From fdc1294993386899d667f04a906801d3406b9064 Mon Sep 17 00:00:00 2001
From: Anders Kaseorg <anders@zulip.com>
Date: Sat, 12 Feb 2022 14:02:43 -0800
Subject: [PATCH] setup-apt-repo: Support installing an APT preferences file.

Signed-off-by: Anders Kaseorg <anders@zulip.com>
---
 scripts/lib/setup-apt-repo | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/scripts/lib/setup-apt-repo b/scripts/lib/setup-apt-repo
index d3bfb0d28a..b35d8e9e0e 100755
--- a/scripts/lib/setup-apt-repo
+++ b/scripts/lib/setup-apt-repo
@@ -13,6 +13,7 @@ set -x
 set -e
 set -u
 set -o pipefail
+shopt -s extglob
 
 verify=false
 args="$(getopt -o '' --long verify,list: -- "$@")"
@@ -40,6 +41,7 @@ done
 mkdir -p /var/lib/zulip
 
 SOURCES_FILE=/etc/apt/sources.list.d/$LIST.list
+PREF_FILE=/etc/apt/preferences.d/$LIST.pref
 STAMP_FILE=/etc/apt/sources.list.d/$LIST.list.apt-update-in-progress
 
 ZULIP_SCRIPTS="$(cd "$(dirname "$(dirname "$0")")" && pwd)"
@@ -64,7 +66,7 @@ EOF
     exit 1
 fi
 
-DEPENDENCIES_HASH=$(sha1sum "$LIST_PATH/"*.asc "$0")
+DEPENDENCIES_HASH="$(sha256sum "$LIST_PATH"/?(*.asc|"$release.list"|"$LIST.pref"|custom.sh) "$ZULIP_SCRIPTS/lib/setup-apt-repo")"
 DEPENDENCIES_HASH_FILE="/var/lib/zulip/setup-repositories-state-$LIST"
 # Ensure that DEPENDENCIES_HASH_FILE exists before hashing it.
 touch "$DEPENDENCIES_HASH_FILE"
@@ -78,11 +80,8 @@ elif [ "$verify" == true ]; then
     exit 1
 fi
 
-# Ensure that the sources file exists
-touch "$SOURCES_FILE"
-
-# Hash it to check if the sources file is changed by the script later.
-zulip_source_hash=$(sha1sum "$SOURCES_FILE")
+# Hash to check if the configuration is changed by the script later.
+hashes=$(sha256sum "$SOURCES_FILE" "$PREF_FILE" 2>/dev/null || true)
 
 pre_setup_deps=(lsb-release apt-transport-https ca-certificates gnupg curl)
 if ! apt-get -dy install "${pre_setup_deps[@]}"; then
@@ -93,14 +92,20 @@ apt-get -y install "${pre_setup_deps[@]}"
 apt-key add "$LIST_PATH/"*.asc
 cp "$LIST_PATH/$release.list" "$SOURCES_FILE"
 
+if [ -e "$LIST_PATH/$LIST.pref" ]; then
+    cp "$LIST_PATH/$LIST.pref" "$PREF_FILE"
+else
+    rm -f "$PREF_FILE"
+fi
+
 if [ -e "$LIST_PATH/custom.sh" ]; then
     export LIST_PATH
     export STAMP_FILE
     bash "$LIST_PATH/custom.sh"
 fi
 
-if [ "$zulip_source_hash" = "$(sha1sum "$SOURCES_FILE")" ] && ! [ -e "$STAMP_FILE" ]; then
-    echo "zulip.list file did not change; skipping apt-get update"
+if [ "$hashes" = "$(sha256sum "$SOURCES_FILE" "$PREF_FILE" 2>/dev/null || true)" ] && ! [ -e "$STAMP_FILE" ]; then
+    echo "APT configuration did not change; skipping apt-get update"
 else
     # We create this stamp file to ensure `apt-get update` will be run
     # the next time this script is invoked, and each time after, until