From 9ca8a5ad6d13e411fe47e0707c2204b7f9cb1ba2 Mon Sep 17 00:00:00 2001
From: David Chang <david.chang@takeoff.com>
Date: Tue, 27 Feb 2024 15:53:43 -0500
Subject: [PATCH] Add a simple way to run both app and database using `docker
 compose`

---
 .env.example       |  2 +-
 Dockerfile         |  2 +-
 README.md          | 22 ++++++++++++++++++----
 docker-compose.yml | 33 +++++++++++++++++++++++++++++++++
 main.go            | 26 ++++++++++++++++++++------
 5 files changed, 73 insertions(+), 12 deletions(-)
 create mode 100644 docker-compose.yml

diff --git a/.env.example b/.env.example
index 74ee532..6f016b4 100644
--- a/.env.example
+++ b/.env.example
@@ -3,5 +3,5 @@ MYSQL_PORT=[3306]
 DB_USER=[root]
 DB_PASSWORD=[password]
 DB_NAME=[local_db]
-DB_CONNECTION_NAME=localhost:$MYSQL_PORT
+DB_CONNECTION_NAME=[mysql:$MYSQL_PORT]
 DB_CONNECTION_STRING=$DB_USER:$DB_PASSWORD@tcp($DB_CONNECTION_NAME)/$DB_NAME?charset=utf8&parseTime=True&loc=Local
diff --git a/Dockerfile b/Dockerfile
index 1dd9783..2ce3740 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.21
+FROM golang:latest
 
 WORKDIR /usr/src/app
 
diff --git a/README.md b/README.md
index 5577221..fe9a707 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,21 @@
 RESTful API for interacting with David Chang programmatically
 
 ## Build & run locally (http://localhost:80)
-### Configure
+
+### Configure, build, and run using `docker compose`
+`$ cp .env.example .env`
+- Fill out all the details for your local database (replace examples in brackets):
+	- ENVIRONMENT=[development]
+	- MYSQL_PORT=[3306]
+	- DB_USER=[root]
+	- DB_PASSWORD=[password]
+	- DB_NAME=[local_db]
+	- DB_CONNECTION_NAME=[mysql:$MYSQL_PORT]
+	- DB_CONNECTION_STRING=$DB_USER:$DB_PASSWORD@tcp($DB_CONNECTION_NAME)/$DB_NAME?charset=utf8&parseTime=True&loc=Local
+- Populate your local environment
+`$ source .env`
+
+### Configure, build, and run manually
 `$ cp .env.example .env`
 - Fill out all the details for your local database (replace examples in brackets):
 	- ENVIRONMENT=[development]
@@ -10,7 +24,7 @@ RESTful API for interacting with David Chang programmatically
 	- DB_USER=[root]
 	- DB_PASSWORD=[password]
 	- DB_NAME=[local_db]
-	- DB_CONNECTION_NAME=localhost:$MYSQL_PORT
+	- DB_CONNECTION_NAME=[localhost:$MYSQL_PORT]
 	- DB_CONNECTION_STRING=$DB_USER:$DB_PASSWORD@tcp($DB_CONNECTION_NAME)/$DB_NAME?charset=utf8&parseTime=True&loc=Local
 - Populate your local environment
 `$ source .env`
@@ -20,9 +34,9 @@ RESTful API for interacting with David Chang programmatically
 `$ docker exec -it local_mysql mysql -u $DB_USER -p`
 (enter password when prompted $DB_PASSWORD)
 `CREATE DATABASE [$DB_NAME]` (replace [$DB_NAME] with password you set up)
-### Build
+#### Build
 `$ docker build -t dev-davidchang-api .`
-### Run
+#### Run
 `$ docker run -p 80:8080 -it --rm --name dev-dc-api dev-davidchang-api`
 
 ## API Design (https://api.davidchang.dev)
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 0000000..2d1ddb5
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,33 @@
+version: '3'
+
+services:
+  api:
+    build:
+      context: .
+    ports:
+      - "80:8080"  # Map host's port 80 to container's port 8080
+    networks:
+      - api-network
+    depends_on:
+      mysql:
+        condition: service_healthy
+    environment:
+      DB_CONNECTION_STRING: "$DB_USER:$DB_PASSWORD@tcp($DB_CONNECTION_NAME)/$DB_NAME?charset=utf8&parseTime=True&loc=UTC"
+
+  mysql:
+    image: mysql:latest
+    environment:
+      MYSQL_ROOT_PASSWORD: ${DB_PASSWORD}
+      MYSQL_DATABASE: ${DB_NAME}
+    ports:
+      - "3306:3306"
+    networks:
+      - api-network
+    healthcheck:
+      test: ["CMD", "mysqladmin" ,"ping", "-h", "localhost"]
+      timeout: 10s
+      retries: 10
+
+networks:
+  api-network:
+    driver: bridge
diff --git a/main.go b/main.go
index 6503b20..4fd6403 100644
--- a/main.go
+++ b/main.go
@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	"github.com/joho/godotenv"
@@ -71,20 +72,33 @@ func setupDB() error {
 		connectionString = fmt.Sprintf("%s:%s@unix(/cloudsql/%s)/%s?charset=utf8&parseTime=True&loc=Local",
 			dbUser, dbPassword, dbConnectionName, dbName)
 	}
+
 	// Open a database connection
-	database, err := gorm.Open(mysql.Open(connectionString), &gorm.Config{})
+	var err error
+	for i := 0; i < 10; i++ { // Attempt to connect 10 times with a delay between attempts
+		db, err = gorm.Open(mysql.Open(connectionString), &gorm.Config{
+			// Set the time zone
+			NowFunc: func() time.Time {
+				return time.Now().UTC()
+			},
+		})
+		if err == nil {
+			break
+		}
+
+		log.Printf("Error connecting to the database: %v. Retrying in 5 seconds...", err)
+		time.Sleep(5 * time.Second)
+	}
+
 	if err != nil {
-		return fmt.Errorf("failed to connect to database: %v", err)
+		return fmt.Errorf("failed to connect to the database after multiple attempts: %v", err)
 	}
 
 	// Auto Migrate the resumé model, Resume
-	if err := database.AutoMigrate(&Resume{}); err != nil {
+	if err := db.AutoMigrate(&Resume{}); err != nil {
 		return fmt.Errorf("failed to migrate database: %v", err)
 	}
 
-	// Assign the database instance to the global variable
-	db = database
-
 	return nil
 }