How to download deb packages using apt in Ubuntu and Debian

In Debian-based systems such as Ubuntu, the Advanced Packaging Tool (APT) and apt-get streamline the process of retrieving, installing, and managing .deb packages from official repositories. These utilities automatically resolve and install dependencies, simplifying software deployment for system administrators.

One powerful feature of APT is its ability to download .deb packages without installing them. This method is useful for offline installations or when preparing packages for use in custom scripts and specialized environments.

When the download-only option is used, the requested package and its dependencies are retrieved and placed in the local cache directory without modifying the system. Administrators can then inspect, store, or transfer the downloaded files for installation on the same or other machines.

1. Launch the terminal.
2. Clear the apt cache directory to delete existing package downloads (optional).

   $ sudo apt clean
   [sudo] password for user:

3. Search for the exact package name if unknown (optional).

   $ sudo apt search mysql
   Sorting... Done
   Full Text Search... Done
   akonadi-backend-mysql/hirsute,hirsute 4:20.12.3-0ubuntu1 all
     MySQL storage backend for Akonadi
   
   apophenia-bin/hirsute 1.0+ds-8build1 amd64
     Apophenia Statistical C Library -- binary package
   
   apophenia-doc/hirsute,hirsute 1.0+ds-8build1 all
     Apophenia Statistical C Library -- reference manual
   
   asterisk-mysql/hirsute 1:16.16.1~dfsg-1 amd64
     MySQL database protocol support for the Asterisk PBX
   
   audiolink/hirsute,hirsute 0.05-4 all
     makes managing and searching for music easier
   
   automysqlbackup/hirsute,hirsute 2.6+debian.4-3 all
     daily, weekly and monthly backup for your MySQL database
   
   autopostgresqlbackup/hirsute,hirsute 1.1-1 all
     Automated tool to make periodic backups of PostgreSQL databases
   
   backup-manager/hirsute,hirsute 0.7.14-1.2 all
     command-line backup tool
   
   backupninja/hirsute,hirsute 1.2.1-1 all
     lightweight, extensible meta-backup system
   
   bacula-common-mysql/hirsute 9.6.7-3 amd64
     network backup service - MySQL common files
   
   bacula-director-mysql/hirsute,hirsute 9.6.7-3 all
     network backup service - MySQL storage for Director
   ##### snipped

4. Download the package and its dependencies using apt.

    $ sudo apt --download-only --assume-yes install mysql-server
   Reading package lists... Done
   Building dependency tree... Done
   Reading state information... Done
   The following additional packages will be installed:
     libaio1 libcgi-fast-perl libcgi-pm-perl libevent-core-2.1-7 libevent-pthreads-2.1-7 libfcgi-bin libfcgi-perl libfcgi0ldbl libhtml-template-perl libmecab2 libprotobuf-lite23
     mecab-ipadic mecab-ipadic-utf8 mecab-utils mysql-client-8.0 mysql-client-core-8.0 mysql-common mysql-server-8.0 mysql-server-core-8.0
   Suggested packages:
     libipc-sharedcache-perl mailx tinyca
   The following NEW packages will be installed:
     libaio1 libcgi-fast-perl libcgi-pm-perl libevent-core-2.1-7 libevent-pthreads-2.1-7 libfcgi-bin libfcgi-perl libfcgi0ldbl libhtml-template-perl libmecab2 libprotobuf-lite23
     mecab-ipadic mecab-ipadic-utf8 mecab-utils mysql-client-8.0 mysql-client-core-8.0 mysql-common mysql-server mysql-server-8.0 mysql-server-core-8.0
   0 upgraded, 20 newly installed, 0 to remove and 0 not upgraded.
   Need to get 29.1 MB of archives.
   ##### snipped
   Fetched 29.1 MB in 19s (1,525 kB/s)                                                                                                                                                 
   Download complete and in download only mode

5. Check the downloaded .deb archives in the apt cache folder.

   $ ll /var/cache/apt/archives/
   total 28524
   drwxr-xr-x 3 root root    16384 Ogos 31 10:06 ./
   drwxr-xr-x 3 root root     4096 Ogos 31 10:04 ../
   -rw-r--r-- 1 root root     6972 Mac  23 05:18 libaio1_0.3.112-9ubuntu1_amd64.deb
   -rw-r--r-- 1 root root    10520 Jul  18  2019 libcgi-fast-perl_1%3a2.15-1_all.deb
   -rw-r--r-- 1 root root   186112 Okt  29  2020 libcgi-pm-perl_4.51-1_all.deb
   -rw-r--r-- 1 root root    89368 Jul  12  2020 libevent-core-2.1-7_2.1.12-stable-1_amd64.deb
   -rw-r--r-- 1 root root     7364 Jul  12  2020 libevent-pthreads-2.1-7_2.1.12-stable-1_amd64.deb
   -rw-r--r-- 1 root root    26076 Jan  12  2021 libfcgi0ldbl_2.4.2-2_amd64.deb
   -rw-r--r-- 1 root root    10744 Jan  12  2021 libfcgi-bin_2.4.2-2_amd64.deb
   -rw-r--r-- 1 root root    21604 Jan  31  2021 libfcgi-perl_0.79+ds-2_amd64.deb
   -rw-r--r-- 1 root root    59124 Dis  24  2020 libhtml-template-perl_2.97-1.1_all.deb
   -rw-r--r-- 1 root root   216892 Dis   8  2020 libmecab2_0.996-14build3_amd64.deb
   -rw-r--r-- 1 root root   189840 Mac  29 14:38 libprotobuf-lite23_3.12.4-1ubuntu2_amd64.deb
   -rw-r----- 1 root root        0 Apr  20 18:59 lock
   -rw-r--r-- 1 root root  6717648 Mei  19  2020 mecab-ipadic_2.7.0-20070801+main-3_all.deb
   -rw-r--r-- 1 root root     4384 Mei  19  2020 mecab-ipadic-utf8_2.7.0-20070801+main-3_all.deb
   -rw-r--r-- 1 root root     4916 Dis   8  2020 mecab-utils_0.996-14build3_amd64.deb
   -rw-r--r-- 1 root root    22016 Jul  26 22:25 mysql-client-8.0_8.0.26-0ubuntu0.21.04.3_amd64.deb
   -rw-r--r-- 1 root root  3918928 Jul  26 22:25 mysql-client-core-8.0_8.0.26-0ubuntu0.21.04.3_amd64.deb
   -rw-r--r-- 1 root root     7496 Ogos 23  2019 mysql-common_5.8+1.0.5ubuntu2_all.deb
   -rw-r--r-- 1 root root     9536 Jul  26 22:25 mysql-server_8.0.26-0ubuntu0.21.04.3_all.deb
   -rw-r--r-- 1 root root  1423236 Jul  26 22:25 mysql-server-8.0_8.0.26-0ubuntu0.21.04.3_amd64.deb
   -rw-r--r-- 1 root root 16211156 Jul  26 22:25 mysql-server-core-8.0_8.0.26-0ubuntu0.21.04.3_amd64.deb
   drwx------ 2 _apt root     4096 Ogos 31 10:06 partial/