git-annex/Assistant/WebApp/Configurators/Ssh.hs
Joey Hess b573d91aa2 broke out fairly generic ssh stuff to Assistant.Ssh so pairing can use it too
I'd rather Utility.Ssh, but the SshData type is not sufficiently clean and
generic for Utility.
2012-09-10 15:21:34 -04:00

318 lines
10 KiB
Haskell

{- git-annex assistant webapp configurator for ssh-based remotes
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE TypeFamilies, QuasiQuotes, MultiParamTypeClasses, TemplateHaskell, OverloadedStrings, RankNTypes #-}
module Assistant.WebApp.Configurators.Ssh where
import Assistant.Common
import Assistant.Ssh
import Assistant.WebApp
import Assistant.WebApp.Types
import Assistant.WebApp.SideBar
import Utility.Yesod
import Assistant.WebApp.Configurators.Local
import qualified Types.Remote as R
import qualified Remote.Rsync as Rsync
import qualified Command.InitRemote
import Logs.UUID
import Logs.Remote
import Yesod
import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Map as M
import Network.BSD
import System.Posix.User
sshConfigurator :: Widget -> Handler RepHtml
sshConfigurator a = bootstrap (Just Config) $ do
sideBarDisplay
setTitle "Add a remote server"
a
data SshServer = SshServer
{ hostname :: Maybe Text
, username :: Maybe Text
, directory :: Maybe Text
}
deriving (Show)
{- SshServer is only used for applicative form prompting, this converts
- the result of such a form into a SshData. -}
mkSshData :: SshServer -> SshData
mkSshData sshserver = SshData
{ sshHostName = fromMaybe "" $ hostname sshserver
, sshUserName = username sshserver
, sshDirectory = fromMaybe "" $ directory sshserver
, sshRepoName = genSshRepoName sshserver
, needsPubKey = False
, rsyncOnly = False
}
sshServerAForm :: (Maybe Text) -> AForm WebApp WebApp SshServer
sshServerAForm localusername = SshServer
<$> aopt check_hostname "Host name" Nothing
<*> aopt check_username "User name" (Just localusername)
<*> aopt textField "Directory" (Just $ Just $ T.pack gitAnnexAssistantDefaultDir)
where
check_hostname = checkM (liftIO . checkdns) textField
checkdns t = do
let h = T.unpack t
r <- catchMaybeIO $ getHostByName h
return $ case r of
-- canonicalize input hostname if it had no dot
Just hostentry
| '.' `elem` h -> Right t
| otherwise -> Right $ T.pack $ hostName hostentry
Nothing -> Left bad_hostname
check_username = checkBool (all (`notElem` "/:@ \t") . T.unpack)
bad_username textField
bad_hostname = "cannot resolve host name" :: Text
bad_username = "bad user name" :: Text
data ServerStatus
= UntestedServer
| UnusableServer Text -- reason why it's not usable
| UsableRsyncServer
| UsableSshServer
deriving (Eq)
usable :: ServerStatus -> Bool
usable UntestedServer = False
usable (UnusableServer _) = False
usable UsableRsyncServer = True
usable UsableSshServer = True
getAddSshR :: Handler RepHtml
getAddSshR = sshConfigurator $ do
u <- liftIO $ T.pack . userName
<$> (getUserEntryForID =<< getEffectiveUserID)
((result, form), enctype) <- lift $
runFormGet $ renderBootstrap $ sshServerAForm (Just u)
case result of
FormSuccess sshserver -> do
(status, needspubkey) <- liftIO $ testServer sshserver
if usable status
then lift $ redirect $ ConfirmSshR $
(mkSshData sshserver)
{ needsPubKey = needspubkey
, rsyncOnly = (status == UsableRsyncServer)
}
else showform form enctype status
_ -> showform form enctype UntestedServer
where
showform form enctype status = do
let authtoken = webAppFormAuthToken
$(widgetFile "configurators/ssh/add")
{- Test if we can ssh into the server.
-
- Two probe attempts are made. First, try sshing in using the existing
- configuration, but don't let ssh prompt for any password. If
- passwordless login is already enabled, use it. Otherwise,
- a special ssh key will need to be generated just for this server.
-
- Once logged into the server, probe to see if git-annex-shell is
- available, or rsync.
-}
testServer :: SshServer -> IO (ServerStatus, Bool)
testServer (SshServer { hostname = Nothing }) = return
(UnusableServer "Please enter a host name.", False)
testServer sshserver = do
status <- probe [sshOpt "NumberOfPasswordPrompts" "0"]
if usable status
then return (status, False)
else do
status' <- probe []
return (status', True)
where
probe extraopts = do
let remotecommand = join ";" $
[ report "loggedin"
, checkcommand "git-annex-shell"
, checkcommand "rsync"
]
knownhost <- knownHost sshserver
let sshopts = filter (not . null) $ extraopts ++
{- If this is an already known host, let
- ssh check it as usual.
- Otherwise, trust the host key. -}
[ if knownhost then "" else sshOpt "StrictHostKeyChecking" "no"
, "-n" -- don't read from stdin
, genSshHost (fromJust $ hostname sshserver) (username sshserver)
, remotecommand
]
parsetranscript . fst <$> sshTranscript sshopts ""
parsetranscript s
| reported "git-annex-shell" = UsableSshServer
| reported "rsync" = UsableRsyncServer
| reported "loggedin" = UnusableServer
"Neither rsync nor git-annex are installed on the server. Perhaps you should go install them?"
| otherwise = UnusableServer $ T.pack $
"Failed to ssh to the server. Transcript: " ++ s
where
reported r = token r `isInfixOf` s
checkcommand c = "if which " ++ c ++ "; then " ++ report c ++ "; fi"
token r = "git-annex-probe " ++ r
report r = "echo " ++ token r
{- user@host or host -}
genSshHost :: Text -> Maybe Text -> String
genSshHost host user = maybe "" (\v -> T.unpack v ++ "@") user ++ T.unpack host
{- host_dir -}
genSshRepoName :: SshServer -> String
genSshRepoName s = (T.unpack $ fromJust $ hostname s) ++
(maybe "" (\d -> '_' : T.unpack d) (directory s))
{- Runs a ssh command; if it fails shows the user the transcript,
- and if it succeeds, runs an action. -}
sshSetup :: [String] -> String -> Handler RepHtml -> Handler RepHtml
sshSetup opts input a = do
(transcript, ok) <- liftIO $ sshTranscript opts input
if ok
then a
else showSshErr transcript
showSshErr :: String -> Handler RepHtml
showSshErr msg = sshConfigurator $
$(widgetFile "configurators/ssh/error")
{- Does ssh have known_hosts data for a hostname? -}
knownHost :: SshServer -> IO Bool
knownHost (SshServer { hostname = Nothing }) = return False
knownHost (SshServer { hostname = Just h }) = do
sshdir <- sshDir
ifM (doesFileExist $ sshdir </> "known_hosts")
( not . null <$> readProcess "ssh-keygen" ["-F", T.unpack h]
, return False
)
getConfirmSshR :: SshData -> Handler RepHtml
getConfirmSshR sshdata = sshConfigurator $ do
let authtoken = webAppFormAuthToken
$(widgetFile "configurators/ssh/confirm")
getMakeSshGitR :: SshData -> Handler RepHtml
getMakeSshGitR = makeSsh False
getMakeSshRsyncR :: SshData -> Handler RepHtml
getMakeSshRsyncR = makeSsh True
makeSsh :: Bool -> SshData -> Handler RepHtml
makeSsh rsync sshdata
| needsPubKey sshdata = do
keypair <- liftIO $ genSshKeyPair
sshdata' <- liftIO $ setupSshKeyPair keypair sshdata
makeSsh' rsync sshdata' (Just keypair)
| otherwise = makeSsh' rsync sshdata Nothing
makeSsh' :: Bool -> SshData -> Maybe SshKeyPair -> Handler RepHtml
makeSsh' rsync sshdata keypair =
sshSetup [sshhost, remoteCommand] "" $
makeSshRepo rsync sshdata
where
sshhost = genSshHost (sshHostName sshdata) (sshUserName sshdata)
remotedir = T.unpack $ sshDirectory sshdata
remoteCommand = join "&&" $ catMaybes
[ Just $ "mkdir -p " ++ shellEscape remotedir
, Just $ "cd " ++ shellEscape remotedir
, if rsync then Nothing else Just $ "git init --bare --shared"
, if rsync then Nothing else Just $ "git annex init"
, maybe Nothing (makeAuthorizedKeys sshdata) keypair
]
makeSshRepo :: Bool -> SshData -> Handler RepHtml
makeSshRepo forcersync sshdata = do
r <- runAnnex undefined $
addRemote $ maker (sshRepoName sshdata) sshurl
syncRemote r
redirect RepositoriesR
where
rsync = forcersync || rsyncOnly sshdata
maker
| rsync = makeRsyncRemote
| otherwise = makeGitRemote
sshurl = T.unpack $ T.concat $
if rsync
then [u, h, ":", sshDirectory sshdata, "/"]
else ["ssh://", u, h, d, "/"]
where
u = maybe "" (\v -> T.concat [v, "@"]) $ sshUserName sshdata
h = sshHostName sshdata
d
| "/" `T.isPrefixOf` sshDirectory sshdata = d
| otherwise = T.concat ["/~/", sshDirectory sshdata]
{- Inits a rsync special remote, and returns the name of the remote. -}
makeRsyncRemote :: String -> String -> Annex String
makeRsyncRemote name location = makeRemote name location $ const $ do
(u, c) <- Command.InitRemote.findByName name
c' <- R.setup Rsync.remote u $ M.union config c
describeUUID u name
configSet u c'
where
config = M.fromList
[ ("encryption", "shared")
, ("rsyncurl", location)
, ("type", "rsync")
]
getAddRsyncNetR :: Handler RepHtml
getAddRsyncNetR = do
((result, form), enctype) <- runFormGet $
renderBootstrap $ sshServerAForm Nothing
let showform status = bootstrap (Just Config) $ do
sideBarDisplay
setTitle "Add a Rsync.net repository"
let authtoken = webAppFormAuthToken
$(widgetFile "configurators/addrsync.net")
case result of
FormSuccess sshserver -> do
knownhost <- liftIO $ knownHost sshserver
keypair <- liftIO $ genSshKeyPair
sshdata <- liftIO $ setupSshKeyPair keypair
(mkSshData sshserver)
{ needsPubKey = True
, rsyncOnly = True
, sshRepoName = "rsync.net"
}
{- I'd prefer to separate commands with && , but
- rsync.net's shell does not support that.
-
- The dd method of appending to the
- authorized_keys file is the one recommended by
- rsync.net documentation. I touch the file first
- to not need to use a different method to create
- it.
-}
let remotecommand = join ";" $
[ "mkdir -p .ssh"
, "touch .ssh/authorized_keys"
, "dd of=.ssh/authorized_keys oflag=append conv=notrunc"
, "mkdir -p " ++ T.unpack (sshDirectory sshdata)
]
let sshopts = filter (not . null) $
[ if knownhost then "" else sshOpt "StrictHostKeyChecking" "no"
, genSshHost (sshHostName sshdata) (sshUserName sshdata)
, remotecommand
]
let host = fromMaybe "" $ hostname sshserver
checkhost host showform $
sshSetup sshopts (sshPubKey keypair) $
makeSshRepo True sshdata
_ -> showform UntestedServer
where
checkhost host showform a
| ".rsync.net" `T.isSuffixOf` T.toLower host = a
| otherwise = showform $ UnusableServer
"That is not a rsync.net host name."