has fostered a whole new way of thinking about application deployment, because con- figuration files are used to declare the creation of container instances and dictate how the platform goes on to deploy into a shared repository on a regular basis. CI is a form of rapid development that emerged as a result of the Agile Manifesto. CI is also a solution to the problem of having too many branches of an application software infrastructure at a datacenter using configuration files that are both ma- chine-readable and human-readable. The configuration files are machine-readable in a structured format (usually YAML)

GitOps is based on the declarative nature of Kubernetes and its automatic deployment of committed files. GitOps leverages these attributes according to the four following principles: Kubernetes is just DevOps refinement, it’s become clear that the ops portion is the least understood by developers. As a result, many teams don’t realize the full benefits of their DevOps environment because the operational

CONFIGURATION DRIFT DETECTION A GitOps approach suggests that your declarative configuration files and application code should be stored together in the Git repository. This is what we call the and SRE teams are adopting GitOps so that you can store all your infrastructure configuration files as code. GitOps innately has Infrastructure as code as one of its characteristics. STRONGER below: HELM Helm is based on the parameterized templating approach where all resource definition files of applications are templated to make them customizable based on the requirement. Nowadays, it is

microservice repo and in that repo, you bundle your application code along with deployment YAML manifest files or a Helm chart that define how your application will run in your cluster. When you push that code com/microservices-demo/microservices-demo - This is the repo that stores the Kubernetes configuration files for the application. The Weave Cloud deployment agent automatically updates the front- end YAML manifest ssh URL with the path to the YAML files for the microservices-demo: SSH URL: git@github.com:/microservices-demo Path to YAML files: deploy/kubernetes/manifests

Target audience ✅ If you want to ... ● play with Istio offerings ● see the actual configuration files ● understand how Istio can be used / installed with other services ● know what multicluster challenges detail with ready-to-be-used configuration files. #IstioCon What is covered in the talk ● Istio multicluster installation and setup ● All configurations in files ● Traffic management offerings in action

automation/scripting, declarative environment minimizes or eliminates this need ● Declarations are yaml files which are easily stored and managed in git OpenShift GitOps Principles ● Separate application source yaml everywhere? Kustomize - What is it? Kustomize lets you customize raw, template-free YAML files for multiple purposes, leaving the original YAML untouched and usable as is. ● Kustomize is a patching

testing. Let’s say that you want to run some smoke tests AFTER a deployment has finished and the result of the tests will decide if a rollback will take place or not. Smoke tests As I said means that you are forced to use your CI solution again in order to run the smoke tests. The end result is a mixture of CI-CD-CI-CD components that goes against the main spirit of GitOps. There are also templates for Kubernetes manifests along with their runtime values that are merged to create the end result of what is deployed in the cluster. While you can provide a values.yml file on the fly when

declaratively. This declarative approach is focused on the result (desired state) rather than the steps needed to achieve the required result. This declarative approach allows users to specify the end

│ ├── ingress.yaml │ ├── prometheusrule.yaml │ ├── deployment.yaml │ └── service.yaml ├── files ## templates 依赖的各种文件 │ ├── http-probe.sh │ ├── offline

staging- api, testing-api, pre-prod-api, Prod-api) 6 解決辦法? •寫5份deployment 的yaml 嗎？ •需要維護5份yaml files •一份deployment yaml在用sed replace嗎? •容易出錯 •把他打包成Helm chart嗎？在帶入variable 嗎？ •複雜度過高 7 Kustomize