82 lines
3 KiB
XML
82 lines
3 KiB
XML
|
<chapter xmlns="http://docbook.org/ns/docbook"
|
|||
|
|
xmlns:xlink="http://www.w3.org/1999/xlink"
|
|||
|
|
xmlns:xi="http://www.w3.org/2001/XInclude"
|
|||
|
|
version="5.0"
|
|||
|
|
xml:id="sec-sharing-packages">
|
|||
|
|
|
|||
|
|
<title>Sharing Packages Between Machines</title>
|
|||
|
|
|
|||
|
|
<para>Sometimes you want to copy a package from one machine to
|
|||
|
|
another. Or, you want to install some packages and you know that
|
|||
|
|
another machine already has some or all of those packages or their
|
|||
|
|
dependencies. In that case there are mechanisms to quickly copy
|
|||
|
|
packages between machines.</para>
|
|||
|
|
|
|||
|
|
<para>The command <command
|
|||
|
|
linkend="sec-nix-copy-closure">nix-copy-closure</command> copies a Nix
|
|||
|
|
store path along with all its dependencies to or from another machine
|
|||
|
|
via the SSH protocol. It doesn’t copy store paths that are already
|
|||
|
|
present on the target machine. For example, the following command
|
|||
|
|
copies Firefox with all its dependencies:
|
|||
|
|
|
|||
|
|
<screen>
|
|||
|
|
$ nix-copy-closure --to alice@itchy.example.org $(type -p firefox)</screen>
|
|||
|
|
|
|||
|
|
See <xref linkend='sec-nix-copy-closure' /> for details.</para>
|
|||
|
|
|
|||
|
|
<para>With <command linkend='refsec-nix-store-export'>nix-store
|
|||
|
|
--export</command> and <command
|
|||
|
|
linkend='refsec-nix-store-import'>nix-store --import</command> you can
|
|||
|
|
write the closure of a store path (that is, the path and all its
|
|||
|
|
dependencies) to a file, and then unpack that file into another Nix
|
|||
|
|
store. For example,
|
|||
|
|
|
|||
|
|
<screen>
|
|||
|
|
$ nix-store --export $(nix-store -qR $(type -p firefox)) > firefox.closure</screen>
|
|||
|
|
|
|||
|
|
writes the closure of Firefox to a file. You can then copy this file
|
|||
|
|
to another machine and install the closure:
|
|||
|
|
|
|||
|
|
<screen>
|
|||
|
|
$ nix-store --import < firefox.closure</screen>
|
|||
|
|
|
|||
|
|
Any store paths in the closure that are already present in the target
|
|||
|
|
store are ignored. It is also possible to pipe the export into
|
|||
|
|
another command, e.g. to copy and install a closure directly to/on
|
|||
|
|
another machine:
|
|||
|
|
|
|||
|
|
<screen>
|
|||
|
|
$ nix-store --export $(nix-store -qR $(type -p firefox)) | bzip2 | \
|
|||
|
|
ssh alice@itchy.example.org "bunzip2 | nix-store --import"</screen>
|
|||
|
|
|
|||
|
|
But note that <command>nix-copy-closure</command> is generally more
|
|||
|
|
efficient in this example because it only copies paths that are not
|
|||
|
|
already present in the target Nix store.</para>
|
|||
|
|
|
|||
|
|
<para>Finally, if you can mount the Nix store of a remote machine in
|
|||
|
|
your local filesystem, Nix can copy paths from the remote Nix store to
|
|||
|
|
the local Nix store <emphasis>on demand</emphasis>. For instance,
|
|||
|
|
suppose that you mount a remote machine containing a Nix store via
|
|||
|
|
<command
|
|||
|
|
xlink:href="http://fuse.sourceforge.net/sshfs.html">sshfs</command>:
|
|||
|
|
|
|||
|
|
<screen>
|
|||
|
|
$ sshfs alice@itchy.example.org:/ /mnt</screen>
|
|||
|
|
|
|||
|
|
You should then set the <envar>NIX_OTHER_STORES</envar> environment
|
|||
|
|
variable to tell Nix about this remote Nix store:
|
|||
|
|
|
|||
|
|
<screen>
|
|||
|
|
$ export NIX_OTHER_STORES=/mnt/nix</screen>
|
|||
|
|
|
|||
|
|
Then if you do any Nix operation, e.g.
|
|||
|
|
|
|||
|
|
<screen>
|
|||
|
|
$ nix-env -i firefox</screen>
|
|||
|
|
|
|||
|
|
and Nix has to build a path that it sees is already present in
|
|||
|
|
<filename>/mnt/nix</filename>, then it will just copy from there
|
|||
|
|
instead of building it from source.</para>
|
|||
|
|
|
|||
|
|
|
|||
|
|
</chapter>
|