Declaration of VAR

and some other stuff

On 19.05.2021 the website was moved to https://decovar.dev/. This is just a mirror now.

  • Managing dependencies in a C++ project with vcpkg

    2022-10-30 | 129 min read

    More than half a year ago I was trying out Conan package manager for resolving dependencies in our C++ project. The research went well, but we never actually proceeded with switching to Conan for the whole project. And then a couple of weeks ago I started looking into vcpkg.

    vcpkg logo

    I’ve heard about vcpkg before and even tried to make a vcpkg package for one library a couple of years ago, but back then I didn’t find documentation for this (as I now understand, that’s because one does not really create a “package”) and abandonned the task. I never thought I’ll be looking at vcpkg again, but recently I discovered that some teams have been switching from Conan to vcpkg, which sounded intriguing and promising, as we still needed a package manager for our projects.

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  • Visitors analytics with Microsoft Graph

    2022-08-15 | 27 min read

    Our company uses Office 365 and Azure Active Directory, which allows us to rely on SAML SSO for authenticating company users on our websites. At some point we got curious about what kind of users visit our websites - not quantities but kind of “corporate demographics”: what is their team/department name, their role/job title, their manager, country where their office is and so on.

    Microsoft Graph and charts

    We don’t collect any of this data on our websites (we probably could, at least on those where we control the authentication process, but we don’t). The only piece of information that we do have about our visitors (aside from IP-addresses in web-servers access logs) is their e-mails and GUIDs, thanks to SAML SSO. That might not seem like much, but knowing just the e-mails (or GUIDs) is actually quite enough, as one can use Microsoft Graph to query more data using those. And for the actual analytics purposes that data can then be visualized/presented using Matplotlib charts.

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  • LDAP authentication in ASP.NET Core MVC

    2022-06-16 | 23 min read

    We needed to make a (yet another) internal portal/website for employees, but this time, as that would be an internal resource, we decided to utilize users accounts data provided via LDAP by our office’s Active Directory, instead of (yet again) implementing “local” user identities like we did before with MySQL and PostgreSQL.

    .NET Core LDAP

    (Of course) we chose ASP.NET Core MVC for making the portal. And as both ASP.NET and Active Directory have been around for a while, and given the fact that both come from the same vendor, one would expect that implementing Active Directory users authentication via LDAP in such a setup to be a well-known topic with detailed documentation, examples and a lot of tutorials available. But as fucking usual, it’s not quite like that.

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  • Querying astronomy databases in ADQL via TAP

    2022-02-26 | 35 min read

    There are several astronomy databases that store various information about space objects such as stars and planets. Some (most?) of those databases expose their data via TAP interface, so it can be queried using ADQL.

    TAP ADQL sandbox

    Here I’ll be telling about how to get data from such sources and what sort of issues/problems one can encounter.

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  • Conan and resolving dependencies in a C++ project

    2022-02-06 | 24 min read

    Like many other teams, we have a fair amount of 3rd-party dependencies in our project (a C++-based SDK, that is). Like fewer other teams, we store those dependencies source code right in our project repository and we build them together with the project sources every time. This is of course a tremendous waste of time and CPU cycles, as it would be much more efficient to build dependencies just once (per version) and link to already pre-built binaries.

    Conan The Librarian

    But where to store pre-built dependencies and how to fetch the correct variants for various platforms, toolchains and configurations? Our investigation on the matter led us to Conan package manager.

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  • KeePass as internal secrets storage for a team

    2022-01-13 | 11 min read

    For a long time in our team we’ve been storing logins, passwords, keys and other things like that in personal password managers or just plain-text files, spread around people’s machines, and no one had the full set. Finally, we decided to stop this chaos and start using one common passwords database.

    Passwords in KeePass XC

    Having evaluated several options, we chose KeePass. It’s not exactly meant for multi-user usage, but we came up with some sort of workaround.

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  • Electric car in Norway, leasing BMW i3

    2021-12-16 | 37 min read

    A couple of years ago we came to a point when having a car had become more of a necessity than a luxury. Having spent about a year to get norwegian driving license, we entered a leasing contract for a new BMW i3.

    BMW i3

    Here I’ll be talking about the leasing process and in general about the experience of owning an electric car in Norway.

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  • Making a deb package with CMake/CPack and hosting it in a private APT repository

    2021-09-23 | 19 min read

    Last time I needed to handle a C++ library project with CMake. This time I was tasked with creating a deb package for one of the libraries in our SDK.

    CMake, CPack, deb package

    And what would you know, CMake can handle packaging too - with CPack utility.

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  • Qt for WebAssembly and custom OpenGL via QQuickFramebufferObject

    2021-08-29 | 13 min read

    It is amazing what kind of crazy ideas people might come up with. One of our users decided that they want to use our visualization engine inside their Qt application on Windows and Linux (so far so good) and also to build a version for WebAssembly to target web-browsers (fucking hell).

    Qt, WebAssembly, QQuickFramebufferObject

    Very surprisingly to me, this actually works!

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  • Azure DevOps Artifacts package promotion

    2021-07-21 | 12 min read

    Some time after we started to publish our packages to Azure DevOps Artifacts, users told us that they cannot see new versions of the packages until those are “promoted to Release view”. And indeed, there is a concept of “views”, and packages can be “promoted” to certain views:

    Azure DevOps Artifacts package version promotion

    Apparently, that is the case when someone consumes packages not directly from your feed, but from their own feed with your feed being an upstream source.

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