This project demonstrates how to create a RESTful API in Go that connects to a MongoDB database, fetches data, sorts it, and returns it in JSON format.
├── cmd
│ ├── api
│ │ └── main.go
│ ├── retrieve
│ │ └── main.go
│ └── scan
│ ├── inventory.yaml
│ └── main.go
├── go.mod
├── go.sum
└── vcsim
- Go 1.23.3 or later
- MongoDB instance running locally or accessible
- GoLand 2024.2.3 (IDE used for this project)
-
Clone the repository:
git clone https://github.com/yourusername/your-repo.git cd your-repo -
Install Go MongoDB driver:
go get go.mongodb.org/mongo-driver/mongo
-
Replace placeholders:
- Update the MongoDB URI, database, and collection names in
retrieve/retrieve.go. - Ensure the import path for the
retrievepackage inmain.gomatches your module path (yourmodule/retrieve).
- Update the MongoDB URI, database, and collection names in
-
Initialize Go modules:
go mod tidy
To run the application, use:
go run main.goThe server will start on port 8080.
Returns a list of documents from the foo collection in the specified MongoDB database, sorted by the _id field in ascending order and limited to 10 documents.
Example Request:
GET /data HTTP/1.1
Host: localhost:8080Example Response:
[
{
"_id": "some_id",
"field1": "value1",
"field2": "value2"
},
...
]This file sets up the HTTP server and defines the route that calls the retrieve.GetData function.
package main
import (
"encoding/json"
"log"
"net/http"
"yourmodule/retrieve" // Ensure this matches the actual module path
)
func handleGetData(w http.ResponseWriter, r *http.Request) {
data, err := retrieve.GetData()
if err != nil {
http.Error(w, "Failed to retrieve data: "+err.Error(), http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(data); err != nil {
http.Error(w, "Failed to write data: "+err.Error(), http.StatusInternalServerError)
}
}
func main() {
http.HandleFunc("/data", handleGetData)
log.Println("Server starting on port 8080...")
if err := http.ListenAndServe(":8080", nil); err != nil {
log.Fatalf("Server failed to start: %v", err)
}
}This file contains the logic to connect to MongoDB, fetch data, sort it, and return it.
package retrieve
import (
"context"
"go.mongodb.org/mongo-driver/bson"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
"log"
)
func GetData() ([]bson.M, error) {
var results []bson.M
// Set client options
clientOptions := options.Client().ApplyURI("mongodb://localhost:27017")
// Connect to MongoDB
client, err := mongo.Connect(context.TODO(), clientOptions)
if err != nil {
log.Fatal(err)
}
// Check the connection
err = client.Ping(context.TODO(), nil)
if err != nil {
return results, err
}
defer client.Disconnect(context.TODO())
collection := client.Database("yourdatabase").Collection("foo")
findOptions := options.Find()
findOptions.SetSort(bson.D{{"_id", 1}}) // Sort by _id in ascending order
findOptions.SetLimit(10) // Limit the number of results to 10
// Perform the query
cursor, err := collection.Find(context.TODO(), bson.D{}, findOptions)
if err != nil {
return results, err
}
defer cursor.Close(context.TODO())
// Iterate through the cursor and store the documents in results
for cursor.Next(context.TODO()) {
var result bson.M
err := cursor.Decode(&result)
if err != nil {
return results, err
}
results = append(results, result)
}
if err := cursor.Err(); err != nil {
return results, err
}
return results, nil
}This project is licensed under the MIT License. See the LICENSE file for details.