Category: Debian

  • Ubuntu show package information

    To see information about a package, run

    apt-cache showpkg PKG_NAME

  • Ubuntu find Dependencies for a package

    To find dependencies for a package, run

    apt-cache depends PACKAGE_NAME

    Example

    root@ubuntu-s-4vcpu-8gb-nyc1-01:~# apt-cache depends php7.2
php7.2
 |Depends: libapache2-mod-php7.2
 |Depends: php7.2-fpm
  Depends: php7.2-cgi
  Depends: php7.2-common
root@ubuntu-s-4vcpu-8gb-nyc1-01:~#

    In above example, when you install php7.2, it install “libapache2-mod-php7.2”, that will install Apache web server. I had a server with ngtinx, when i install php7.2 package, apache get installed.

    You can also use

    apt depends PACKAGE_NAME

    To find reverse dependency, run

    apt-cache rdepends PACKAGE_NAME

    apt-cache
    apt

  • gpg: failed to start the dirmngr

    When i add a key with apt-key command, i get error

    root@ip-172-31-47-128:~# apt-key adv –recv-keys –keyserver keys.gnupg.net E1F958385BFE2B6E
    Executing: /tmp/apt-key-gpghome.0BP6Ro2t54/gpg.1.sh –recv-keys –keyserver keys.gnupg.net E1F958385BFE2B6E
    gpg: failed to start the dirmngr ‘/usr/bin/dirmngr’: No such file or directory
    gpg: connecting dirmngr at ‘/tmp/apt-key-gpghome.0BP6Ro2t54/S.dirmngr’ failed: No such file or directory
    gpg: keyserver receive failed: No dirmngr
    root@ip-172-31-47-128:~#

    To fix this, run

    apt -y install dirmngr

    Once installed, apt-key command worked properly.

    root@ip-172-31-47-128:~# apt-key adv –recv-keys –keyserver keys.gnupg.net E1F958385BFE2B6E
    Executing: /tmp/apt-key-gpghome.BLNQkuFGIQ/gpg.1.sh –recv-keys –keyserver keys.gnupg.net E1F958385BFE2B6E
    gpg: key E1F958385BFE2B6E: public key “X2go Debian/Ubuntu Packaging ” imported
    gpg: Total number processed: 1
    gpg: imported: 1
    root@ip-172-31-47-128:~#

    See Install x2go server in Debian 9

  • Install Remote Desktop in Debian/Ubuntu

    To install and use Linux remote server as desktop, first install lite weight desktop environment like XFCE on your server.

    apt update
apt install xfce4 -y

    Install XRDP

    apt install xrdp

    You need to create a user to be used for desktop.

    useradd -m -s /bin/bash desktop

    Set password for the user

    passwd desktop

    Now login as this user and create .xsession file.

    su - desktop
echo xfce4-session >~/.xsession

    Exit out of this user 

    exit

    Restart XRDP

    service xrdp restart

    Now you will be able to connect to this server with any RDP client like you connect to Windows Server (Windows Remote Desktop).

  • Debian

    When I install Debian 9 from CD, it did install with /etc/apt/sources.list pointing to CD.

    To get this work properly, you need to edit the file 

    vi /etc/apt/sources.list

    Replace content with

    deb http://security.debian.org/ stretch/updates main
deb-src http://security.debian.org/ stretch/updates main
deb http://ftp.debian.org/debian/ stretch-updates main
deb-src http://ftp.debian.org/debian/ stretch-updates main
deb http://ftp.us.debian.org/debian stable main contrib non-free

    Debian Upgrade

  • Install Monit on Ubuntu

    Install Monit on Ubuntu

    Monit can be used to monitor services, restart them if required. To install monit, run

    apt -y install monit

    To start monit, run

    systemctl start monit

    Monitor Apache

    vi /etc/monit/conf-available/apache2-custom

    Add

    check process apache with pidfile /var/run/apache2/apache2.pid
    group www-data
    start program = "/etc/init.d/apache2 start"
    stop program  = "/etc/init.d/apache2 stop"
    if failed host localhost port 80 protocol http then restart
    if 5 restarts within 5 cycles then timeout

    Activate the rule with

    ln -s /etc/monit/conf-available/apache2-custom /etc/monit/conf-enabled/apache2-custom

    Restart monit with

    systemctl restart monit

    Testing If Monit works

    Open 2 terminals. On one, tail the monit logs with

    tail -f /var/log/monit.log

    On other terminal, stop Apache

    service apache2 stop

    Within 2 minutes, monit will restart apache web server.

    monit

  • Install ionCube on Debian 9

    Install ionCube on Debian 9

    Download latest version of ionCube loader from

    cd /usr/local/src
wget https://downloads.ioncube.com/loader_downloads/ioncube_loaders_lin_x86-64.tar.gz
tar xvf ioncube_loaders_lin_x86-64.tar.gz
cd ioncube/

    Check PHP version with

    php -v

    On Debian 9, default will be PHP 7.0, so you need to use file ioncube_loader_lin_7.0.so

    Find PHP extension_dir, this is where you need to put PHP extensions.

    root@ip-172-31-44-173:/usr/local/src/ioncube# php -i | grep  extension_dir
extension_dir => /usr/lib/php/20151012 => /usr/lib/php/20151012
root@ip-172-31-44-173:/usr/local/src/ioncube#

    Copy the file to extension directory

    cp /usr/local/src/ioncube/ioncube_loader_lin_7.0.so /usr/lib/php/20151012

    Enable ionCube loader with

    echo "zend_extension=ioncube_loader_lin_7.0.so" > /etc/php/7.0/mods-available/ioncube.ini
ln -s /etc/php/7.0/mods-available/ioncube.ini /etc/php/7.0/cli/conf.d/01-ioncube.ini
ln -s /etc/php/7.0/mods-available/ioncube.ini /etc/php/7.0/apache2/conf.d/01-ioncube.ini

    Now php -m will show ioncube

    root@ip-172-31-44-173:~# php -m | grep ion
ionCube Loader
Reflection
session
the ionCube PHP Loader (enabled) + Intrusion Protection from ioncube24.com (unconfigured)
root@ip-172-31-44-173:~#

    Restart apache

    service apache2 restart

    ioncube | ionCube on Debian 8

  • Install GeoIP PHP Module in Ubuntu

    To install GeoIP php module in Ubuntu, run

    apt install php-geoip

    To enable module, run

    phpenmod geoip

    You can see the PHP module with command php -m

    root@ip-172-31-26-233:~# php -m | grep geoip
geoip
root@ip-172-31-26-233:~#

    Also it will be listed in phpinfo page.

    geoip

  • Install pureftpd on Ubuntu

    To install pure-ftpd on Ubuntu, run

    apt install pure-ftpd -y

    Create a system user

    useradd -d /var/www -s /bin/bash USERNAME
chown -R USERNAME:USERNAME /var/www
passwd USERNAME

    Enable Unix Authentication

    To allow system user to login using FTP, edit file

    vi /etc/pure-ftpd/pure-ftpd.conf

    Uncomment the line

    UnixAuthentication           yes

    Or

    echo 'yes' > /etc/pure-ftpd/conf/UnixAuthentication

    On Ubuntu, after default install, you have following settins.

    root@server:/etc/pure-ftpd/auth# ll
total 8
drwxr-xr-x 2 root root 4096 Jan 28 05:52 ./
drwxr-xr-x 5 root root 4096 Jan 28 06:20 ../
lrwxrwxrwx 1 root root   26 Feb  5  2018 65unix -> ../conf/UnixAuthentication
lrwxrwxrwx 1 root root   25 Feb  5  2018 70pam -> ../conf/PAMAuthentication
root@server:~# cat /etc/pure-ftpd/auth/65unix 
no
root@server:~# cat /etc/pure-ftpd/auth/70pam 
yes
root@server:~#

    PAMAuthentication enabled. UnixAutehticiation disabled. This allow system users to login using PAM.

    pureftpd

  • Reinstall a package using apt

    To reinstall a package, run

    apt install --reinstall PKG_NAME

    Example

    apt reinstall

    dpkg apt

  • dpkg

    To force delete a package, run

    dpkg --purge --force-depends PKG_NAME

    List all Installed packages

    dpkg -l

    List all files in a package

    dpkg -L PKG_NAME

    To find which package provides a file

    dpkg -S /usr/bin/nmap

    Apt