feta/process/handlers.go

package process

import (
	"encoding/json"
	"fmt"
	"net/http"
	"runtime"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
)

type hash map[string]interface{}

func (a *Server) instances() []hash {
	resp := make([]hash, 0)
	now := time.Now()
	for _, v := range a.feta.manager.ListInstances() {
		i := make(hash)
		// FIXME figure out why a very short lock here deadlocks
		v.Lock()
		i["hostname"] = v.Hostname
		i["nextCheck"] = v.NextFetch.UTC().Format(time.RFC3339)
		i["nextCheckAfter"] = (-1 * now.Sub(v.NextFetch)).String()
		i["successCount"] = v.SuccessCount
		i["errorCount"] = v.ErrorCount
		i["identified"] = v.Identified
		i["status"] = v.Status()
		i["software"] = "unknown"
		i["version"] = "unknown"
		if v.Identified {
			i["software"] = v.ServerImplementationString
			i["version"] = v.ServerVersionString
		}
		v.Unlock()
		resp = append(resp, i)
	}
	return resp
}

func (a *Server) instanceSummary() map[string]int {
	resp := make(map[string]int)
	for _, v := range a.feta.manager.ListInstances() {
		v.Lock()
		resp[fmt.Sprintf("STATUS_%s", v.Status())]++
		if v.ServerImplementationString != "" {
			//FIXME(sneak) sanitize this to a-z0-9, it is server-provided
			resp[fmt.Sprintf("SOFTWARE_%s", strings.ToUpper(v.ServerImplementationString))]++
		}
		v.Unlock()
	}
	return resp
}

func (a *Server) getInstanceListHandler() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {

		result := &gin.H{
			"instances": a.instances(),
		}

		json, err := json.Marshal(result)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.Header().Set("Content-Type", "application/json")
		w.Write(json)
	}
}

func (a *Server) getIndexHandler() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		index := &gin.H{
			"server": &gin.H{
				"now":        time.Now().UTC().Format(time.RFC3339),
				"uptime":     a.feta.uptime().String(),
				"goroutines": runtime.NumGoroutine(),
				"goversion":  runtime.Version(),
				"version":    a.feta.version,
				"buildarch":  a.feta.buildarch,
			},
			"instanceSummary": a.instanceSummary(),
		}

		json, err := json.Marshal(index)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.Header().Set("Content-Type", "application/json")
		w.Write(json)
	}
}

func (a *Server) getHealthCheckHandler() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		resp := &gin.H{
			"status": "ok",
			"now":    time.Now().UTC().Format(time.RFC3339),
			"uptime": a.feta.uptime().String(),
		}

		json, err := json.Marshal(resp)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		w.Write(json)
	}
}