engine-report-analysis

package main

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"os"

	"gopkg.in/yaml.v2"
)

func main() {
	files := os.Args[1:]
	if len(files) == 0 {
		log.Fatal("expected at least on file")
	}
	rules := []Rule{
		NewRaftRule(),
	}
	for _, file := range files {
		f, err := os.Open(file)
		if err != nil {
			log.Fatal(err)
		}

		row1, _, err := bufio.NewReader(f).ReadLine()
		if err != nil {
			log.Fatal(err)
		}

		_, err = f.Seek(int64(len(row1)), io.SeekStart)
		if err != nil {
			log.Fatal(err)
		}

		var report Report
		if err := yaml.NewDecoder(f).Decode(&report); err != nil {
			log.Fatal(err)
		}

		// TODO (pick a better name somehow - agent.name?)
		name := report.Manifolds["agent"].Report.Agent
		for _, rule := range rules {
			rule.Run(name, report)
		}
	}

	fmt.Println("Analysis of Engine Report:")
	fmt.Println("")
	for _, rule := range rules {
		fmt.Println(rule.Summary())
		fmt.Println("\t", rule.Analyse())
	}
}

type Report struct {
	Manifolds map[string]Worker `yaml:"manifolds"`
}

type Worker struct {
	Inputs     []string     `yaml:"inputs"`
	Report     WorkerReport `yaml:"report"`
	StartCount int          `yaml:"start-count"`
	Started    string       `yaml:"started"`
	State      string       `yaml:"state"`
}

type WorkerReport struct {
	Agent string `yaml:"agent"`
	State string `yaml:"state"`
}

type Rule interface {
	Run(string, Report)
	Summary() string
	Analyse() string
}

type RaftRule struct {
	found   map[string]bool
	leaders map[string]bool
}

func NewRaftRule() *RaftRule {
	return &RaftRule{
		found:   make(map[string]bool),
		leaders: make(map[string]bool),
	}
}

func (r *RaftRule) Run(name string, report Report) {
	raft, ok := report.Manifolds["raft"]
	if !ok {
		r.found[name] = false
		return
	}

	r.found[name] = true
	r.leaders[name] = raft.Report.State == "Leader"
}

func (r *RaftRule) Summary() string {
	return "Raft Leader:"
}

func (r *RaftRule) Analyse() string {
	var leader bool
	var ctrl string
	for name, ldr := range r.leaders {
		if leader && ldr {
			// Two or more leaders
			return "Two or leaders have been found in the files."
		}
		if ldr {
			leader = true
			ctrl = name
		}
	}
	if !leader {
		return fmt.Sprintf("There are no leaders found.")
	}
	return fmt.Sprintf("%s is the leader.", ctrl)
}