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-rw-r--r--krebs/5pkgs/genid/default.nix22
1 files changed, 22 insertions, 0 deletions
diff --git a/krebs/5pkgs/genid/default.nix b/krebs/5pkgs/genid/default.nix
new file mode 100644
index 000000000..c75bec317
--- /dev/null
+++ b/krebs/5pkgs/genid/default.nix
@@ -0,0 +1,22 @@
+{ lib, pkgs, ... }:
+
+pkgs.writeScriptBin "genid" ''
+ #! /bin/sh
+ # usage: genid NAME
+ set -euf
+
+ export PATH=${lib.makeSearchPath "bin" (with pkgs; [
+ bc
+ coreutils
+ ])}
+
+ name=$1
+ hash=$(printf %s "$name" | sha1sum | cut -d\ -f1 | tr a-f A-F)
+ echo "
+ min=2^24 # bigger than nobody and nogroup, see <nixos/modules/misc/ids.nix>
+ # and some spare for stuff like lxd.
+ max=2^32 # see 2^(8*sizeof(uid_t))
+ ibase=16
+ ($hash + min) % max
+ " | bc
+''