chore:heroku env vars update script (#1334)

* chore: script for updating env vars for a review app

* chore: add instructions to script

scripts/.env.heroku

@@ -0,0 +1,3 @@
+SNAPSHOT_STATUS_ENABLED='true'
+SNAPSHOT_STATUS_MAX_ERROR_BUFFER_SIZE=30
+SNAPSHOT_STATUS_ERROR_RATE_THRESHOLD=0.33

scripts/update-env-vars.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+# To run this script:
+# - jq for parsing JSON (sudo apt-get install jq or brew install jq)
+# - heroku CLI installed and authenticated
+# - awk should already be on your system
+# Put in the .env.heroku all the variables your want to add or overwrite to the review app
+
+TARGET_APP=$1
+
+if [[ -z "$TARGET_APP" ]]; then
+  echo "Missing app name"
+  exit 1
+fi
+
+EXISTING_VARS=$(heroku config --json --app=${TARGET_APP} | jq -r 'to_entries|map("\(.key)=\(.value)")|.[]')
+NEW_VARS=$(awk -F= '/.+/ { print $1"="$2 }' ./.env.heroku)
+MERGED_VARS=$(echo -e "${EXISTING_VARS}\n${NEW_VARS}")
+
+# Update env vars for the specified review app
+echo "Updating env vars for ${TARGET_APP}..."
+heroku config:set --app=${TARGET_APP} ${MERGED_VARS}
+echo "Env vars updated for ${TARGET_APP}"
+
+echo "You're good."