Example:
$ ./ssh-test host.list.txt
ssh.steve.org.uk ... OK
www.steve.org.uk ... OK
foo.example.com:222 ... OK
$ cat host.list.txt
ssh.steve.org.uk
www.steve.org.uk
foo.example.com:222
The format of the input-file is:
[user@]hostname1[:port]
[user@]hostname2[:port]
..
splay
Sleep for a random amount of time, limited by the given max value. (Default is 5 minutes).
Example:
$ ./splay -v
Sleeping for 77 seconds from max splay-time of 300 seconds
$ ./splay -v -m 20
Sleeping for 7 seconds from max splay-time of 20 seconds
Existing alternatives:
ssl-expiry-date
Report the date, and number of days, until the given SSL certificate expires. Multiple domain-names may be accepted and each is tested in turn.
The default output is "noisy", but you may add "-d" to simplify this to the domain-name and the number of days remaining on the certificate.
Example:
./ssl-expiry-date bbc.co.uk
bbc.co.uk
Expires: Sep 18 13:50:57 2016 GMT
Days: 266
./ssl-expiry-date -d bbc.co.uk steve.org.uk
bbc.co.uk: 266
steve.org.uk: 82
timeout
Timeout allows you to run a command which will be killed after the given number of seconds.
Example:
# Kill the command after 63 seconds.
./timeout -t 63 top
# Kill the command after two minutes, five seconds.
./timeout -t 2:5 top
# Kill the command after three hours, five minutes, and seven seconds
./timeout -t 3:5:7 top
until-success
Repeat the specific command until it succeeds - run at least once always.
Example:
./until-success ssh example.com -l root -i ~/.ssh/example.com.key
Trivial (ba)sh alternatives:
- while true ; do $cmd; done
- watch -n 2 $cmd
when-up
Waits until a given host is online, determined by ping, until executing a given command.
Example:
$ ./when-up 1.2.3.4 ssh user@1.2.3.4
Waiting for 1.2.3.4 to come online...
Last login: Sat Dec 28 23:25:01 2013 from 5.6.7.8
user@1.2.3.4:~#
Alternatives:
until-success ping -c 1 1.2.3.4; ssh user@1.2.3.4
until-error
Repeat the specific command until it fails - run at least once always.
Example:
./until-error ssh example.com -l root -i ~/.ssh/example.com.key
Trivial (ba)sh alternatives:
- while true ; do $cmd; done
- watch -n 2 $cmd
when-down
Waits until a given host is down
Example:
$ ./when-down 1.2.3.4 echo "down"
Waiting for 1.2.3.4 to get down...
down
Alternatives:
until-error ping -c 1 -W 1 1.2.3.4; echo "down"
which-shell
Identify the shell we're running under.
For example:
$ which-shell
dash
Existing alternatives:
ls -l /bin/sh
with-lock
Run a command, unless an existing copy of that command is already running, via the creation of a temporary lockfile.
For example:
with-lock rsync ...
The lockfile-name is based upon the SHA1 hash of the command to be executed and the current User-ID.
Existing alternatives:
- lckdo - Requires you to build your own lockfile name.
- flock - Requires you to build your own lockfile name.
Problems
Please report any issue/suggestions via the github repository:
- https://github.com/skx/sysadmin-util
Author
Steve Kemp steve@steve.org.uk