Go Fun

This repository follows the philosophy of Learning by Doing. It includes plays, experiments with Golang and its frameworks to learn. Later Kubernetes including Docker, Istio (Service Mesh), Performance testing is also included.

• FunApp

  FunApp is a Sample Rest App which tries to use various golang Frameworks commonly required. It tries to follow good practices and standards. It runs without any dependencies with in memory sqlite3 database by default.

  • Setup

    • Onetime

      • We will use Make for Project Management.
      • Installs required dependencies and tools, make prepare
      • To check what all is available run make to display Help.
    • Run make reset will do Complete Build, Test, Coverage and Show Info.
    • Use make info (or infos) for displaying Info.

  • Play

    Easy ways to Play with FunApp without Dev Setup.
    • Start
      • Golang: make run
      • Docker Image: docker run amanfdk/fun-app
    • Testing
      • Unit and Integration Testing is done via Ginkgo.
      • Run Tests: make test test-slow (Excludes that require separate setup.)
    • Performance Test Vegeta is the tool of choice here. Gum helps in prompts.
      • Installation: brew install gum vegeta
      • Run: make -C ./components/fun-app/it setup
    • Linting
      • make lint will do Code Linting using golangci-lint

  • Dev Setup

    This section guides on setup for Development Setup for this Repository. We are using Vscode and Kubernetes for this example.

    • Vscode

      • Use Command Palatte and run application using > Select and Start Debugging and then Select FunApp
      • Change ENV to override default Configuration.
      • 

    • Development Container

      • Development help you live debug an application in K8 Cluster.
      • It is configured to Auto Reload Code Changes.
      • This Sets Up Dev Container in fun-app Namespace.
      • Try:
        • Run make space, Open http://localhost:8080/metrics
        • Tests: make space-test
        • Cleanup: make space-purge
        • Check Environment Vars: make infos
        • Override Vars: devspace list vars --var DB="mysql-primary",RATE_LIMIT=10
      • 

    • Kubernetes Cluster

      • Below Section requires running Kubernetes Cluster and Helm CLI. Charts can be used from local or from Github.
      • Via Github
        • Setup: helm install -n fun-app fun-app go-fun/fun-app (Onetime Setup Needed)
        • Cleanup: helm -n fun-app delete fun-app
      • Via Local
        • Deploys FunApp and Vegeta Container (for Load Test).
        • Setup: make -C ./components/fun-app/charts setup (or reset)
        • Clean: make -C ./components/fun-app/charts clean (or info)
      • Access
        • Open: http://localhost:9090/metrics (Tunnel required for forwarding: minikube tunnel)
        • Load Test (From Vegeta Container): echo 'GET http://fun-app:9090/person/all' | vegeta attack | vegeta report
        • Log Analyzer : make -C ./components/fun-app/charts analyse
      • 

• Tools

  • Kubernetes

    To ease development and easy setup of dependencies we use Kubernetes. Also K9S provides easy interface to manage containers, see logs etc. Helms are used to setup various services which application can depend on.

    • Minikube

      • To setup kubernetes there are multiple options available like minikube, kind, k89, k3s etc. In this project we are using minikube.
      • This will also setup traifik ingress for easy access.
        • DNS Mapping via /etc/hosts is done as part of Onetime Prepration.
        • User needs to give sudo for port 80 forward.
      • Setup - make -C ./Kubernetes setup (or reset for clean and setup)
      • Teardown - make -C ./Kubernetes clean
      • Useful Targets: Istio Setup istio, Info (info or infos), Portforward port, K8 Dashboard dashboard.
      • 

    • Services

      • Package has multiple service which can be setup on top of Minikube. This helps in easy setup of complex dependencies like Mysql Cluster, Load Testing, Mongo, Prometheus, Sonar and many more ...
      • Service Script allows you to configure a set of Services. This can then be installed, upgraded or deleted.
      • Select: make -C ./Kubernetes/services select will show a gum menu (Multiselect) to choose one or more services.
      • Setup: make -C ./Kubernetes/services setup (or reset) to deploy selected services.
      • Update: make -C ./Kubernetes/services update to update values or helm chart changes.
      • Stop: make -C ./Kubernetes/services clean to remove deployed helms. (Configured Services only)
      • Info: make -C ./Kubernetes/services info (or infos)
      • 

  • Log Analyzer

    • Monitor Logs via GoAccess
      • Terminal Access: go run main.go | goaccess --log-format='%^ %d - %t | %s | %~%D | %b | %~%h | %^ | %m %U' --date-format='%Y/%m/%d' --time-format '%H:%M:%S'
      • Web Access
        • Add Flags to Above Command -o report.html --real-time-html.
        • Open report.html in Browser and it should auto refresh.
    • Useful Fields

      • Mandatory Fields: %d (Date), %h (Host), %r/%m %U (Request)

      • Skip: Ignore (%^) , Skip Space (%~)

      • DateTime: (%x/--datetime-format) OR Time (%t/--date-format) + Date (%d/--time-format)

      • Host: IP (%h) OR Virtual Host (%v)

      • Request: Full With Quotes (%r) or Method (%m), URL (%U), Query (%q), PROTOCOL (%H),

      • Response: Status Code (%s), Size (%b)

      • Latency: MicroSecond (%D), MilliSecond.MicroSecond (%T), MilliSecond With Decimal (%L)

      • User Info: User-Agent (%u), Referrer (%R)

        TODO: Add GIF

    • Custom Log Monitoring
      • Custom Logs require configuring various flags.
      • Identify Date and Time Format.
        • Configured via flag --date-format and --time-format
        • Verify Format, bash run: date '+%Y/%m/%d - %H:%M:%S' for output 2023/01/23 - 14:38:2
      • Identify Log Format
        • Configured via flag --log-format
        • Start with initial fields and progress further for easy debug.
      • Debug Mode: -l debug.log
  • TODO Tree Extension
    • TODO Long Planned Enhancement in Code
    • FIXME Medium Sized fix or Unhandled Case.
    • HACK Remove Hacky way to Do Things.
    • BUG Small Bug which is observed but need Fix.
    • XXX Someday Tasks which may or may not be Done.
    • #A #B #C for Priortizations. Eg. BUG: #A Some Message

• Golang

  This section covers common practices and tools for Golang.

  • Module Management

    This is multi module project. Each module has its own go mod file. Modules can be managed using semver tags. Eg. v1.0.0
    • Sync Modules using make sync. This is automatically done before builds.
    • Mod
      • New Module run go mod init github.com/amanhigh/go-fun/components/fun-app and to work using go work use ./components/fun-app
      • Link Module to new Release using go mod tidy or go get -u github.com/amanhigh/go-fun/models
      • Recursive Depdency Update find . -name "go.mod" -execdir sh -c 'go get -u && go mod tidy'; (Run it in ProjectBase Dir)
    • Tags
      • See existing tags. git tag | grep common
      • Tag New Release. git tag common/v1.0.0 followed by git push --tags
      • Remove Release involves deleting Tag with git push --delete origin common/v1.0.0

  • Release Management

    Release management includes build and release of Artifacts like binaries, dockers etc.
    • Build Only - make build docker-build (add clean to remove residue)
    • Release - make release release-docker VER=v1.0.3
    • Delete Release - make unrelease VER=v1.0.3 (Not Recommended)