feat: Request new Runner token if invalid (#425)

* Request new Runner token if invalid

* Escape the "%{" sequence

* Fix template error accessing variables

template/gitlab-runner.tpl

@@ -58,8 +58,17 @@ 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")
-if [[ `echo ${runners_token}` == "__REPLACED_BY_USER_DATA__" && `echo $token` == "null" ]]
+
+valid_token=true
+if [[ `echo $token` != "null" ]]
+then
+  valid_token_response=$(curl -s -o /dev/null -w "%%{response_code}" --request POST -L "${runners_gitlab_url}/api/v4/runners/verify" --form "token=$token" )
+  [[ `echo $valid_token_response` != "200" ]] && valid_token=false
+fi
+
+if [[ `echo ${runners_token}` == "__REPLACED_BY_USER_DATA__" && `echo $token` == "null" ]] || [[ `echo $valid_token` == "false" ]]
 then
   token=$(curl --request POST -L "${runners_gitlab_url}/api/v4/runners" \
     --form "token=${gitlab_runner_registration_token}" \