Replace Debian MySQL with Alpine Postgres

Dockerfile

@@ -1,5 +1,5 @@
 FROM golang:1.9.2 as builder
-RUN go get -d -v github.com/gorilla/mux github.com/go-sql-driver/mysql
+RUN go get -d -v github.com/gorilla/mux github.com/lib/pq
 ADD . /go/src/github.com/teslagov/clarakm-projects-go/
 WORKDIR /go/src/github.com/teslagov/clarakm-projects-go/
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

app.go

@@ -1,16 +1,13 @@
-// app.go
-
 package main
 
 import (
 	"database/sql"
 	"encoding/json"
 	"fmt"
-	_ "github.com/go-sql-driver/mysql"
+	_ "github.com/lib/pq"
 	"github.com/gorilla/mux"
 	"log"
 	"net/http"
-	"os"
 	"strconv"
 )
 
@@ -22,10 +19,10 @@ type App struct {
 
 // Initialize DB connections and router
 func (a *App) Initialize(user, password, host, dbname string) {
-	connectionString := fmt.Sprintf("%s:%s@tcp(%s:3306)/%s", user, password, host, dbname)
+	connectionString := fmt.Sprintf("user=%s password=%s host=%s dbname=%s sslmode=disable", user, password, host, dbname)
 
 	var err error
-	a.DB, err = sql.Open("mysql", connectionString)
+	a.DB, err = sql.Open("postgres", connectionString)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -40,22 +37,13 @@ func (a *App) Run(addr string) {
 }
 
 func (a *App) initializeRoutes() {
-	a.Router.HandleFunc("/hello", a.hello).Methods("GET")
 	a.Router.HandleFunc("/users", a.getUsers).Methods("GET")
 	a.Router.HandleFunc("/user", a.createUser).Methods("POST")
 	a.Router.HandleFunc("/user/{id:[0-9]+}", a.getUser).Methods("GET")
 	a.Router.HandleFunc("/user/{id:[0-9]+}", a.updateUser).Methods("PUT")
 	a.Router.HandleFunc("/user/{id:[0-9]+}", a.deleteUser).Methods("DELETE")
 }
 
-func (a *App) hello(w http.ResponseWriter, r *http.Request) {
-	user := os.Getenv("MYSQL_USER")
-	pass := os.Getenv("MYSQL_PASSWORD")
-	host := os.Getenv("MYSQL_HOST")
-	db := os.Getenv("MYSQL_DATABASE")
-	respondWithJSON(w, http.StatusOK, fmt.Sprintf("Hello, world! You're DB URL is: %s:%s@tcp(%s:3306)/%s", user, pass, host, db))
-}
-
 func (a *App) getUsers(w http.ResponseWriter, r *http.Request) {
 	count, _ := strconv.Atoi(r.FormValue("count"))
 	start, _ := strconv.Atoi(r.FormValue("start"))

docker-compose.yml

@@ -7,26 +7,17 @@ services:
     ports:
       - "8080:8080"
     environment:
-      - MYSQL_HOST=db
-      - MYSQL_DATABASE=clarakm-projects
-      - MYSQL_USER=clara
-      - MYSQL_PASSWORD=password
+      - DB_HOST=db
+      - DB_DATABASE=clarakm-projects
+      - DB_USER=clara
+      - DB_PASSWORD=password
     depends_on:
       - db
 
   db:
     container_name: clarakm-projects-db
-    image: mysql:5.7.20
+    image: postgres:10.1-alpine
     environment:
-      - MYSQL_ROOT_PASSWORD=root
-      - MYSQL_DATABASE=clarakm-projects
-      - MYSQL_USER=clara
-      - MYSQL_PASSWORD=password
-    ports:
-      - "13306:3306"
-    volumes:
-      - projects-data-volume:/var/lib/mysql
-
-volumes:
-  projects-data-volume:
-    driver: local
+      - POSTGRES_DB=clarakm-projects
+      - POSTGRES_USER=clara
+      - POSTGRES_PASSWORD=password

main.go

@@ -1,5 +1,3 @@
-// main.go
-
 package main
 
 import (
@@ -9,10 +7,10 @@ import (
 func main() {
 	a := App{}
 
-	user := os.Getenv("MYSQL_USER")
-	pass := os.Getenv("MYSQL_PASSWORD")
-	host := os.Getenv("MYSQL_HOST")
-	db := os.Getenv("MYSQL_DATABASE")
+	user := os.Getenv("DB_USER")
+	pass := os.Getenv("DB_PASSWORD")
+	host := os.Getenv("DB_HOST")
+	db := os.Getenv("DB_DATABASE")
 
 	a.Initialize(user, pass, host, db)
 

model.go

@@ -1,5 +1,3 @@
-// model.go
-
 package main
 
 import (
@@ -31,14 +29,9 @@ func (u *user) deleteUser(db *sql.DB) error {
 }
 
 func (u *user) createUser(db *sql.DB) error {
-	statement := fmt.Sprintf("INSERT INTO users(name, age) VALUES('%s', %d)", u.Name, u.Age)
-	_, err := db.Exec(statement)
-
-	if err != nil {
-		return err
-	}
+	statement := fmt.Sprintf("INSERT INTO users(name, age) VALUES('%s', %d) returning id", u.Name, u.Age)
 
-	err = db.QueryRow("SELECT LAST_INSERT_ID()").Scan(&u.ID)
+	err := db.QueryRow(statement).Scan(&u.ID)
 
 	if err != nil {
 		return err

seed-data.sh

@@ -4,7 +4,7 @@ main() {
     SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
     local db_container_id=$(docker ps -aqf "name=clarakm-projects-db")
     local path_to_sql_ddl_file=${SCRIPT_DIR}/seed-data.sql
-    cat ${path_to_sql_ddl_file} | docker exec -i ${db_container_id} /usr/bin/mysql -uclara -ppassword clarakm-projects
+    cat ${path_to_sql_ddl_file} | docker exec -i ${db_container_id} /usr/local/bin/psql --username=clara --password clarakm-projects
 }
 
 main "$@"

seed-data.sql

@@ -1,7 +1,7 @@
 DROP TABLE IF EXISTS users;
 CREATE TABLE users (
-  id int(8) NOT NULL AUTO_INCREMENT,
-  name varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
-  age int(8) NOT NULL,
-  PRIMARY KEY (id)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+  id int GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name character varying(255) NOT NULL,
+  age integer NOT NULL,
+  Created date
+) WITH (OIDS=FALSE);