Metadata API

Token Expired

When you encounter a “401 - Unauthorized" error code while interacting with the Metadata service, it often indicates an issue with your token. Common token-related issues include:

Invalid or missing token

To address this issue:

• Ensure token presence: Verify that your request includes a valid token in the required header.
• Check token validity: Ensure the token hasn't expired.
• Avoid token reuse: If you're using a token from a different instance, it will be rejected. Each instance has its own unique token.

Token expiration

To address this issue:

• Set an appropriate TTL: When creating a token, specify a suitable time to live (TTL) to prevent premature expiration.
• Monitor the TTL: Regularly check the token's remaining TTL to avoid unexpected expiration.
• Renew the token: For long-running processes, periodically renew the token to extend its validity.

Incorrect usage

To address this issue:

• Check the header: Ensure that the token is included in the correct (Metadata-Token) HTTP header.

cloud-init

View cloud-init logs

If you encounter issues with cloud-init or your user data, you can review the logs and output logs by running one of the commands below:

cat /var/log/cloud-init.log
cat /var/log/cloud-init-output.log

If you are not able to access your system through SSH, you can use Lish or boot your Compute Instance into rescue mode and mount your disks.

Run the cloud-init command

The cloud-init command-line tool can be used to gather more information or perform certain actions. Here are some commands you can use to help troubleshoot cloud-init.

• cloud-init status --long: This provides information about the status of cloud-init. You will notice different output depending on if it is actively running or if it has run in the past. See cloud-init status.
• cloud-init query v1 and cloud-init query userdata: This outputs either the instance data or the user data provided by the Metadata service. Other metadata is also exposed by entering a different query key. See cloud-init query.