feat: godoxy agent

agent/pkg/agent/config.go

@@ -0,0 +1,185 @@
+package agent
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/json"
+	"net"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/rs/zerolog"
+	"github.com/yusing/go-proxy/agent/pkg/certs"
+	"github.com/yusing/go-proxy/internal/gperr"
+	"github.com/yusing/go-proxy/internal/logging"
+	gphttp "github.com/yusing/go-proxy/internal/net/gphttp"
+	"github.com/yusing/go-proxy/internal/net/types"
+	"github.com/yusing/go-proxy/internal/task"
+	"github.com/yusing/go-proxy/pkg"
+	"golang.org/x/net/context"
+)
+
+type AgentConfig struct {
+	Addr string
+
+	httpClient *http.Client
+	tlsConfig  *tls.Config
+	name       string
+	l          zerolog.Logger
+}
+
+const (
+	EndpointVersion    = "/version"
+	EndpointName       = "/name"
+	EndpointProxyHTTP  = "/proxy/http"
+	EndpointHealth     = "/health"
+	EndpointLogs       = "/logs"
+	EndpointSystemInfo = "/system_info"
+
+	AgentHost = CertsDNSName
+
+	APIEndpointBase = "/godoxy/agent"
+	APIBaseURL      = "https://" + AgentHost + APIEndpointBase
+
+	DockerHost = "https://" + AgentHost
+
+	FakeDockerHostPrefix    = "agent://"
+	FakeDockerHostPrefixLen = len(FakeDockerHostPrefix)
+)
+
+var (
+	AgentURL              = types.MustParseURL(APIBaseURL)
+	HTTPProxyURL          = types.MustParseURL(APIBaseURL + EndpointProxyHTTP)
+	HTTPProxyURLPrefixLen = len(APIEndpointBase + EndpointProxyHTTP)
+)
+
+func IsDockerHostAgent(dockerHost string) bool {
+	return strings.HasPrefix(dockerHost, FakeDockerHostPrefix)
+}
+
+func GetAgentAddrFromDockerHost(dockerHost string) string {
+	return dockerHost[FakeDockerHostPrefixLen:]
+}
+
+func (cfg *AgentConfig) FakeDockerHost() string {
+	return FakeDockerHostPrefix + cfg.Addr
+}
+
+func (cfg *AgentConfig) Parse(addr string) error {
+	cfg.Addr = addr
+	return nil
+}
+
+func withoutBuildTime(version string) string {
+	return strings.Split(version, "-")[0]
+}
+
+func checkVersion(a, b string) bool {
+	return withoutBuildTime(a) == withoutBuildTime(b)
+}
+
+func (cfg *AgentConfig) StartWithCerts(parent task.Parent, ca, crt, key []byte) error {
+	clientCert, err := tls.X509KeyPair(crt, key)
+	if err != nil {
+		return err
+	}
+
+	// create tls config
+	caCertPool := x509.NewCertPool()
+	ok := caCertPool.AppendCertsFromPEM(ca)
+	if !ok {
+		return gperr.New("invalid ca certificate")
+	}
+
+	cfg.tlsConfig = &tls.Config{
+		Certificates: []tls.Certificate{clientCert},
+		RootCAs:      caCertPool,
+		ServerName:   CertsDNSName,
+	}
+
+	// create transport and http client
+	cfg.httpClient = cfg.NewHTTPClient()
+
+	ctx, cancel := context.WithTimeout(parent.Context(), 5*time.Second)
+	defer cancel()
+
+	// check agent version
+	version, _, err := cfg.Fetch(ctx, EndpointVersion)
+	if err != nil {
+		return err
+	}
+
+	versionStr := string(version)
+	// skip version check for dev versions
+	if strings.HasPrefix(versionStr, "v") && !checkVersion(versionStr, pkg.GetVersion()) {
+		return gperr.Errorf("agent version mismatch: server: %s, agent: %s", pkg.GetVersion(), versionStr)
+	}
+
+	// get agent name
+	name, _, err := cfg.Fetch(ctx, EndpointName)
+	if err != nil {
+		return err
+	}
+
+	cfg.name = string(name)
+	cfg.l = logging.With().Str("agent", cfg.name).Logger()
+
+	logging.Info().Msgf("agent %q initialized", cfg.name)
+	return nil
+}
+
+func (cfg *AgentConfig) Start(parent task.Parent) gperr.Error {
+	certData, err := os.ReadFile(certs.AgentCertsFilename(cfg.Addr))
+	if err != nil {
+		return gperr.Wrap(err, "failed to read agent certs")
+	}
+
+	ca, crt, key, err := certs.ExtractCert(certData)
+	if err != nil {
+		return gperr.Wrap(err, "failed to extract agent certs")
+	}
+
+	return gperr.Wrap(cfg.StartWithCerts(parent, ca, crt, key))
+}
+
+func (cfg *AgentConfig) NewHTTPClient() *http.Client {
+	return &http.Client{
+		Transport: cfg.Transport(),
+	}
+}
+
+func (cfg *AgentConfig) Transport() *http.Transport {
+	return &http.Transport{
+		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+			if addr != AgentHost+":443" {
+				return nil, &net.AddrError{Err: "invalid address", Addr: addr}
+			}
+			if network != "tcp" {
+				return nil, &net.OpError{Op: "dial", Net: network, Source: nil, Addr: nil}
+			}
+			return cfg.DialContext(ctx)
+		},
+		TLSClientConfig: cfg.tlsConfig,
+	}
+}
+
+func (cfg *AgentConfig) DialContext(ctx context.Context) (net.Conn, error) {
+	return gphttp.DefaultDialer.DialContext(ctx, "tcp", cfg.Addr)
+}
+
+func (cfg *AgentConfig) Name() string {
+	return cfg.name
+}
+
+func (cfg *AgentConfig) String() string {
+	return cfg.name + "@" + cfg.Addr
+}
+
+func (cfg *AgentConfig) MarshalJSON() ([]byte, error) {
+	return json.Marshal(map[string]string{
+		"name": cfg.Name(),
+		"addr": cfg.Addr,
+	})
+}