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#!/bin/bash
# --
# Test if Docker daemon disk space usage is above a given limit in bytes.
#
# Example 1: Docker disk space usage is above limit 
#
#    $ source is_docker_disk_space_usage_above_limit.sh
#    $ is_docker_disk_space_usage_above_limit 1
#    Docker disk space usage is above limit (actual: 1050000005B, limit: 1B)
#    $ printf $?

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How To Ignore Multiple tfsec Errors

I stumbled upon this today when I wanted to get a precommit hook running again that runs tfsec.

If we want to ignore multiple errors with tfsec, then we can use the -e flag and a comma separated string.

E.g. if we have a s3.tf violating AWS001, AWS002, and AWS017, we'll get the following output from tfsec:

$ tfsec

fkurz

Shell scripting with Haskell

Problem

Shell scripting is kinda broken:

• Shell scripting languages differ or are interpreted with subtle differences
• Higher level language concepts are typically missing

Can Haskell be a good replacement for Bash—or similar languages—as a shell scripting language?

fkurz

We can export a mermaid diagram to PNG very simply using the official Mermaid CLI Tool.

Installation via npm

npm i -g mermaid.cli

Usage:

fkurz

This is more or less a note-to-self.

Note: this doesn't seem to be the simplest solution. See edit from 27th June 2021 below.

If ZSH's compaudit complains about insecure directories on a Mac, removing write permissions will fix the issue (see this SO answer):

chmod g-w ${insecure-directories}

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If you run a multi-user setup, [Brew][brew-home]'s doctor command will likely report lack of write permission on directories under /usr/local (e.g. /usr/local/etc).

The suggested fix is to chown -R $(whoami) ${directory} for all directories ${directory} without write permission by the current user. While this is a quick fix, it will force us to do the same procedure over again when we change to another user.

A better solution is to create a brew user group and add every user to this group that uses Brew as detailed [in this blog post][brew-multi-user]. While it's possible to add a user group via the command line. The simpler solution is to just use System Preferences > Users & Groups.

Once the group is created — called brew-users in this example — we can run the following to change the group for all files/directories managed by Brew (i.e. those stored under $(brew --prefix)) to the Brew user group and give the group writing

fkurz

Create a Manjaro Linux USB Boot Drive on MacOS

1. Download Manjaro Distribution

   Download page

2. Format USB Drive

   To find the volume identifier of our USB stick, we run

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Creating Instant Vectors with Arbitrary Labels in PromQl

Problem

We need to create an instant vector with a given label set.

An example use case would be supplying a default value in combination with or.

Solution

fkurz

Protobuf Python: Generating Code With Working Import Statements

Problem

The import statements in Python code generated from factored Protobuf files do not correctly point to the modules to be imported.

Note: By factored, I mean at least two files a.proto and b.proto with potential of mutual dependencies.

Solution

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Snippet: Generating Protobuf Message Serializations from the Command Line

Problem

We want to send some protobuf serialized data to an implemented RPC API endpoint for testing.

Note: This is especially helpful if you work with [Twirp][3] and code in Python since the code generator does not yield a JSON Protobuf client.

Solution

You can use the protoc command to generate binary data and then pass them to curl (see [1] and [2]).