diff options
| -rw-r--r-- | doc/guix.texi | 75 | ||||
| -rw-r--r-- | gnu/services/ssh.scm | 106 |
2 files changed, 180 insertions, 1 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 0020739aec..812d08a8ef 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -79,6 +79,7 @@ Copyright @copyright{} 2020 Naga Malleswari@* Copyright @copyright{} 2020 Brice Waegeneire@* Copyright @copyright{} 2020 R Veera Kumar@* Copyright @copyright{} 2020 Pierre Langlois@* +Copyright @copyright{} 2020 pinoaffe@* Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or @@ -14390,6 +14391,80 @@ Whether to enable password-based authentication. @end table @end deftp +@cindex AutoSSH +@deffn {Scheme Variable} autossh-service-type +This is the type for the @uref{https://www.harding.motd.ca/autossh, +AutoSSH} program that runs a copy of @code{ssh} and monitors it, +restarting it as necessary should it die or stop passing traffic. +AutoSSH can be run manually from the commandline by passing arguments to +the binary @code{autossh} from the package @code{autossh}, but it can +also be run as a guix service. This latter usecase is documented here. + +AutoSSH can be used to forward local traffic to a remote machine using an SSH tunnel, +and it respects the @file{~/.ssh/config} of the user it is run as. + +For example, to specify a service running autossh as the user @code{pino} +and forwarding all local connections to port @code{8081} to @code{remote:8081} +using an SSH tunnel, add this call to the operating system's @code{services} field: + +@lisp +(service autossh-service-type + (autossh-configuration + (user "pino") + (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net")))) +@end lisp +@end deffn + +@deftp {Data Type} autossh-configuration +This data type represents the configuration of an AutoSSH service. + +@table @asis + +@item @code{user} (default @code{"autossh"}) +The user as which the AutoSSH service is to be run. +This assumes that the specified user exists. + +@item @code{poll} (default @code{600}) +Specifies the connection poll time in seconds. + +@item @code{first-poll} (default @code{#f}) +Specifies how long autossh waits before the first connection test in seconds. +After this first test, polling is resumed at the pace defined in @code{poll}. +When set to @code{#f}, the first poll is not treated specially and +will also use the connection poll specified in @code{poll} + +@item @code{gate-time} (default @code{30}) +Specifies (in seconds) how long an SSH connection must be active +before it is considered successful. + +@item @code{log-level} (default @code{1}) +The log level, corresponding to the levels used by syslog +(so @code{0} is the most silent while @code{7} is the chattiest.) + +@item @code{max-start} (default @code{#f}) +The maximum number of times SSH may be (re)started before AutoSSH exits. +When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely. + +@item @code{message} (default @code{""}) +The message to append to the echo message sent when testing connections. + +@item @code{port} (default @code{"0"}) +The ports used for monitoring the connection. When set to @code{"0"}, +monitoring is disabled. When set to @code{"n"} where @code{n} is a positive integer, +ports @code{n} and @code{n+1} are used for monitoring the connection, such that +port @code{n} is the base monitoring port and @code{n+1} is the echo port. +When set to @code{"n:m"} where @code{n} and @code{m} are positive integers, +the ports @code{n} and @code{n+1} are used for monitoring the connection, such +that port @code{n} is the base monitoring port and @code{m} is the echo port. + +@item @code{ssh-options} (default @code{'()}) +The list of commandline arguments to pass to ssh when it is run. +Options @code{-f} and @code{-M ....} are reserved for AutoSSH +and may cause undefined behaviour. + +@end table +@end deftp + @defvr {Scheme Variable} %facebook-host-aliases This variable contains a string for use in @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each diff --git a/gnu/services/ssh.scm b/gnu/services/ssh.scm index d2dbb8f80d..ced21c0742 100644 --- a/gnu/services/ssh.scm +++ b/gnu/services/ssh.scm @@ -4,6 +4,7 @@ ;;; Copyright © 2016 Julien Lepiller <julien@lepiller.eu> ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org> ;;; Copyright © 2019 Ricardo Wurmus <rekado@elephly.net> +;;; Copyright © 2020 pinoaffe <pinoaffe@airmail.cc> ;;; ;;; This file is part of GNU Guix. ;;; @@ -45,7 +46,11 @@ dropbear-configuration dropbear-configuration? dropbear-service-type - dropbear-service)) + dropbear-service + + autossh-configuration + autossh-configuration? + autossh-service-type)) ;;; Commentary: ;;; @@ -628,4 +633,103 @@ daemon} with the given @var{config}, a @code{<dropbear-configuration>} object." (service dropbear-service-type config)) + +;;; +;;; AutoSSH. +;;; + + +(define-record-type* <autossh-configuration> + autossh-configuration make-autossh-configuration + autossh-configuration? + (user autossh-configuration-user + (default "autossh")) + (poll autossh-configuration-poll + (default 600)) + (first-poll autossh-configuration-first-poll + (default #f)) + (gate-time autossh-configuration-gate-time + (default 30)) + (log-level autossh-configuration-log-level + (default 1)) + (max-start autossh-configuration-max-start + (default #f)) + (message autossh-configuration-message + (default "")) + (port autossh-configuration-port + (default "0")) + (ssh-options autossh-configuration-ssh-options + (default '()))) + +(define (autossh-file-name config file) + "Return a path in /var/run/autossh/ that is writable + by @code{user} from @code{config}." + (string-append "/var/run/autossh/" + (autossh-configuration-user config) + "/" file)) + +(define (autossh-shepherd-service config) + (shepherd-service + (documentation "Automatically set up ssh connections (and keep them alive).") + (provision '(autossh)) + (start #~(make-forkexec-constructor + (list #$(file-append autossh "/bin/autossh") + #$@(autossh-configuration-ssh-options config)) + #:user #$(autossh-configuration-user config) + #:group (passwd:gid (getpw #$(autossh-configuration-user config))) + #:pid-file #$(autossh-file-name config "pid") + #:log-file #$(autossh-file-name config "log") + #:environment-variables + '(#$(string-append "AUTOSSH_PIDFILE=" + (autossh-file-name config "pid")) + #$(string-append "AUTOSSH_LOGFILE=" + (autossh-file-name config "log")) + #$(string-append "AUTOSSH_POLL=" + (number->string + (autossh-configuration-poll config))) + #$(string-append "AUTOSSH_FIRST_POLL=" + (number->string + (or + (autossh-configuration-first-poll config) + (autossh-configuration-poll config)))) + #$(string-append "AUTOSSH_GATETIME=" + (number->string + (autossh-configuration-gate-time config))) + #$(string-append "AUTOSSH_LOGLEVEL=" + (number->string + (autossh-configuration-log-level config))) + #$(string-append "AUTOSSH_MAXSTART=" + (number->string + (or (autossh-configuration-max-start config) + -1))) + #$(string-append "AUTOSSH_MESSAGE=" + (autossh-configuration-message config)) + #$(string-append "AUTOSSH_PORT=" + (autossh-configuration-port config))))) + (stop #~(make-kill-destructor)))) + +(define (autossh-service-activation config) + (with-imported-modules '((guix build utils)) + #~(begin + (use-modules (guix build utils)) + (define %user + (getpw #$(autossh-configuration-user config))) + (let* ((directory #$(autossh-file-name config "")) + (log (string-append directory "/log"))) + (mkdir-p directory) + (chown directory (passwd:uid %user) (passwd:gid %user)) + (call-with-output-file log (const #t)) + (chown log (passwd:uid %user) (passwd:gid %user)))))) + +(define autossh-service-type + (service-type + (name 'autossh) + (description "Automatically set up ssh connections (and keep them alive).") + (extensions + (list (service-extension shepherd-root-service-type + (compose list autossh-shepherd-service)) + (service-extension activation-service-type + autossh-service-activation))) + (default-value (autossh-configuration)))) + ;;; ssh.scm ends here |