From 633b30798b3ac7af096f1d1d38e00a910b83d180 Mon Sep 17 00:00:00 2001
From: Ivan Chavero <ichavero@chavero.com.mx>
Date: Wed, 06 Nov 2019 03:01:47 +0100
Subject: [PATCH] Change go-mysql application code to serve quotes
---
go-mysql/main.go | 156 +++++++++++++++++++++++++++++++++------------------
1 files changed, 101 insertions(+), 55 deletions(-)
diff --git a/go-mysql/main.go b/go-mysql/main.go
index 9596ad0..23594e8 100644
--- a/go-mysql/main.go
+++ b/go-mysql/main.go
@@ -2,13 +2,13 @@
import (
"database/sql"
+ "fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/gorilla/mux"
"html/template"
"log"
"net/http"
"os"
- "strconv"
)
// Global variables
@@ -16,10 +16,9 @@
var username, password, database, host string
var DB *sql.DB
-type User struct {
- ID int
- Username string
- Password string
+type Quote struct {
+ ID int
+ Message string
}
func main() {
@@ -28,16 +27,19 @@
database, _ = os.LookupEnv("MYSQL_DATABASE")
host, _ = os.LookupEnv("MYSQL_HOST")
DB = db_connect(username, password, database, host)
+ if DB == nil {
+ log.Printf("Could not connect to the databse: %s", database)
+ }
defer DB.Close()
- Setup()
+ setup()
r := mux.NewRouter()
r.HandleFunc("/", HomeHandler)
- r.HandleFunc("/get", HomeHandler)
- r.HandleFunc("/add", AddHandler)
+ r.HandleFunc("/random", RandHandler)
r.HandleFunc("/env", EnvHandler)
+ r.HandleFunc("/status", StatusHandler)
http.Handle("/", r)
- log.Printf("Starting Application\nServices:\n/\n/get\n/add")
+ log.Printf("Starting Application\nServices:\n/\n/random\n/env\n/status")
log.Fatal(http.ListenAndServe(":8000", r))
}
@@ -45,22 +47,29 @@
func HomeHandler(w http.ResponseWriter, r *http.Request) {
tmpl := template.Must(template.ParseFiles("layout.html"))
- err := DB.Ping()
- if err != nil {
- panic(err.Error())
- }
- users := get_data()
- next := users[len(users)-1].ID + 1
+ quotes := get_all_quotes()
data := struct {
- Users []User
- Next int
+ Quotes []Quote
}{
- users,
- next,
+ quotes,
}
- err = tmpl.Execute(w, data)
+ err := tmpl.Execute(w, data)
if err != nil {
log.Printf("Error while executing template: %s", err)
+ }
+}
+
+func RandHandler(w http.ResponseWriter, r *http.Request) {
+ quote := get_random_quote()
+ fmt.Fprintf(w, "%d: %s", quote.ID, quote.Message)
+}
+
+func StatusHandler(w http.ResponseWriter, r *http.Request) {
+ err := DB.Ping()
+ if err != nil {
+ fmt.Fprintf(w, "Database connection error: %s", err)
+ } else {
+ fmt.Fprintf(w, "Database connection OK\n")
}
}
@@ -71,7 +80,7 @@
MYSQL_PASSWORD string
MYSQL_DATABASE string
MYSQL_HOST string
- Users []User
+ Quotes []Quote
}{
username,
password,
@@ -87,35 +96,56 @@
}
-func AddHandler(w http.ResponseWriter, r *http.Request) {
- i, _ := strconv.Atoi(r.FormValue("id"))
- u := r.FormValue("username")
- p := r.FormValue("password")
- insert_data(User{
- ID: i,
- Username: u,
- Password: p,
- })
- log.Printf("New user added\n")
- http.Redirect(w, r, "http://localhost:8000/", http.StatusFound)
-}
-
func Setup() {
+ var messages = []string{
+ "When words fail, music speaks.\n- William Shakespeare\n",
+ "Happines depends upon ourselves.\n- Aristotle\n",
+ "The secret of change is to focus all your energy not on fighting the old but on building the new.\n- Socrates\n",
+ "Nothing that glitters is gold.\n- Mark Twain",
+ "Imagination is more important than knowledge.\n- Albert Einstein\n",
+ "Hell, if I could explain it to the average person, it wouldn't have been worth the Nobel prize.\n- Richard Feynman\n",
+ "Young man, in mathematics you don't understand things. You just get used to them.\n- John von Neumann\n",
+ "Those who can imagine anything, can create the impossible.\n- Alan Turing\n",
+ }
log.Print("Creating schema")
db_create_schema()
log.Printf("Database Setup Completed\n")
- insert_data(User{
- ID: 1,
- Username: "FirstUser",
- Password: "FirstPass",
- })
-
+ for _, s := range messages {
+ insert_data(s)
+ }
}
// Data functions
+func setup() {
+ var rows string
+
+ // Check if the databse connection is active
+ err := DB.Ping()
+ if err != nil {
+ log.Fatalf("Database connection error: %s", err)
+ } else {
+ log.Printf("Database connection OK\n")
+ }
+
+ // Get table rows to check if there's data already
+ err = DB.QueryRow("SELECT count(*) FROM quotes").Scan(&rows)
+ if err == nil && rows != "0" {
+ log.Printf("Database already setup, ignoring")
+ return
+ }
+
+ log.Print("Creating schema")
+ db_create_schema()
+ log.Print("Adding quotes")
+ for _, s := range messages {
+ insert_data(s)
+ }
+ log.Printf("Database Setup Completed\n")
+}
+
func db_create_schema() {
- crt, err := DB.Prepare("CREATE TABLE test_mysql (id int NOT NULL AUTO_INCREMENT, username varchar(20), password varchar(20), CONSTRAINT id_pk PRIMARY KEY (id))")
+ crt, err := DB.Prepare("CREATE TABLE quotes (id int NOT NULL AUTO_INCREMENT, message text, CONSTRAINT id_pk PRIMARY KEY (id))")
if err != nil {
log.Printf("Error preparing the database creation: %s", err)
}
@@ -131,36 +161,52 @@
log.Print("Connecting to the database: " + connstring)
db, err := sql.Open("mysql", connstring)
if err != nil {
- panic(err.Error())
+ log.Printf("Error preparing database connection:%s", err.Error())
+ return nil
}
+
return db
}
-func insert_data(user User) {
- stmtIns, err := DB.Prepare("INSERT INTO test_mysql VALUES( ?, ?, ? )")
+func insert_data(message string) {
+ stmtIns, err := DB.Prepare("INSERT INTO quotes (message) VALUES( ? )")
+ log.Printf("Adding quote: %s", message)
if err != nil {
panic(err.Error())
}
- stmtIns.Exec(user.ID, user.Username, user.Password)
- log.Printf("Data added\n")
+
+ _, err = stmtIns.Exec(message)
+ if err != nil {
+ panic(err.Error())
+ }
stmtIns.Close()
}
-func get_data() []User {
+func get_all_quotes() []Quote {
var id int
- var username string
- var password string
- var users []User
- rows, err := DB.Query("SELECT id, username, password FROM test_mysql order by id asc")
+ var message string
+ var quotes []Quote
+ rows, err := DB.Query("SELECT id, message FROM quotes order by id asc")
defer rows.Close()
for rows.Next() {
- err = rows.Scan(&id, &username, &password)
+ err = rows.Scan(&id, &message)
if err != nil {
log.Printf("Error: %v", err.Error())
}
- users = append(users, User{ID: id, Username: username, Password: password})
- log.Printf("Users: %d", len(users))
+ quotes = append(quotes, Quote{ID: id, Message: message})
}
- return users
+ return quotes
+}
+
+func get_random_quote() Quote {
+ var id int
+ var message string
+ err := DB.QueryRow("SELECT id, message FROM quotes order by RAND() LIMIT 1").Scan(&id, &message)
+ if err != nil {
+ log.Printf("Error: %v", err.Error())
+ }
+
+ log.Printf("Quote: %s", message)
+ return Quote{ID: id, Message: message}
}
--
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