All Blog posts

Enabling Audit Logs for Docker Desktop's Kubernetes

Have you ever needed to turn on audit logs for the Kubernetes cluster bundled with Docker Desktop and wasn't sure how? Well, here's how!

Creating Tenant Node Pools with Karpenter

While attempting to build a multi-tenant Kubernetes platform, I decided to use Karpenter to help create node pools for each tenant. Here's how we made each pool and forced tenants into the pool.

Making Kubernetes Multi-tenant

At Virginia Tech, I've been leading an effort to build a multi-tenant platform, currently on top of Kubernetes. But, there are a lot of things needed to pull this off. We'll dive into some of those in this post.

Deploying Karpenter with Terraform

Karpenter is a new auto-scaling component from AWS and its docs are still growing. Here's how to deploy it using Terraform.

Build Once and Deploy Everywhere for SPAs

It's often tempting to use process.env in your frontend code. But, that means you either have to run Node in all environments or need to build the app for each location. How can we build once, deploy anywhere? In this post, we'll talk about externalizing our configuration.

Compose with K8s and Flux

Compose has slowly been adding support for additional backends, including an experimental k8s backend. I've been doing some digging to figure out how to support GitOps workflows, yet hook into the Docker Compose tooling.

Deploying Compose Apps using Helm

I've been working to standardize app deployments using the Compose spec. By creating a special chart that accepts a Compose file as its values file, teams can deploy apps on k8s using only Compose. And it's fully GitOps compatible! Learn more here!

EKS Pod Identity Webhook Deep-Dive

While exploring the EKS Pod Identity Webhook, I realized there isn't much written about how it works. This helps solve that!

DockerCon Recording Setup

Several folks asked about my recording setup for my DockerCon 2020 talk. So, here's my hardware, as well as some tips I learned along the way!

Creating a Kubernetes Monitor with BlinkSticks

In an effort to learn more about ServiceAccounts and how to talk to the k8s API from inside a container, I built an app that displays the current status of the cluster with lights! Here's how I did it!

Running Traefik on Worker Nodes More Securely

Running Traefik in a Swarm cluster on non-managers can be tricky. There are quick and easy ways, but there are more secure ways. In this post, we'll talk about using a Docker Socket proxy to better protect us.

Using SSH Connections in Docker Contexts

Docker Contexts make it easy to manage remote Docker machines. Here's how to use SSH to connect to your remote machines.

Using DB queries as Prometheus metrics

Monitoring large migrations can be tough. But, with query-exporter, we were able to export custom queries as Prometheus metrics to feed a Grafana dashboard. Here's how we did it!

Creating an Elastic QA Env using AWS

How can you build an elastic QA environment that can support many concurrent stacks, be quickly available, yet minimize costs? I'll tell you how we did it!

Keeping Docker App Updated

In my last post, I talked about how we're using Docker App in development. In this post, I dive into how we keep it up-to-date when using several upstream component repos.

Using Docker App in Development

My dev team has been using Docker App for 8 months and it has changed everything. Here's what our environment looks like now.

Sharing Network Namespaces in Docker

I recently wanted to test a multi-container ECS task definition locally, which means using a single network namespace. But, how? And what does it buy me?

2018 Recap and 2019 Goals

2018 was quite a year! Here's a quick recap, as well as goals for the upcoming year!

Using EC2 Tags to Dynamically Join ECS Cluster

Here's a quick tip on how to join an ECS cluster at startup using EC2 tags

DockerCon EU 2018 Takeaways

DockerCon EU 2018 has come and gone! It was a blast and here are my key takeaways!

Pro-tip - Using socat to see Docker socket traffic

Quick pro-tip - use socat to "sniff" the Docker client/server traffic

Letting Traefik run on Worker Nodes

If you're using Traefik in Swarm mode, it needs to listen to Docker events. Here's how to do it without having all of your traffic go through manager nodes.

Leveraging Multi-stage Builds to use a Single Dockerfile for Dev and Prod

Using multi-stage builds with the target flag, we can use a single Dockerfile for dev and prod

Sign your commits... or else!

Why's it important to sign your commits? Here's why! And here's how GitHub/GitLab can make things better

"You build it, you run it" with Docker and SAM

We've been working hard to support "You build it, you run it" at Virginia Tech. Here's our journey...

2017 Recap and 2018 Goals

2017 was a fantastic year for me. Here's a few of my highlights, as well as where I'd like to go this year.

DockerCon EU 2017 - Dino Behind the Scenes

Go behind the scenes to find out the story of the dinos at DockerCon EU!

Pro Tip - Fail chained commands in Dockerfile RUN

You build an image. Great! It runs. But, not everything is there. Why not? Could it be a bad RUN command?

Using Docker Secrets during Development

Docker Secrets are amazing! Using them in development can be tricky though. Here are four methods to help out.

Docker is NOT a Hypervisor

Docker is often portrayed as a hypervisor, but it's not. Here's a quick reminder...

Introducing Docker Multi-Stage Builds

Docker has recently merged in support to perform "multi-stage builds." In other words, it allows you to orchestrate a pipeline of builds within a single Dockerfile. Here's a quick rundown...

Managing Secrets in Docker Swarm

Docker 1.13 was released just a few days ago (blog post here). With it came several improvements to Docker Swarm. One highly anticipated improvement (at least by me anyways) is secrets management. In this post, we'll see how to add secrets to a swarm and how to make them available to running services.

Using Docker to Proxy WebSockets on AWS ELBs

At the time of this blog post, AWS ELBs don't support WebSocket proxying when using the HTTP(s) protocol listeners. There are a few blog posts on how to work around it, but it takes some work and configuration. Using Docker, these complexities can be minimized.

In this post, we'll start at the very beginning. We'll spin up an ELB, configure its listeners, and then deploy an application to an EC2 instance.

Create a Docker 1.12+ Swarm using docker-machine

In case you missed it, DockerCon 2016 was amazing! There were several great features announced, with most of it stemming from orchestration is now built-in. You get automatic load balancing (the routing mesh is crazy cool!), easy roll-outs (with healthcheck support), and government-level security by default (which is crazy hard to do by yourself).

In case you're a little confused on how to spin up a mini-cluster, this post will show you how. It's pretty easy to do!

Writing Functional Tests with Drone and Graphene that Don't Suck

I've been writing functional tests with Drone and Graphene for a while and have picked up a few "best practices" for myself. These best practices are designed around 1) make it obvious what you're testing and 2) use abstractions when available. After all…

Using Arquillian Drone and Graphene in Standalone Mode

I've been using Arquillian and its testing framework for a few years now and absolutely love it! It's super easy to manage a server's lifecycle, deploy applications, and then test them. Drone and Graphene's extensions also make it incredibly easy to write browser-based tests without getting too down and dirty with the Selenium WebDriver API (which is a little messy).

Since I love Drone and Graphene, it would be nice to use the page abstractions/fragments on non-Java apps (sure, you can use Arquillian Cube too… but that's another post). This post will go over what's needed to run Drone and Graphene in standalone mode.

Pushing to ECR Using Jenkins Pipeline Plugin

I've been recently spending quite a bit of time in the DevOps space and working to build out better CI/CD pipelines, mostly utilizing Docker. In this post, I demonstrate building out a pipeline that will create a simple Docker image and push it to Amazon's EC2 Container Registry.

Creating a Wildfly Docker image with PostgreSQL

If you've been following my blog, you probably already know that I've been playing with Docker for a while now. In this post, I will show you how I'm putting together a base Wildfly image and explain why I made some of the decisions I did.

Converting my blog from Wordpress to Jekyll

I recently made the decision to cut over my blog from using Wordpress to Jekyll. Might seem like an odd decision, but I'm loving it so far! Here's why…

Lessons after using Docker for a Month

If you haven't read the other posts about the Docker environment, I'd suggest going to check those out now. Otherwise, this post may not make a ton of sense.

Now that I've been running a Docker-based QA environment for a good month, there's been a few things I've learned that are worth mentioning. So… here goes!

Using Docker for QA Testing

At work, I’ve recently helped lead a migration to use a Docker-based approach for our QA testing. But first, if you haven’t read about we do our QA testing, you’ll probably want to read that here.

How we do QA Testing in Agile

There are many different ideas and approaches for doing QA testing, many of which depend on what project management style you’re using, the developers on the team, and if you have a QA/functional testing team. However, this is how I’ve found it to be successful, based on my observations working on the CREST team at Virginia Tech.

Marshalling Interfaces in JAX-RS

In Java, interfaces are used all over the place. Occasionally, these will need to be marshalled into XML/JSON. However, JAX-RS creates its own JAXBContext on its own. So, you may see exceptions like this…

Foo is an interface, and JAXB can't handle interfaces.
    this problem is related to the following location:
        at Foo
        at public Foo[] Response.getFoo()
        at Response
 
    at org.jboss.resteasy.plugins.providers.jaxb.AbstractJAXBProvider.getMarshaller(AbstractJAXBProvider.java:160) [resteasy-jaxb-provider-3.0.6.Final.jar:]
    at org.jboss.resteasy.plugins.providers.jaxb.AbstractJAXBProvider.writeTo(AbstractJAXBProvider.java:122) [resteasy-jaxb-provider-3.0.6.Final.jar:]
    at org.jboss.resteasy.core.interception.AbstractWriterInterceptorContext.writeTo(AbstractWriterInterceptorContext.java:129) [resteasy-jaxrs-3.0.6.Final.jar:]
    at org.jboss.resteasy.core.interception.ServerWriterInterceptorContext.writeTo(ServerWriterInterceptorContext.java:62) [resteasy-jaxrs-3.0.6.Final.jar:]
        ...

Ugly, huh? Here's how to fix it…

Using JDBC Security Domain in Wildfly

As I was going through this task, I ran into the whole “there’s so much documentation, but none of it is working or makes sense” problem that’s so common with the JBoss Application Server. So, this post is designed to help out!

Using Weld (CDI), JSF, and JAX-RS in Tomcat

We’ve recently been in the transition from using Spring in a Tomcat environment to Java EE7 in Wildfly? (still finalizing the container of choice).

Since we’re in transition, we’d like to run the application in both Tomcat and Wildfly, without having to make changes to the bundled application. It should just work on deploy. Here’s how to do it…

Give a home machine a subdomain using Dreamhost

Sometimes, it’s nice to give a home machine a subdomain for development purposes, or just for fun! Here’s how to do it through Dreamhost.

Adding Images to GitHub Wiki Repo

[Update on April 9, 2014] – updated URL patterns to reflect change in raw GitHub domain names

Adding images to GitHub is pretty straight forward if you can host the images somewhere or if you can put them into your main repository. But, what if you want them ONLY in the wiki? Here’s how to do it!

Sharing Web Resources using Maven

One of the advantages of using Maven is the ability to share common resources across projects. But, how do you do that with web resources, such as CSS, Javascript, and images? Here’s how…

Continuous Integration with Stash and Jenkins

[UPDATE] 10/14/2013 – Updated to match version 2.0 of the Stash Webhook for Jenkins

There are lots of posts about connecting Jenkins with GitHub, but not a lot about connecting Jenkins to Stash. So, hopefully this helps!

Starting Activity from Sleeping Device

Building off our AlarmManager, we want the ability to have the alarm appear, even if the device is locked. Here’s how.

Android – Creating an Alarm with AlarmManager

There aren’t a lot of good write-ups on how to use the AlarmManager, so here is an example that launches an Activity using the AlarmManager.

Google Voice Vulnerability

I’m the type of person that likes to figure out how stuff is architected and built. Whether it’s a building or software, it doesn’t matter.

One day, I was interested to find out how the process of adding a forwarding number works and if it might be possible to mess with it. Luckily for me, I did find such a way.