git-annex/Assistant/WebApp/Configurators/Ssh.hs
Joey Hess d35132810a Got removable media mount detection working on Android.
Bionic has an amusing stub for `getmntent` that prints out
"FIX ME! implement getmntent()"

But, `/proc/mounts` is there, so I just parse it.
2013-05-04 16:19:25 -04:00

378 lines
13 KiB
Haskell

{- git-annex assistant webapp configurator for ssh-based remotes
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE TypeFamilies, QuasiQuotes, MultiParamTypeClasses, TemplateHaskell, OverloadedStrings, RankNTypes #-}
{-# LANGUAGE CPP #-}
module Assistant.WebApp.Configurators.Ssh where
import Assistant.WebApp.Common
import Assistant.Ssh
import Assistant.MakeRemote
import Utility.Rsync (rsyncUrlIsShell)
import Logs.Remote
import Remote
import Logs.PreferredContent
import Types.StandardGroups
import Utility.UserInfo
import qualified Data.Text as T
import qualified Data.Map as M
import Network.Socket
sshConfigurator :: Widget -> Handler RepHtml
sshConfigurator = page "Add a remote server" (Just Configuration)
data SshInput = SshInput
{ inputHostname :: Maybe Text
, inputUsername :: Maybe Text
, inputDirectory :: Maybe Text
, inputPort :: Int
}
deriving (Show)
{- SshInput is only used for applicative form prompting, this converts
- the result of such a form into a SshData. -}
mkSshData :: SshInput -> SshData
mkSshData s = SshData
{ sshHostName = fromMaybe "" $ inputHostname s
, sshUserName = inputUsername s
, sshDirectory = fromMaybe "" $ inputDirectory s
, sshRepoName = genSshRepoName
(T.unpack $ fromJust $ inputHostname s)
(maybe "" T.unpack $ inputDirectory s)
, sshPort = inputPort s
, needsPubKey = False
, rsyncOnly = False
}
mkSshInput :: SshData -> SshInput
mkSshInput s = SshInput
{ inputHostname = Just $ sshHostName s
, inputUsername = sshUserName s
, inputDirectory = Just $ sshDirectory s
, inputPort = sshPort s
}
sshInputAForm :: (Field WebApp WebApp Text) -> SshInput -> AForm WebApp WebApp SshInput
sshInputAForm hostnamefield def = SshInput
<$> aopt check_hostname "Host name" (Just $ inputHostname def)
<*> aopt check_username "User name" (Just $ inputUsername def)
<*> aopt textField "Directory" (Just $ Just $ fromMaybe (T.pack gitAnnexAssistantDefaultDir) $ inputDirectory def)
<*> areq intField "Port" (Just $ inputPort def)
where
#ifndef __ANDROID__
check_hostname = checkM (liftIO . checkdns) hostnamefield
checkdns t = do
let h = T.unpack t
let canonname = Just $ defaultHints { addrFlags = [AI_CANONNAME] }
r <- catchMaybeIO $ getAddrInfo canonname (Just h) Nothing
return $ case catMaybes . map addrCanonName <$> r of
-- canonicalize input hostname if it had no dot
Just (fullname:_)
| '.' `elem` h -> Right t
| otherwise -> Right $ T.pack fullname
Just [] -> Right t
Nothing -> Left bad_hostname
#else
-- getAddrInfo currently broken on Android
check_hostname = hostnamefield -- unchecked
#endif
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
| UsableSshInput
deriving (Eq)
usable :: ServerStatus -> Bool
usable UntestedServer = False
usable (UnusableServer _) = False
usable UsableRsyncServer = True
usable UsableSshInput = True
getAddSshR :: Handler RepHtml
getAddSshR = postAddSshR
postAddSshR :: Handler RepHtml
postAddSshR = sshConfigurator $ do
u <- liftIO $ T.pack <$> myUserName
((result, form), enctype) <- lift $
runFormPost $ renderBootstrap $ sshInputAForm textField $
SshInput Nothing (Just u) Nothing 22
case result of
FormSuccess sshinput -> do
s <- liftIO $ testServer sshinput
case s of
Left status -> showform form enctype status
Right sshdata -> lift $ redirect $ ConfirmSshR sshdata
_ -> showform form enctype UntestedServer
where
showform form enctype status = $(widgetFile "configurators/ssh/add")
sshTestModal :: Widget
sshTestModal = $(widgetFile "configurators/ssh/testmodal")
{- To enable an existing rsync special remote, parse the SshInput from
- its rsyncurl, and display a form whose only real purpose is to check
- if ssh public keys need to be set up. From there, we can proceed with
- the usual repo setup; all that code is idempotent.
-
- Note that there's no EnableSshR because ssh remotes are not special
- remotes, and so their configuration is not shared between repositories.
-}
getEnableRsyncR :: UUID -> Handler RepHtml
getEnableRsyncR = postEnableRsyncR
postEnableRsyncR :: UUID -> Handler RepHtml
postEnableRsyncR u = do
m <- fromMaybe M.empty . M.lookup u <$> liftAnnex readRemoteLog
case (parseSshRsyncUrl =<< M.lookup "rsyncurl" m, M.lookup "name" m) of
(Just sshinput, Just reponame) -> sshConfigurator $ do
((result, form), enctype) <- lift $
runFormPost $ renderBootstrap $ sshInputAForm textField sshinput
case result of
FormSuccess sshinput'
| isRsyncNet (inputHostname sshinput') ->
void $ lift $ makeRsyncNet sshinput' reponame (const noop)
| otherwise -> do
s <- liftIO $ testServer sshinput'
case s of
Left status -> showform form enctype status
Right sshdata -> enable sshdata
{ sshRepoName = reponame }
_ -> showform form enctype UntestedServer
_ -> redirect AddSshR
where
showform form enctype status = do
description <- liftAnnex $ T.pack <$> prettyUUID u
$(widgetFile "configurators/ssh/enable")
enable sshdata = lift $ redirect $ ConfirmSshR $
sshdata { rsyncOnly = True }
{- Converts a rsyncurl value to a SshInput. But only if it's a ssh rsync
- url; rsync:// urls or bare path names are not supported.
-
- The hostname is stored mangled in the remote log for rsync special
- remotes configured by this webapp. So that mangling has to reversed
- here to get back the original hostname.
-}
parseSshRsyncUrl :: String -> Maybe SshInput
parseSshRsyncUrl u
| not (rsyncUrlIsShell u) = Nothing
| otherwise = Just $ SshInput
{ inputHostname = val $ unMangleSshHostName host
, inputUsername = if null user then Nothing else val user
, inputDirectory = val dir
, inputPort = 22
}
where
val = Just . T.pack
(userhost, dir) = separate (== ':') u
(user, host) = if '@' `elem` userhost
then separate (== '@') userhost
else (userhost, "")
{- 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. Note that, ~/.ssh/git-annex-shell may be
- present, while git-annex-shell is not in PATH.
-}
testServer :: SshInput -> IO (Either ServerStatus SshData)
testServer (SshInput { inputHostname = Nothing }) = return $
Left $ UnusableServer "Please enter a host name."
testServer sshinput@(SshInput { inputHostname = Just hn }) = do
status <- probe [sshOpt "NumberOfPasswordPrompts" "0"]
if usable status
then ret status False
else do
status' <- probe []
if usable status'
then ret status' True
else return $ Left status'
where
ret status needspubkey = return $ Right $ (mkSshData sshinput)
{ needsPubKey = needspubkey
, rsyncOnly = status == UsableRsyncServer
}
probe extraopts = do
let remotecommand = shellWrap $ intercalate ";"
[ report "loggedin"
, checkcommand "git-annex-shell"
, checkcommand "rsync"
, checkcommand shim
]
knownhost <- knownHost hn
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
, "-p", show (inputPort sshinput)
, genSshHost
(fromJust $ inputHostname sshinput)
(inputUsername sshinput)
, remotecommand
]
parsetranscript . fst <$> sshTranscript sshopts Nothing
parsetranscript s
| reported "git-annex-shell" = UsableSshInput
| reported shim = UsableSshInput
| 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
shim = "~/.ssh/git-annex-shell"
{- 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 (Just input)
if ok
then a
else showSshErr transcript
showSshErr :: String -> Handler RepHtml
showSshErr msg = sshConfigurator $
$(widgetFile "configurators/ssh/error")
getConfirmSshR :: SshData -> Handler RepHtml
getConfirmSshR sshdata = sshConfigurator $
$(widgetFile "configurators/ssh/confirm")
getRetrySshR :: SshData -> Handler ()
getRetrySshR sshdata = do
s <- liftIO $ testServer $ mkSshInput sshdata
redirect $ either (const $ ConfirmSshR sshdata) ConfirmSshR s
getMakeSshGitR :: SshData -> Handler RepHtml
getMakeSshGitR = makeSsh False setupGroup
getMakeSshRsyncR :: SshData -> Handler RepHtml
getMakeSshRsyncR = makeSsh True setupGroup
makeSsh :: Bool -> (Remote -> Handler ()) -> SshData -> Handler RepHtml
makeSsh rsync setup sshdata
| needsPubKey sshdata = do
keypair <- liftIO genSshKeyPair
sshdata' <- liftIO $ setupSshKeyPair keypair sshdata
makeSsh' rsync setup sshdata' (Just keypair)
| sshPort sshdata /= 22 = do
sshdata' <- liftIO $ setSshConfig sshdata []
makeSsh' rsync setup sshdata' Nothing
| otherwise = makeSsh' rsync setup sshdata Nothing
makeSsh' :: Bool -> (Remote -> Handler ()) -> SshData -> Maybe SshKeyPair -> Handler RepHtml
makeSsh' rsync setup sshdata keypair =
sshSetup [sshhost, remoteCommand] "" $
makeSshRepo rsync setup sshdata
where
sshhost = genSshHost (sshHostName sshdata) (sshUserName sshdata)
remotedir = T.unpack $ sshDirectory sshdata
remoteCommand = shellWrap $ intercalate "&&" $ catMaybes
[ Just $ "mkdir -p " ++ shellEscape remotedir
, Just $ "cd " ++ shellEscape remotedir
, if rsync then Nothing else Just "if [ ! -d .git ]; then git init --bare --shared; fi"
, if rsync then Nothing else Just "git annex init"
, if needsPubKey sshdata
then addAuthorizedKeysCommand (rsyncOnly sshdata) remotedir . sshPubKey <$> keypair
else Nothing
]
makeSshRepo :: Bool -> (Remote -> Handler ()) -> SshData -> Handler RepHtml
makeSshRepo forcersync setup sshdata = do
r <- liftAssistant $ makeSshRemote forcersync sshdata Nothing
setup r
redirect $ EditNewCloudRepositoryR $ Remote.uuid r
getAddRsyncNetR :: Handler RepHtml
getAddRsyncNetR = postAddRsyncNetR
postAddRsyncNetR :: Handler RepHtml
postAddRsyncNetR = do
((result, form), enctype) <- runFormPost $
renderBootstrap $ sshInputAForm hostnamefield $
SshInput Nothing Nothing Nothing 22
let showform status = page "Add a Rsync.net repository" (Just Configuration) $
$(widgetFile "configurators/addrsync.net")
case result of
FormSuccess sshinput
| isRsyncNet (inputHostname sshinput) -> do
let reponame = genSshRepoName "rsync.net"
(maybe "" T.unpack $ inputDirectory sshinput)
makeRsyncNet sshinput reponame setupGroup
| otherwise ->
showform $ UnusableServer
"That is not a rsync.net host name."
_ -> showform UntestedServer
where
hostnamefield = textField `withExpandableNote` ("Help", help)
help = [whamlet|
<div>
When you sign up for a Rsync.net account, you should receive an #
email from them with the host name and user name to put here.
<div>
The host name will be something like "usw-s001.rsync.net", and the #
user name something like "7491"
|]
makeRsyncNet :: SshInput -> String -> (Remote -> Handler ()) -> Handler RepHtml
makeRsyncNet sshinput reponame setup = do
knownhost <- liftIO $ maybe (return False) knownHost (inputHostname sshinput)
keypair <- liftIO $ genSshKeyPair
sshdata <- liftIO $ setupSshKeyPair keypair $
(mkSshData sshinput)
{ sshRepoName = reponame
, needsPubKey = True
, rsyncOnly = True
}
{- 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 = intercalate ";"
[ "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
]
sshSetup sshopts (sshPubKey keypair) $
makeSshRepo True setup sshdata
isRsyncNet :: Maybe Text -> Bool
isRsyncNet Nothing = False
isRsyncNet (Just host) = ".rsync.net" `T.isSuffixOf` T.toLower host
setupGroup :: Remote -> Handler ()
setupGroup r = liftAnnex $ setStandardGroup (Remote.uuid r) TransferGroup