itsthenetwork/alpine-ncat repository overview

A handy basic image comprising of;

• Alpine Linux⁠ v3.8.1. A security-oriented, lightweight Linux distribution based on musl libc⁠ and BusyBox⁠.
• nmap-ncat⁠ v7.70. A network exploration tool and security/port scanner.

For previous version 1:

• Alpine v3.6 (containing this vulnerability: https://justi.cz/security/2018/09/13/alpine-apk-rce.html⁠)
• nmap-ncat v7.40

⁠Usage

I'd expect you use this image as a simple network connectivity testing tool.

⁠Pulling

Use this command to pull the image manually before runtime:

sudo docker pull itsthenetwork/alpine-ncat:latest

⁠Runtime

This command will start the container interactively and attempt to open a connection to google.com on port 443. The container will be automatically removed when the command completes.

sudo docker run -it --rm itsthenetwork/alpine-ncat -vz -w1 google.com 443

Success might look like this:

Ncat: Version 7.40 ( https://nmap.org/ncat ) Ncat: Connected to 209.85.202.101:443. Ncat: 0 bytes sent, 0 bytes received in 0.02 seconds.

If you expect to use this image often, perhaps use some aliases at the CLI or in your ~/.bashrc file:

alias nc="ncat" alias ncat="sudo docker run -it --rm itsthenetwork/alpine-ncat"

⁠Dockerfile

You'll find the Dockerfile used to build this image at the root of the file system. Here it is anyway:

FROM alpine:latest
MAINTAINER Steven Iveson <[email protected]>
LABEL maintainer "Steven Iveson <[email protected]>"
COPY Dockerfile /

RUN apk add --no-cache --update --verbose grep bash nmap-ncat && \
    rm -rf /var/cache/apk/* /tmp/* /sbin/halt /sbin/poweroff /sbin/reboot

ENTRYPOINT ["/usr/bin/ncat"]

⁠Additional Packages

If you wanted to install additional packages and build your own image based upon this one you'd start your Dockerfile like this:

FROM itsthenetwork/alpine-ncat:latest

RUN apk -add U -v package_name package_name

...