Cogini Blog
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Deploying an Elixir app to Digital Ocean with mix_deploy Port forwarding with iptables
Incrementally migrating large Rails apps to Phoenix
Here are the slides for the presentation on incrementally migrating large Rails apps to Phoenix I gave at Ruby Elixir Conf Taiwan 2018. Read more…
Is Elixir/Phoenix ready for production?
How I evaluated Elixir in 2014 when we were deciding whether it was mature enough Read more…
Setting Ansible variables based on the environment
When deploying applications, we we usually have the same basic architecture in different environments (dev, test, prod), but settings differ. Some settings are common to all the machines in the environment, e.g. the db server connection string. We need to vary the size of instances depending on the environment … Read more…
What makes a language popular?
In the recent HackerRank developer survey, we can see "Which languages do employers look for by industry?" and "Which languages are developers planning to learn next?" In terms of popularity, there is a definite swing to JavaScript and Python. In terms of mind share with language enthusiasts, not so much … Read more…
KYC wall of shame
There is a saying that frustration is an occupational hazard of being a user experience designer (or an excessively logical engineer). Once you start designing processes, you see process problems everywhere, whether or not you want to. As an American living in Taiwan, I am used to being the weird … Read more…
Debugging your space probe
Years ago we were building an embedded vehicle tracker for commercial vehicles. The hardware used an ARM7 CPU, GPS and GPRS modem, running uClinux. We ran into a tough bug in the initial application startup process. The program that read from the GPS and sent location updates to the network … Read more…
Is it time for Lisp in DevOps?
We have been working on a project migrating a big Rails app from physical hardware to AWS, and I have been doing a lot of automation work. It strikes me how we are doing the same thing over and over with different tools: reading variables, templating files and running semi-declarative … Read more…
PayPal Know Your Customer failure
Applying for a merchant account so you can accept credit cards traditionally takes weeks. You meet with the bank, show them your financial statements, and explain your business. Then they make you an offer for e.g. 2.8% + $0.30 per transaction (plus other mystery fees that you find … Read more…
Secure web applications with GraphQL and Elixir
In traditional applications, the web application talks directly to the database. It has rights to do anything, relying on application rules to control access. If an attacker compromises it, then they can do anything, e.g. grab all the data or create a funds transfer transaction. When security is critical … Read more…
Incrementally migrating a legacy app to Phoenix
Over the years we have done lots of projects where we migrated an application from one platform to another. We might do this to solve performance issues or to switch to a better technology stack. This can be a challenge when you have a big app that is in production … Read more…