houston-be/cmd/app/server.go

package app

import (
	"fmt"
	"houston/cmd/app/handler"
	"houston/pkg/slackbot"
	"houston/service"
	"net/http"
	"strconv"
	"strings"
	"time"

	"houston/internal/clients"
	"houston/internal/metrics"

	"github.com/gin-gonic/gin"
	"github.com/spf13/viper"
	"go.uber.org/zap"
	"gorm.io/gorm"
)

type Server struct {
	gin           *gin.Engine
	logger        *zap.Logger
	db            *gorm.DB
	mjolnirClient *clients.MjolnirClient
}

func NewServer(gin *gin.Engine, logger *zap.Logger, db *gorm.DB, mjolnirClient *clients.MjolnirClient) *Server {
	return &Server{
		gin:           gin,
		logger:        logger,
		db:            db,
		mjolnirClient: mjolnirClient,
	}
}

func (s *Server) Handler() {
	s.readinessHandler()
	s.incidentClientHandler()

	s.gin.Use(s.createMiddleware())
	s.teamHandler()
	s.severityHandler()
	s.incidentHandler()
	s.usersHandler()
	s.filtersHandler()

	metrics.AdminHandler()
	//this should always be at the end since it opens websocket to connect to slackbot
	s.houstonHandler()
}

func (s *Server) createMiddleware() gin.HandlerFunc {

	return func(c *gin.Context) {
		whitelistedDomains := getWhitelistedDomains()

		//auth handling
		isAuthEnabled := viper.GetBool("auth.enabled")
		if isAuthEnabled {
			sessionResponse, err := s.mjolnirClient.GetSessionResponse(c.Request.Header.Get("X-Session-Token"))
			if err != nil || sessionResponse.StatusCode == 401 {
				c.AbortWithStatus(http.StatusUnauthorized)
				return
			}
		}

		//cors handling
		c.Writer.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS, GET, PUT")
		c.Writer.Header().Set("Access-Control-Allow-Headers", viper.GetString("allowed.custom.headers"))
		origin := c.Request.Header.Get("Origin")
		if !whitelistedDomains[origin] {
			c.AbortWithStatus(http.StatusUnauthorized)
			return
		}
		c.Writer.Header().Set("Access-Control-Allow-Origin", origin)

		if c.Request.Method == "OPTIONS" {
			c.AbortWithStatus(http.StatusOK)
			return
		}

		startTime := time.Now()
		c.Next()
		endTime := float64(time.Since(startTime))

		//metrics publishing
		status := strconv.Itoa(c.Writer.Status())
		metrics.HoustonApiRequestCounter.WithLabelValues(c.Request.URL.Path, c.Request.Method, status).Inc()
		metrics.HoustonApiRequestLatencySum.WithLabelValues(c.Request.URL.Path, c.Request.Method, status).Add(endTime)
		metrics.HoustonApiRequestLatencyHistogram.WithLabelValues(c.Request.URL.Path, c.Request.Method, status).Observe(endTime)
		metrics.HoustonApiRequestLatencySummary.WithLabelValues(c.Request.URL.Path, c.Request.Method, status).Observe(endTime)
	}
}

func getWhitelistedDomains() map[string]bool {
	allowedList := make(map[string]bool)
	domains := strings.Split(viper.GetString("whitelisted.domains"), ",")
	for _, domain := range domains {
		domainLocal := domain
		allowedList[domainLocal] = true
	}
	return allowedList
}

func (s *Server) houstonHandler() {
	houstonClient := NewHoustonClient(s.logger)
	houstonHandler := handler.NewSlackHandler(s.logger, s.db, houstonClient.socketModeClient)
	houstonHandler.HoustonConnect()
}

func (s *Server) teamHandler() {
	houstonClient := NewHoustonClient(s.logger)
	slackClient := slackbot.NewSlackClient(s.logger, houstonClient.socketModeClient)
	teamHandler := service.NewTeamService(s.gin, s.logger, s.db, slackClient)

	s.gin.GET("/teams", teamHandler.GetTeams)
	s.gin.GET("/teams/:id", teamHandler.GetTeams)
	s.gin.POST("/teams", teamHandler.UpdateTeam)
}

func (s *Server) severityHandler() {
	houstonClient := NewHoustonClient(s.logger)
	slackClient := slackbot.NewSlackClient(s.logger, houstonClient.socketModeClient)
	severityHandler := service.NewSeverityService(s.gin, s.logger, s.db, slackClient)

	s.gin.GET("/severities", severityHandler.GetSeverities)
	s.gin.GET("/severities/:id", severityHandler.GetSeverities)
	s.gin.POST("/severities", severityHandler.UpdateSeverities)
}

func (s *Server) incidentClientHandler() {
	houstonClient := NewHoustonClient(s.logger)
	incidentHandler := service.NewIncidentService(s.gin, s.logger, s.db, houstonClient.socketModeClient)

	s.gin.POST("/create-incident", incidentHandler.CreateIncident)
}

func (s *Server) incidentHandler() {
	houstonClient := NewHoustonClient(s.logger)
	incidentHandler := service.NewIncidentService(s.gin, s.logger, s.db, houstonClient.socketModeClient)

	s.gin.GET("/incidents", incidentHandler.GetIncidents)
	s.gin.GET("/incidents/:id", incidentHandler.GetIncidents)
	s.gin.POST("/incidents", incidentHandler.UpdateIncident)
	s.gin.GET("/incidents/header", incidentHandler.GetIncidentHeader)
}

func (s *Server) usersHandler() {
	houstonClient := NewHoustonClient(s.logger)
	slackClient := slackbot.NewSlackClient(s.logger, houstonClient.socketModeClient)
	usersHandler := service.NewUserService(s.gin, s.logger, slackClient)

	s.gin.GET("/users/:id", usersHandler.GetUserInfo)
	s.gin.GET("/users", usersHandler.GetUsersInConversation)
}

func (s *Server) filtersHandler() {
	filtersHandler := service.NewFilterService(s.gin, s.logger, s.db)

	s.gin.GET("/filters", filtersHandler.GetFilters)
}

func (s *Server) readinessHandler() {
	readinessHandler := service.NewReadinessService(s.gin)
	s.gin.GET("/ping", readinessHandler.Ping)
}

func (s *Server) Start() {
	s.logger.Info("starting houston server", zap.String("port", viper.GetString("port")))
	s.gin.Run(fmt.Sprintf(":%v", "8080"))
}