feature: Adds backend system and basic API.

This adds the backend API, as well as backend infrastructure, including
autostarting and basic communication between the Goroutine + Application.
This commit is contained in:
greysoh 2024-12-23 15:52:16 -05:00
parent 611d7f24f8
commit 0b73b4aa47
Signed by: imterah
GPG key ID: 8FA7DD57BA6CEA37
12 changed files with 777 additions and 44 deletions

View file

@ -0,0 +1,237 @@
package backendruntime
import (
"context"
"fmt"
"net"
"os"
"os/exec"
"time"
"git.terah.dev/imterah/hermes/backendlauncher"
"git.terah.dev/imterah/hermes/commonbackend"
"github.com/charmbracelet/log"
)
var (
AvailableBackends []*Backend
RunningBackends map[uint]*Runtime
TempDir string
)
func init() {
RunningBackends = make(map[uint]*Runtime)
}
func handleCommand(commandType string, command interface{}, sock net.Conn, rtcChan chan interface{}) {
bytes, err := commonbackend.Marshal(commandType, command)
if err != nil {
log.Warnf("Failed to marshal message: %s", err.Error())
rtcChan <- fmt.Errorf("failed to marshal message: %s", err.Error())
return
}
if _, err := sock.Write(bytes); err != nil {
log.Warnf("Failed to write message: %s", err.Error())
rtcChan <- fmt.Errorf("failed to write message: %s", err.Error())
return
}
_, data, err := commonbackend.Unmarshal(sock)
if err != nil {
log.Warnf("Failed to unmarshal message: %s", err.Error())
rtcChan <- fmt.Errorf("failed to unmarshal message: %s", err.Error())
return
}
rtcChan <- data
}
func (runtime *Runtime) goRoutineHandler() error {
log.Debug("Starting up backend runtime")
log.Debug("Running socket acquisition")
logLevel := os.Getenv("HERMES_LOG_LEVEL")
sockPath, sockListener, err := backendlauncher.GetUnixSocket(TempDir)
if err != nil {
return err
}
runtime.currentListener = sockListener
log.Debugf("Acquired unix socket at: %s", sockPath)
go func() {
log.Debug("Creating new goroutine for socket connection handling")
for {
log.Debug("Waiting for Unix socket connections...")
sock, err := runtime.currentListener.Accept()
if err != nil {
log.Warnf("Failed to accept Unix socket connection in a backend runtime instance: %s", err.Error())
return
}
log.Debug("Recieved connection. Initializing...")
defer sock.Close()
for {
commandRaw := <-runtime.RuntimeCommands
log.Debug("Got message from server")
switch command := commandRaw.(type) {
case *commonbackend.AddProxy:
handleCommand("addProxy", command, sock, runtime.RuntimeCommands)
case *commonbackend.BackendStatusRequest:
handleCommand("backendStatusRequest", command, sock, runtime.RuntimeCommands)
case *commonbackend.BackendStatusResponse:
handleCommand("backendStatusResponse", command, sock, runtime.RuntimeCommands)
case *commonbackend.CheckClientParameters:
handleCommand("checkClientParameters", command, sock, runtime.RuntimeCommands)
case *commonbackend.CheckParametersResponse:
handleCommand("checkParametersResponse", command, sock, runtime.RuntimeCommands)
case *commonbackend.CheckServerParameters:
handleCommand("checkServerParameters", command, sock, runtime.RuntimeCommands)
case *commonbackend.ProxyClientConnection:
handleCommand("proxyClientConnection", command, sock, runtime.RuntimeCommands)
case *commonbackend.ProxyConnectionsRequest:
handleCommand("proxyConnectionsRequest", command, sock, runtime.RuntimeCommands)
case *commonbackend.ProxyConnectionsResponse:
handleCommand("proxyConnectionsResponse", command, sock, runtime.RuntimeCommands)
case *commonbackend.ProxyInstanceResponse:
handleCommand("proxyInstanceResponse", command, sock, runtime.RuntimeCommands)
case *commonbackend.ProxyInstanceRequest:
handleCommand("proxyInstanceRequest", command, sock, runtime.RuntimeCommands)
case *commonbackend.ProxyStatusRequest:
handleCommand("proxyStatusRequest", command, sock, runtime.RuntimeCommands)
case *commonbackend.ProxyStatusResponse:
handleCommand("proxyStatusResponse", command, sock, runtime.RuntimeCommands)
case *commonbackend.RemoveProxy:
handleCommand("removeProxy", command, sock, runtime.RuntimeCommands)
case *commonbackend.Start:
handleCommand("start", command, sock, runtime.RuntimeCommands)
case *commonbackend.Stop:
handleCommand("stop", command, sock, runtime.RuntimeCommands)
default:
log.Warnf("Recieved unknown command type from channel: %q", command)
runtime.RuntimeCommands <- fmt.Errorf("unknown command recieved")
}
}
}
}()
for {
log.Debug("Starting process...")
ctx := context.Background()
runtime.currentProcess = exec.CommandContext(ctx, runtime.ProcessPath)
runtime.currentProcess.Env = append(runtime.currentProcess.Env, fmt.Sprintf("HERMES_API_SOCK=%s", sockPath), fmt.Sprintf("HERMES_LOG_LEVEL=%s", logLevel))
runtime.currentProcess.Stdout = runtime.logger
runtime.currentProcess.Stderr = runtime.logger
err := runtime.currentProcess.Run()
if err != nil {
if err, ok := err.(*exec.ExitError); ok {
if err.ExitCode() != -1 && err.ExitCode() != 0 {
log.Warnf("A backend process died with exit code '%d' and with error '%s'", err.ExitCode(), err.Error())
}
} else {
log.Warnf("A backend process died with error: %s", err.Error())
}
} else {
log.Debug("Process exited gracefully.")
}
if !runtime.isRuntimeRunning {
return nil
}
log.Debug("Sleeping 5 seconds, and then restarting process")
time.Sleep(5 * time.Second)
}
}
func (runtime *Runtime) Start() error {
if runtime.isRuntimeRunning {
return fmt.Errorf("runtime already running")
}
runtime.RuntimeCommands = make(chan interface{})
runtime.logger = &writeLogger{
Runtime: runtime,
}
go func() {
err := runtime.goRoutineHandler()
if err != nil {
log.Errorf("Failed during execution of runtime: %s", err.Error())
}
}()
runtime.isRuntimeRunning = true
return nil
}
func (runtime *Runtime) Stop() error {
if !runtime.isRuntimeRunning {
return fmt.Errorf("runtime not running")
}
runtime.isRuntimeRunning = false
if runtime.currentProcess != nil && runtime.currentProcess.Cancel != nil {
err := runtime.currentProcess.Cancel()
if err != nil {
return fmt.Errorf("failed to stop process: %s", err.Error())
}
} else {
log.Warn("Failed to kill process (Stop recieved), currentProcess or currentProcess.Cancel is nil")
}
if runtime.currentListener != nil {
err := runtime.currentListener.Close()
if err != nil {
return fmt.Errorf("failed to stop listener: %s", err.Error())
}
} else {
log.Warn("Failed to kill listener, as the listener is nil")
}
return nil
}
func NewBackend(path string) *Runtime {
return &Runtime{
ProcessPath: path,
}
}
func Init(backends []*Backend) error {
var err error
TempDir, err = os.MkdirTemp("", "hermes-sockets-")
if err != nil {
return err
}
AvailableBackends = backends
return nil
}

View file

@ -0,0 +1,34 @@
package backendruntime
import (
"net"
"os/exec"
"strings"
)
type Backend struct {
Name string `validate:"required"`
Path string `validate:"required"`
}
type Runtime struct {
isRuntimeRunning bool
logger *writeLogger
currentProcess *exec.Cmd
currentListener net.Listener
ProcessPath string
Logs []string
RuntimeCommands chan interface{}
}
type writeLogger struct {
Runtime *Runtime
}
func (writer writeLogger) Write(p []byte) (n int, err error) {
logSplit := strings.Split(string(p), "\n")
writer.Runtime.Logs = append(writer.Runtime.Logs, logSplit...)
return len(p), err
}

View file

@ -0,0 +1,271 @@
package backends
import (
"encoding/base64"
"encoding/json"
"fmt"
"net/http"
"git.terah.dev/imterah/hermes/api/backendruntime"
"git.terah.dev/imterah/hermes/api/dbcore"
"git.terah.dev/imterah/hermes/api/jwtcore"
"git.terah.dev/imterah/hermes/api/permissions"
"git.terah.dev/imterah/hermes/commonbackend"
"github.com/charmbracelet/log"
"github.com/gin-gonic/gin"
"github.com/go-playground/validator/v10"
)
type BackendCreationRequest struct {
Token string `validate:"required"`
Name string `validate:"required"`
Description *string
Backend string `validate:"required"`
BackendParameters interface{} `json:"connectionDetails" validate:"required"`
}
func CreateBackend(c *gin.Context) {
var req BackendCreationRequest
if err := c.BindJSON(&req); err != nil {
c.JSON(http.StatusBadRequest, gin.H{
"error": fmt.Sprintf("Failed to parse body: %s", err.Error()),
})
return
}
if err := validator.New().Struct(&req); err != nil {
c.JSON(http.StatusBadRequest, gin.H{
"error": fmt.Sprintf("Failed to validate body: %s", err.Error()),
})
return
}
user, err := jwtcore.GetUserFromJWT(req.Token)
if err != nil {
if err.Error() == "token is expired" || err.Error() == "user does not exist" {
c.JSON(http.StatusForbidden, gin.H{
"error": err.Error(),
})
return
} else {
log.Warnf("Failed to get user from the provided JWT token: %s", err.Error())
c.JSON(http.StatusInternalServerError, gin.H{
"error": "Failed to parse token",
})
return
}
}
if !permissions.UserHasPermission(user, "backends.add") {
c.JSON(http.StatusForbidden, gin.H{
"error": "Missing permissions",
})
return
}
var backendParameters []byte
switch parameters := req.BackendParameters.(type) {
case string:
backendParameters = []byte(parameters)
case map[string]interface{}:
backendParameters, err = json.Marshal(parameters)
if err != nil {
log.Warnf("Failed to marshal JSON recieved as BackendParameters: %s", err.Error())
c.JSON(http.StatusInternalServerError, gin.H{
"error": "Failed to prepare parameters",
})
return
}
default:
c.JSON(http.StatusBadRequest, gin.H{
"error": fmt.Sprintf("Invalid type for connectionDetails (recieved %T)", parameters),
})
return
}
var backendRuntimeFilePath string
for _, runtime := range backendruntime.AvailableBackends {
if runtime.Name == req.Backend {
backendRuntimeFilePath = runtime.Path
}
}
if backendRuntimeFilePath == "" {
c.JSON(http.StatusBadRequest, gin.H{
"error": "Unsupported backend recieved",
})
return
}
backend := backendruntime.NewBackend(backendRuntimeFilePath)
err = backend.Start()
if err != nil {
log.Warnf("Failed to start backend: %s", err.Error())
c.JSON(http.StatusInternalServerError, gin.H{
"error": "Failed to start backend",
})
return
}
backend.RuntimeCommands <- &commonbackend.CheckServerParameters{
Type: "checkServerParameters",
Arguments: backendParameters,
}
backendParamCheckResponse := <-backend.RuntimeCommands
switch responseMessage := backendParamCheckResponse.(type) {
case error:
log.Warnf("Failed to get response for backend: %s", responseMessage.Error())
err = backend.Stop()
if err != nil {
log.Warnf("Failed to stop backend: %s", err.Error())
}
c.JSON(http.StatusInternalServerError, gin.H{
"error": "Failed to get status response from backend",
})
return
case *commonbackend.CheckParametersResponse:
if responseMessage.InResponseTo != "checkServerParameters" {
log.Errorf("Got illegal response to CheckServerParameters: %s", responseMessage.InResponseTo)
err = backend.Stop()
if err != nil {
log.Warnf("Failed to stop backend: %s", err.Error())
}
c.JSON(http.StatusInternalServerError, gin.H{
"error": "Failed to get status response from backend",
})
return
}
if !responseMessage.IsValid {
err = backend.Stop()
if err != nil {
log.Warnf("Failed to stop backend: %s", err.Error())
}
var errorMessage string
if responseMessage.Message == "" {
errorMessage = "Unkown error while trying to parse connectionDetails"
} else {
errorMessage = fmt.Sprintf("Invalid backend parameters: %s", responseMessage.Message)
}
c.JSON(http.StatusBadRequest, gin.H{
"error": errorMessage,
})
return
}
default:
log.Warnf("Got illegal response type for backend: %T", responseMessage)
}
log.Info("Passed backend checks successfully")
backendInDatabase := &dbcore.Backend{
UserID: user.ID,
Name: req.Name,
Description: req.Description,
Backend: req.Backend,
BackendParameters: base64.StdEncoding.EncodeToString(backendParameters),
}
if result := dbcore.DB.Create(&backendInDatabase); result.Error != nil {
log.Warnf("Failed to create backend: %s", result.Error.Error())
err = backend.Stop()
if err != nil {
log.Warnf("Failed to stop backend: %s", err.Error())
}
c.JSON(http.StatusInternalServerError, gin.H{
"error": "Failed to add backend into database",
})
return
}
backend.RuntimeCommands <- &commonbackend.Start{
Type: "start",
Arguments: backendParameters,
}
backendStartResponse := <-backend.RuntimeCommands
switch responseMessage := backendStartResponse.(type) {
case error:
log.Warnf("Failed to get response for backend: %s", responseMessage.Error())
err = backend.Stop()
if err != nil {
log.Warnf("Failed to stop backend: %s", err.Error())
}
c.JSON(http.StatusInternalServerError, gin.H{
"error": "Failed to get status response from backend",
})
return
case *commonbackend.BackendStatusResponse:
if !responseMessage.IsRunning {
err = backend.Stop()
if err != nil {
log.Warnf("Failed to start backend: %s", err.Error())
}
var errorMessage string
if responseMessage.Message == "" {
errorMessage = "Unkown error while trying to start the backend"
} else {
errorMessage = fmt.Sprintf("Failed to start backend: %s", responseMessage.Message)
}
c.JSON(http.StatusBadRequest, gin.H{
"error": errorMessage,
})
return
}
default:
log.Warnf("Got illegal response type for backend: %T", responseMessage)
}
backendruntime.RunningBackends[backendInDatabase.ID] = backend
c.JSON(http.StatusOK, gin.H{
"success": true,
})
}

View file

@ -12,7 +12,10 @@ import (
"github.com/golang-jwt/jwt/v5"
)
var JWTKey []byte
var (
JWTKey []byte
developmentMode bool
)
func SetupJWT() error {
var err error
@ -32,6 +35,10 @@ func SetupJWT() error {
JWTKey = []byte(jwtDataString)
}
if os.Getenv("HERMES_DEVELOPMENT_MODE") != "" {
developmentMode = true
}
return nil
}
@ -83,8 +90,14 @@ func GetUserFromJWT(token string) (*dbcore.User, error) {
}
func Generate(uid uint) (string, error) {
timeMultiplier := 3
if developmentMode {
timeMultiplier = 60 * 24
}
token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.RegisteredClaims{
ExpiresAt: jwt.NewNumericDate(time.Now().Add(3 * time.Minute)),
ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Duration(timeMultiplier) * time.Minute)),
IssuedAt: jwt.NewNumericDate(time.Now()),
NotBefore: jwt.NewNumericDate(time.Now()),
Audience: []string{strconv.Itoa(int(uid))},

View file

@ -1,44 +1,34 @@
package main
import (
"encoding/base64"
"encoding/json"
"fmt"
"os"
"path"
"path/filepath"
"strings"
"git.terah.dev/imterah/hermes/api/backendruntime"
"git.terah.dev/imterah/hermes/api/controllers/v1/backends"
"git.terah.dev/imterah/hermes/api/controllers/v1/users"
"git.terah.dev/imterah/hermes/api/dbcore"
"git.terah.dev/imterah/hermes/api/jwtcore"
"git.terah.dev/imterah/hermes/commonbackend"
"github.com/charmbracelet/log"
"github.com/gin-gonic/gin"
"github.com/urfave/cli/v2"
"gorm.io/gorm"
)
func main() {
logLevel := os.Getenv("HERMES_LOG_LEVEL")
func entrypoint(cCtx *cli.Context) error {
developmentMode := false
if os.Getenv("HERMES_DEVELOPMENT_MODE") != "" {
log.Warn("You have development mode enabled. This may weaken security.")
developmentMode = true
}
if logLevel != "" {
switch logLevel {
case "debug":
log.SetLevel(log.DebugLevel)
case "info":
log.SetLevel(log.InfoLevel)
case "warn":
log.SetLevel(log.WarnLevel)
case "error":
log.SetLevel(log.ErrorLevel)
case "fatal":
log.SetLevel(log.FatalLevel)
}
}
log.Info("Hermes is initializing...")
log.Debug("Initializing database and opening it...")
@ -51,13 +41,117 @@ func main() {
log.Debug("Running database migrations...")
if err := dbcore.DoDatabaseMigrations(dbcore.DB); err != nil {
log.Fatalf("Failed to run database migrations: %s", err)
return fmt.Errorf("Failed to run database migrations: %s", err)
}
log.Debug("Initializing the JWT subsystem...")
if err := jwtcore.SetupJWT(); err != nil {
log.Fatalf("Failed to initialize the JWT subsystem: %s", err.Error())
return fmt.Errorf("Failed to initialize the JWT subsystem: %s", err.Error())
}
log.Debug("Initializing the backend subsystem...")
backendMetadataPath := cCtx.String("backends-path")
backendMetadata, err := os.ReadFile(backendMetadataPath)
if err != nil {
return fmt.Errorf("Failed to read backends: %s", err.Error())
}
availableBackends := []*backendruntime.Backend{}
err = json.Unmarshal(backendMetadata, &availableBackends)
if err != nil {
return fmt.Errorf("Failed to parse backends: %s", err.Error())
}
for _, backend := range availableBackends {
backend.Path = path.Join(filepath.Dir(backendMetadataPath), backend.Path)
}
backendruntime.Init(availableBackends)
log.Debug("Enumerating backends...")
backendList := []dbcore.Backend{}
if err := dbcore.DB.Find(&backendList).Error; err != nil {
return fmt.Errorf("Failed to enumerate backends: %s", err.Error())
}
for _, backend := range backendList {
log.Infof("Starting up backend #%d: %s", backend.ID, backend.Name)
var backendRuntimeFilePath string
for _, runtime := range backendruntime.AvailableBackends {
if runtime.Name == backend.Backend {
backendRuntimeFilePath = runtime.Path
}
}
if backendRuntimeFilePath == "" {
log.Errorf("Unsupported backend recieved for ID %d: %s", backend.ID, backend.Backend)
continue
}
backendInstance := backendruntime.NewBackend(backendRuntimeFilePath)
err = backendInstance.Start()
if err != nil {
log.Errorf("Failed to start backend #%d: %s", backend.ID, err.Error())
continue
}
backendParameters, err := base64.StdEncoding.DecodeString(backend.BackendParameters)
if err != nil {
log.Errorf("Failed to decode backend parameters for backend #%d: %s", backend.ID, err.Error())
continue
}
backendInstance.RuntimeCommands <- &commonbackend.Start{
Type: "start",
Arguments: backendParameters,
}
backendStartResponse := <-backendInstance.RuntimeCommands
switch responseMessage := backendStartResponse.(type) {
case error:
log.Warnf("Failed to get response for backend #%d: %s", backend.ID, responseMessage.Error())
err = backendInstance.Stop()
if err != nil {
log.Warnf("Failed to stop backend: %s", err.Error())
}
continue
case *commonbackend.BackendStatusResponse:
if !responseMessage.IsRunning {
err = backendInstance.Stop()
if err != nil {
log.Warnf("Failed to start backend: %s", err.Error())
}
if responseMessage.Message == "" {
log.Errorf("Unkown error while trying to start the backend #%d", backend.ID)
} else {
log.Errorf("Failed to start backend: %s", responseMessage.Message)
}
continue
}
default:
log.Errorf("Got illegal response type for backend #%d: %T", backend.ID, responseMessage)
continue
}
backendruntime.RunningBackends[backend.ID] = backendInstance
log.Infof("Successfully started backend #%d", backend.ID)
}
log.Debug("Initializing API...")
@ -97,10 +191,55 @@ func main() {
engine.POST("/api/v1/users/remove", users.RemoveUser)
engine.POST("/api/v1/users/lookup", users.LookupUser)
log.Infof("Listening on: %s", listeningAddress)
engine.POST("/api/v1/backends/create", backends.CreateBackend)
log.Infof("Listening on '%s'", listeningAddress)
err = engine.Run(listeningAddress)
if err != nil {
log.Fatalf("Error running web server: %s", err.Error())
return fmt.Errorf("Error running web server: %s", err.Error())
}
return nil
}
func main() {
logLevel := os.Getenv("HERMES_LOG_LEVEL")
if logLevel != "" {
switch logLevel {
case "debug":
log.SetLevel(log.DebugLevel)
case "info":
log.SetLevel(log.InfoLevel)
case "warn":
log.SetLevel(log.WarnLevel)
case "error":
log.SetLevel(log.ErrorLevel)
case "fatal":
log.SetLevel(log.FatalLevel)
}
}
app := &cli.App{
Name: "hermes",
Usage: "port forwarding across boundaries",
Flags: []cli.Flag{
&cli.StringFlag{
Name: "backends-path",
Aliases: []string{"b"},
Usage: "path to the backend manifest file",
Required: true,
},
},
Action: entrypoint,
}
if err := app.Run(os.Args); err != nil {
log.Fatal(err)
}
}