Files
servicedemon/cmd/spoke-agent/main.go

132 lines
2.8 KiB
Go

package main
import (
"crypto/tls"
"crypto/x509"
"encoding/json"
"fmt"
"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)
client, err := HubClient()
if err != nil {
logger.Fatal(err)
}
registered := false
for !registered {
state := getCurrentState(client, logger)
switch state {
case "pending_approval":
logger.Println("waiting for approval")
case "registered":
registered = true
logger.Println("application registered!")
default:
logger.Println("retrying")
}
time.Sleep(3 * time.Second)
}
}
func HubClient() (*http.Client, error) {
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)
}
pool := x509.NewCertPool()
pool.AppendCertsFromPEM(caCert)
certPath := requiredVars["SPOKE_AGENT_CERT_FILE"]
keyPath := requiredVars["SPOKE_AGENT_KEY_FILE"]
cert, err := tls.LoadX509KeyPair(certPath, keyPath)
if err != nil {
return nil, fmt.Errorf("failed to load keypair: %w", err)
}
client := &http.Client{
Transport: &http.Transport{
TLSClientConfig: &tls.Config{
RootCAs: pool,
Certificates: []tls.Certificate{cert},
},
},
}
HUB_BASE_URL = requiredVars["HUB_SERVER_URL"]
return client, nil
}
func getCurrentState(client *http.Client, logger *log.Logger) string {
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)
}
if resp.StatusCode > 399 {
logger.Printf("ERROR: getCurrentState: failed to get status [%d]", resp.StatusCode)
return ""
}
out := map[string]string{}
body, err := io.ReadAll(resp.Body)
if err != nil {
log.Printf("ERROR: getCurrentState: parsing response body: %v", err)
return ""
}
err = json.Unmarshal(body, &out)
if err != nil {
log.Printf("ERROR: getCurrentState: failed to unmarshal response: %s '%s'", err, body)
return ""
}
switch resp.StatusCode {
case http.StatusCreated:
logger.Printf("successfully started application registration")
return "pending_approval"
case http.StatusOK:
return out["status"]
default:
return ""
}
}