varie migliorie

.env.example

@@ -0,0 +1,3 @@
+HOST=:8080
+SECRET=secret
+AUTHPDS_TOKEN=123

.gitignore

@@ -0,0 +1,3 @@
+
+.env
+bin/

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:latest
+FROM golang:alpine
 
 WORKDIR /app
 
@@ -6,6 +6,6 @@ COPY go.mod go.sum ./
 RUN go mod download && go mod verify
 
 COPY . .
-RUN go build -v -o ./bin/drone-example .
+RUN go build -v -o ./bin/go-maths-api .
 
-CMD ["./bin/drone-example"]
+CMD ["./bin/go-maths-api"]

README.md

@@ -3,29 +3,55 @@
 A simple Go API whose only purpose is to check whether an user is a Maths student or not.
 
 ## Prerequisites
+
 -   An environment variable `AUTHPDS_TOKEN` containing the authentication token for the external API.
+
 -   An environment variable named `SECRET` containing the secret token for authorization.
 
-## Docker
+## Development
+
+### Development
+
+```bash shell
+# Create a ".env" file from the given template and update as needed
+$ cp .env.example .env
+
+# Start the server
+$ go run -v .
+
+# Build to binary
+$ go build -v -o ./bin/go-maths-api .
+```
+
+### Deploy
+
 
 To build and run the image from the provided `Dockerfile`:
 
 ```bash shell
+# Create a ".env" file from the given template and update as needed
+$ cp .env.example .env
+
 $ docker build -t go-maths-api .
-$ docker run -d --restart always -p 127.235.203.11:1099 --env 'AUTHPDS_TOKEN' --env 'SECRET' --name go-maths-api go-maths-api
+$ docker run -d --restart always -p 8080:8080 --name go-maths-api go-maths-api
 ```
 
-## Client Usage
+### Client Usage
 
 An example request to the local Docker image (with `SECRET` defined in your environment):
-```
-curl -X GET "http://asdf:8080/check-maths-user?user=f.minnocci" -H "Authorization: Bearer $SECRET"
+
+```bash shell
+$ curl "localhost:8080/check-maths-user?user=f.minnocci" -H "Authorization: Bearer $SECRET"
 ```
 
 Successful JSON response:
 
-```
+```json
 {
     "result": true
 }
 ```
+
+## Notes
+
+- TODO: Add a small 1-day cache

go.mod

@@ -1,3 +1,5 @@
 module git.phc.dm.unipi.it/phc/go-maths-api
 
 go 1.21.1
+
+require github.com/joho/godotenv v1.5.1

go.sum

@@ -0,0 +1,2 @@
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

main.go

@@ -3,78 +3,114 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io"
+	"log"
 	"net/http"
 	"os"
 	"strings"
+
+	"github.com/joho/godotenv"
+)
+
+var (
+	Host         string
+	AuthPDSToken string
+	Secret       string
 )
 
 func main() {
-	http.HandleFunc("/check-maths-user", CheckMathsUserHandler)
-	port := ":8080"
+	godotenv.Load()
+
+	if v, present := os.LookupEnv("HOST"); present {
+		Host = v
+	} else {
+		Host = ":8080"
+	}
+
+	if v, present := os.LookupEnv("AUTHPDS_TOKEN"); present {
+		AuthPDSToken = v
+	} else {
+		log.Fatal(`missing AUTHPDS_TOKEN`)
+	}
 
-	fmt.Printf("Listening on port %s...\n", port)
-	http.ListenAndServe(port, nil)
+	if v, present := os.LookupEnv("SECRET"); present {
+		Secret = v
+	} else {
+		log.Fatal(`missing SECRET`)
+	}
+
+	r := http.NewServeMux()
+	r.HandleFunc("/check-maths-user", checkMathsUserHandler)
+
+	log.Printf("Starting server on %s...\n", Host)
+	http.ListenAndServe(Host, r)
+}
+
+func checkMathsUserHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
 	}
 
-func CheckMathsUserHandler(w http.ResponseWriter, r *http.Request) {
 	// Get the username from the query parameters
 	userName := r.URL.Query().Get("user")
 
-	// Get the AUTHORIZATION header value, which should include the secret token
-	authHeader := r.Header.Get("Authorization")
-	expectedAuthHeader := "Bearer " + os.Getenv("SECRET")
-
 	// Check if the provided authorization header matches the expected secret token
-	if authHeader != expectedAuthHeader {
+	if r.Header.Get("Authorization") != "Bearer "+Secret {
 		http.Error(w, "Unauthorized", http.StatusUnauthorized)
 		return
 	}
 
-	// Get the AUTHPDS_TOKEN from an environment variable
-	authPdsToken := os.Getenv("AUTHPDS_TOKEN")
+	userApiUrl := fmt.Sprintf("https://api.unipi.it/authPds/api/Carriera/studente/uid/%s/", userName)
 
-	// Make a GET request to the external API
-	apiURL := fmt.Sprintf("https://api.unipi.it/authPds/api/Carriera/studente/uid/%s/", userName)
-	req, err := http.NewRequest("GET", apiURL, nil)
+	// Create a GET request to the external API
+	ateneoRequest, err := http.NewRequest("GET", userApiUrl, nil)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 
-	req.Header.Add("accept", "*/*")
-	req.Header.Add("Authorization", "Bearer "+authPdsToken)
+	ateneoRequest.Header.Add("Accept", "*/*")
+	ateneoRequest.Header.Add("Authorization", "Bearer "+AuthPDSToken)
 
-	// Execute the request
-	client := &http.Client{}
-	resp, err := client.Do(req)
+	// Make the request to the external API
+	ateneoResponse, err := http.DefaultClient.Do(ateneoRequest)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-	defer resp.Body.Close()
+	defer ateneoResponse.Body.Close()
 
-	// Check if the response contains the desired keywords
-	body := make([]byte, 0)
-	_, err = resp.Body.Read(body)
+	isMatematica, err := checkUtenteDiMatematica(ateneoResponse)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 
-	containsKeywords := false
+	w.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(
+		map[string]any{
+			"result": isMatematica,
+		},
+	); err != nil {
+		log.Printf(`encode error: %v`, err)
+		return
+	}
+}
+
+func checkUtenteDiMatematica(r *http.Response) (bool, error) {
+	// Check if the response contains the desired keywords
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		return false, err
+	}
+
 	keywords := []string{"MATEMATICA", "Mobilit", "Transizione"}
 	for _, keyword := range keywords {
 		if strings.Contains(string(body), keyword) {
-			containsKeywords = true
-			break
+			return true, nil
 		}
 	}
 
-	// Create a JSON response
-	response := map[string]bool{
-		"result": containsKeywords,
-	}
-
-	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(response)
+	return false, nil
 }