Pull Requests (or whatever their equivalents are called in your favorite Git distribution) are a norm. Most of us adopted them as the primary way of reviewing and accepting changes that will ultimately be deployed to production. They work hand-in-hand with feature branches.
I stand by my claim that "you do not need to understand Kubernetes to use Jenkins X." To be more precise, those who do not want to know Kubernetes and its ecosystem in detail can benefit from Jenkins X ability to simplify the processes around software development lifecycle. That's the promise or, at least, one of the driving ideas behind the project. Nevertheless, for that goal to reach as wide of an audience as possible, we need a variety of build packs. The more we have, the more use cases can be covered with a single
jx import or
jx quickstart command. The problem is that there is an infinite number of types of applications and combinations we might have. Not all can be covered with community-based packs. No matter how much effort the community puts into creating build packs, they will always be a fraction of what we might need. That's where you come in.
If you're reading this, the chances are that you do not want to use
jx cluster create to create a new cluster that will host Jenkins X. That is OK, or even welcome. That likely means that you are already experienced with Kubernetes and that you already have applications running in Kubernetes. That's a sign of maturity and your desire to add Jenkins X to the mix of whichever applications you are already running there. After all, it would be silly to create a new cluster for each set of applications.
However, using an existing Kubernetes cluster is risky. Many people think that they are so smart that they will assemble their Kubernetes cluster from scratch. "We're so awesome that we don't need tools like Rancher to create a cluster for us." "We'll do it with
kubeadm." Then, after a lot of sweat, we announce that the cluster is operational, only to discover that there is no StorageClass or that networking does not work. So, if you assembled your own cluster and you want to use Jenkins X inside it, you need to ask yourself whether that cluster is set up correctly. Does it have everything we need? Does it comply with standards, or did you tweak it to meet your corporate restrictions? Did you choose to remove StorageClass because all your applications are stateless? Were you forced by your security department to restrict communication between Namespaces? Is the Kubernetes version too old? We can answer those and many other questions by running compliance tests.
To understand intricacies and inner workings of Jenkins X, we need to understand Kubernetes. But, you do not need to understand Kubernetes to use Jenkins X. That is one of the main contributions of the project. Jenkins X allows us to harness the power of Kubernetes without spending eternity learning the ever-growing list of the things it does. Jenkins X helps us by simplifying complex processes into concepts that can be adopted quickly and without spending months in trying to figure out "the right way to do stuff." It helps by removing and simplifying some of the problems caused by the overall complexity of Kubernetes and its ecosystem. If you are indeed a Kubernetes ninja, you will appreciate all the effort put into Jenkins X. If you're not, you will be able to jump right in and harness the power of Kubernetes without ripping your hair out of frustration caused by Kubernetes complexity.
When I finished the last book (The DevOps 2.5 Toolkit: Monitoring, Logging, and Auto-Scaling Kubernetes), I wanted to take a break from writing for a month or two. I thought that would clear my mind and help me decide which subject to tackle next. Those days were horrible. I could not make up my mind. So many cool and useful tech is emerging and being adopted. I was never as undecided as those weeks. Which should be my next step?
I could explore serverless. That's definitely useful, and it might be considered the next big thing. Or I could dive into Istio. It is probably the biggest and the most important project sitting on top of Kubernetes. Or I could tackle some smaller subjects. Kaniko is the missing link in continuous delivery. Building containers might be the only thing we still do on the host level, and Kaniko allows us to move that process inside containers. How about security scanning? It is one of the things that are mandatory in most organizations, and yet I did not include it in "The DevOps 2.4 Toolkit: Continuous Deployment To Kubernetes". Then there is skaffold, prow, KNative, and quite a few other tools that are becoming stable and very useful.
The DevOps 2.5 Toolkit: Monitoring, Logging, and Auto-Scaling Kubernetes is finally finished!!!
What do we do in Kubernetes after we master deployments and automate all the processes? We dive into monitoring, logging, auto-scaling, and other topics aimed at making our cluster resilient, self-sufficient, and self-adaptive.
There are quite a few candidates for your need for centralized logging. Which one should you choose? Will it be Papertrail, Elasticsearch-Fluentd-Kibana stack (EFK), AWS CloudWatch, GCP Stackdriver, Azure Log Analytics, or something else?
When possible and practical, I prefer a centralized logging solution provided as a service, instead of running it inside my clusters. Many things are easier when others are making sure that everything works. If we use Helm to install EFK, it might seem like an easy setup. However, maintenance is far from trivial. Elasticsearch requires a lot of resources. For smaller clusters, compute required to run Elasticsearch alone is likely higher than the price of Papertrail or similar solutions. If I can get a service managed by others for the same price as running the alternative inside my own cluster, service wins most of the time. But, there are a few exceptions.
What to automate? Which parts of the delivery process are good candidates? Which applications will benefit from automation? At first, those sound like silly questions. Automate all your repetitive processes. If you think that you'll do the same thing manually more than once, automate it. Why would you waste your creative potential and knowledge by doing things that are much better done by scripts? If we can create robots that assemble cars, we can surely create a Jenkins job that builds software, runs tests, and deploys containers. Car assembly is undoubtedly harder to accomplish than building software. Yet, an average company does not adhere to that logic. Why is that?
Two main culprits prevent many companies from automating all the repetitive process; silos and legacy code.
Kubernetes HorizontalPodAutoscaler (HPA) and Cluster Autoscaler (CA) provide essential, yet very rudimentary mechanisms to scale our Pods and clusters. While they do scaling decently well, they do not solve our need to be alerted when there's something wrong, nor do they provide enough information required to find the cause of an issue. We'll need to expand our setup with additional tools that will allow us to store and query metrics as well as to receive notifications when there is an issue.
If we focus on tools that we can install and manage ourselves, there is very little doubt about what to use. If we look at the list of Cloud Native Computing Foundation (CNCF) projects, only two graduated so far (October 2018). Those are Kubernetes and Prometheus. Given that we are looking for a tool that will allow us to store and query metrics and that Prometheus fulfills that need, the choice is straightforward. That is not to say that there are no other similar tools worth considering. There are, but they are all service based. We might explore them later but, for now, we're focused on those that we can run inside our cluster. So, we'll add Prometheus to the mix and try to answer a simple question. What is Prometheus?
Unlike GKE, EKS does not come with Cluster Autoscaler. We'll have to configure it ourselves. We'll need to add a few tags to the Autoscaling Group dedicated to worker nodes, to put additional permissions to the Role we're using, and to install Cluster Autoscaler.