Make more configurable

cmd/spoke-agent/main.go

@@ -8,10 +8,13 @@ import (
 	"io"
 	"log"
 	"net/http"
+	"net/url"
 	"os"
 	"time"
 )
 
+var HUB_BASE_URL string = ""
+
 func main() {
 	logger := log.New(os.Stdout, "main: ", log.LstdFlags|log.Lshortfile)
 
@@ -39,10 +42,25 @@ func main() {
 }
 
 func HubClient() (*http.Client, error) {
-	caFile, err := os.Open("./certs/ca.pem")
+	requiredVars := map[string]string{
+		"SPOKE_AGENT_CA_CERT_FILE": "",
+		"SPOKE_AGENT_CERT_FILE":    "",
+		"SPOKE_AGENT_KEY_FILE":     "",
+		"HUB_SERVER_URL":           "",
+	}
+	for k := range requiredVars {
+		val, isSet := os.LookupEnv(k)
+		if !isSet {
+			return nil, fmt.Errorf("spoke agent: required environment variables is unset: %s", k)
+		}
+		requiredVars[k] = val
+	}
+
+	caFile, err := os.Open(requiredVars["SPOKE_AGENT_CA_CERT_FILE"])
 	if err != nil {
 		return nil, fmt.Errorf("failed to open ca cert: %w", err)
 	}
+
 	caCert, err := io.ReadAll(caFile)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read the ca cert: %w", err)
@@ -51,8 +69,8 @@ func HubClient() (*http.Client, error) {
 	pool := x509.NewCertPool()
 	pool.AppendCertsFromPEM(caCert)
 
-	certPath := "./certs/app1.pem"
-	keyPath := "./certs/app1-key.pem"
+	certPath := requiredVars["SPOKE_AGENT_CERT_FILE"]
+	keyPath := requiredVars["SPOKE_AGENT_KEY_FILE"]
 
 	cert, err := tls.LoadX509KeyPair(certPath, keyPath)
 	if err != nil {
@@ -68,11 +86,17 @@ func HubClient() (*http.Client, error) {
 		},
 	}
 
+	HUB_BASE_URL = requiredVars["HUB_SERVER_URL"]
 	return client, nil
 }
 
 func getCurrentState(client *http.Client, logger *log.Logger) string {
-	resp, err := client.Post("https://example.net:3001/register", "application/json", nil)
+	reqURL, err := url.JoinPath(HUB_BASE_URL, "/register")
+	if err != nil {
+		logger.Fatalf("failed to setup register URL: %v", err)
+	}
+
+	resp, err := client.Post(reqURL, "application/json", nil)
 	if err != nil {
 		logger.Fatalf("registration failed: %v", err)
 	}