pyrox.dev
1# vmTools {#sec-vm-tools}
2
3A set of VM related utilities, that help in building some packages in more advanced scenarios.
4
5## `vmTools.createEmptyImage` {#vm-tools-createEmptyImage}
6
7A bash script fragment that produces a disk image at `destination`.
8
9### Attributes {#vm-tools-createEmptyImage-attributes}
10
11* `size`. The disk size, in MiB.
12* `fullName`. Name that will be written to `${destination}/nix-support/full-name`.
13* `destination` (optional, default `$out`). Where to write the image files.
14
15## `vmTools.runInLinuxVM` {#vm-tools-runInLinuxVM}
16
17Run a derivation in a Linux virtual machine (using Qemu/KVM).
18By default, there is no disk image; the root filesystem is a `tmpfs`, and the Nix store is shared with the host (via the [9P protocol](https://wiki.qemu.org/Documentation/9p#9p_Protocol)).
19Thus, any pure Nix derivation should run unmodified.
20
21If the build fails and Nix is run with the `-K/--keep-failed` option, a script `run-vm` will be left behind in the temporary build directory that allows you to boot into the VM and debug it interactively.
22
23### Attributes {#vm-tools-runInLinuxVM-attributes}
24
25* `preVM` (optional). Shell command to be evaluated *before* the VM is started (i.e., on the host).
26* `memSize` (optional, default `512`). The memory size of the VM in MiB.
27* `diskImage` (optional). A file system image to be attached to `/dev/sda`.
28 Note that currently we expect the image to contain a filesystem, not a full disk image with a partition table etc.
29
30### Examples {#vm-tools-runInLinuxVM-examples}
31
32Build the derivation hello inside a VM:
33```nix
34{ pkgs }: with pkgs; with vmTools;
35runInLinuxVM hello
36```
37
38Build inside a VM with extra memory:
39```nix
40{ pkgs }: with pkgs; with vmTools;
41runInLinuxVM (hello.overrideAttrs (_: { memSize = 1024; }))
42```
43
44Use VM with a disk image (implicitly sets `diskImage`, see [`vmTools.createEmptyImage`](#vm-tools-createEmptyImage)):
45```nix
46{ pkgs }: with pkgs; with vmTools;
47runInLinuxVM (hello.overrideAttrs (_: {
48 preVM = createEmptyImage {
49 size = 1024;
50 fullName = "vm-image";
51 };
52}))
53```
54
55## `vmTools.extractFs` {#vm-tools-extractFs}
56
57Takes a file, such as an ISO, and extracts its contents into the store.
58
59### Attributes {#vm-tools-extractFs-attributes}
60
61* `file`. Path to the file to be extracted.
62 Note that currently we expect the image to contain a filesystem, not a full disk image with a partition table etc.
63* `fs` (optional). Filesystem of the contents of the file.
64
65### Examples {#vm-tools-extractFs-examples}
66
67Extract the contents of an ISO file:
68```nix
69{ pkgs }: with pkgs; with vmTools;
70extractFs { file = ./image.iso; }
71```
72
73## `vmTools.extractMTDfs` {#vm-tools-extractMTDfs}
74
75Like [](#vm-tools-extractFs), but it makes use of a [Memory Technology Device (MTD)](https://en.wikipedia.org/wiki/Memory_Technology_Device).
76
77## `vmTools.runInLinuxImage` {#vm-tools-runInLinuxImage}
78
79Like [](#vm-tools-runInLinuxVM), but instead of using `stdenv` from the Nix store, run the build using the tools provided by `/bin`, `/usr/bin`, etc. from the specified filesystem image, which typically is a filesystem containing a [FHS](https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard)-based Linux distribution.
80
81## `vmTools.makeImageTestScript` {#vm-tools-makeImageTestScript}
82
83Generate a script that can be used to run an interactive session in the given image.
84
85### Examples {#vm-tools-makeImageTestScript-examples}
86
87Create a script for running a Fedora 27 VM:
88```nix
89{ pkgs }: with pkgs; with vmTools;
90makeImageTestScript diskImages.fedora27x86_64
91```
92
93Create a script for running an Ubuntu 20.04 VM:
94```nix
95{ pkgs }: with pkgs; with vmTools;
96makeImageTestScript diskImages.ubuntu2004x86_64
97```
98
99## `vmTools.diskImageFuns` {#vm-tools-diskImageFuns}
100
101A set of functions that build a predefined set of minimal Linux distributions images.
102
103### Images {#vm-tools-diskImageFuns-images}
104
105* Fedora
106 * `fedora26x86_64`
107 * `fedora27x86_64`
108* CentOS
109 * `centos6i386`
110 * `centos6x86_64`
111 * `centos7x86_64`
112* Ubuntu
113 * `ubuntu1404i386`
114 * `ubuntu1404x86_64`
115 * `ubuntu1604i386`
116 * `ubuntu1604x86_64`
117 * `ubuntu1804i386`
118 * `ubuntu1804x86_64`
119 * `ubuntu2004i386`
120 * `ubuntu2004x86_64`
121 * `ubuntu2204i386`
122 * `ubuntu2204x86_64`
123* Debian
124 * `debian10i386`
125 * `debian10x86_64`
126 * `debian11i386`
127 * `debian11x86_64`
128
129### Attributes {#vm-tools-diskImageFuns-attributes}
130
131* `size` (optional, defaults to `4096`). The size of the image, in MiB.
132* `extraPackages` (optional). A list names of additional packages from the distribution that should be included in the image.
133
134### Examples {#vm-tools-diskImageFuns-examples}
135
1368GiB image containing Firefox in addition to the default packages:
137```nix
138{ pkgs }: with pkgs; with vmTools;
139diskImageFuns.ubuntu2004x86_64 { extraPackages = [ "firefox" ]; size = 8192; }
140```
141
142## `vmTools.diskImageExtraFuns` {#vm-tools-diskImageExtraFuns}
143
144Shorthand for `vmTools.diskImageFuns.<attr> { extraPackages = ... }`.
145
146## `vmTools.diskImages` {#vm-tools-diskImages}
147
148Shorthand for `vmTools.diskImageFuns.<attr> { }`.