diff options
author | Colin L Rice <colin@daedrum.net> | 2020-07-01 12:04:51 -0400 |
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committer | Colin L Rice <colin@daedrum.net> | 2022-01-05 22:44:22 -0500 |
commit | fee76f189c53266391aa7485f017de3a51f86461 (patch) | |
tree | 80de719442957b3f51a16d1a0f1db7a40c171a5c /nixos/lib/make-btrfs-fs.nix | |
parent | ddbdf98a33edb4ff27925e2119171bee06d27b6e (diff) |
lib: Create make-btrfs-fs library to match make-ext4-fs.
I wrote this up when I was playing with a btrfs sd card, and figured that it would be useful for others.
Diffstat (limited to 'nixos/lib/make-btrfs-fs.nix')
-rw-r--r-- | nixos/lib/make-btrfs-fs.nix | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/nixos/lib/make-btrfs-fs.nix b/nixos/lib/make-btrfs-fs.nix new file mode 100644 index 0000000000000..fceeea8d5755b --- /dev/null +++ b/nixos/lib/make-btrfs-fs.nix @@ -0,0 +1,45 @@ +# Builds an btrfs image containing a populated /nix/store with the closure +# of store paths passed in the storePaths parameter, in addition to the +# contents of a directory that can be populated with commands. The +# generated image is sized to only fit its contents, with the expectation +# that a script resizes the filesystem at boot time. +{ pkgs +, lib +# List of derivations to be included +, storePaths +# Shell commands to populate the ./files directory. +# All files in that directory are copied to the root of the FS. +, populateImageCommands ? "" +, volumeLabel +, uuid ? "44444444-4444-4444-8888-888888888888" +, btrfs-progs +}: + +let + sdClosureInfo = pkgs.buildPackages.closureInfo { rootPaths = storePaths; }; +in +pkgs.stdenv.mkDerivation { + name = "btrfs-fs.img"; + + nativeBuildInputs = [ btrfs-progs ]; + + buildCommand = + '' + set -x + ( + mkdir -p ./files + ${populateImageCommands} + ) + + mkdir -p ./files/nix/store + cp ${sdClosureInfo}/registration ./files/nix-path-registration + + # Add the closures of the top-level store objects. + for p in $(cat ${sdClosureInfo}/store-paths); do + echo cp -r $p "./files/nix/store" + done + + touch $out + mkfs.btrfs -L ${volumeLabel} -U ${uuid} -r ./files --shrink $out + ''; +} |