1 files changed, 22 insertions, 0 deletions
diff --git a/krebs/5pkgs/genid.nix b/krebs/5pkgs/genid.nix
new file mode 100644
index 00000000..c75bec31
--- /dev/null
+++ b/krebs/5pkgs/genid.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
+''