Description of the Metadata API

Tilaa has implemented an Amazon EC2 compatible metadata service. Just like Amazon EC2, it's running at http://169.254.169.254/

The metadata service is most commonly used to bootstrap servers at first boot, using a tool like cloud-init or cloud-config.

Three Types of Metadata

Descriptive Metadata

Describes a resource for purposes such as discovery and identification. It can include elements such as title, abstract, author, and keywords.

Structural Metadata

Indicates how compound objects are put together, for example, how pages are ordered to form chapters.

Administrative Metadata

Provides information to help manage a resource, such as when and how it was created, file type and other technical information, and who can access it. There are several subsets of administrative data; two that are sometimes listed as separate metadata types are:

- Rights Management Metadata, which deals with intellectual property rights.
- Preservation Metadata, which contains information needed to archive and preserve a resource.

Querying the Metadata Service from Your VPS

You can query the metadata service from your VPS, for example using curl commands:

bash Copy

        $ curl http://169.254.169.254/latest/meta-data/instance-id
50977499-7c1c-477e-957f-0ecb2e1327bf

Using Tools like Cloud-Init

Tools like cloud-init can be used to configure your VPS. For example, you can use the following configuration snippet to set up a user:

yaml Copy

        users:
  - name: foobar
    gecos: Foo Bar
    sudo: ALL=(ALL) NOPASSWD:ALL
    groups: users, admin
    ssh_import_id: None
    lock_passwd: true
    ssh_authorized_keys:
      - <ssh pub key 1>
      - <ssh pub key 2>

Configuration Examples

Here are some more configuration examples:

yaml Copy

        users:
  - name: cloudy
    gecos: Magic Cloud App Daemon User
    inactive: '5'
    system: true
  - name: fizzbuzz
    sudo: False
    ssh_authorized_keys:
      - <ssh pub key 1>
      - <ssh pub key 2>
  - snapuser: joe@joeuser.io
  - name: nosshlogins
    ssh_redirect_user: true

For more in-depth information, you can check cloud-init's documentation.