fix: use IMDSv2 url when setting PARENT_INSTANCE_ID (#497)

Author: snoord

template/gitlab-runner.tpl

@@ -1,5 +1,10 @@
+# Install jq if not exists
+if ! [ -x "$(command -v jq)" ]; then
+  yum install jq -y
+fi
+
 # Provide the parent instance id in the spawned runner tags
-PARENT_INSTANCE_ID=$(curl http://169.254.169.254/latest/meta-data/instance-id);
+PARENT_INSTANCE_ID=$(curl -s -H "X-aws-ec2-metadata-token: $token" http://169.254.169.254/latest/dynamic/instance-identity/document | jq -r .instanceId)
 PARENT_TAG="gitlab-runner-parent-id,$${PARENT_INSTANCE_ID}"
 
 mkdir -p /etc/gitlab-runner
@@ -62,11 +67,6 @@ docker-machine rm -y dummy-machine
 unset HOME
 unset USER
 
-# Install jq if not exists
-if ! [ -x "$(command -v jq)" ]; then
-  yum install jq -y
-fi
-
 # fetch Runner token from SSM and validate it
 token=$(aws ssm get-parameters --names "${secure_parameter_store_runner_token_key}" --with-decryption --region "${secure_parameter_store_region}" | jq -r ".Parameters | .[0] | .Value")