Files
RustProxy/docker-agent/main.go
T
2026-10-04 11:15:58 +02:00

120 lines
3.9 KiB
Go

package main
import (
"context"
"errors"
"flag"
"fmt"
"log"
"net"
"net/http"
"os"
"os/signal"
"strconv"
"strings"
"syscall"
"time"
)
func envOr(name, fallback string) string {
if value := strings.TrimSpace(os.Getenv(name)); value != "" {
return value
}
return fallback
}
func envBool(name string, fallback bool) bool {
raw := strings.TrimSpace(os.Getenv(name))
if raw == "" {
return fallback
}
value, err := strconv.ParseBool(raw)
if err != nil {
return fallback
}
return value
}
func main() {
hostname, _ := os.Hostname()
cfg := config{}
flag.StringVar(&cfg.Listen, "listen", envOr("RUSTPROXY_DOCKER_AGENT_LISTEN", "127.0.0.1:9876"), "listen address")
flag.StringVar(&cfg.Token, "token", envOr("RUSTPROXY_DOCKER_AGENT_TOKEN", ""), "Bearer token (prefer environment variable)")
flag.StringVar(&cfg.DockerSock, "docker-socket", envOr("RUSTPROXY_DOCKER_SOCKET", "/var/run/docker.sock"), "Docker Engine unix socket")
flag.StringVar(&cfg.AdvertiseIP, "advertise-ip", envOr("RUSTPROXY_DOCKER_ADVERTISE_IP", ""), "optional preferred host IP; all usable host addresses are still reported")
flag.StringVar(&cfg.PublicIPURL, "public-ip-url", envOr("RUSTPROXY_DOCKER_PUBLIC_IP_URL", "https://api.ipify.org"), "public IP lookup URL; empty disables")
flag.StringVar(&cfg.Hostname, "hostname", envOr("RUSTPROXY_DOCKER_HOSTNAME", hostname), "reported host name")
flag.BoolVar(&cfg.TLS, "tls", envBool("RUSTPROXY_DOCKER_AGENT_TLS", true), "serve HTTPS; enabled by default")
flag.StringVar(&cfg.CertFile, "cert-file", envOr("RUSTPROXY_DOCKER_AGENT_CERT_FILE", "/var/lib/rustproxy-docker-agent/agent.crt"), "TLS certificate file")
flag.StringVar(&cfg.KeyFile, "key-file", envOr("RUSTPROXY_DOCKER_AGENT_KEY_FILE", "/var/lib/rustproxy-docker-agent/agent.key"), "TLS private key file")
initCert := flag.Bool("init-cert", false, "create the self-signed TLS certificate if missing and exit")
printFingerprint := flag.Bool("print-fingerprint", false, "print SHA-256 certificate fingerprint and exit")
flag.Parse()
if *initCert {
fingerprint, created, err := ensureSelfSignedCertificate(cfg.CertFile, cfg.KeyFile, cfg.Hostname)
if err != nil {
log.Fatal(err)
}
fmt.Printf("%s\n", fingerprint)
if created {
log.Printf("created self-signed certificate %s", cfg.CertFile)
}
return
}
if *printFingerprint {
fingerprint, err := certificateFingerprint(cfg.CertFile)
if err != nil {
log.Fatal(err)
}
fmt.Printf("%s\n", fingerprint)
return
}
if len(cfg.Token) < 24 {
log.Fatal("RUSTPROXY_DOCKER_AGENT_TOKEN must contain at least 24 characters")
}
if _, err := os.Stat(cfg.DockerSock); err != nil {
log.Fatalf("Docker socket unavailable: %v", err)
}
if _, _, err := net.SplitHostPort(cfg.Listen); err != nil {
log.Fatalf("invalid listen address: %v", err)
}
if cfg.TLS {
fingerprint, created, err := ensureSelfSignedCertificate(cfg.CertFile, cfg.KeyFile, cfg.Hostname)
if err != nil {
log.Fatalf("TLS certificate: %v", err)
}
cfg.Fingerprint = fingerprint
if created {
log.Printf("generated self-signed TLS certificate; SHA-256 %s", fingerprint)
}
}
server := &http.Server{Addr: cfg.Listen, Handler: handler(cfg), ReadHeaderTimeout: 3 * time.Second, IdleTimeout: 30 * time.Second, MaxHeaderBytes: 16 << 10}
ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
defer stop()
go func() {
<-ctx.Done()
shutdown, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
_ = server.Shutdown(shutdown)
}()
scheme := "http"
if cfg.TLS {
scheme = "https"
}
log.Printf("RustProxy Docker Agent %s listening on %s://%s", version, scheme, cfg.Listen)
if cfg.Fingerprint != "" {
log.Printf("TLS certificate SHA-256: %s", cfg.Fingerprint)
}
var err error
if cfg.TLS {
err = server.ListenAndServeTLS(cfg.CertFile, cfg.KeyFile)
} else {
err = server.ListenAndServe()
}
if err != nil && !errors.Is(err, http.ErrServerClosed) {
log.Fatal(err)
}
}