Shell linter evaluation and usage

Tomorrow, the 1st of August is a national holiday in Switzerland … So I do one day off and have some time. For a long time I wanted to deal with Shell lint. After some research, i found a few open-source tools. By the way … linters are being written for many programming languages and document formats.


For evaluation i will not install the tools on my local system,… so Vagrant (with CentOS 7) is my choice.

Note: I created the Vagrant box “lupin/centos” via Packer … here my GitHub repository.

Shell option -n

Many shell’s already offer a very simple script analysis. The option -n read commands in script, but do not execute them (syntax check).

Okay … but not really what I want… (more details are welcome)

shlint and checkbashisms

I found the repository here.

Note: for both tools you should change the shebang to “#!/bin/sh”

For shlint… I don’t get it. For checkbashisms … good if will write portable Shell scripts.


I found it here on Pypi.

Nice … but not really all Standards.


Shellcheck is known! Here the online service and here the repository.

I stay with that tool. Currently there are packages for almost every known OS.


Who knows me … knows that I do not like Installer and prefer Docker use. Here’s some fun.

😉 just for fun…

Docker, Telegraf, InfluxDB and Grafana

I have already presented various tutorials on docker monitoring. This time we will use Telegraf.

Project preparation

InfluxDB preparation

Telegraf preparation

… Read more about Telegraf on documentation page …

Note: The space after /etc is just because of security settings of my provider.

… after short time …

Grafana preparation

After login (admin:admin) you can add new Data Source.

Grafana InfluxDB Telegraf DataSource

Okay … all done … you can start to create Dashboards or search for existing Dashboards for import.

Penetration testing report via Serpico

Penetration testing make fun but writing penetration testing reports is boring. When you start you will look for templates or software which supports you. Here comes Serpico into the game. Serpico is a collaboration and report generation tool. The best… it is open-source.

Usage via Docker

Now you can use Serpico in your favorite browser…

Login with created credentials (admin/test123) and create your reports. On Youtube is a good introduction. If you don’t have Microsoft Words installed, you can view your reports online.


Open Source GUI tools for macOS

Tiny list for Open Source GUI tools for macOS to increase productivity…






Package Manager







Docker, cAdvisor, InfluxDB and Grafana

In previous tutorials I showed the basics for docker monitoring with Prometheus and Jenkins. Here are now the basics with cAdvisor. Many steps are similar and can be implemented just as quickly.


InfluxDB preparation

This time we start with InfluxDB, because cAdvisor needs it for connection!

cAdvisor preparation

Now we will use User, Password and Database name. You can find the documentation here.

After a while we can also see if cAdvisor sends metrics to InfluxDB.

prepare and run Grafana

After login (admin:admin) configure new DataSource for InfluxDB.

DataSource InfluxDB

When DataSource is configured we import the Grafana Dashboard. (ID: 1367)

Dashboard Search cAdvisor

… be patient (don’t press any button) …

Import cAdvisor Dashboard

Select already created DataSource (InfluxDB) and press “Import” button. Now you should see the Grafana Dashboard.

macOS, Docker, Prometheus and Grafana

I like Grafana … the dashboards are just cool! Here (again) a tutorial about docker monitoring. In less minutes you should be done. As a comment … for Linux and Windows you can do that too! There are only partial changes.

Prepare Project

Replace <yourLocalIP> with your IP. On Docker website you can find templates for Linux and Windows, too!

Configure Docker

This step is very easy. Just open Docker “Preferences” and specify in section “Daemon” -> “Advanced” the metrics-address. Just ensure that you use valid JSON!

macOS Docker Metrics

When you are done, press “Apply and Restart” button.

Prepare Prometheus

Note: The space after /etc is just because of security settings of my provider! Please remove the space.

prometheus WebUI

Just for fun you can create already some graphs in Prometheus.

prometheus Graph

Prepare and run Grafana

After login (admin:admin) configure new DataSource for Prometheus.

Grafana DataSource Prometheus

Import Dashboard (ID: 1229)

Grafana Import Dashboard

… enter ID 1229 …

Grafana Dashboard Search

… be patient (don’t press any button) …

Docker Engine Metrics Dashboard

Select already created DataSource (Prometheus) and press “Import” button. Now you should see the awesome Grafana Dashboard.

macOS ScreenShots

I know there are already a lot of tutorials for this topic, but partly incomplete or no longer up to date. That’s why I’m trying now, since software testers create very often screenshots. 😉


The first possibility is the … here you can easily select with the mouse what you want to do. ScreenShots

via Keyboard

The next possibility are shortcuts. Here you don’t need to start!

Capture the entire screen

[Shift] + [Command] + [3]

Capture via specific selection

[Shift] + [Command] + [4]

Capture window/menu

[Shift] + [Command] + [4]

here you can press [Space] to toggle

Capture the current Touch Bar

[Shift] + [Command] + [6]

For save to clipboard press [Control] on all actions.

via Terminal

Note: please see man-pages – here you find more options!

ScreenShot Settings

Jenkins, InfluxDB and Grafana

Today an basic introduction to Jenkins, InfluxDB and Grafana. Docker is used to save some time. Okay,… let’s start.


Jenkins preparation

Now open your favorite browser with URL http://localhost:8080 and unlook Jenkins with following steps.

unlook jenkins

  1. unlook with password from cli
  2. install suggested plugins
  3. create your admin user
  4. start using jenkins

Next, the InfluxDB plug-in must be installed.

influxdb plugin jenkins

InfluxDB preparation

Connect Jenkins with InfluxDB

Add new InfluxDB target on Jenkins

jenkins influxdb settings

Save and create a new freestyle job. For example with following configuration.

jenkins job influxdb

When you are done, run the job.

Add Grafana

Open you browser with URL http://localhost:3000, login with credentials (admin/admin) and add a new InfluxDB data source.

grafana data source

From now on, you can create and share dashboards in Grafana, which shows all Jenkins metrics.