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authorLudovic Courtès <ludo@gnu.org>2014-03-02 22:39:48 +0100
committerLudovic Courtès <ludo@gnu.org>2016-11-25 23:44:20 +0100
commit21531add3205e400707c8fbfd841845f9a71863a (patch)
tree8a88aa7b2fe01f5707bcf130fe09d54c0a95d33f /doc
parent6634180f9eabc70cdc5bc8e9ce2ff0f9250625bc (diff)
offload: Use Guile-SSH instead of GNU lsh.
* guix/scripts/offload.scm (<build-machine>)[ssh-options]: Remove. [host-key, host-key-type]: New fields. (%lsh-command, %lshg-command, user-lsh-private-key): Remove. (user-openssh-private-key, private-key-from-file*): New procedures. (host-key->type+key, open-ssh-session): New procedures. (remote-pipe): Remove 'mode' parameter. Rewrite in terms of 'open-ssh-session' etc. Update users. (send-files)[missing-files]: Rewrite using the bidirectional channel port. Remove call to 'call-with-compressed-output-port'. (retrieve-files): Remove call to 'call-with-decompressed-port'. (machine-load): Remove exit status logic. * doc/guix.texi (Requirements): Mention Guile-SSH. (Daemon Offload Setup): Document 'host-key' and 'private-key'. Show the default value on each @item line. * m4/guix.m4 (GUIX_CHECK_GUILE_SSH): New macro. * config-daemon.ac: Use 'GUIX_CHECK_GUILE_SSH'. Set 'HAVE_DAEMON_OFFLOAD_HOOK' as a function of that.
Diffstat (limited to 'doc')
-rw-r--r--doc/guix.texi69
1 files changed, 49 insertions, 20 deletions
diff --git a/doc/guix.texi b/doc/guix.texi
index ebb138e15d..f1cb007aa9 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -567,6 +567,12 @@ guix import}). It is of
interest primarily for developers and not for casual users.
@item
+@c Note: We need at least 0.10.2 for 'channel-send-eof'.
+Support for build offloading (@pxref{Daemon Offload Setup}) depends on
+@uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
+version 0.10.2 or later.
+
+@item
When @url{http://zlib.net, zlib} is available, @command{guix publish}
can compress build byproducts (@pxref{Invoking guix publish}).
@end itemize
@@ -814,9 +820,11 @@ available on the system---making it much harder to view them as
@cindex offloading
@cindex build hook
-When desired, the build daemon can @dfn{offload}
-derivation builds to other machines
-running Guix, using the @code{offload} @dfn{build hook}. When that
+When desired, the build daemon can @dfn{offload} derivation builds to
+other machines running Guix, using the @code{offload} @dfn{build
+hook}@footnote{This feature is available only when
+@uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
+present.}. When that
feature is enabled, a list of user-specified build machines is read from
@file{/etc/guix/machines.scm}; every time a build is requested, for
instance via @code{guix build}, the daemon attempts to offload it to one
@@ -832,16 +840,18 @@ The @file{/etc/guix/machines.scm} file typically looks like this:
(list (build-machine
(name "eightysix.example.org")
(system "x86_64-linux")
+ (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
(user "bob")
- (speed 2.)) ; incredibly fast!
+ (speed 2.)) ;incredibly fast!
(build-machine
(name "meeps.example.org")
(system "mips64el-linux")
+ (host-key "ssh-rsa AAAAB3Nza@dots{}")
(user "alice")
(private-key
(string-append (getenv "HOME")
- "/.lsh/identity-for-guix"))))
+ "/.ssh/identity-for-guix"))))
@end example
@noindent
@@ -875,31 +885,50 @@ The user account to use when connecting to the remote machine over SSH.
Note that the SSH key pair must @emph{not} be passphrase-protected, to
allow non-interactive logins.
+@item host-key
+This must be the machine's SSH @dfn{public host key} in OpenSSH format.
+This is used to authenticate the machine when we connect to it. It is a
+long string that looks like this:
+
+@example
+ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
+@end example
+
+If the machine is running the OpenSSH daemon, @command{sshd}, the host
+key can be found in a file such as
+@file{/etc/ssh/ssh_host_ed25519_key.pub}.
+
+If the machine is running the SSH daemon of GNU@tie{}lsh,
+@command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
+similar file. It can be converted to the OpenSSH format using
+@command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
+
+@example
+$ lsh-export-key --openssh < /etc/lsh/host-key.pub
+ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
+@end example
+
@end table
A number of optional fields may be specified:
-@table @code
-
-@item port
-Port number of SSH server on the machine (default: 22).
+@table @asis
-@item private-key
-The SSH private key file to use when connecting to the machine.
+@item @code{port} (default: @code{22})
+Port number of SSH server on the machine.
-Currently offloading uses GNU@tie{}lsh as its SSH client
-(@pxref{Invoking lsh,,, GNU lsh Manual}). Thus, the key file here must
-be an lsh key file. This may change in the future, though.
+@item @code{private-key} (default: @file{~/.ssh/id_rsa})
+The SSH private key file to use when connecting to the machine, in
+OpenSSH format.
-@item parallel-builds
-The number of builds that may run in parallel on the machine (1 by
-default.)
+@item @code{parallel-builds} (default: @code{1})
+The number of builds that may run in parallel on the machine.
-@item speed
+@item @code{speed} (default: @code{1.0})
A ``relative speed factor''. The offload scheduler will tend to prefer
machines with a higher speed factor.
-@item features
+@item @code{features} (default: @code{'()})
A list of strings denoting specific features supported by the machine.
An example is @code{"kvm"} for machines that have the KVM Linux modules
and corresponding hardware support. Derivations can request features by
@@ -915,7 +944,7 @@ machines, since offloading works by invoking the @code{guix archive} and
this is the case by running:
@example
-lsh build-machine guile -c "'(use-modules (guix config))'"
+ssh build-machine guile -c "'(use-modules (guix config))'"
@end example
There is one last thing to do once @file{machines.scm} is in place. As