fix: Fetch S3 credentials for S3 upload of crash dumps (#747)

Using the details given by https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-iam-roles.html we will fetch key and secret given the container IAM roles

mix.exs

@@ -4,7 +4,7 @@ defmodule Realtime.MixProject do
   def project do
     [
       app: :realtime,
-      version: "2.25.38",
+      version: "2.25.39",
       elixir: "~> 1.14.0",
       elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,

tailscale/wrapper.sh

@@ -14,19 +14,24 @@ export ERL_CRASH_DUMP=/tmp/erl_crash.dump
 
 function upload_crash_dump_to_s3 {
     EXIT_CODE=${?:-0}
-
     bucket=$ERL_CRASH_DUMP_S3_BUCKET
     s3Key=$ERL_CRASH_DUMP_S3_KEY
     s3Secret=$ERL_CRASH_DUMP_S3_SECRET
     s3Host=$ERL_CRASH_DUMP_S3_HOST
     s3Port=$ERL_CRASH_DUMP_S3_PORT
 
+    if [ "${AWS_CONTAINER_CREDENTIALS_RELATIVE_URI-}" ]; then
+        response=$(curl -s http://169.254.170.2$AWS_CONTAINER_CREDENTIALS_RELATIVE_URI)
+        s3Key=$(echo "$response" | grep -o '"AccessKeyId": *"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"')
+        s3Secret=$(echo "$response" | grep -o '"SecretAccessKey": *"[^"]*"' | grep -o '"[^"]*"$' | tr -d '"')
+    fi
+
     filePath=${ERL_CRASH_DUMP_FOLDER:-tmp}/$(date +%s)_${ERL_CRASH_DUMP_FILE_NAME:-erl_crash.dump}
 
     if [ -f "${ERL_CRASH_DUMP_FOLDER:-tmp}/${ERL_CRASH_DUMP_FILE_NAME:-erl_crash.dump}" ]; then
         mv ${ERL_CRASH_DUMP_FOLDER:-tmp}/${ERL_CRASH_DUMP_FILE_NAME:-erl_crash.dump} $filePath
 
-        resource="/${bucket}${filePath}"
+        resource="/${bucket}/realtime/crash_dumps${filePath}"
 
         contentType="application/octet-stream"
         dateValue=$(date -R)