Alpine Linux is a security-oriented, lightweight Linux distribution based on musl libc and busybox. It is an operating system designed for use with microservices. Its security, simplicity, and resource efficiency has been a catalyst in its adoption. The base OS is minimal with few packages only required to boot the system.
In this guide. I’ll show you how to install Telnet on Alpine Linux. This article has been written with the assumption that you already have a running Alpine Linux system. You can confirm telnet is not available on Alpine Linux by default.
/ # telnet /bin/sh: telnet: not found
As of Alpine Linux version 3.7, the telnet package was moved into busybox-extras subpackage.
Install Telnet on Alpine Linux
Update the system for busybox-extras subpackage to be visible.
/ # apk update fetch http://dl-cdn.alpinelinux.org/alpine/v3.9/main/x86_64/APKINDEX.tar.gz ERROR: http://dl-cdn.alpinelinux.org/alpine/v3.9/main: network error (check Internet connection and firewall) fetch http://dl-cdn.alpinelinux.org/alpine/v3.9/community/x86_64/APKINDEX.tar.gz v3.9.6-16-ged6fdd587d [http://dl-cdn.alpinelinux.org/alpine/v3.9/main] v3.9.6-13-gfbfc29c6a0 [http://dl-cdn.alpinelinux.org/alpine/v3.9/community] 1 errors; 9781 distinct packages available
Install Telnet on Alpine Linux through busybox-extras package:
# apk add busybox-extras (1/1) Installing busybox-extras (1.29.3-r10) Executing busybox-extras-1.29.3-r10.post-install Executing busybox-1.29.3-r10.trigger OK: 21 MiB in 31 packages
Check if telnet command is now available on Alpine Linux.
/ # telnet BusyBox v1.29.3 (2019-01-24 07:45:27 UTC) multi-call binary. Usage: telnet [-a] [-l USER] HOST [PORT] Connect to telnet server -a Automatic login with $USER variable -l USER Automatic login as USER
Enjoy using Telnet to test connectivity on Alpine Linux.
busybox-extras telnet 172.21.200.10 80