From 4454fa998c9da1f1eee1602c8e8cd2732505c104 Mon Sep 17 00:00:00 2001
From: onur-ozkan <work@onurozkan.dev>
Date: Sat, 12 Oct 2024 07:41:39 +0300
Subject: [PATCH] add new CI step: "setup upstream remote"

Signed-off-by: onur-ozkan <work@onurozkan.dev>
---
 .github/workflows/ci.yml                |  3 +++
 src/ci/scripts/setup-upstream-remote.sh | 24 ++++++++++++++++++++++++
 src/ci/shared.sh                        | 12 ++++++++++++
 3 files changed, 39 insertions(+)
 create mode 100755 src/ci/scripts/setup-upstream-remote.sh

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b6dc27f123465..003c1e5d7ebbe 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -122,6 +122,9 @@ jobs:
           # which then uses log commands to actually set them.
           EXTRA_VARIABLES: ${{ toJson(matrix.env) }}
 
+      - name: setup upstream remote
+        run: src/ci/scripts/setup-upstream-remote.sh
+
       - name: ensure the channel matches the target branch
         run: src/ci/scripts/verify-channel.sh
 
diff --git a/src/ci/scripts/setup-upstream-remote.sh b/src/ci/scripts/setup-upstream-remote.sh
new file mode 100755
index 0000000000000..52b4c98a89016
--- /dev/null
+++ b/src/ci/scripts/setup-upstream-remote.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+# In CI environments, bootstrap is forced to use the remote upstream based
+# on "git_repository" and "nightly_branch" values from src/stage0 file.
+# This script configures the remote as it may not exist by default.
+
+set -euo pipefail
+IFS=$'\n\t'
+
+ci_dir=$(cd $(dirname $0) && pwd)/..
+source "$ci_dir/shared.sh"
+
+git_repository=$(parse_stage0_file_by_key "git_repository")
+nightly_branch=$(parse_stage0_file_by_key "nightly_branch")
+
+# Configure "rust-lang/rust" upstream remote only when it's not origin.
+if [ -z "$(git config remote.origin.url | grep $git_repository)" ]; then
+    echo "Configuring https://github.com/$git_repository remote as upstream."
+    git remote add upstream "https://github.com/$git_repository"
+    REMOTE_NAME="upstream"
+else
+    REMOTE_NAME="origin"
+fi
+
+git fetch $REMOTE_NAME $nightly_branch
diff --git a/src/ci/shared.sh b/src/ci/shared.sh
index 2b0a10e4d08d9..1e6a008a5de81 100644
--- a/src/ci/shared.sh
+++ b/src/ci/shared.sh
@@ -136,3 +136,15 @@ function releaseChannel {
         echo $RUST_CI_OVERRIDE_RELEASE_CHANNEL
     fi
 }
+
+# Parse values from src/stage0 file by key
+function parse_stage0_file_by_key {
+    local key="$1"
+    local file="$ci_dir/../stage0"
+    local value=$(awk -F= '{a[$1]=$2} END {print(a["'$key'"])}' $file)
+    if [ -z "$value" ]; then
+        echo "ERROR: Key '$key' not found in '$file'."
+        exit 1
+    fi
+    echo "$value"
+}