Philipp Neugebauer's blog

Backup Strategies

Sun, 20 Dec 2020 05:00:33 +0000

2020 with its craziness gave me time think about and to revise my backup setup. I started several years ago with SVN repositories to store and share my sensible data across several machines and added at some point after switching to macOS Time Machine with an external drive. This setup annoyed me a lot since I always needed to grab my drive and these rare backups then took so long that it annoyed me even more. All in all, my strategy wasn’t as sophisticated as I wanted it to be.

I’ve now added Duplicati and Kopia backing up my sensible data encrypted to several cloud providers like Dropbox and Wasabi. This makes me independent from a specific cloud and also backup tool provider and allowed me to avoid a single point of failure.

In addition to the cloud backups, I also bought a Raspberry Pi, connected my old SSDs via USB to it and set up a Time Machine endpoint with netatalk as well as a simple SFTP server for local backups of Duplicati and Kopia.

In detail, the setup of tools on the Pi is described in the following blog posts: https://jeremycollins.net/using-a-raspberry-pi-as-a-nas-mac-os-time-machine-2020-edition https://gist.github.com/jhanzo/f1df54b303307c5a6350de0ca3abd5af https://linuxconfig.org/how-to-setup-sftp-server-on-ubuntu-20-04-focal-fossa-linux https://www.digitalocean.com/community/tutorials/how-to-set-up-vsftpd-for-a-user-s-directory-on-ubuntu-18-04

Furthermore, I deactivated the automated backups from Time Machine and use the Time Machine Editor to ensure weekly backups.

To properly use the Raspberry Pi with the connected drives, I needed to buy a USB hub since the Pi itself couldn’t power all of them.

Sicher(er) im Neuland unterwegs

Thu, 03 Dec 2020 16:54:33 +0000

Da der Post auch für Verwandtschaft und Freunde gedacht ist, ausnahmsweise mal auf Deutsch.

Absolute Pflicht ist ein Passwortmanager, vorzugsweise mit Backup im Internet, damit man auch bei Rechnerverlust noch an die Daten herankommt. Eine App sollte dabei sein, damit man ihn auch am Handy nutzen kann. Dafür gibt es vermutlich 1000 Services im Internet mit vermutlich genauso vielen Vergleichen. Oftmals gibt es dazu eingeschränkte, kostenlose Angebote, die aber vermutlich für die meisten ausreichend sind. Da die Daten verschlüsselt sind, hat der Anbieter normalerweise keinen Zugriff auf die Daten, die damit auch sicher sind. Die größten Anbieter sind wohl Lastpass und 1Password. Ich nutze enpass, weil ich dort selbst unter Kontrolle habe, wo ich meine Daten speichere und der Services mich nicht einfach aussperren kann. Erfordert dafür aber ein paar mehr Technikkenntnisse. Bei den großen Services ist dieses Risiko aber eher minimal.

Zusätzlich kann man noch auf 2-Faktor-Authentifizierung setzen. Das bedeutet, neben Username und Passwort braucht man noch einen weiteren Input, um sich anmelden zu können, so dass der gestohlene Username und das Password doch nicht ausreichen, um Unfug anrichten zu können. Ich habe dazu einen YubiKey gekauft, der aber nicht immer unterstützt wird. Er ist aber dann sehr bequem. Als Backup/Alternative nutze ich die Smartphone-App Authy, die ich auch am Laptop nutzen kann. Das dauernde Suchen nach dem Handy ging mir sehr schnell auf den Geist, weil es halt doch immer gerade da liegt, wo man selbst nicht ist. Aber auch hier gibt es andere Alternativen wie die Authenticator von Microsoft, Google oder eben Lastpass, die das zusätzlich zum Passwortmanager auch anbieten. Sinnvoll ist es darauf zu achten, dass man die Daten im Verlustfall des Handys wiederherstellen kann, da man sich ansonsten aus seinen Diensten ausschließen könnte.

Des Weiteren bietet es sich an, ein vernünftig gesichertes Postfach zuzulegen und eben keine kostenlosen Services zu nutzen. Da diese auch Geld verdienen müssen, bezahlt man im Zweifel mit den Daten, die bspw. automatisiert analysiert werden, um passende Werbung einblenden zu können. Solche Dienste kosten in der Regel nur einen geringen Obolus (ca. 1€/Monat). Ich selbst nutze mailbox.org, Alternativen wären beispielsweise posteo, ProtonMail und runbox. Generell schadet es nicht, Services zu vermeiden, die in den USA ansässig sind.

Zu guter Letzt sinnvoll ist es die eigene Festplatte zu verschlüsseln. Damit schützt man die eigenen Dateien vor unbefugtem Zugriff. Unter Windows geht das folgendermaßen.

Sqlite3 Gem Installation with self Compiled Binaries

Mon, 04 Jul 2016 19:53:33 +0000

The hardest problem to solve by using a new version of Ruby for Rails on Windows had always been the absence of precompiled binaries for the sqlite3 gem. Since there exist many solutions which did not work out on my environments, I present the working solution which I successfully applied.

First, you need to download sqlite-autoconf-xxx.tar.gz and sqlite-dll-winyy-xyy-xxx.zip from sqlite.org. In the second step, you extract both files to the same directory on your system but you also need to copy the dll files to a folder contained by your system $path. Next, you open a linux terminal in your sqlite folder, e.g. the msys.bat in your DevKit folder. Then, you execute the three following commands which compile the sqlite3 code:

./configure
make
make install

After the successful compilation, you can install your sqlite3 gem whereby path represents the binary folder:

gem install sqlite3 --platform=ruby -- --with-sqlite3-include=path --with-sqlite3-lib=path --with-sqlite3-dir=path

Errors

If you get a checking for sqlite3_libversion_number() in -lsqlite3... no error, you need to add --with-sqlite3-dir=path to gem installation command.

If you receive a checking for sqlite3.h... no error, then your pointed path does not include the binaries of sqlite.

Sources: GitHub StackOverflow

Useful Tools for Writing a Thesis with LaTeX

Sat, 30 Jan 2016 11:21:27 +0000

This post presents and highlights useful and probably important tools for writing a thesis with LaTeX. The tools are categorized in the following to allow the simple finding of appropriate tools for your thesis. In general, the posts explains only existing methods from other authors so that I also reference my sources.

MISQ Style

First, I needed to adopt the style of MISQ for my thesis. Luckily, Ryan Schützler created a wonderful template for the easy adoption. This template requires the usage of biber instead of bibtex for the bibliography management. biber enables simple changes of citation styles and reuses the bibtex infrastructure so that only slight changes must be conducted. In detail, [1] presents biber and the different citation styles. [2] provides a great overview on the different bibtex styles which I found very helpful when they were missing.

Font Change

I never liked the default font style of LaTeX and even a particular font was prescribed for my thesis. Unfortunately, font change handling can be quite complex since many side-effects must be considered. Depending on the used font type, the math support may need to be reenabled.

\usepackage{helvet}
\usepackage[eulergreek]{sansmath}

When you are using the tikz package, you also need to change its default font [3]:

\renewcommand{\familydefault}{\sfdefault}

Furthermore, the url font must be adapted [4]:

\urlstyle{\sfdefault}

Booktabs

Although many people consider the creation of tables simple, many mistakes can be done, even though the look of tables can be easily improved. The booktabs package for LaTeX is a good and simple way for improving the look, understanding and speed of information adoption. I found a great guide from Markus Püschel with further and detailled information. Restrictively, dashed separation lines were considered as appropriate, but they shouldn’t be realized with the arydshline package. It introduces problems with the booktabs package [5], seems to break their space alignment [6] and even the loading of the package can lead to compilation errors [8]. On the downside, alternative colored rows for a better row separation are harder to implement with booktabs. Considering these instructions [1], my LaTeX table code is presented in the following:

General Table Look Improvements

This paragraph presents various possibilities to enhance the looking of LaTeX tables. First, too long table captions are by default poorly rendered which can be resolved through the using of the caption package [7]:

\usepackage[justification=centering]{caption}

Secondly, very long booktabs tables can be improved with the alternative coloring of rows (guide), which is easily implemented through the rowcolors command and a color package [4].

\rowcolors{<starting row index>}{<odd row color>}{<even row color>}

On the downside, the alternative row coloring only colors the rows, so that a workaround is required to color the space between the last row and the end line of the table. This is solved by [8] which changes the settings of the default booktabs table rules:

Furthermore, booktabs requires another solution for the size adjustment of colored rows because it removes the trailing space of the rows at the beginning and end. This can be fixed through kern [9]:

\begin{tabular}{>{\kern-\tabcolsep}*{x}{>$c<$}<{\kern-\tabcolsep}}

Next, multirows requires the alignment of single lines through optional parameters [10]:

\multirow{2}[3]{*}{Sample}

Thereby, also cmidrule has an optional aligning parameter which you should use:

\cmidrule(lr)

The longtable environment introduced the problem of bad caption spacing which can be resolved by using the caption package [11].

\usepackage{caption}
\captionsetup[longtable]{skip=1em}

If you need a vertical longtable environment, employ the pdflscape package [12].

\usepackage{pdflscape}
...
\begin{landscape}
\begin{longtable}
...
\end{longtable}
\end{landscape}

Lastly, the cmidrule needs an adaption if you have a very long table header, so that the content is centered below and looks good [13].

Tikz Diagrams

Using tikz is a great oppurtunity to include good-looking diagrams into your LaTeX document. Saying that, a few settings can improve the look even more. The alignment of associated values can be enhanced by appending them [14]: every node near coord/.append style={font=\tiny}

Another simple upgrade is the avoidance of exponents in the axis labeling [15]:

scaled ticks=false,xticklabel style={/pgf/number format/fixed,/pgf/number format/precision=4}

Regarding these two fixes, my final design of bars was also influenced by these described designs and their code ([16], [17], [18]). The next listing presents my bar chart design.

PDF Compilation Speedup

After approaching the look enhancement, this paragraph lists the speed up opportunities for the compilation step.

Although the application of tikz provides nice features, a special adaption is required to improve its performance. The externalization of such diagrams is a possibility and can be realized with the following settings according to its documentation [19, Section 50.4].

\usetikzlibrary{external}
\tikzexternalize

Furthermore, the compilation process commands must be adapted:

pdflatex -shell-escape

Since that’s only a very simple example, a setup for big files with a lot of diagrams is preferable. [20] suggests it:

\tikzexternalize[prefix=figures/]

\tikzsetnextfilename{diagram1}
\begin{tikzpicture}
...
\end{tikzpicture}

Another chance is enabled by the right selection of the data type and its settings. [21] presents and evaluates that:

Photos: Use the JPG format and crop it to the size and viewport your need using an image processing program, e.g. Gimp or Photoshop. DO NOT use JPG for anything else, it is really just thought for photos. It can handle other stuff as well but not as good as other formats.

Screenshoots and other Artificial Pixel-graphics: Use PNG format and again crop it to the size and viewport needed. The PNG format is lossless, i.e. doesn't create artifacts like JPG. Its compresses this kind of images well.

Diagrams, Pictures and other Vector-graphics: Should really be included as vector-graphics and not as pixel-graphics (and if so NOT as JPG!). You should export them as PDF or EPS which is then converted to PDF
(e.g. epstopdf). Extra whitespace from margins etc. can be removed by pdfcrop.

Beside that, the compilation command setup of LaTeX can be further improved [22]. Since three compilation executions are in general recommended, the first two executions can be conducted without regarding pictures through -draftmode:

pdflatex -draftmode file

The split-up of documents in subdocuments and their isolated compilation enables as well as the avoidance of the input command a further performance boost [23]. Also other compilation setups like pdflatex -interaction=batchmode are considered to enhance the compilation time [24]. The syntonly package [25] and a precompiled preamble accelerate the speed as well [26], but I haven’t utilized them in my thesis. In general, use as few packages as possible and only include required packages because useless packages can slow down the compilation or cause problems!

Code Listing Formatting

Since I was studying computer science, code was an essential part of my thesis. You can take advantage of the listings package to present it. [27] gives a good overview and [28] presents a good code design. In general, breakatwhitespace=true and a small tabsize=x must be recommended since the space is limited for documents.

I used the following code listing settings for my thesis:

Miscellaneous Simple Improvements

The last paragraph describes various simple enhancements for your thesis. If you want to change the colors of your hyperlinks, e.g. to improve the readability, you just need to apply different settings [29].

\usepackage[colorlinks, urlcolor=black, linkcolor=black, filecolor=black, citecolor=black]{hyperref}

To enhance the look of footnote cites and to indent more line citations, LaTeX settings must be overridden [24]:

\makeatletter
\renewcommand\@makefntext[1]{\leftskip=2em\hskip-2em\@makefnmark#1}
\makeatother

Moreover, the pifont package provides nice looking Xs and ticks [30]. Thanks to croeck for the tip! If you need to have a footnote at different places and to avoid duplicates,footnotemark can help you out [31]. Line breaks in footnotes can be resolved for urls by usepackage[hyphens]{url} [32]. Additionally, the depth of chapter levels and their display in the table of content can be set by setcounter{secnumdepth}{x} and setcounter{tocdepth}{x} [33]. Furthermore, spacing between values and units is simply realized by [34]:

\newcommand{\unit}[2]{#1$\mskip3mu$#2}

Tables can be a pain in the ass in LaTeX, but there are tools for a better table handling [35]. I used Lyx and it was absolutely fine with me.

Do you know missing essential packages others should consider? Just drop a comment and start the discussion :)

Comparison of SmartGit and SourceTree (UPDATE 29.01.2016)

Wed, 16 Dec 2015 22:49:18 +0000

This blog post approaches the comparison of the git gui tools SmartGit 7.0.3 and SourceTree 1.6.23.0 on Windows. I mostly use the command line for simple stuff, but I prefer gui tools for file merging and the faster separation of commits through git add -p. The comparison of both tools is divided into different categories to better highlight each’s advantages and disadvantages and represented in the following table.

UPDATE 29.01.2016: Bad hunk button accessibility for big changes in SourceTree!

	SmartGit	SourceTree
Text Comparison	character by character	line by line, does not always work
Binary Documents	no support	content and diffs of pdfs and office documents are displayed
		buttons for fast file opening
License	commercial: fee-based	free of charge, registration required
Language	english	system language
Hunk Selection	no selection of lines by cursor	selection of lines by cursor
	sometimes no fine-granular hunk selection	bad recognition of hunks and no intuitive right-clicks
Merging	visualization and comparison	only whole file is displayed like in git
	of different file states	console
Miscellaneous		wants to change git settings
		cannot consistently handle umlauts
		big files or changes require a lot of scrolling and therefore cause a bad accessibility of the hunk handling buttons

The code to demonstrate my findings is published in this GitHub repository.

Since both tools have their pros and cons, there is no best tool which outperforms the other tool. In consequence, you should select the best fitting tool based on my findings and your impression. A free license in a commercial environment leads to the selection of SourceTree, while an important support for text change displays favors the application of SmartGit.

Do you know other important factors I didn’t consider? Do some points need to be clarified?

New Version of MarkAverageComputer Published

Sun, 09 Aug 2015 00:01:20 +0000

In addition to the development on the simple_controller gem, I published version v2.2 of my mark average computer. It supports now the CTRL+S shortcut for saving and visualizes the mark average development during your studies. Further, I simplified and improved the code to allow an easier maintaining.

Finally, I plan to publish the code as open source when the code refactoring is completed. The jar can be found here and further instructions and details are available here.

New Version of SimpleController Published

Sat, 08 Aug 2015 23:53:30 +0000

Today, I was able to publish version 0.1.0 of my simple_controller gem. It supports now module names in the controllers and includes fixes for the path redirecting problem. Additionally, I resolved the problem with the code coverage and therefore Code Climate confirms now a great coverage of 96%.

Have a look at it.

Git Windows Path Problem

Wed, 08 Apr 2015 22:45:14 +0000

Not the first time I ran in the problem that the .ssh folder in Windows changed from the .ssh of the specific user folder to the folder of the Git installation. Now I tried to investigate what actually causes the problem.

I was able to verify that the presence of the binaries of the Git installation in the Windows PATH was responsible for the problem, e.g. C:\Program Files (x86)\Git\bin. Unfortunately, I wasn’t able to solve or understand it, but I suggest a better way to get around the problem. Furthermore, the problem also affects only the Windows command line but not Git tools like SourceTree.

Although the simplest solution is just to copy the .ssh folder so that consequently 2 ssh key locations exist, I suggest to create a symbolic link on Windows by executing mklink /D your_git_installation_path/.ssh your_user_folder\.ssh which allows you to avoid the redundancy of two same folders.

Automated Post File Generation

Wed, 08 Apr 2015 17:59:56 +0000

All the time, I was really annoyed about the blog post creation in Jekyll when I needed to create a new file and then to rename it to day-title.markdown. Today, I just searched for a better solution and found this great approach which I slightly adapted to my needs.

Because I’m not satisfied by the syntax of the post generation through the parameter passing with Rake, I will do in the future further investigation to solve it. For now, it’s fine and better than to create post files manually. Actually, the rewriting research wasn’t easy because the syntax of Rake changed probably somewhen in 2012 which made it really hard to find actual solutions to the problem.

The other possible solution compared to the environment variable passing would be:

task :post, [:title] do |task, args|
  		title = args.title

It is then called with rake post["Title"]. Compared to the to the environment variable solution it is much uglier as you can see:

task :post do
	title = ENV['title']

That is simple called with rake post title='your_title' which is much more beautiful.

Exchange Calendar in Thunderbird

Tue, 07 Apr 2015 01:50:00 +0000

When I was searching for a long time to find a good solution to integrate my Microsoft Exchange calendar to Thunderbird, I found this solution. Although Microsoft hasn’t implemented a solution themself, these guys did this job and provide a great solution. It allows you to read and write(!) appointments into your calendar.

If you need to integrate e.g. an Office 365 calendar, you can find some tips for the setup from the original author here.