http://junctionbox.ca/ JunctionBox.ca - Nathan Fisher's DevOps blog en-us Thu, 05 Jun 2025 01:59:47 +0000 Thu, 05 Jun 2025 01:59:47 +0000 http://junctionbox.ca/2023/03/25/algebra-matrix-multiplication.html Sat, 25 Mar 2023 00:00:00 +0000 http://junctionbox.ca/2023/03/25/algebra-matrix-multiplication Matrix multiplication is part of a series of calculations that lead into the fundamentals of machine learning. This article gives an overview of the properties of a matrix multiplication and provides an example function in Go. http://junctionbox.ca/2023/03/25/algebra-dot-product.html Sat, 25 Mar 2023 00:00:00 +0000 http://junctionbox.ca/2023/03/25/algebra-dot-product A dot product is part of a series of calculations that lead into the fundamentals of machine learning. This article gives an overview of the properties of a dot product calculation and provides an example function in Go. http://junctionbox.ca/2022/07/06/golang-testing-helper.html Wed, 06 Jul 2022 00:00:00 +0000 http://junctionbox.ca/2022/07/06/golang-testing-helper The receiver (*Testing).Helper was added back in 2017 but is an underrated tool in writing helper functions. http://junctionbox.ca/2022/06/22/stacked-commits.html Wed, 22 Jun 2022 00:00:00 +0000 http://junctionbox.ca/2022/06/22/stacked-commits Ruminations on Git stacked commits. http://junctionbox.ca/2022/05/30/react-tabular-data.html Mon, 30 May 2022 00:00:00 +0000 http://junctionbox.ca/2022/05/30/react-tabular-data React tabular components are often developed in what feels like a strange inversion of the rendering flow. http://junctionbox.ca/2022/05/18/petit-parser.html Wed, 18 May 2022 00:00:00 +0000 http://junctionbox.ca/2022/05/18/petit-parser Petit parser is a small lightweight parser that I recently gave a spin to write a PromQL API. http://junctionbox.ca/2020/11/06/docker-hubocalypse.html Fri, 06 Nov 2020 00:00:00 +0000 http://junctionbox.ca/2020/11/06/docker-hubocalypse Docker is understandably changing it's terms of service for pull requests by anonymous accounts. This will have a big impact on many companies but there are a few approaches you can take to minimise the impact on your Kubernetes clusters. http://junctionbox.ca/2020/06/19/bazel-java-starter.html Fri, 19 Jun 2020 00:00:00 +0000 http://junctionbox.ca/2020/06/19/bazel-java-starter Bazel can be daunting to setup for your first project this series of posts aims to provide an approach to setting up a new Java project with Bazel. http://junctionbox.ca/2020/06/13/state-of-http2.html Sat, 13 Jun 2020 00:00:00 +0000 http://junctionbox.ca/2020/06/13/state-of-http2 The HTTP2 spec was published as an Internet Draft May 30th, 2015. Five years later and the capabilities seem to vary wildly across libraries. With HTTP3 fast approaching I was curious the current state of play for some of the bigger libraries I encounter regularly. http://junctionbox.ca/2019/06/20/Maven-to-bazel-prep.html Thu, 20 Jun 2019 00:00:00 +0000 http://junctionbox.ca/2019/06/20/Maven-to-bazel-prep Bazel is a fast build tool that works well with a monorepo. This post aims to provide some quick guidelines when migrating from maven to Bazel. http://junctionbox.ca/2018/04/06/Docker-for-Development.html Fri, 06 Apr 2018 00:00:00 +0000 http://junctionbox.ca/2018/04/06/Docker-for-Development Containers as a concept seem here to stay but there’s a lot of smart cookies exploring “what is the best utility of it for daily development” in particular the reason for this post was “what is the best practise for using security credentials in a container”. This post is my naive attempt at cracking that nut with the hope of getting some healthy feedback. http://junctionbox.ca/2018/03/01/Recreational-GraphQL-use.html Thu, 01 Mar 2018 00:00:00 +0000 http://junctionbox.ca/2018/03/01/Recreational-GraphQL-use GraphQLs hype seems to have hit a fever pitch in my tech circle. Like any new technology I figured it’s utility was somewhere between nil and unicorn pixie dust that will “revolutionise” the way I code. The only way to find out was to roll up my sleeves and start coding. http://junctionbox.ca/2018/01/04/clojure-class-prefetching.html Thu, 04 Jan 2018 00:00:00 +0000 http://junctionbox.ca/2018/01/04/clojure-class-prefetching This is my second article in a series on Clojure start-up timings. The focus for this article is Class Prefetching. http://junctionbox.ca/2017/12/26/clojure-startup-walkthrough.html Tue, 26 Dec 2017 00:00:00 +0000 http://junctionbox.ca/2017/12/26/clojure-startup-walkthrough Clojure start-up is sometimes painful. There's lots of methods to amortise the cost such as execution of commands in REPLs, and stand-by JVM's using nail servers and the like. This article aims to illustrate where that time is being spent. http://junctionbox.ca/2017/10/01/buck-on-travis-ci.html Sun, 01 Oct 2017 00:00:00 +0000 http://junctionbox.ca/2017/10/01/buck-on-travis-ci Lightspeed is too slow. We'll have to go directly to ludicrous speed!! Buck is a ludicrously fast build tool but is not a widely available default on many of the OSS CI services. Here's how I got it up and running for Java. http://junctionbox.ca/2017/01/20/java.util.logging-properties.html Fri, 20 Jan 2017 00:00:00 +0000 http://junctionbox.ca/2017/01/20/java.util.logging-properties I like to minimise my dependencies. Sadly the java.util.logging library is rather sparse on documentation when it comes to Uberjars. Read on for how I tamed this particular beast (more of a rabbit than a big cat). http://junctionbox.ca/2017/01/14/analysis-of-arc-2016.html Sat, 14 Jan 2017 00:00:00 +0000 http://junctionbox.ca/2017/01/14/analysis-of-arc-2016 I've been intrigued about the idea of an Atlantic crossing by sailboat since I've lived in London. I used to race on friends boats back in Toronto for a number of years and I rather miss it in London. http://junctionbox.ca/2016/09/11/clojure-one-repl-to-rule-them-all.html Sun, 11 Sep 2016 00:00:00 +0000 http://junctionbox.ca/2016/09/11/clojure-one-repl-to-rule-them-all A typical clojure invocation will gobble up close to 500MB. If you're running a ClojureScript project that'll be 1G for figwheel and a Clojure nREPL. I think I've found an improved workflow that reduces that memory pressure. http://junctionbox.ca/2016/09/03/clojurescript-reagent-reframe.html Sat, 03 Sep 2016 00:00:00 +0000 http://junctionbox.ca/2016/09/03/clojurescript-reagent-reframe In this article I cover off how I've adapted the React/Redux Presentational and Container Component pattern to ClojureScript using Reagent and Re-Frame. http://junctionbox.ca/2016/08/19/clojure-builds-bitbucket-pipelines.html Fri, 19 Aug 2016 00:00:00 +0000 http://junctionbox.ca/2016/08/19/clojure-builds-bitbucket-pipelines Bitbucket Pipelines is out and in Beta. I recently received an account but with so many distractions I didn't have an opportunity to dig into the offering until recently. Bitbucket Pipelines only supports a handful of languages directly but I'll show you how to quickly get Leiningen building your project using the Clojure Docker image. http://junctionbox.ca/2016/08/02/clojure-testing.html Tue, 02 Aug 2016 00:00:00 +0000 http://junctionbox.ca/2016/08/02/clojure-testing Clojure start-up time can be expensive especially when using ClojureScript. This article is a quick post to aggregate what I use to improve the testing feedback cycle in Clojure. http://junctionbox.ca/2015/09/23/uniquely-identify-me.html Wed, 23 Sep 2015 00:00:00 +0000 http://junctionbox.ca/2015/09/23/uniquely-identify-me I recently revisited the landscape for autonomous and uncoordinated identity generation. I came across a couple of criticisms on the use of UUID's and I wanted to explore and validate those criticisms. http://junctionbox.ca/2015/05/02/golang-aws-cloudformation.html Sat, 02 May 2015 00:00:00 +0000 http://junctionbox.ca/2015/05/02/golang-aws-cloudformation AWS is one of the top cloud providers. Amazon CloudFormation makes it easier to manage an entire environment and Golang is an efficient language to develop that tooling in. Combining the two and you have an efficient tool to manage an environments life-cycle. http://junctionbox.ca/2013/06/27/R-data-analysis.html Thu, 27 Jun 2013 00:00:00 +0000 http://junctionbox.ca/2013/06/27/R-data-analysis R is a great tool for statistical analysis. It particularly comes in handy when you want to load and normalise data as illustrated here. http://junctionbox.ca/2013/05/10/dropwizard-liquibase-migrations.html Fri, 10 May 2013 00:00:00 +0000 http://junctionbox.ca/2013/05/10/dropwizard-liquibase-migrations Database migrations are a way to programmatically manage, apply and track changes to a databases schema. http://junctionbox.ca/2013/04/09/calendar-tables-for-postgresql-data-warehousing.html Tue, 09 Apr 2013 00:00:00 +0000 http://junctionbox.ca/2013/04/09/calendar-tables-for-postgresql-data-warehousing Hadoop and MapReduce has made data warehousing all the rage but, don't give up on the trusty old RDBMS. Learn how to populate a calendar table using only PostgreSQL built-in features. http://junctionbox.ca/2013/03/21/evolving-capistrano-deployments.html Thu, 21 Mar 2013 00:00:00 +0000 http://junctionbox.ca/2013/03/21/evolving-capistrano-deployments Is capistrano the best way to handle your deployments? You may want to consider an alternative approach for modern rails apps. http://junctionbox.ca/2013/01/26/puppet-configuration-management-guidelines.html Sat, 26 Jan 2013 00:00:00 +0000 http://junctionbox.ca/2013/01/26/puppet-configuration-management-guidelines Puppet is a configuration management tool that induces a love/hate relationship in many delivery teams. This guideline provides some practises that I've found beneficial for maintaining manifests. http://junctionbox.ca/2013/01/09/s3-rewrite-rule-limit.html Wed, 09 Jan 2013 00:00:00 +0000 http://junctionbox.ca/2013/01/09/s3-rewrite-rule-limit Amazon S3 rewrite rules are limited and not explicitly defined in the documentation where you would expect. Find out the limit in this article. http://junctionbox.ca/2012/11/14/devops-geeknight.html Wed, 14 Nov 2012 00:00:00 +0000 http://junctionbox.ca/2012/11/14/devops-geeknight A 45m talk on the tools and practises used in DevOps from build to deployment to monitoring. http://junctionbox.ca/2012/08/18/energy-cost-of-the-internet.html Sat, 18 Aug 2012 00:00:00 +0000 http://junctionbox.ca/2012/08/18/energy-cost-of-the-internet Servers are power hungry, this article explores just how hungry those 33m servers that run the internet are. http://junctionbox.ca/2012/08/04/kings-college-and-the-power-of-play.html Sat, 04 Aug 2012 00:00:00 +0000 http://junctionbox.ca/2012/08/04/kings-college-and-the-power-of-play A brief post with with photos from Kings College in Cambridge. http://junctionbox.ca/2011/06/18/branching-by-abstraction.html Sat, 18 Jun 2011 00:00:00 +0000 http://junctionbox.ca/2011/06/18/branching-by-abstraction Branching by Abstraction is like milk and honey for Continuous Delivery. This article discusses some of the issues and motivation for using it. http://junctionbox.ca/2011/05/28/feature-flags-101.html Sat, 28 May 2011 00:00:00 +0000 http://junctionbox.ca/2011/05/28/feature-flags-101 Feature Flags aid Continuous Delivery by allowing the release of incomplete or untested features. See the simple example in this post. http://junctionbox.ca/2011/02/10/bootstrapping-windows.html Thu, 10 Feb 2011 00:00:00 +0000 http://junctionbox.ca/2011/02/10/bootstrapping-windows http://junctionbox.ca/2010/10/05/initial-configuration-of-puppetd-on-os-x.html Tue, 05 Oct 2010 00:00:00 +0000 http://junctionbox.ca/2010/10/05/initial-configuration-of-puppetd-on-os-x http://junctionbox.ca/2010/08/01/dance-and-pivot-sql-style.html Sun, 01 Aug 2010 00:00:00 +0000 http://junctionbox.ca/2010/08/01/dance-and-pivot-sql-style http://junctionbox.ca/2010/04/17/simplified-tdd-with-sinatra-autotest.html Sat, 17 Apr 2010 00:00:00 +0000 http://junctionbox.ca/2010/04/17/simplified-tdd-with-sinatra-autotest http://junctionbox.ca/2010/03/24/dom-a-regato-my-tests-are-auto.html Wed, 24 Mar 2010 00:00:00 +0000 http://junctionbox.ca/2010/03/24/dom-a-regato--my-tests-are-auto http://junctionbox.ca/2010/02/23/fresh-book-it.html Tue, 23 Feb 2010 00:00:00 +0000 http://junctionbox.ca/2010/02/23/fresh-book-it http://junctionbox.ca/2009/12/12/approaching-bliss-tdd+php+mvc.html Sat, 12 Dec 2009 00:00:00 +0000 http://junctionbox.ca/2009/12/12/approaching-bliss--tdd+php+mvc http://junctionbox.ca/2009/11/03/kick-dependence-here-s-an-injection.html Tue, 03 Nov 2009 00:00:00 +0000 http://junctionbox.ca/2009/11/03/kick-dependence--here-s-an-injection http://junctionbox.ca/2009/06/17/tripping-over-rubies-while-camping.html Wed, 17 Jun 2009 00:00:00 +0000 http://junctionbox.ca/2009/06/17/tripping-over-rubies-while-camping http://junctionbox.ca/2008/09/23/rest-+-less-weekend-while-camping.html Tue, 23 Sep 2008 00:00:00 +0000 http://junctionbox.ca/2008/09/23/rest-+-less-weekend-while-camping http://junctionbox.ca/2008/09/19/sprout-an-aswing.html Fri, 19 Sep 2008 00:00:00 +0000 http://junctionbox.ca/2008/09/19/sprout-an-aswing http://junctionbox.ca/2008/09/04/ruby-be-nimble-ruby-be-swf.html Thu, 04 Sep 2008 00:00:00 +0000 http://junctionbox.ca/2008/09/04/ruby-be-nimble--ruby-be-swf--- http://junctionbox.ca/2008/08/26/watch-for-flying-bitmaps.html Tue, 26 Aug 2008 00:00:00 +0000 http://junctionbox.ca/2008/08/26/watch-for-flying-bitmaps http://junctionbox.ca/2008/07/25/beware-the-garbage-man-s-scope.html Fri, 25 Jul 2008 00:00:00 +0000 http://junctionbox.ca/2008/07/25/beware-the-garbage-man-s-scope http://junctionbox.ca/2008/07/04/regular-expression-parsed-elation.html Fri, 04 Jul 2008 00:00:00 +0000 http://junctionbox.ca/2008/07/04/regular-expression---parsed-elation http://junctionbox.ca/2008/06/26/subversive-lyrics-with-subversion.html Thu, 26 Jun 2008 00:00:00 +0000 http://junctionbox.ca/2008/06/26/subversive-lyrics-with-subversion http://junctionbox.ca/2008/06/26/scrollpane-woes-to-fix-the-flow.html Thu, 26 Jun 2008 00:00:00 +0000 http://junctionbox.ca/2008/06/26/scrollpane-woes-to-fix-the-flow http://junctionbox.ca/2006/04/17/rsync-daily-snapshots.html Mon, 17 Apr 2006 00:00:00 +0000 http://junctionbox.ca/2006/04/17/rsync-daily-snapshots