forgejo/cmd/serv.go
wxiaoguang 061b68e995
Refactor path & config system (#25330) (#25416)
Backport #25330

# The problem

There were many "path tricks":

* By default, Gitea uses its program directory as its work path
* Gitea tries to use the "work path" to guess its "custom path" and
"custom conf (app.ini)"
* Users might want to use other directories as work path
* The non-default work path should be passed to Gitea by GITEA_WORK_DIR
or "--work-path"
* But some Gitea processes are started without these values
    * The "serv" process started by OpenSSH server
    * The CLI sub-commands started by site admin
* The paths are guessed by SetCustomPathAndConf again and again
* The default values of "work path / custom path / custom conf" can be
changed when compiling

# The solution

* Use `InitWorkPathAndCommonConfig` to handle these path tricks, and use
test code to cover its behaviors.
* When Gitea's web server runs, write the WORK_PATH to "app.ini", this
value must be the most correct one, because if this value is not right,
users would find that the web UI doesn't work and then they should be
able to fix it.
* Then all other sub-commands can use the WORK_PATH in app.ini to
initialize their paths.
* By the way, when Gitea starts for git protocol, it shouldn't output
any log, otherwise the git protocol gets broken and client blocks
forever.

The "work path" priority is: WORK_PATH in app.ini > cmd arg --work-path
> env var GITEA_WORK_DIR > builtin default

The "app.ini" searching order is: cmd arg --config > cmd arg "work path
/ custom path" > env var "work path / custom path" > builtin default


## ⚠️ BREAKING

If your instance's "work path / custom path / custom conf" doesn't meet
the requirements (eg: work path must be absolute), Gitea will report a
fatal error and exit. You need to set these values according to the
error log.
2023-06-22 16:27:18 +00:00

359 lines
12 KiB
Go

// Copyright 2014 The Gogs Authors. All rights reserved.
// Copyright 2016 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package cmd
import (
"context"
"fmt"
"net/url"
"os"
"os/exec"
"path/filepath"
"regexp"
"strconv"
"strings"
"time"
"unicode"
asymkey_model "code.gitea.io/gitea/models/asymkey"
git_model "code.gitea.io/gitea/models/git"
"code.gitea.io/gitea/models/perm"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/json"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/pprof"
"code.gitea.io/gitea/modules/private"
"code.gitea.io/gitea/modules/process"
repo_module "code.gitea.io/gitea/modules/repository"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/services/lfs"
"github.com/golang-jwt/jwt/v4"
"github.com/kballard/go-shellquote"
"github.com/urfave/cli"
)
const (
lfsAuthenticateVerb = "git-lfs-authenticate"
)
// CmdServ represents the available serv sub-command.
var CmdServ = cli.Command{
Name: "serv",
Usage: "This command should only be called by SSH shell",
Description: "Serv provides access auth for repositories",
Action: runServ,
Flags: []cli.Flag{
cli.BoolFlag{
Name: "enable-pprof",
},
cli.BoolFlag{
Name: "debug",
},
},
}
func setup(ctx context.Context, debug bool) {
if debug {
setupConsoleLogger(log.TRACE, false, os.Stderr)
} else {
setupConsoleLogger(log.FATAL, false, os.Stderr)
}
setting.MustInstalled()
if debug {
setting.RunMode = "dev"
}
// Check if setting.RepoRootPath exists. It could be the case that it doesn't exist, this can happen when
// `[repository]` `ROOT` is a relative path and $GITEA_WORK_DIR isn't passed to the SSH connection.
if _, err := os.Stat(setting.RepoRootPath); err != nil {
if os.IsNotExist(err) {
_ = fail(ctx, "Incorrect configuration, no repository directory.", "Directory `[repository].ROOT` %q was not found, please check if $GITEA_WORK_DIR is passed to the SSH connection or make `[repository].ROOT` an absolute value.", setting.RepoRootPath)
} else {
_ = fail(ctx, "Incorrect configuration, repository directory is inaccessible", "Directory `[repository].ROOT` %q is inaccessible. err: %v", setting.RepoRootPath, err)
}
return
}
if err := git.InitSimple(context.Background()); err != nil {
_ = fail(ctx, "Failed to init git", "Failed to init git, err: %v", err)
}
}
var (
allowedCommands = map[string]perm.AccessMode{
"git-upload-pack": perm.AccessModeRead,
"git-upload-archive": perm.AccessModeRead,
"git-receive-pack": perm.AccessModeWrite,
lfsAuthenticateVerb: perm.AccessModeNone,
}
alphaDashDotPattern = regexp.MustCompile(`[^\w-\.]`)
)
// fail prints message to stdout, it's mainly used for git serv and git hook commands.
// The output will be passed to git client and shown to user.
func fail(ctx context.Context, userMessage, logMsgFmt string, args ...interface{}) error {
if userMessage == "" {
userMessage = "Internal Server Error (no specific error)"
}
// There appears to be a chance to cause a zombie process and failure to read the Exit status
// if nothing is outputted on stdout.
_, _ = fmt.Fprintln(os.Stdout, "")
_, _ = fmt.Fprintln(os.Stderr, "Gitea:", userMessage)
if logMsgFmt != "" {
logMsg := fmt.Sprintf(logMsgFmt, args...)
if !setting.IsProd {
_, _ = fmt.Fprintln(os.Stderr, "Gitea:", logMsg)
}
if userMessage != "" {
if unicode.IsPunct(rune(userMessage[len(userMessage)-1])) {
logMsg = userMessage + " " + logMsg
} else {
logMsg = userMessage + ". " + logMsg
}
}
_ = private.SSHLog(ctx, true, logMsg)
}
return cli.NewExitError("", 1)
}
// handleCliResponseExtra handles the extra response from the cli sub-commands
// If there is a user message it will be printed to stdout
// If the command failed it will return an error (the error will be printed by cli framework)
func handleCliResponseExtra(extra private.ResponseExtra) error {
if extra.UserMsg != "" {
_, _ = fmt.Fprintln(os.Stdout, extra.UserMsg)
}
if extra.HasError() {
return cli.NewExitError(extra.Error, 1)
}
return nil
}
func runServ(c *cli.Context) error {
ctx, cancel := installSignals()
defer cancel()
// FIXME: This needs to internationalised
setup(ctx, c.Bool("debug"))
if setting.SSH.Disabled {
println("Gitea: SSH has been disabled")
return nil
}
if len(c.Args()) < 1 {
if err := cli.ShowSubcommandHelp(c); err != nil {
fmt.Printf("error showing subcommand help: %v\n", err)
}
return nil
}
keys := strings.Split(c.Args()[0], "-")
if len(keys) != 2 || keys[0] != "key" {
return fail(ctx, "Key ID format error", "Invalid key argument: %s", c.Args()[0])
}
keyID, err := strconv.ParseInt(keys[1], 10, 64)
if err != nil {
return fail(ctx, "Key ID parsing error", "Invalid key argument: %s", c.Args()[1])
}
cmd := os.Getenv("SSH_ORIGINAL_COMMAND")
if len(cmd) == 0 {
key, user, err := private.ServNoCommand(ctx, keyID)
if err != nil {
return fail(ctx, "Key check failed", "Failed to check provided key: %v", err)
}
switch key.Type {
case asymkey_model.KeyTypeDeploy:
println("Hi there! You've successfully authenticated with the deploy key named " + key.Name + ", but Gitea does not provide shell access.")
case asymkey_model.KeyTypePrincipal:
println("Hi there! You've successfully authenticated with the principal " + key.Content + ", but Gitea does not provide shell access.")
default:
println("Hi there, " + user.Name + "! You've successfully authenticated with the key named " + key.Name + ", but Gitea does not provide shell access.")
}
println("If this is unexpected, please log in with password and setup Gitea under another user.")
return nil
} else if c.Bool("debug") {
log.Debug("SSH_ORIGINAL_COMMAND: %s", os.Getenv("SSH_ORIGINAL_COMMAND"))
}
words, err := shellquote.Split(cmd)
if err != nil {
return fail(ctx, "Error parsing arguments", "Failed to parse arguments: %v", err)
}
if len(words) < 2 {
if git.CheckGitVersionAtLeast("2.29") == nil {
// for AGit Flow
if cmd == "ssh_info" {
fmt.Print(`{"type":"gitea","version":1}`)
return nil
}
}
return fail(ctx, "Too few arguments", "Too few arguments in cmd: %s", cmd)
}
verb := words[0]
repoPath := words[1]
if repoPath[0] == '/' {
repoPath = repoPath[1:]
}
var lfsVerb string
if verb == lfsAuthenticateVerb {
if !setting.LFS.StartServer {
return fail(ctx, "Unknown git command", "LFS authentication request over SSH denied, LFS support is disabled")
}
if len(words) > 2 {
lfsVerb = words[2]
}
}
// LowerCase and trim the repoPath as that's how they are stored.
repoPath = strings.ToLower(strings.TrimSpace(repoPath))
rr := strings.SplitN(repoPath, "/", 2)
if len(rr) != 2 {
return fail(ctx, "Invalid repository path", "Invalid repository path: %v", repoPath)
}
username := strings.ToLower(rr[0])
reponame := strings.ToLower(strings.TrimSuffix(rr[1], ".git"))
if alphaDashDotPattern.MatchString(reponame) {
return fail(ctx, "Invalid repo name", "Invalid repo name: %s", reponame)
}
if c.Bool("enable-pprof") {
if err := os.MkdirAll(setting.PprofDataPath, os.ModePerm); err != nil {
return fail(ctx, "Error while trying to create PPROF_DATA_PATH", "Error while trying to create PPROF_DATA_PATH: %v", err)
}
stopCPUProfiler, err := pprof.DumpCPUProfileForUsername(setting.PprofDataPath, username)
if err != nil {
return fail(ctx, "Unable to start CPU profiler", "Unable to start CPU profile: %v", err)
}
defer func() {
stopCPUProfiler()
err := pprof.DumpMemProfileForUsername(setting.PprofDataPath, username)
if err != nil {
_ = fail(ctx, "Unable to dump Mem profile", "Unable to dump Mem Profile: %v", err)
}
}()
}
requestedMode, has := allowedCommands[verb]
if !has {
return fail(ctx, "Unknown git command", "Unknown git command %s", verb)
}
if verb == lfsAuthenticateVerb {
if lfsVerb == "upload" {
requestedMode = perm.AccessModeWrite
} else if lfsVerb == "download" {
requestedMode = perm.AccessModeRead
} else {
return fail(ctx, "Unknown LFS verb", "Unknown lfs verb %s", lfsVerb)
}
}
results, extra := private.ServCommand(ctx, keyID, username, reponame, requestedMode, verb, lfsVerb)
if extra.HasError() {
return fail(ctx, extra.UserMsg, "ServCommand failed: %s", extra.Error)
}
// LFS token authentication
if verb == lfsAuthenticateVerb {
url := fmt.Sprintf("%s%s/%s.git/info/lfs", setting.AppURL, url.PathEscape(results.OwnerName), url.PathEscape(results.RepoName))
now := time.Now()
claims := lfs.Claims{
RegisteredClaims: jwt.RegisteredClaims{
ExpiresAt: jwt.NewNumericDate(now.Add(setting.LFS.HTTPAuthExpiry)),
NotBefore: jwt.NewNumericDate(now),
},
RepoID: results.RepoID,
Op: lfsVerb,
UserID: results.UserID,
}
token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
// Sign and get the complete encoded token as a string using the secret
tokenString, err := token.SignedString(setting.LFS.JWTSecretBytes)
if err != nil {
return fail(ctx, "Failed to sign JWT Token", "Failed to sign JWT token: %v", err)
}
tokenAuthentication := &git_model.LFSTokenResponse{
Header: make(map[string]string),
Href: url,
}
tokenAuthentication.Header["Authorization"] = fmt.Sprintf("Bearer %s", tokenString)
enc := json.NewEncoder(os.Stdout)
err = enc.Encode(tokenAuthentication)
if err != nil {
return fail(ctx, "Failed to encode LFS json response", "Failed to encode LFS json response: %v", err)
}
return nil
}
var gitcmd *exec.Cmd
gitBinPath := filepath.Dir(git.GitExecutable) // e.g. /usr/bin
gitBinVerb := filepath.Join(gitBinPath, verb) // e.g. /usr/bin/git-upload-pack
if _, err := os.Stat(gitBinVerb); err != nil {
// if the command "git-upload-pack" doesn't exist, try to split "git-upload-pack" to use the sub-command with git
// ps: Windows only has "git.exe" in the bin path, so Windows always uses this way
verbFields := strings.SplitN(verb, "-", 2)
if len(verbFields) == 2 {
// use git binary with the sub-command part: "C:\...\bin\git.exe", "upload-pack", ...
gitcmd = exec.CommandContext(ctx, git.GitExecutable, verbFields[1], repoPath)
}
}
if gitcmd == nil {
// by default, use the verb (it has been checked above by allowedCommands)
gitcmd = exec.CommandContext(ctx, gitBinVerb, repoPath)
}
process.SetSysProcAttribute(gitcmd)
gitcmd.Dir = setting.RepoRootPath
gitcmd.Stdout = os.Stdout
gitcmd.Stdin = os.Stdin
gitcmd.Stderr = os.Stderr
gitcmd.Env = append(gitcmd.Env, os.Environ()...)
gitcmd.Env = append(gitcmd.Env,
repo_module.EnvRepoIsWiki+"="+strconv.FormatBool(results.IsWiki),
repo_module.EnvRepoName+"="+results.RepoName,
repo_module.EnvRepoUsername+"="+results.OwnerName,
repo_module.EnvPusherName+"="+results.UserName,
repo_module.EnvPusherEmail+"="+results.UserEmail,
repo_module.EnvPusherID+"="+strconv.FormatInt(results.UserID, 10),
repo_module.EnvRepoID+"="+strconv.FormatInt(results.RepoID, 10),
repo_module.EnvPRID+"="+fmt.Sprintf("%d", 0),
repo_module.EnvDeployKeyID+"="+fmt.Sprintf("%d", results.DeployKeyID),
repo_module.EnvKeyID+"="+fmt.Sprintf("%d", results.KeyID),
repo_module.EnvAppURL+"="+setting.AppURL,
)
// to avoid breaking, here only use the minimal environment variables for the "gitea serv" command.
// it could be re-considered whether to use the same git.CommonGitCmdEnvs() as "git" command later.
gitcmd.Env = append(gitcmd.Env, git.CommonCmdServEnvs()...)
if err = gitcmd.Run(); err != nil {
return fail(ctx, "Failed to execute git command", "Failed to execute git command: %v", err)
}
// Update user key activity.
if results.KeyID > 0 {
if err = private.UpdatePublicKeyInRepo(ctx, results.KeyID, results.RepoID); err != nil {
return fail(ctx, "Failed to update public key", "UpdatePublicKeyInRepo: %v", err)
}
}
return nil
}