Posts Tagged ‘Usage’

How to run SSH server Mac OS X and set it to auto boot on Mac Book system start

Monday, February 5th, 2024

mac os X

How to run SSH Server on Mac OS X to administrate remotely your MAC OS to access remote MacBook Air or Mac OS 

Linux / UNIX users know it is pretty easy to run OpenSSH server on old Linux SystemV releases

it is done with cmd:

# /etc/init.d/sshd start


On newer Linux distros where systemd is the standard it is done wtih:

# systemctl start ssh.service

To enable ssh service on boot on systemd distros

# systemctl enable ssh.service


To enable SSH access on Mac OS X this is done wtih a simple command

To check the status of SSH server being on or OFF, either connect with netcat to TCP port 22, which is usually installed by default on most MAC OS-es or run:

# systemsetup -getremotelogin

To start and enable SSH service on Mac OS X run:

# systemsetup -setremotelogin on 


If you later need to turn off the SSH service

# systemsetup -setremotelogin off

Actually systemsetup command can do pretty much on MAC OS X and it is worthy to take a look at it, if you're running a MAC PC or Mac Book laptop.

systemsetup can set the current date, change time server host, set computer name (hostname) and much more.

sh-3.2# systemsetup -help

systemsetup Help Information
————————————-
Usage: systemsetup -getdate
        Display current date.

Usage: systemsetup -setdate <mm:dd:yy>
        Set current date to <mm:dd:yy>.

Usage: systemsetup -gettime
        Display current time.

Usage: systemsetup -settime <hh:mm:ss>
        Set current time to <hh:mm:ss>.

Usage: systemsetup -gettimezone
        Display current time zone.

Usage: systemsetup -settimezone <timezone>
        Set current time zone to <timezone>. Use "-listtimezones" to list time zones.

Usage: systemsetup -listtimezones
        List time zones supported by this machine.

Usage: systemsetup -getusingnetworktime
        Display whether network time is on or off.

Usage: systemsetup -setusingnetworktime <on off>
        Set using network time to either <on> or <off>.

Usage: systemsetup -getnetworktimeserver
        Display network time server.

Usage: systemsetup -setnetworktimeserver <timeserver>
        Set network time server to <timeserver>.

Usage: systemsetup -getsleep
        Display amount of idle time until computer, display and hard disk sleep.

Usage: systemsetup -setsleep <minutes>
        Set amount of idle time until computer, display and hard disk sleep to <minutes>.
        Specify "Never" or "Off" for never.

Usage: systemsetup -getcomputersleep
        Display amount of idle time until computer sleeps.

Usage: systemsetup -setcomputersleep <minutes>
        Set amount of idle time until compputer sleeps to <minutes>.
        Specify "Never" or "Off" for never.

Usage: systemsetup -getdisplaysleep
        Display amount of idle time until display sleeps.

Usage: systemsetup -setdisplaysleep <minutes>
        Set amount of idle time until display sleeps to <minutes>.
        Specify "Never" or "Off" for never.

Usage: systemsetup -getharddisksleep
        Display amount of idle time until hard disk sleeps.

Usage: systemsetup -setharddisksleep <minutes>
        Set amount of idle time until hard disk sleeps to <minutes>.
        Specify "Never" or "Off" for never.

Usage: systemsetup -getwakeonmodem
        Display whether wake on modem is on or off.

Usage: systemsetup -setwakeonmodem <on off>
        Set wake on modem to either <on> or <off>.

Usage: systemsetup -getwakeonnetworkaccess
        Display whether wake on network access is on or off.

Usage: systemsetup -setwakeonnetworkaccess <on off>
        Set wake on network access to either <on> or <off>.

Usage: systemsetup -getrestartpowerfailure
        Display whether restart on power failure is on or off.

Usage: systemsetup -setrestartpowerfailure <on off>
        Set restart on power failure to either <on> or <off>.

Usage: systemsetup -getrestartfreeze
        Display whether restart on freeze is on or off.

Usage: systemsetup -setrestartfreeze <on off>
        Set restart on freeze to either <on> or <off>.

Usage: systemsetup -getallowpowerbuttontosleepcomputer
        Display whether the power button is able to sleep the computer.

Usage: systemsetup -setallowpowerbuttontosleepcomputer <on off>
        Enable or disable whether the power button can sleep the computer.

Usage: systemsetup -getremotelogin
        Display whether remote login is on or off.

Usage: systemsetup -setremotelogin <on off>
        Set remote login to either <on> or <off>. Use "systemsetup -f -setremotelogin off" to suppress prompting when turning remote login off.

Usage: systemsetup -getremoteappleevents
        Display whether remote apple events are on or off.

Usage: systemsetup -setremoteappleevents <on off>
        Set remote apple events to either <on> or <off>.

Usage: systemsetup -getcomputername
        Display computer name.

Usage: systemsetup -setcomputername <computername>
        Set computer name to <computername>.

Usage: systemsetup -getlocalsubnetname
        Display local subnet name.

Usage: systemsetup -setlocalsubnetname <name>
        Set local subnet name to <name>.

Usage: systemsetup -getstartupdisk
        Display current startup disk.

Usage: systemsetup -setstartupdisk <disk>
        Set current startup disk to <disk>.

Usage: systemsetup -liststartupdisks
        List startup disks on this machine.

Usage: systemsetup -getwaitforstartupafterpowerfailure
        Get the number of seconds after which the computer will start up after a power failure.

Usage: systemsetup -setwaitforstartupafterpowerfailure <seconds>
        Set the number of seconds after which the computer will start up after a power failure. The <seconds> value must be a multiple of 30 seconds.

Usage: systemsetup -getdisablekeyboardwhenenclosurelockisengaged
        Get whether or not the keyboard should be disabled when the X Serve enclosure lock is engaged.

Usage: systemsetup -setdisablekeyboardwhenenclosurelockisengaged <yes no>
        Set whether or not the keyboard should be disabled when the X Serve enclosure lock is engaged.

Usage: systemsetup -version
        Display version of systemsetup tool.

Usage: systemsetup -help
        Display help.

Usage: systemsetup -printCommands
        Display commands.

 

Enabling SSH in Mac OS X computers can be done also from Graphical interface for the lazy ones.

enable-ssh-mac-remote-login-from-mac-OS-X-gui

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Posted in Linux, Mac OS X, Networking, Various | No Comments »

Check weather forecast from console (terminal) on GNU / Linux and FreeBSD howto

Friday, August 23rd, 2019

how to get weather forecast prognosis from command line text terminal / console on Linux and FreeBSD

Doing everything in Linux console / terminal is a question perhaps every Linux / BSD hacker wants to do as Graphical user interface and using web search or using Graphical Environment plugins is an unneded complexity + googling or duckduckgoing for weather to check your next vacation destination city has been more and more of a terrible experience (for me) as I'm not a big fan of using the OS in a GUI.
In that manner of thoughts, as a Linux console geek and hard core ASCII art fan. I was recently happy to find that  possible to check weather forecast in tty console or Linux terminal in a beautiful ascii art way easily through a Web wttr.in service – a web application weather forecast service that supports displaying the current and few days in future, weather forecast either in browser as a plain text or from the command line by simply accessing it with your favourite web access / transfer tool such as;
wget / curl or any of your favourite text browser elinks / lynx / w3m or if on *BSDs use fetch command.

 

Install Curl data transfer tool if it is not already


Wget is installed by default across most Linux distributions and fetch is present by default on BSDs, displaying it in text browser would perhaps be never used but if you decide to give it a try maybe try with elinks (to get colorful output), w3m and lynx will display a black and white results.

In case if you miss curl, install it:

On Debian distro

 

aptitude install -y curl


or Fedora

yum install -y curl
…


Of course to use wttr.in as it is Internet based Weather Forecast service the minimum you need to have is to have Internet connection to your Linux / BSD desktop computer.

Text based Weather Forecast Web App currently supports:

display the current weather as well as a 3-day weather forecast, split into morning, noon, evening and night

  • Temperature is displayed for morning, noon, evening and night (includes temperature range, wind speed and direction, viewing distance, precipitation amount and probability)
  • Provide results for Weather based on City / town / village location
  • Supports display of Moon Phases Forecast in calendar days
  • Supports multilingual names (Bulgarian Phonetic cyrillic / Russian and other exotic UTF-8 encodings such as Chineese and Japanese),  50+ languages are currently supported
  • Has ability for prognosis for hostname (domain) location based on an its IP GeoIP location on the Globe
  • Geographical locations / landmarks such as Lakes / Mountains etc. can be easily queried
  • Query results metrics could be configured, e.g. USCS units or EU and rest of world accepted ones (SI) metric
  • Displayed result could be either in ANSI (if from terminal / console / HTML if queried from browser or in PNG – if needed)

 

Where wttr.in could be useful ?

The best applications use, I can think of are for server (shell) / perl scripting automation purposes, it could be useful especially in TOO HOT, TOO, COLD, TOO WET location in Small and Middle sized Data Centers Green Energy (Sun Panel) Parks / Wind Energy situated Linux monitoring hosts to track possible problems of overheats or overcolding of servers due to abnormal excessive temperatures such as the ones we experienced this summer here All across in Europe or in too Cold DC locations such as heat locations Deserts in African Countries, Saudi Arabia or Chukotka or Siberia in Russia.
Other application is as a backup option to other normal Weather report services by PHP or Python scripts that fetch data, from multiple places.
Of course since this is a third party controlled service, the downtime is due to excessive connection requests, the service could get flooded and stopped working, but I guess for any Commercial use, wttr.in creator Igor Chubin would be happy to sell a specific crafted service for any end user candidates.


Here is few examples of the beautiful returned ASCII art formatted output of wttr.in.
 

1. Getting a three days Weather Forecast prognosis for city / town location

To get what is current weather in my current city of Living, Sofia Bulgaria just pass the city to the URL address

curl http://wttr.in/Sofia

text-console-wttr.in-Weather-forecast-Sofia-for-Linux

 

links http://wttr.in/Dobrich

 

curl-Linux-show--Dobrich-Weather-forecast-in-lynx-text-browser


Default links (Linux) www text browser produces ugly black and white

2. Displaying Weather forecast with wget

 

wget -O- -q http://wttr.in


getting-weather-forecast-on-linux-terminal-console-with-wget-command

If you're lazy you can even omit the http:// as wget will look for HyperText Transmission Protocol by itself

 

wget -O- -q wttr.in

 

3. Getting Forecast results for a Tourist Destination


Lets get the weather forecast for the popular tourist Bulgarian destination of the Seven Rila Lakes (near Rila Monastery), situated in the Rila Mountain BG.

 

curl http://wttr.in/Seven+Rila+Lakes

 

Console-terminal-Weather-forecast-Linux-Seven-Rila-Lakes

 

 

4. Display Forecast for a specific server IP


Displaying information on specific server IP address current situated in GeoIP database, of course could be not really true, as the IP could be just a Load Balancer a router that does NAT to some internal DMZ-ed location server, but anyways it is a cool feature.

Lets get information on what is the weather on Google Global's Public DNS server IP 8.8.8.8 so commonly used to guarantee a Windows and Linux Desktop client machines Internet connectivity.
 

curl wttr.in/@8.8.8.8

 

wttr.in-Linux-text--forecast-service-curl-screenshot Google Public DNS location weather forecast

5. Download PNG image picture from wttr.in service

 


Lets say you want to get a 3 days standard Weather forecast for the popular Black Sea Resort town in Bulgaria Pomorie (a beautiful sea city which has even a functioning 5 Monks Monastery Pomorie Monastery situated near sea coast)

 

curl http://wttr.in/Pomorie.png
 

 

–2019-08-22 20:15:51–  http://wttr.in/Pomorie.png
Resolving wttr.in (wttr.in)… 5.9.243.187
Connecting to wttr.in (wttr.in)|5.9.243.187|:80… connected.
HTTP request sent, awaiting response… 200 OK
Length: 42617 (42K) [image/png]
Saving to: ‘Pomorie.png’

Pomorie.png                                     100%[=======================================================================================================>]  41.62K  –.-KB/s    in 0.07s   

2019-08-22 20:15:52 (586 KB/s) – ‘Pomorie.png’ saved [42617/42617]

 

Note: The generated .png is again the ASCII art produced by a direct text fetch bug in pic format

 

6. Displaying Current Moon Phase


If you want to enjoy a text based Moon phase picture through wttr.in 🙂

wget -O- -q wttr.in/Moon


Display-current-Phase-of-Moon-in-terminal-console-Linux-wttr.in-service

You can also get a Moon Phase prognosis for a current future date or get a previous date phase

 

curl wttr.in/moon@2019-09-15

Full-Moon-Weather-forecast-text-console-reporting-via-wttr.in-on-Gnu_Linux


Full Moon Madness !! – Vampires are out beaware and Enjoy the ultra kewl ASCII Colorful Art 🙂
 

7. Getting help for wttr.in terminal Waether Forecast results

 

 

$ curl wttr.in/:help
Usage:

 

    $ curl wttr.in          # current location
    $ curl wttr.in/muc      # weather in the Munich airport

Supported location types:

    /paris                  # city name
    /~Eiffel+tower          # any location
    /Москва                 # Unicode name of any location in any language
    /muc                    # airport code (3 letters)
    /@stackoverflow.com     # domain name
    /94107                  # area codes
    /-78.46,106.79          # GPS coordinates

Special locations:

    /moon                   # Moon phase (add ,+US or ,+France for these cities)
    /moon@2016-10-25        # Moon phase for the date (@2016-10-25)

Units:

    m                       # metric (SI) (used by default everywhere except US)
    u                       # USCS (used by default in US)
    M                       # show wind speed in m/s

View options:

    0                       # only current weather
    1                       # current weather + 1 day
    2                       # current weather + 2 days
    A                       # ignore User-Agent and force ANSI output format (terminal)
    F                       # do not show the "Follow" line
    n                       # narrow version (only day and night)
    q                       # quiet version (no "Weather report" text)
    Q                       # superquiet version (no "Weather report", no city name)
    T                       # switch terminal sequences off (no colors)

PNG options:

    /paris.png              # generate a PNG file
    p                       # add frame around the output
    t                       # transparency 150
    transparency=…        # transparency from 0 to 255 (255 = not transparent)

Options can be combined:

    /Paris?0pq
    /Paris?0pq&lang=fr
    /Paris_0pq.png          # in PNG the file mode are specified after _
    /Rome_0pq_lang=it.png   # long options are separated with underscore

Localization:

    $ curl fr.wttr.in/Paris
    $ curl wttr.in/paris?lang=fr
    $ curl -H "Accept-Language: fr" wttr.in/paris

Supported languages:

    af da de el et fr fa hu id it nb nl pl pt-br ro ru tr uk vi (supported)
    az be bg bs ca cy cs eo es fi ga hi hr hy is ja jv ka kk ko ky lt lv mk ml nl fy nn pt pt-br sk sl sr sr-lat sv sw th te uz zh zu he (in progress)

Special URLs:

    /:help                  # show this page
    /:bash.function         # show recommended bash function wttr()
    /:translation           # show the information about the translators

 


 

 

8. Comparing two cities weather from command line

 


One useful use of wttr.in if you plan to travel from Location city A to Location city B is to compare the temperatures with a simple bash one liner script:

 

 

 

diff -Naur <(curl -s http://wttr.in/Sofia ) <(curl -s http://wttr.in/Beograd )

 

 

9. Using ansiweather command to get Weather Temperature / Wind / Humidity in one line beuatiful text

 


If you go and install answeather Linux package

 

apt-get install –yes ansiweather


You will get a shell script wrapper with ANSI colors and Unicode symbols support. Weather data comes from OpenWeatherMap, this is useful if wttr.in is not working due to some URL malfunction (due to service is DoS-ed) etc.

 

ansiweather -l Atina

 

ansiweather-Atina-weather-forecast-result-linux-text-console

Lets use ansiweather to print the weather prognosis for upcoming 5 days for near port of Burgas, BG
 

ansiweather -F -l Burgas

ansiweather-print-weather-forecast-prognosis-for-5-days-in-Linux-text-terminal

 

10. Get all Weather current forecast for each Capital in the world


You can download and use this simple plain text file list of All Country Capitals in the World (country-capitals-all-world.txt) with ansiweather and a bash loop to get displayed each and every current day Weather Forecast in the World, here is how:

 

while read line; do ansiweather -l $line; sleep 3; done < country-capitals-all-world.txt


ansiweather-all-countires-capitals-result

As you can see some of the very exotic third world capitals does not return data so 'ERROR: Cannot fetch weather data' is returned.


You can also substitute ansiweather with curl wttr.in/$line to do get the beautiful ASCII art 3 days weather forecast via wttr.in

 

while read line; do curl http://wttr.in/$line; sleep 3; done < country-capitals-all-world.txt


I'll be happy to know other nice ASCII Art supporting Web service to enjoy from text terminal on Linux (nomatter useful or) just funny joyful prank maniacal pranks such as Watching text ASCII version remake of Star Wars Classic Movie by simply telnetting to towel.blinkenlights.nl (if you haven't so just telnet and enjoy the streamed ASCIIs ! 🙂

 

telnet towel.blinkenlights.nl

 

watch-star-wars-ascii-art-version-remake-online-with-telnet-on-linux-console-terminal

 

Talking about fun and ASCII, its worthy to mention hollywood Linux package

hipo@jeremiah:~/Desktop$ apt-cache show hollywood|grep -i desc -A 3
Description-en: fill your console with Hollywood melodrama technobabble
 This utility will split your console into a multiple panes of genuine
 technobabble, perfectly suitable for any Hollywood geek melodrama.
 It is particularly suitable on any number of computer consoles in the
—
Description-md5: 768f44c76220ea2b35f855ea34c8bc35
Homepage: http://launchpad.net/hollywood
Section: games
Priority: optional


Once installed on Debian with:

aptitude install -y hollywood
…

You can get in a rapid manner plenty of tmux (screen like – virtual console emulator) split screen statistics about your notebook / workstation / server CPU usage, mlocate.db status, info about plugged in machine voltage, Speedometer (statistics about Network bandwidth usage), System load avarage (CPU Count, Memory Utilization) and some other random info coming out of dmesg kernel log and more. The information displayed in splitted windows changes rapidly and (assuming you run it at home Desktop with a soundblaster) and not remotely, a james bond Agent 007 soundtrack is played on the back, that brings up one's adrenaline and makes it look even cooler.

hollywood-melodrama-technobubble-split-console-multiple-panes-for-genuine-technobubble

To give you an idea what to expect, here is shot of /usr/games/hollywood (the program start binary location) on Debian GNU / Linux running, Enjoy! 🙂
 

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Posted in Curious Facts, Educational, Linux, Linux and FreeBSD Desktop | No Comments »

How to list and exclude table names from a database in MySQL (exclude table names from an show tables in MySQL) by using information_schema

Wednesday, March 30th, 2011

Listing all table names from a MySQL database is a very easy and trivial task that every sql or system administrator out there is aware of.

However excluding certain table names from a whole list of tables belonging to a database is not that commonly used and therefore I believe many people have no clue how to do it when they have to.

Today for one of my sql backup scripts it was necessary that certain tables from a database to be excluded from the whole list of tables for a database I’m backupping.
My example database has the sample name exampledatabase and usually I do list all the table contents from that database with the well known command:

mysql> SHOW tables from exampledatabase;

However as my desire was to exclude certain tables from the list (preferrably with a certain SQL query) I had to ask around in irc.freenode.net for some hints on a ways to achieve my exclude table goals.

I was adviced by some people in #mysql that what I need to achieve my goal is the information_schema mysql structure, which is available since MySQL version 5.0.

After a bit of look around in the information_schema and the respective documentation on mysql.com, thanksfully I could comprehend the idea behind the information_schema, though to be honest the first time I saw the documentation it was completly foggy on how to use this information_schema;
It seems using the information_schema is very easy and is not much different from your normal queries syntax used to do trivial operations in the mysql server.

If you wonder just like I did what is mysql’s information_schema go and use the information_schema database (which I believe is a virtual database that is stored in the system memory).

For instance:

mysql> use information_schema;
Database changed
mysql> show tables
+---------------------------------------+
| Tables_in_information_schema |
+---------------------------------------+
| CHARACTER_SETS |
| COLLATIONS |
| COLLATION_CHARACTER_SET_APPLICABILITY |
| COLUMNS |
| COLUMN_PRIVILEGES |
| KEY_COLUMN_USAGE |
| PROFILING |
| ROUTINES |
| SCHEMATA |
| SCHEMA_PRIVILEGES |
| STATISTICS |
| TABLES |
| TABLE_CONSTRAINTS |
| TABLE_PRIVILEGES |
| TRIGGERS |
| USER_PRIVILEGES |
| VIEWS |
+---------------------------------------+
17 rows in set (0.00 sec)

To get a general view on what each of the tables in the information_schema database contains I used the normal SELECT command for example

mysql> select * from TABLES limit 10;

I used the limit clause in order to prevent being overfilled with data, where I could still see the table fields name to get general and few lines of the table to get an idea what kind of information the TABLES table contains.

If you haven’t got any ecperience with using the information_schema I would advice you do follow my example select and look around through all the listed tables in the information_schema database

That will also give you a few hints about the exact way the MySQL works and comprehends it’s contained data structures.

In short information_schema virtual database and it’s existing tables provides a very thorough information and if you’re an SQL admin you certainly want to look over it every now and then.

A bit of playing with it lead me to a command which is actually a good substitute for the normal SHOW TABLES; mysql command.
To achieve a SHOW TABLES from exampledatabase via the information_schema info structure you can for example issue:

select TABLE_NAME from TABLES where TABLE_SCHEMA='exampledatabase';

Now as I’ve said a few words about information_schema let me go back to the main topic of this small article, which is How to exclude table names from a SHOW tables list

Here is how exclude a number of tables from a complete list of tables belonging to a database:

select TABLE_NAME from TABLES where TABLE_SCHEMA='exampledatabase'
AND TABLE_NAME not in
('mysql_table1_to_exlude_from_list', 'mysql_table2_to_exclude_from_list', 'table3_to_exclude');

In this example the above mysql command will list all the tables content belonging to exampledatabase and instruct the MySQL server not to list the table names with names mysql_table1_to_exlude_from_list, mysql_table2_to_exclude_from_list, table3_to_exclude

If you need to exclude more tables from your mysql table listing just add some more tables after the …’table3_to_exclude’, ‘new_table4_to_exclude’,’etc..’);

Of course this example can easily be adopted to a MySQL backup script which requires the exclusion of certain tables from a backed up database.

An example on how you can use the above table exclude command straight from the bash shell would be:

debian:~# echo "use information_schema; select TABLE_NAME from TABLES where
TABLE_SCHEMA='exampledatabase' AND TABLE_NAME not in
('mysql_table1_to_exlude_from_list', 'mysql_table2_to_exclude_from_list', 'table3_to_exclude',);"
| mysql -u root -p

Now this little bash one-liner can easily be customized to a backup script to create backups of a certain databases with a certain tables (e.g. with excluded number of tables) from the backup.

It’s seriously a pity that by default the mysqldump command does not have an option for a certain tables exclude while making a database dump.
I’ve saw the mysqldump exclude option, being suggested somewhere online as a future feature of mysqldump, I’ve also seen it being reported in the mysql.com’s bug database, I truly hope in the upcoming releases we will see the exclude option to appear as a possible mysqldump argument.
 

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Posted in Linux, MySQL, Programming, System Administration | 2 Comments »

How to clear Squid Proxy Cache on Debian and Ubuntu

Saturday, July 16th, 2011

Squid proxy cache clear logo

It was necessery to clean up some squid cache for some proxy users on a Debian host. Until now I’ve used to run only custom build Squid server on Slackware Linux.

Thus I was curious if Debian guys were smart enough to implement a proxy cache cleaning option as an option to be passed on to squid’s init script.

Honestly I was quite suprised squid clear cache option is not there;

squid-cache:~# /etc/init.d/squid3
Usage: /etc/init.d/squid3 {start|stop|reload|force-reload|restart}
squid-cache:/#

As it was not embedded into init script I still hoped, there might be some Debian way to do the proxy cache clearing, so I spend some 10 minutes checking online as well as checked in squid3‘s manual just to find there is no specific command or Debian accepted way to clean squid’s cache.

Since I couldn’t find any Debian specific, way I did it the old fashioned way 😉 (deleted directory/file structures in /var/spool/squid3/* and used squid’s -z option, to recreate the swap directories.

Here is how:

squid-cache:~# /etc/init.d/squid3 stop;
squid-cache:~# rm -Rf /var/spool/squid3/*;
squid-cache:~# squid3 -z; /etc/init.d/squid3 start

Finally I was quite amazed to realize, there was not even a crontab script to periodically clear and re-create proxy cache.

My previous experience with maintaning an office Squid proxy cache has prooved, that periodic cache clean ups are very helpful, especially to resolve issues with cached unreslovable DNS entries in the server.
Clearing up squid cache every week or something, guarantees that failure to resolve certain hosts at certain times would not stay unresolvable like forever 😉

In that manner of thougths, I decided to put the following crontab which will twice a month clear up proxy’s cache, to possibly solve some failed squid DNS issues.

squid-cache:~# crontab -u root -l > file;
echo '00 04 12,26 * * /etc/init.d/squid3 stop; rm -Rf /var/spool/squid3/*; squid3 -z; /etc/init.d/squid3 start >/dev/null 2>&1'
>> file; crontab file

By the way, implementing the squid clear cache in Debian and Ubuntu ‘s init scripts and putting a periodic proxy clear up cron, seems like a feature worthy to be proposed to the distro developers and hopefully be embbed in some of the upcoming distro releases 😉

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Posted in Linux, System Administration | No Comments »

How to generate user password for digest_pw_auth SQUID digest authentication

Wednesday, July 6th, 2011

Squid Proxy pass prompt / real squid fun picture

I needed to generate new password for proxy user configured on SQUID proxy server configured with digest user authentication.
My dear colleague was kind to provide me with the below script, which generates the one line string which needs to go to the squid user password file:

#!/bin/sh
user="$1";
realm="$2";
pass="$3";
if [ -z "$1" -o -z "$2" -o -z "$3" ] ; then
echo "Usage: $0 user password 'realm'";
exit 1
fi
ha1=$(echo -n "$user:$realm:$pass"|md5sum |cut -f1 -d' ')
echo "$user:$realm:$ha1"

You can alternatively download the squid_generate_pass.sh script here

The script accepts three arguments;
proxy-server:~# ./squid_generate_pass.sh
Usage: ./squid_generate_pass.sh user password 'realm'

Thus to generate a new user and password and insert it immediately into let’s say a squid configured user/pass file in /etc/squid3/users execute command:

proxy-server:~# ./squid_generate_pass.sh admin_user MySecretPassword 'Squid_Configured_Realm'
>> /etc/squid3/users

Where Squid_Configured_Realm depends on the realm name configured in squid.conf, for example if squid.conf includes some auth configuration similar to:

auth_param digest program /usr/lib/squid3/digest_pw_auth -c /etc/squid3/users
auth_param digest children 2
auth_param digest realm My_Proxy_Realm
acl localusers proxy_auth REQUIRED

The realm script argument should be My_Proxy_realm . If squid_generate_pass does completes without errors, it should add a line to /etc/squid3/users file similar to:

proxy-server:~# cat /etc/squid3/users
admin_user:My_Proxy_realm:3bbcb35e505c52a0024ef2e3ab1910b0

Cheers 😉

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