diff options
Diffstat (limited to 'nixos/doc/manual/development/building-parts.chapter.md')
-rw-r--r-- | nixos/doc/manual/development/building-parts.chapter.md | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/nixos/doc/manual/development/building-parts.chapter.md b/nixos/doc/manual/development/building-parts.chapter.md new file mode 100644 index 00000000000..79ddaa37140 --- /dev/null +++ b/nixos/doc/manual/development/building-parts.chapter.md @@ -0,0 +1,74 @@ +# Building Specific Parts of NixOS {#sec-building-parts} + +With the command `nix-build`, you can build specific parts of your NixOS +configuration. This is done as follows: + +```ShellSession +$ cd /path/to/nixpkgs/nixos +$ nix-build -A config.option +``` + +where `option` is a NixOS option with type "derivation" (i.e. something +that can be built). Attributes of interest include: + +`system.build.toplevel` + +: The top-level option that builds the entire NixOS system. Everything + else in your configuration is indirectly pulled in by this option. + This is what `nixos-rebuild` builds and what `/run/current-system` + points to afterwards. + + A shortcut to build this is: + + ```ShellSession + $ nix-build -A system + ``` + +`system.build.manual.manualHTML` + +: The NixOS manual. + +`system.build.etc` + +: A tree of symlinks that form the static parts of `/etc`. + +`system.build.initialRamdisk` , `system.build.kernel` + +: The initial ramdisk and kernel of the system. This allows a quick + way to test whether the kernel and the initial ramdisk boot + correctly, by using QEMU's `-kernel` and `-initrd` options: + + ```ShellSession + $ nix-build -A config.system.build.initialRamdisk -o initrd + $ nix-build -A config.system.build.kernel -o kernel + $ qemu-system-x86_64 -kernel ./kernel/bzImage -initrd ./initrd/initrd -hda /dev/null + ``` + +`system.build.nixos-rebuild` , `system.build.nixos-install` , `system.build.nixos-generate-config` + +: These build the corresponding NixOS commands. + +`systemd.units.unit-name.unit` + +: This builds the unit with the specified name. Note that since unit + names contain dots (e.g. `httpd.service`), you need to put them + between quotes, like this: + + ```ShellSession + $ nix-build -A 'config.systemd.units."httpd.service".unit' + ``` + + You can also test individual units, without rebuilding the whole + system, by putting them in `/run/systemd/system`: + + ```ShellSession + $ cp $(nix-build -A 'config.systemd.units."httpd.service".unit')/httpd.service \ + /run/systemd/system/tmp-httpd.service + # systemctl daemon-reload + # systemctl start tmp-httpd.service + ``` + + Note that the unit must not have the same name as any unit in + `/etc/systemd/system` since those take precedence over + `/run/systemd/system`. That's why the unit is installed as + `tmp-httpd.service` here. |