90 lines
2.1 KiB
Go
90 lines
2.1 KiB
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
_ "github.com/go-sql-driver/mysql"
|
|
"github.com/gorilla/mux"
|
|
"log"
|
|
"net/http"
|
|
)
|
|
|
|
const DEBUG = true
|
|
|
|
func main() {
|
|
err := setup()
|
|
defer teardown()
|
|
if err == nil {
|
|
startServer()
|
|
}
|
|
}
|
|
|
|
func setup() error {
|
|
err := InitDb()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func teardown() {
|
|
CloseDb()
|
|
}
|
|
|
|
func startServer() {
|
|
port := "8001"
|
|
r := mux.NewRouter()
|
|
r.HandleFunc("/", showCharts).Methods("GET")
|
|
r.HandleFunc("/data/", sendData).Methods("GET")
|
|
r.HandleFunc("/", saveSnapshot).Methods("POST")
|
|
r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("static/"))))
|
|
http.Handle("/", r)
|
|
fmt.Printf("Listening on port %s...\n", port)
|
|
log.Fatal(http.ListenAndServe(":"+port, nil))
|
|
}
|
|
|
|
func showCharts(w http.ResponseWriter, r *http.Request) {
|
|
http.ServeFile(w, r, "charts.html")
|
|
}
|
|
|
|
func sendData(w http.ResponseWriter, r *http.Request) {
|
|
records, err := getSnapshotRecordsFromDb(50)
|
|
if err != nil {
|
|
sendInternalError(fmt.Errorf("couldn't read rows from the database: %w", err), w, r)
|
|
return
|
|
}
|
|
json, err := createJsonFromSnapshotRecords(records)
|
|
if err != nil {
|
|
sendInternalError(fmt.Errorf("couldn't create a json from the records: %w", err), w, r)
|
|
return
|
|
}
|
|
w.Header().Set("Content-Type", "application/json")
|
|
_, err = fmt.Fprintf(w, string(json))
|
|
if err != nil {
|
|
sendInternalError(err, w, r)
|
|
return
|
|
}
|
|
}
|
|
|
|
func saveSnapshot(w http.ResponseWriter, r *http.Request) {
|
|
snapshotSub, err := createSnapshotSubFromJsonBodyStream(r.Body)
|
|
if err != nil {
|
|
sendInternalError(fmt.Errorf("couldn't create snapshot from JSON: %w", err), w, r)
|
|
}
|
|
err = writeSnapshotToDb(snapshotSub)
|
|
if err != nil {
|
|
sendInternalError(fmt.Errorf("couldn't submit snapshot into the database: %w", err), w, r)
|
|
}
|
|
}
|
|
|
|
func sendInternalError(err error, w http.ResponseWriter, r *http.Request) {
|
|
errorMessage := "Internal Server Error!"
|
|
if DEBUG {
|
|
errorMessage += fmt.Sprintf(" Happened during %s request for pattern '%s': %s",
|
|
r.Method,
|
|
r.URL,
|
|
err.Error())
|
|
}
|
|
fmt.Println(errorMessage)
|
|
http.Error(w, errorMessage, 500)
|
|
}
|