server: Fail early for non-existent service name

The default value is 5 for interval.

.drone.yml

@@ -0,0 +1,68 @@
+kind: pipeline
+name: Build Application
+steps:
+- name: Build
+  image: golang:1.14
+  commands:
+  - go build ./...
+  volumes:
+  - name: deps
+    path: /go
+- name: Test
+  image: golang:1.14
+  commands:
+  - go test ./...
+  volumes:
+  - name: deps
+    path: /go
+- name: Lint
+  image: golangci/golangci-lint:v1.25.0
+  commands:
+  - golangci-lint run -v
+  volumes:
+  - name: deps
+    path: /go
+
+volumes:
+- name: deps
+  temp: {}
+
+---
+kind: pipeline
+name: Build Docker Image
+steps:
+- name: Build Docker Image
+  image: plugins/docker
+  settings:
+    registry: docker.teamortix.com
+    username: droneci
+    password:
+      from_secret: docker_password
+    repo: docker.teamortix.com/teamortix/status
+    tags: test
+    purge: true
+trigger:
+  event:
+    exclude:
+    - tag
+depends_on:
+  - Build Application
+
+---
+kind: pipeline
+name: Continuous Deployment
+steps:
+- name: Deploy Docker Image
+  image: plugins/docker
+  settings:
+    registry: docker.teamortix.com
+    username: droneci
+    password:
+      from_secret: docker_password
+    repo: docker.teamortix.com/teamortix/status
+    auto_tag: true
+trigger:
+  event:
+    - tag
+depends_on:
+  - Build Application

Dockerfile

@@ -0,0 +1,10 @@
+FROM golang:1.14.2 AS build
+WORKDIR /root/
+COPY . .
+RUN go build -o Status .
+
+FROM golang:1.14.2
+WORKDIR /root/
+COPY --from=build /root/Status .
+EXPOSE 8080
+CMD ["./Status"]

check/check.go

@@ -1,6 +1,7 @@
 package check
 
 import (
+	"encoding/json"
 	"time"
 )
 
@@ -32,3 +33,19 @@ func statusFromSuccessCount(count int) Result {
 func divide(t time.Duration, dividend int) time.Duration {
 	return time.Duration(int(t) / dividend)
 }
+
+func (r Result) String() string {
+	switch r {
+	case Online:
+		return "online"
+	case Unstable:
+		return "unstable"
+	case Offline:
+		return "offline"
+	}
+	panic("Unexpected value")
+}
+
+func (r Result) MarshalJSON() ([]byte, error) {
+	return json.Marshal(r.String())
+}

config.go

@@ -7,6 +7,7 @@ import (
 
 type Config struct {
 	Targets []checkTarget
+	Port    int
 }
 
 func ReadConfig(file string) (Config, error) {
@@ -15,6 +16,6 @@ func ReadConfig(file string) (Config, error) {
 		return Config{}, err
 	}
 	var result Config
-	json.Unmarshal(bytes, &result)
-	return result, nil
+	err = json.Unmarshal(bytes, &result)
+	return result, err
 }

db/ping.go

@@ -3,18 +3,15 @@ package db
 import (
 	"time"
 
-	"github.com/jinzhu/gorm"
-
 	"status/check"
 )
 
 //PingEntry represents an entry of Ping that is persisted in the DB.
 type PingEntry struct {
-	gorm.Model
-	ServiceName string
-	Time        time.Time
-	Ping        int64
-	Status      check.Result
+	ServiceName string       `json:"service_name"`
+	Time        time.Time    `json:"query_time"`
+	Ping        int64        `json:"ping"`
+	Status      check.Result `json:"status"`
 }
 
 func (p PingEntry) AddToDB() {
@@ -24,8 +21,12 @@ func (p PingEntry) AddToDB() {
 	db.Create(&p)
 }
 
-func GetFromDB(serviceName string, from, to time.Time) []*PingEntry {
-	entries := make([]*PingEntry, 0)
-	db.Where("service_name = ? AND time BETWEEN ? AND ?", serviceName, from, to).Find(&entries)
+func GetFromDB(serviceName string, from, to time.Time) []PingEntry {
+	entries := make([]PingEntry, 0)
+	if serviceName == "" {
+		db.Where("time BETWEEN ? AND ?", from, to).Find(&entries)
+	} else {
+		db.Where("service_name = ? AND time BETWEEN ? AND ?", serviceName, from, to).Find(&entries)
+	}
 	return entries
 }

main.go

@@ -1,9 +1,18 @@
 package main
 
+import (
+	"status/server"
+)
+
 func main() {
 	cfg, err := ReadConfig("config.json")
 	if err != nil {
 		panic(err)
 	}
-	checkLoop(cfg.Targets)
+	go checkLoop(cfg.Targets)
+	validServices := make([]string, 0, len(cfg.Targets))
+	for _, v := range cfg.Targets {
+		validServices = append(validServices, v.ServiceName)
+	}
+	server.StartServer(cfg.Port, validServices)
 }

server/api.go

@@ -0,0 +1,102 @@
+package server
+
+import (
+	"encoding/json"
+	"net/http"
+	"strconv"
+	"time"
+
+	"status/db"
+)
+
+func writeJSON(w http.ResponseWriter, a interface{}) {
+	bytes, err := json.Marshal(a)
+	if err != nil {
+		http.Error(w, "500 Internal Server Error", http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	_, err = w.Write(bytes)
+	if err != nil {
+		http.Error(w, "500 Internal Server Error", http.StatusInternalServerError)
+	}
+}
+
+func allStatus(w http.ResponseWriter, req *http.Request) {
+	status := getStatus()
+	writeJSON(w, status)
+}
+
+func dayHistory(w http.ResponseWriter, req *http.Request) {
+	keys, ok := req.URL.Query()["service_name"]
+	if !ok || len(keys) == 0 || len(keys[0]) < 1 {
+		http.Error(w, "`service_name` not provided", http.StatusBadRequest)
+		return
+	}
+	if len(keys) >= 2 {
+		http.Error(w, "Only one `service_name` allowed", http.StatusBadRequest)
+		return
+	}
+	service_name := keys[0]
+	if !validTarget[service_name] {
+		http.Error(w, "Invalid `service_name` requested", http.StatusBadRequest)
+		return
+	}
+	keys, ok = req.URL.Query()["interval"]
+	var interval = 5
+	if len(keys) >= 2 {
+		http.Error(w, "Only one `interval` allowed", http.StatusBadRequest)
+		return
+	}
+	if ok && len(keys) == 1 && len(keys[0]) >= 1 {
+		var err error
+		interval, err = strconv.Atoi(keys[0])
+		if err != nil || interval < 1 || interval > 1440 {
+			http.Error(w, "Invalid `interval` provided. Must be integer in [1, 1440]", http.StatusBadRequest)
+			return
+		}
+	}
+	if service_name == "all" {
+		service_name = ""
+	}
+	entries := db.GetFromDB(service_name, time.Now().Add(time.Duration(-24)*time.Hour), time.Now())
+	if interval == 1 {
+		writeJSON(w, entries)
+		return
+	}
+	filteredEntries := make([]db.PingEntry, 0, len(entries)/interval)
+	for i := 0; i < len(entries); i += interval {
+		filteredEntries = append(filteredEntries, entries[i])
+	}
+	writeJSON(w, filteredEntries)
+}
+
+func weekHistory(w http.ResponseWriter, req *http.Request) {
+	history(w, req, 7)
+}
+
+func monthHistory(w http.ResponseWriter, req *http.Request) {
+	history(w, req, 31)
+}
+
+func yearHistory(w http.ResponseWriter, req *http.Request) {
+	history(w, req, 366)
+}
+
+func history(w http.ResponseWriter, req *http.Request, dayCount int) {
+	keys, ok := req.URL.Query()["service_name"]
+	if !ok || len(keys) == 0 || len(keys[0]) < 1 {
+		http.Error(w, "`service_name` not provided", http.StatusBadRequest)
+		return
+	}
+	if len(keys) >= 2 {
+		http.Error(w, "Only one `service_name` allowed", http.StatusBadRequest)
+		return
+	}
+	if !validTarget[keys[0]] {
+		http.Error(w, "Invalid `service_name` requested", http.StatusBadRequest)
+		return
+	}
+	entries := getHistoryDay(keys[0], dayCount)
+	writeJSON(w, entries)
+}

server/cache.go

@@ -0,0 +1,60 @@
+package server
+
+import (
+	"time"
+
+	"status/check"
+	"status/db"
+)
+
+type stat struct {
+	StartTime    time.Time    `json:"start_time"`
+	TotalPing    int64        `json:"total_ping"`
+	SampleCount  int          `json:"sample_count"`
+	SuccessCount int          `json:"success_count"`
+	FailCount    int          `json:"fail_count"`
+	Summary      check.Result `json:"summary"`
+}
+
+var dayAggregation = make(map[string]map[time.Time]stat)
+
+func convertToResult(successCount, totalCount int) check.Result {
+	if successCount >= totalCount*99/100 {
+		return check.Online
+	}
+	if successCount >= totalCount*9/10 {
+		return check.Unstable
+	}
+	return check.Offline
+}
+
+func getDay(serviceName string, day time.Time) stat {
+	if _, ok := dayAggregation[serviceName]; !ok {
+		dayAggregation[serviceName] = make(map[time.Time]stat)
+	}
+	if cached, ok := dayAggregation[serviceName][day]; ok {
+		return cached
+	}
+	entries := db.GetFromDB(serviceName, day.AddDate(0, 0, -1), day)
+	result := stat{
+		StartTime: day,
+	}
+	for _, v := range entries {
+		result.SampleCount++
+		result.TotalPing += v.Ping
+		switch v.Status {
+		case check.Online:
+			result.SuccessCount++
+		case check.Offline:
+			result.FailCount++
+		}
+	}
+	result.Summary = convertToResult(result.SuccessCount, result.SampleCount)
+	dayAggregation[serviceName][day] = result
+	return result
+}
+
+func today() time.Time {
+	now := time.Now()
+	return time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.UTC)
+}

server/data.go

@@ -0,0 +1,33 @@
+package server
+
+import (
+	"time"
+
+	"status/db"
+)
+
+func getStatus() map[string]db.PingEntry {
+	entries := db.GetFromDB("", time.Now().Add(time.Duration(-2)*time.Minute), time.Now())
+	result := make(map[string]db.PingEntry)
+	for _, v := range entries {
+		if v.Time.Before(result[v.ServiceName].Time) {
+			continue
+		}
+		result[v.ServiceName] = v
+	}
+	return result
+}
+
+func getHistoryDay(serviceName string, dayCount int) []stat {
+	currentDay := today()
+	result := make([]stat, 0)
+	for i := 0; i >= -dayCount+1; i-- {
+		dayData := getDay(serviceName, currentDay.AddDate(0, 0, i))
+		if dayData.SampleCount > 0 {
+			result = append(result, dayData)
+		} else {
+			break
+		}
+	}
+	return result
+}

server/server.go

@@ -0,0 +1,30 @@
+package server
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+)
+
+var (
+	validTarget = make(map[string]bool)
+)
+
+func apiEndpoints() {
+	http.HandleFunc("/api/latest", allStatus)
+	http.HandleFunc("/api/history/day", dayHistory)
+	http.HandleFunc("/api/history/week", weekHistory)
+	http.HandleFunc("/api/history/month", monthHistory)
+	http.HandleFunc("/api/history/year", yearHistory)
+}
+
+func StartServer(port int, validTargets []string) {
+	for _, v := range validTargets {
+		validTarget[v] = true
+	}
+	apiEndpoints()
+	err := http.ListenAndServe(":"+strconv.Itoa(port), nil)
+	if err != nil {
+		fmt.Printf("ListenAndServe returned an error: %v", err)
+	}
+}