max / alloy

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1	# privilege.sh — how the build scripts become root. Sourced, never executed.
2	#
3	# Alloy names run0 as the way a person becomes root (wiki alloy-privilege,
4	# "run0-first, not sudo"). These scripts are the one place that could not
5	# follow, because they run on the dev host rather than on the shipped OS,
6	# and the x86_64 build host is fw13: Pop!_OS, systemd 255, no run0 at all.
7	# So the mechanism resolves here, once, instead of being hardcoded to either
8	# one. When every build host is on systemd 256 or newer this file loses its
9	# else-branch and becomes two lines.
10	#
11	# Two functions, because run0 runs its child on a pty by default and sudo
12	# does not:
13	#
14	# priv output is for the person watching. The pty is right: podman keeps
15	# its progress rendering and dd redraws its status line in place.
16	# privc output is captured, piped, or consumed as an exit status. --pipe
17	# suppresses the pty, without which every captured line arrives
18	# carrying a carriage return and `$(privc du -h X \| cut -f1)`
19	# returns "1.2G" with a \r stuck to the end of it.
20	#
21	# The rule for a new call site: if a human reads it as it scrolls past, priv.
22	# Anything else, privc.
23	#
24	# Working directory is the other thing run0 does not inherit the way sudo
25	# does. Every privileged call site under build/ passes absolute paths, built
26	# from $REPO_ROOT, so it does not matter — verified 2026-08-10 across
27	# build-iso.sh, build-image.sh and write-device.sh. A new call site taking a
28	# relative path is the thing that would break it, so check rather than assume.
29	#
30	# PRIV_NAME is the resolved command, for scripts that print a root command
31	# for the operator to type. A message naming sudo on a machine where the
32	# script itself used run0 teaches the wrong one.
33
34	if command -v run0 >/dev/null 2>&1; then
35	PRIV_NAME="run0"
36	priv() { run0 "$@"; }
37	privc() { run0 --pipe "$@"; }
38	else
39	PRIV_NAME="sudo"
40	priv() { sudo "$@"; }
41	privc() { sudo "$@"; }
42	fi
43