blob: c4cc04ce24d8cf8f1cd3d6cad1d56b2c1461a1ff (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
<refentry 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-nix-channel">
<refmeta>
<refentrytitle>nix-channel</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo class="source">Nix</refmiscinfo>
<refmiscinfo class="version"><xi:include href="../version.txt" parse="text"/></refmiscinfo>
</refmeta>
<refnamediv>
<refname>nix-channel</refname>
<refpurpose>manage Nix channels</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>nix-channel</command>
<group choice='req'>
<arg choice='plain'><option>--add</option> <replaceable>url</replaceable> <arg choice='opt'><replaceable>name</replaceable></arg></arg>
<arg choice='plain'><option>--remove</option> <replaceable>url</replaceable></arg>
<arg choice='plain'><option>--list</option></arg>
<arg choice='plain'><option>--update</option> <arg rep='repeat'><replaceable>names</replaceable></arg></arg>
<arg choice='plain'><option>--rollback</option> <arg choice='opt'><replaceable>generation</replaceable></arg></arg>
</group>
</cmdsynopsis>
</refsynopsisdiv>
<refsection><title>Description</title>
<para>A Nix channel is mechanism that allows you to automatically stay
up-to-date with a set of pre-built Nix expressions. A Nix channel is
just a URL that points to a place containing a set of Nix expressions
and a <command>nix-push</command> manifest. <phrase
condition="manual">See also <xref linkend="sec-channels"
/>.</phrase></para>
<para>This command has the following operations:
<variablelist>
<varlistentry><term><option>--add</option> <replaceable>url</replaceable> [<replaceable>name</replaceable>]</term>
<listitem><para>Adds a channel named
<replaceable>name</replaceable> with URL
<replaceable>url</replaceable> to the list of subscribed channels.
If <replaceable>name</replaceable> is omitted, it defaults to the
last component of <replaceable>url</replaceable>, with the
suffixes <literal>-stable</literal> or
<literal>-unstable</literal> removed.</para></listitem>
</varlistentry>
<varlistentry><term><option>--remove</option> <replaceable>name</replaceable></term>
<listitem><para>Removes the channel named
<replaceable>name</replaceable> from the list of subscribed
channels.</para></listitem>
</varlistentry>
<varlistentry><term><option>--list</option></term>
<listitem><para>Prints the names and URLs of all subscribed
channels on standard output.</para></listitem>
</varlistentry>
<varlistentry><term><option>--update</option> [<replaceable>names</replaceable>…]</term>
<listitem><para>Downloads the Nix expressions of all subscribed
channels (or only those included in
<replaceable>names</replaceable> if specified), makes them the
default for <command>nix-env</command> operations (by symlinking
them from the directory <filename>~/.nix-defexpr</filename>), and
performs a <command>nix-pull</command> on the manifests of all
channels to make pre-built binaries available.</para></listitem>
</varlistentry>
<varlistentry><term><option>--rollback</option> [<replaceable>generation</replaceable>]</term>
<listitem><para>Reverts the previous call to <command>nix-channel
--update</command>. Optionally, you can specify a specific channel
generation number to restore.</para></listitem>
</varlistentry>
</variablelist>
</para>
<para>Note that <option>--add</option> does not automatically perform
an update.</para>
<para>The list of subscribed channels is stored in
<filename>~/.nix-channels</filename>.</para>
<para>A channel consists of two elements: a bzipped Tar archive
containing the Nix expressions, and a manifest created by
<command>nix-push</command>. These must be stored under
<literal><replaceable>url</replaceable>/nixexprs.tar.bz2</literal> and
<literal><replaceable>url</replaceable>/MANIFEST</literal>,
respectively.</para>
</refsection>
<refsection><title>Examples</title>
<para>To subscribe to the Nixpkgs channel and install the GNU Hello package:</para>
<screen>
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable
$ nix-channel --update
$ nix-env -iA nixpkgs.hello</screen>
<para>You can revert channel updates using <option>--rollback</option>:</para>
<screen>
$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.nixpkgsVersion'
"14.04.527.0e935f1"
$ nix-channel --rollback
switching from generation 483 to 482
$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.nixpkgsVersion'
"14.04.526.dbadfad"
</screen>
</refsection>
<refsection><title>Files</title>
<variablelist>
<varlistentry><term><filename>/nix/var/nix/profiles/<replaceable>username</replaceable>/channels</filename></term>
<listitem><para><command>nix-channel</command> uses a
<command>nix-env</command> profile to keep track of previous
versions of the subscribed channels. Every time you run
<command>nix-channel --update</command>, a new channel generation
(that is, a symlink to the channel Nix expressions in the Nix store)
is created. This enables <command>nix-channel --rollback</command>
to revert to previous versions.</para></listitem>
</varlistentry>
<varlistentry><term><filename>~/.nix-defexpr/channels</filename></term>
<listitem><para>This is a symlink to
<filename>/nix/var/nix/profiles/<replaceable>username</replaceable>/channels</filename>. It
ensures that <command>nix-env</command> can find your channels. In
a multi-user installation, you may also have
<filename>~/.nix-defexpr/channels_root</filename>, which links to
the channels of the root user.</para></listitem>
</varlistentry>
</variablelist>
</refsection>
</refentry>
|
