The catalog has a concept of processors to perform catalog ingestion tasks,
such as reading raw entity data from a remote source, parsing it, transforming
it, and validating it. These processors are configured under the
catalog.processors configuration key.
Static Location Configuration
The simplest configuration for the catalog, as shown in the default
@backstage/create-app template, is to declaratively add locations pointing to
YAML files with static configuration.
Locations are added to the catalog under the
catalog: locations: - type: url target: https://github.com/backstage/backstage/blob/master/packages/catalog-model/examples/artist-lookup-component.yaml
url type locations are handled by a standard processor included with the
UrlReaderProcessor), so no processor configuration is needed. This
processor does however need an integration to
understand how to retrieve a given URL. For the example above, you would need to
configure the GitHub integration to
read files from github.com.
The locations added through static configuration cannot be removed through the catalog locations API. To remove these locations, you must remove them from the configuration.
Integrations may simply provide a mechanism to handle
url location type for an
external provider, or they may also include additional processors out of the
box, such as the GitHub discovery
processor that scans a GitHub organization for
entity descriptor files.
Check the integrations documentation to see what is offered by each integration.
To ingest entities from an existing system already tracking software, you can also write a custom processor to convert between the existing system and Backstage's descriptor format. This is documented in External Integrations.
By default the catalog will only allow ingestion of entities with the kind
Location. In order to allow entities of other kinds to
be added, you need to add rules to the catalog. Rules are added either in a
catalog.rules key, or added to statically configured locations.
For example, given the following configuration:
catalog: rules: - allow: [Component, API, Location, Template] locations: - type: url target: https://github.com/org/example/blob/master/org-data.yaml rules: - allow: [Group]
We are able to add entities of kind
Template from any location, and
Group entities from the
which will also be read as statically configured location.
Note that if the
catalog.rules key is present it will replace the default
value, meaning that you need to add rules for the default kinds if you want
those to still be allowed.
The following configuration will reject any kind of entities from being added to the catalog:
catalog: rules: 
Processors provides a good way to automate ingestion of entities when combined
with Static Location Configuration or a
discovery processor like
GitHub Discovery. To enforce usage of
processors to locate entities we can configure the catalog into
This configuration disables the mutating backend catalog APIs and disallows
users from registering new entities at run-time.
catalog: readonly: true
Note that any plugin relying on the catalog API for creating, updating and deleting entities will not work in this mode.
A common use case for this configuration is when organizations have a remote source that should be mirrored into backstage. If we want backstage to be a mirror of this remote source we cannot allow users to also register entities with e.g. catalog-import plugin.