Have you ever wished you could easily copy code blocks directly from your Sphinx-generated documentation? The sphinx-copybutton extension makes this a reality. By adding a small button to each code block, you can effortlessly copy the code to your clipboard.This is a fantastic way to enhance user experience and make your documentation more user-friendly as it allows readers to quickly copy code…
GitHub Actions is a powerful tool for automating your CI/CD pipelines. It allows you to run your tests, build your code, and deploy your applications with ease. One of the most common use cases for GitHub Actions is building and testing Docker images. The example below shows how to use Docker Compose in a GitHub Workflow to build and test a Docker image when the docker-compose.test.yml file is…
Dependabot is a service that automatically updates your project dependencies by creating pull requests. It is a great tool to keep your project up-to-date with the latest security patches and bug fixes. However, managing these pull requests can be time-consuming, especially if you have many dependencies. As a result, many teams end up ignoring Dependabot pull requests, which can lead to security…
GitHub is a great platform for hosting open source projects. It provides a lot of features for free, including a wiki for documentation. However, the wiki is primarily designed to be edited through the web interface. This is not ideal for a lot of reasons as it makes it difficult to track changes from the repository. But there is a way to automatically upload to the wiki using GitHub Actions as…
Creating and maintaining a website is a lot of work and it is nice to know which pages are being visited and how people are finding your site. Google Analytics is a great tool for this and it is easy to add to your Sphinx site. But adding it to your Sphinx Sphinx blog is not as easy as it could be. This post will show you how to add Google Analytics to your Sphinx site instead of modifiying the…
In Python, there are two magic methods that can be used to implement the behavior of the subscript operator []. These methods are object.__setitem__() and object.__getitem__(). The first one is used to assign a value to an item, the second one is used to retrieve an item.The following example shows how to use these methods to implement a memory class as a list of bytes that was used in the 6502…
Method chaining is a programming style in which multiple method calls are made on the same object, in sequence. Each method call returns the object itself, so the next method can be called on it without having to assign the object to a variable in between.This can make code more concise and readable, as it can be written as a single line of code instead of multiple lines. It can also make code…
Hardcoded variables are never a good idea and one solution is the update the during deployment with Ansible for example. Another option is to set read those variables from the environment and maintaining them via systemd via a separate environment file or as part of the container deployment.The example below is how Django reads the environment variables to configure the database connection to…
In Extending GitHub Actions with Annotations the output of GitHub Actions was transformed into Annotations that could be shown in the web interface. The example shows that part for Flake8 which is a framework for different plugins to be combined and scan Python code on common mistakes and improvements. But later in 2023 a plugin was release for Flake8 to generate a report that can be used by…
Flake8 is a Python tool that checks Python code for style, programming errors, and help reduce code complexity. It is a wrapper around PyFlakes, pycodestyle, and Ned Batchelder’s McCabe script. Flake8 has a plugin structure and there are many plugins available. One of the plugins is Flake8 Bugbear. Flake8 Bugbear is a plugin for Flake8 that finds likely bugs and design problems in your program. It…
Systemd timers are a great way to replace cron jobs. They are more flexible and can have dependencies that can defined in easy statements instead of creating a script to check for the dependency. One of the use-cases is to use systemd timers to create PostgreSQL backups and remove old backups. In this example, we will create a backup of two databases, db1 and db2, and remove backups older than 10…
Home automation is a great way to put your home to work for you. With Google Home, you can build your own automated routines to make your home smarter and more comfortable. You can also use the Google Home app to control your smart home devices from anywhere. And while other solutions exist, Google Home is a platform that is easy to use by most people. The options were only limited but now you can…
Systemd timers are a great way to replace cron jobs. They are more flexible and can have dependencies that can defined in easy statements instead of creating a script to check for the dependency. One of the use-cases is to use systemd timers to create MariaDB backups and remove old backups. In this example, we will create a backup of two databases, db1 and db2, and remove backups older than 10…
Running a backup MX host is a good idea if you want to ensure that e-mails are not lost if your primary MX host is down. With Postfix, this is easy to set up on a Debian or Ubuntu system as both are shipped with Postfix.Mail servers that are misconfigured can be used to send spam. Therefore, you should closely monitor your mail server and make sure that it is not misused by spammers. In case of…
Python 3.9 introduced new methods called python:bytearray.removeprefix() and python:bytearray.removesuffix() via PEP 616 to remove a prefix or suffix from a string. These methods are similar to python:str.lstrip() and python:str.rstrip() but they are more efficient and easier to use as they use a string instead of a set of characters. The latter is useful when you want to remove a prefix or suffix…
With systemd you can manage services like in post Environment variables set by systemd, but managing multiple instances of the same service is not so easy. For example, you have a service that runs a web server, and you want to run multiple instances of that service, each with different configuration. You can do that by creating multiple service files, but that is not very elegant. You can also…
In posts Installing Ansible on Ubuntu 22.04 and Installing Ansible on Debian 12 Ansible was installed via the package manager. Another option is to install Ansible with Python in a virtual environment so you can have multiple Ansible versions installed on the same machine.Since Ansible is written in Python, it can be installed in a Python virtual environment which is a self-contained directory…
Ansible is a great tool for automating tasks on multiple servers. It is easy to learn and use and it is very powerful. Ansible is written in Python and it uses SSH to connect to the servers or devices you want to manage like routers, switches, etc. There needs to be a central server where Ansible is installed and from there you can manage all your servers or devices.In this post, we will create…
Cloudflare Pages is a great way to host your static website. It’s fast, easy, and free to start with. While the egress traffic is free, you still pay in other forms as some bots will crawl your website. This is where robots.txt comes in handy. You can use it to block bots from crawling your website without having to configure anything with in Cloudflare.The file robots.txt is used to tell bots…
Pinning Terraform versions is a good practice to ensure that your infrastructure-as-code (IaC) is always deployed with a known version of Terraform. This is especially important when using Terraform Cloud, as the version of Terraform used to plan and apply changes is not always the same as the version used to develop the IaC. This can lead to unexpected errors and behavior, but this also requires…
In previous post Run Terraform within GitHub Codespaces the Terraform environment was setup within GitHub Codespaces. The next step is to run Terraform with GitHub Actions via Terraform Cloud as part of a workflow and scan the Terraform code with KICS is the first step to reduce technical debt as described in the post KICS.Let’s start with the workflow file .github/workflows/terraform.yml to run a…
Ansible is a great tool for automating tasks on multiple servers. It is easy to learn and use and it is very powerful. Ansible is written in Python and it uses SSH to connect to the servers or devices you want to manage like routers, switches, etc. There needs to be a central server where Ansible is installed and from there you can manage all your servers or devices.In this post, we will create…
Installing Linux on a physical or virtual machine can be fun for a couple of time, but configuring a system can be combursome after a couple of times. Red Hat developed Kickstart to install and configure machines via the network, but also as part of an ISO file that can used in a virtual CD-ROM drive or on a bootable USB-drive.The following steps are required to create a bootable ISO file with a…
Ansible roles are a great way to organize and share your infrastructure-as-code between projects. Those roles can be tested with Molecule, which is a great tool to test your roles against multiple platforms and Ansible versions. Running these tests in a CI/CD pipeline is a great way to ensure that your roles are working as expected and that you don’t introduce regressions.These tests can be…
Websites are usually made up of HTML, CSS, and Javascript. These files are usually not minified, which means that they are not compressed. This means that the files are not optimized for the web. This can cause the website to load slower than it should. This is especially true for mobile users. This is where minification comes in. Minification is the process of removing unnecessary characters from…
PNG is a lossless image format that supports transparency. It is a good alternative to JPEG for images with a lot of detail and/or transparency. However, PNG images can be quite large. This post shows how to optimize PNG images instead of converting images to WebP as not everyone is ready to publish WebP images yet.With optipng you can optimize PNG images. It is available in the repositories of…
Websites have been using PNG and JPEG images for a long time. PNG images are lossless and JPEG images are lossy. PNG images are larger in size than JPEG images. WebP is a new image format that is developed by Google. WebP images are smaller in size than PNG and JPEG images and can be both lossy and lossless. WebP images are supported by all modern browsers nowadays and making it ideal see how you…
Adding issues to projects on GitHub is a great way to keep track of what needs to be done. This action will add issues to a project board on GitHub when they are opened or labeled. But adding issues to a project board is a manual process. The action actions/add-to-project automates the process of adding issues to a project board.In the workflows the environment variable ADD_TO_PROJECT_URL is used…
Implementing a Content Security Policy (CSP) for a website can be a daunting and difficult task as it can break your website when done incorrectly. But a CSP can help to guard against cross-site script attacks and data injection attacks on a website as it defines which resources are all allowed to be loaded or executed. This also reduces the risk of including unauthorized third-party content to be…
Ansible allows for structured configurations on how to deploy applications and servers, but also for repetitive tasks. All these actions are defined in YAML files that rely on indentation and this is where Ansible can act in a way that isn’t expected. With yamllint most formatting and layout issues can be found, but with ansible-lint also common mistakes for Ansible can be detected.As ansible-lint…
Issues and pull-requests are part of projects and repositories, but can also be forgotten when they grow out of control. You could search for stale issues manually once in a while, but it is another task on someone’s calendar that has been done. Like with post Add labels to GitHub pull requests this also can be automated. This way the backlog can be kept small so the team working on doesn’t have…
Labels on issues and pull requests can make it easier to understand the content, but also make paying attention to what has changed and selecting them easier. If a pull request only has the label terraform for example it indicates that only infrastructure changes are in play.While multiple GitHub Actions exist the two main solutions are Probot Autolabeler and GitHub Actions Labeler. The first…
In post Custom GitHub templates for issues, the first step was made to automate the workflow more by defining issue templates on the organizational level and assigning labels when creating a new issue. A human still needs to create the issue manually while some issues must be created on a schedule to deploy new certificates or run an Ansible playbook to patch servers for example.Like in post Start…
Automating workflows reduces the need to think about them, but can also guide new people in the right direction. One of these workflows is creating issues for example. One could use the default templates provided by GitHub to create an issue for a bug or a new feature. Only default templates may not fulfill all requirements needed for a smooth workflow for a project on GitHub.By default, GitHub…
With the introduction of GitHub Actions automated testing became more accessible and integrated into the pull requests to make it more clear what is being merged and if it checks off all requirements. This makes other services like Dependabot easy to use and keep your code up to date, but these small changes in dependencies for example. Reviewing code or documentation changes can be more difficult…
HashiCorp offers Terraform Cloud as a service to run Terraform and keep the state instead of having a local copy of the state databases. This is great to make full use of Infrastructure-as-Code tools like Terraform and everyone can run them without losing the correct state. But when setting up a deployment plan a specific version of Terraform has to be selected manually in the webinterface, and…
Vagrant is a tool for building and managing virtual machines locally with just a few commands and a single file. It is a good way to get started with infrastructure-as-code on your local machine. Vagrant is also shipped with Fedora to make it easier to install and use as it uses libvirt to manage the virtual machines running on Linux with kernel virtualization to provide virtual hardware. This…
Using GitHub Codespaces allows you to work on your code from almost any place in the world without an Internet connection. Only the devcontainers powering Codespaces are mended to be short-lived and not contain any credentials. This may pose a challenge when you’re depending on remote services like Terraform Cloud that require an API-token to work properly.Most devcontainers are following the…
During a recent OWASP Netherlands meetup security scanners were discussed to prevent mistakes and also Checkmarx presented their tool KICS for scanning for security vulnerabilities and configuration errors in Infrastructure-as-Code. Development of KICS goes fast since late 2020 and can catch some common mistakes with known Infrastructure-as-Code definitions like Terraform, Cloudformation, and…
Python is a powerful language to quickly and efficiently do work with data, but it requires a more in-depth knowledge of the language to write more elegant and readable code. For many new Python programmers, this is a catch-22 as they’re still learning all the details and it takes time. Let’s take a simple example about finding the longest string in a list and simplify some code. Secondly making…
On Unix systems, dotfiles are files that are stored in the home directory and contain configuration information. The XDG Base Directory Specification already splitted them in three categories and most applications how store their files in .cache, .config, and .local based on their purpose. And a small subset of application sticks to the root of the home directory like the most shells. In most…
The command getent is not known to many users but it is very useful when you need to get information about users, groups, or other entities. The command can be used to get information about users, groups, or other entities for example without having to know where the information is stored.The syntax of the getent command is simple to use as it takes the name of the data source and possibly the…
Terraform keeps a cache of state files in the .terraform directory stored in Terraform Cloud so that it can be accessed by everyone in the organization. For existing resources Terraform has to import the state for a defined resource otherwise it will fail. Sometimes the state is invalid or an API will return an unexpected code and Terraform will fail to proceed.The example below passed the error…
What started as a custom content management system quickly moved to WordPress to improve its maintainability and that solution served its purpose over the years. Having an easy web-based editor to maintain every is a good thing, but sadly also a bad thing. WordPress is a known target for attacks and you have to keep up to not be compromised, but this also means you have to keep up with how…
GitHub bought a service called Dependabot a while back and is now integrating this service as a GitHub Application into the ecosystem. This allows GitHub users to automatically do dependency management and get alerted when a security-related update has been found. For a while this service was in beta but it is now enabled for all public repositories and can be enabled for private repositories as…
YouTube is one of the biggest video streaming sites on the Internet and you can find a video for basically everything on it. But in some cases, you can’t find a video anymore or it has been taken down or set to private for some reason. Having a local copy for personal or legal purposes can be useful, but by default YouTube only allows creators to export their content.With the tool…
A lot has changed since 2018 when exFAT was kept out of Fedora due to patent issues and a third-party FUSE-driver needed to be used. Until recently the GPLv2 based driver from Microsoft wasn’t enabled in the kernel as it was based on an older specification and wasn’t fully functional for everyday use.Fedora 32 recently received an upgrade to kernel 5.7 and with that, the native exFAT driver was…
For Developing inside a Container with Visual Studio Code, one of the requirements is to use Docker Community Editon as the version of Docker that ships with Fedora is too old and misses certain features. Also the new Docker alternative Podman from Red Hat isn’t supported by Visual Studio Code.After installing Docker CE on Fedora 31, cgroups version 1 needs to be enabled as Linux switched over to…
Applications sometimes need environment variables to be set for triggering certain behavior like giving debug output or routing traffic via a HTTP-proxy for example. A common way is to modify the start-stop script, but with systemd on most Linux systems, like Debian and Red Hat based distributions, this can also be directly set within the unit file and you don’t have to export the variables…
Phasing out legacy cryptographic algorithms can always be an interesting endeavor as terminating too early breaks stuff and too late can lead to a compromise. OpenSSH disabled Digital Signature Algorithm (DSA) with version 7.0 in March 2015 as 5 years earlier it was discovered that DSA was compromised and labeled as insecure. Normally this shouldn’t be a problem with a normal software life cycle,…