package main
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import (
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"database/sql"
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"fmt"
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_ "github.com/go-sql-driver/mysql"
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"github.com/gorilla/mux"
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"html/template"
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"log"
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"net/http"
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"os"
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)
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// Global variables
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var username, password, database, host string
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var DB *sql.DB
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type Quote struct {
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ID int
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Message string
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}
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func main() {
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username, _ = os.LookupEnv("MYSQL_USER")
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password, _ = os.LookupEnv("MYSQL_PASSWORD")
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database, _ = os.LookupEnv("MYSQL_DATABASE")
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host, _ = os.LookupEnv("MYSQL_HOST")
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DB = db_connect(username, password, database, host)
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if DB == nil {
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log.Printf("Could not connect to the databse: %s", database)
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}
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defer DB.Close()
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setup()
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r := mux.NewRouter()
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r.HandleFunc("/", HomeHandler)
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r.HandleFunc("/random", RandHandler)
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r.HandleFunc("/env", EnvHandler)
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r.HandleFunc("/status", StatusHandler)
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http.Handle("/", r)
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log.Printf("Starting Application\nServices:\n/\n/random\n/env\n/status")
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log.Fatal(http.ListenAndServe(":8000", r))
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}
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// Handlers
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func HomeHandler(w http.ResponseWriter, r *http.Request) {
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tmpl := template.Must(template.ParseFiles("layout.html"))
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quotes := get_all_quotes()
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data := struct {
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Quotes []Quote
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}{
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quotes,
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}
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err := tmpl.Execute(w, data)
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if err != nil {
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log.Printf("Error while executing template: %s", err)
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}
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}
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func RandHandler(w http.ResponseWriter, r *http.Request) {
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quote := get_random_quote()
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fmt.Fprintf(w, "%d: %s", quote.ID, quote.Message)
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}
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func StatusHandler(w http.ResponseWriter, r *http.Request) {
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err := DB.Ping()
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if err != nil {
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fmt.Fprintf(w, "Database connection error: %s", err)
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} else {
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fmt.Fprintf(w, "Database connection OK\n")
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}
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}
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func EnvHandler(w http.ResponseWriter, r *http.Request) {
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tmpl := template.Must(template.ParseFiles("layout.html"))
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data := struct {
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MYSQL_USER string
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MYSQL_PASSWORD string
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MYSQL_DATABASE string
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MYSQL_HOST string
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Quotes []Quote
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}{
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username,
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password,
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database,
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host,
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nil,
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}
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err := tmpl.Execute(w, data)
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if err != nil {
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log.Printf("Error while executing template: %s", err)
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}
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log.Printf("Database Setup Variables:\nMYSQL_USER: %s\nMYSQL_PASSWORD: %s\nMYSQL_DATABASE: %s\nMYSQL_HOST: %s\n", username, password, database, host)
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}
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func Setup() {
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var messages = []string{
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"When words fail, music speaks.\n- William Shakespeare\n",
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"Happines depends upon ourselves.\n- Aristotle\n",
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"The secret of change is to focus all your energy not on fighting the old but on building the new.\n- Socrates\n",
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"Nothing that glitters is gold.\n- Mark Twain",
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"Imagination is more important than knowledge.\n- Albert Einstein\n",
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"Hell, if I could explain it to the average person, it wouldn't have been worth the Nobel prize.\n- Richard Feynman\n",
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"Young man, in mathematics you don't understand things. You just get used to them.\n- John von Neumann\n",
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"Those who can imagine anything, can create the impossible.\n- Alan Turing\n",
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}
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log.Print("Creating schema")
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db_create_schema()
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log.Printf("Database Setup Completed\n")
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for _, s := range messages {
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insert_data(s)
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}
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}
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// Data functions
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func setup() {
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var rows string
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// Check if the databse connection is active
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err := DB.Ping()
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if err != nil {
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log.Fatalf("Database connection error: %s", err)
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} else {
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log.Printf("Database connection OK\n")
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}
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// Get table rows to check if there's data already
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err = DB.QueryRow("SELECT count(*) FROM quotes").Scan(&rows)
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if err == nil && rows != "0" {
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log.Printf("Database already setup, ignoring")
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return
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}
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log.Print("Creating schema")
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db_create_schema()
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log.Print("Adding quotes")
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for _, s := range messages {
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insert_data(s)
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}
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log.Printf("Database Setup Completed\n")
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}
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func db_create_schema() {
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crt, err := DB.Prepare("CREATE TABLE quotes (id int NOT NULL AUTO_INCREMENT, message text, CONSTRAINT id_pk PRIMARY KEY (id))")
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if err != nil {
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log.Printf("Error preparing the database creation: %s", err)
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}
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_, err = crt.Exec()
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if err != nil {
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log.Printf("Error creating the database: %s", err)
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}
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crt.Close()
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}
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func db_connect(username string, password string, database string, host string) *sql.DB {
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connstring := username + ":" + password + "@tcp(" + host + ":3306)/" + database
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log.Print("Connecting to the database: " + connstring)
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db, err := sql.Open("mysql", connstring)
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if err != nil {
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log.Printf("Error preparing database connection:%s", err.Error())
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return nil
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}
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return db
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}
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func insert_data(message string) {
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stmtIns, err := DB.Prepare("INSERT INTO quotes (message) VALUES( ? )")
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log.Printf("Adding quote: %s", message)
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if err != nil {
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panic(err.Error())
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}
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_, err = stmtIns.Exec(message)
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if err != nil {
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panic(err.Error())
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}
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stmtIns.Close()
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}
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func get_all_quotes() []Quote {
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var id int
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var message string
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var quotes []Quote
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rows, err := DB.Query("SELECT id, message FROM quotes order by id asc")
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defer rows.Close()
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for rows.Next() {
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err = rows.Scan(&id, &message)
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if err != nil {
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log.Printf("Error: %v", err.Error())
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}
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quotes = append(quotes, Quote{ID: id, Message: message})
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}
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return quotes
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}
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func get_random_quote() Quote {
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var id int
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var message string
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err := DB.QueryRow("SELECT id, message FROM quotes order by RAND() LIMIT 1").Scan(&id, &message)
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if err != nil {
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log.Printf("Error: %v", err.Error())
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}
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log.Printf("Quote: %s", message)
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return Quote{ID: id, Message: message}
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}
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