or Publishing a cleanup script for Oracle 12c+ At the moment I’m just for fun collecting Linux scripts from my direct colleagues. And while I was busy to think up a wiki page for internal use, for a moment I felt like Uncle Scrooge, gathering riches from other minds. Which, […]
Continuous Generation and Publication of Docstring Documentation on Azure – using Sphinx, Pydoc, Storage Account and App Service
In this blog I will explain how to generate static HTML pages from your projects Pydoc (docstring) comments with Sphinx. Then we are going to host it in an Azure Web App so that everyone in your team is able to access it. Because we use a Storage Mount, when […]
Stop DELETE_IN_PROGRESS when custom resources fail in AWS CloudFormation
Script to stop the execution of CloudFormation when you made a small error in a custom resource (Lambda function).
Preparation for migrating data to Oracle Virtual Private Database
preparation for migrating data to Oracle Virtual Private Database Introduction Recently I was part of a team involved in the preparation of migration data belonging to multiple business units into a single Oracle 19c database with Virtual Private Database (VPD). The VPD solution is used for the virtual separation […]
Play environment for WebGoat, WebWolf and Juice Shop
In this blog post, I will show how you can install the OWASP training tools WebGoat, WebWolf and JuiceShop on your local laptop using Vagrant.
How to use single sign on between multiple OCI environments
Since we provide support for several clients in OCI, we regularly need to login into different OCI-tenancies. How nice would it be to have Single Sign-On (SSO) functionality between these different customer environments. Just 1 credential for all environments, granting and revoking access a lot easier. Also no need to […]
How to run Jenkins with Chrome from a Docker container
In this blog I will show you how to run a Jenkins agent that can use chrome from a docker container. The Dockerfile and docker-compose.yml file are explained in this article.
Measure the Quality of your Source Code!
Quality is something which is hard to define. Different areas of expertise use their own definitions of what quality is. Without an objective standard which carries weight, anyone can claim to provide a quality product or service according to some standard. This makes it difficult to compare products and to […]
The Release Formula: R = ΔF + ΔNF + ΔQ
TL;DR: a software release introduces changes in three areas: functional, non-functional and quality. Each change should contribute to identified objectives – and the contribution should be measurable. Product teams should strive for release statements that identify the changes, the objective they contribute to and the metric used for measuring their […]
The True Cost of a Feature–Kill your darlings
TL;DR: the true cost of a software feature includes a long tail of operational and maintenance cost that should be taken into consideration when first implementing the feature. The continuance or deprecation of features should be evaluated periodically, based on the actual usage and true value of the feature – […]
Migrate Oracle VM to KVM easily and without reconfiguration
Oracle VM is end-of-life and is, since March 2021, in extended support1. In looking for a replacement hypervisor AMIS has turned to KVM. Oracle itself also uses KVM, albeit its own brand of KVM, OLKVM, in Oracle Cloud and on the new versions of its Oracle Database Appliance. Topped with […]
Polling Rank – Interactive Visualization Component for Ordering Options
TL;DR: live demo of the Poll Rank component on Code Pen: https://codepen.io/lucasjellema/pen/NWpoBeM Bringing things to order is a common requirement. Making clear how things are mutually ordered, which comes first and which comes next, is often relevant. Order by value, by time or by preference are just some of the […]
What the Ether, part 1 – Ethereum
Just like in 2017, blockchain has been all the craze this year. With Bitcoin reaching prices over three times higher than the previous all-time high, everybody has been talking about cryptocurrency and blockchains. And one of the blockchains that has been taking the spotlight is Ethereum. That is why in […]
Visualizing Recipes in aid of Freshman Cooks
I am not the best cook in the world – it has been said. But I am making an effort to step up my game. My two sons have started participating in our family’s meal planning and with the rising quality and complexity of the meals they prepare I feel […]
Implementing Serverless Multi Client Session Synchronization with Oracle Cloud Infrastructure
TL;DR – Multi Client Sessions can be facilitated in a fully serverless fashion. Two players playing Tic Tac Toe or Chess, teams collaborating on a document or diagram, an audience witnessing a presenter’s demonstration – these are just examples where multiple distributed application instances should be kept in synch. This […]
Serverless Distributed Multi User Browser Session Synchronization
Assume a browser based (or desktop electron) stand alone, client side only application. Multiple users are working with that application at the same time, on their own laptops and at (possibly very) different locations, possibly across the globe. It is conceivable that they are working on a common object. A […]
Introduction to D3 Force for Simulation and Animation
The D3 library is great for creating rich and interactive data visualizations running in your browser. D3 is a JavaScript library that provides an easy bridge between the power of SVG (Scalable Vector Graphics) in the browser and your (and my) own JavaScript applications. Whether you use React, Angular, Vue […]
Review: Greenshot, Easy tool for screenshots
Is it possible to make something simple as making a screenshot easier? Yes, I have been using the free and open-source tool Greenshot for the past year. And I noticed missing the features when I got a new Windows image on my laptop. I would recommend installing this for anyone […]
Check for RunAs accounts in Automation Accounts
Introduction Some time ago, I wrote about the new preview feature in Azure Automation Accounts to use Managed Identities [1]. I think that it is useful to migrate to this new feature as soon as possible: managed identities are used in many places in Azure and it is better to […]
OBS Studio: How to record online presentations (Zoom, Teams, Webex, Meet, …)
Sometimes you want to record online presentations to maybe re-watch them later or share them with colleagues. It is not always possible to easily do this from within the tool which is used for the presentation. An easy alternative is to record such sessions using OBS Studio, a free and […]
Starting my own Game Studio–on the ease and the power of SVG
My very first steps in programming consisted of typing in the BASIC program listings from computer magazines. Usually very simple games with very poor UX. That probably is the closest I got to “creating” games. And then I went into computers professionally – with a primary focus on the backend, […]
Blog milestone: 200 blog posts, 1M page views!
This is my 200th blog post. Also I reached 1M page-views recently. In those 200 blog posts, I used approximately 325K words. An average non-fiction book is somewhere between 70K to 80K words. So that would amount to somewhere around 4 books. Why did I write so many blog posts, […]
Using a Managed Identity with Azure Automation Accounts
Introduction I think that every production environment in Azure uses Automation Accounts for f.e. scheduled tasks. Up to recently, you were forced to use the Run As user to do so. This solution has, however, two drawbacks. The first one is that this Run As user has way too many […]
Jenkins: Obtaining and displaying credentials
Jenkins is a solid CI/CD platform which has proven itself over the years. Many organizations use it to build, test and deploy their applications. In Jenkins it is possible to define credentials or to use an external credential store. You can then use these inside your pipelines and jobs. Direct […]
SonarCloud: OWASP Dependency-Check reports
SonarCloud is a hosted SonarQube SaaS solution which helps you with code quality management. It is free to use for open source projects. You cannot install 3rd party plugins in SonarCloud however. This puts some limitations on the kind of data you can put in SonarCloud. For Java this is […]
GitHub Actions and SonarCloud
GitHub Actions allow you to do most CI/CD tasks for free, directly from your GitHub repository. One of the challenges however is that there is no build-in facility like for example SonarQube to manage code quality. Luckily, SonarSource provides SonarCloud; a SonarQube SaaS offering which is free for public projects! […]
GitHub Actions: A first impression
I’m a regular user of GitHub. Recently I discovered GitHub also has a build-in CI/CD workflow solution called GitHub Actions. Curious about how this would work I decided to try it out. I had previously build a Jenkins Pipeline to perform several static and dynamic application security tests on a Java project […]
OWASP ZAP: A quick introduction to a versatile open source DAST tool
OWASP ZAP (Zed Attack Proxy) is an open source dynamic application security testing (DAST) tool. It is available here and has a website with documentation here. I recently encountered it when looking for open source security test tools to embed in a CI/CD pipeline (here). I was surprised by how versatile this tool […]
Delete play-resources from Azure using runbooks
Learning a new cloud can be frighting: do I configure this right? And, when I click here, don’t I end up with a huge bill at the end of the month? In general, these fears can be solved quite easily: when you follow along with a training, the trainer will […]
Executing JavaScript from PL/SQL in Oracle Database 21c with Multi Language Engine
Oracle Database Release 7 – end of 1993 – introduced PL/SQL as language for Stored Procedures, Functions and Triggers. This was just before I joined Oracle Corporation, in May 1994. I have made extensive use of PL/SQL. With Oracle 8i we saw the advent of the Embedded JVM that made […]
How to build [a CI/CD pipeline for] an Oracle Database application–kicking off a six part series
![How to build [a CI/CD pipeline for] an Oracle Database application–kicking off a six part series](https://technology.amis.nl/wp-content/uploads/2021/03/image-20.png)
Build is an overloaded term in the world of software engineering. Building software used to be mainly a fancy way of saying “programming”. Now after the construction of the code, the actual build process is kicked off, that takes the work from the individual programmer and turns it into something […]
How to unit test a SQL query?
A simple challenge: I am working on a SQL query. Not a trivial query. I am trying various approaches. I believe I may have found a solution that works. That produces the correct solution. How can I be sure? How can I try to further refine the query while maintaining […]
How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (1)
What’s in a name? A title is important and I hope that it describes well what I do want to share with you in this series of articles. It is not so much about how to use the back-end part (Oracle Database) or the front-end (Oracle APEX, Java, Node, React […]
Java Security: Open Source tools for use in CI/CD pipelines
It is often expected of a DevOps team to also take security into consideration when delivering software. Often however, this does not get the attention it deserves. In this blog post I’ll describe some easy to use, CI/CD pipeline friendly, open source tools you can use to perform several checks […]
SQL–Only Counting Records Sufficiently Spaced apart using Analytics with Windowing Clause and Anti Join
A nice SQL challenge was presented to me by a colleague. The challenges basically consisted of this table. A table contains records that describe login events. Each record has a login timestamp and the identifier of the person logging in. The challenge is to count “unique” login events. These have […]
How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (6)
Last time in “How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (5)”, I told you about Git, Subversion, Maven and Flyway. In this final article, I will discuss the following tools & methods: Oracle SQL Developer, utPLSQL, SonarQube, Perl, Ant and DevOps. Oracle […]
How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (5)
Last time in “How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (4)”, I told you about the Oracle SQL Developer Data Modeler. This time I will discuss the following tools: Git, Subversion, Maven and Flyway. Flyway The first tool I would like to […]
How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (4)
Last time in “How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (3)”, I told you about the Oracle Database and Oracle APEX. This time I will discuss Oracle SQL Developer Data Modeler. Oracle SQL Developer Data Modeler A book I can recommend is Oracle […]
How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (3)
Last time in “How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (2)”, I did show you the database structure. This time I will elaborate on the base tools, the Oracle Database and Oracle APEX. Oracle Database How to use it? I can tell […]
How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (2)
Last time in “How to build an Oracle Database application (that supports APEX, Java, React or any other front-end) (1)”, I gave you an introduction. This time I will elaborate on the database structure. Project folder layout The following top level directories may exist for every database application project: Directory Description […]