This is a proxy that allows FreeDB aware software to access metadata from the Gracenote CD database.
The root cddb package can also be used as a rudimentary Gracenote library.
The proxy requires a valid Gracenote Client and User ID. You can get these at https://developer.gracenote.com/web-api.
The proxy provides multiple ways to configure it's settings.
Configuration values are taken with the following priority: Command line switch > Environment variable > Compile time option
| Switch | Description |
|---|---|
| -address | The address to listen on |
| -port | The port to listen on (default "8080") |
| -client | Gracenote Client ID |
| -user | Gracenote User ID |
| Variable | Description |
|---|---|
| ADDR | The address to listen on |
| PORT | The port to listen on |
| CLIENT_KEY | Gracenote Client ID |
| USER_KEY | Gracenote User ID |
CLIENT_KEY and USER_KEY can be configured for App Engine using the gracenote.yaml file in cmd/cddb.
Note that the end user typically does not have to set these, they're handled by Google App Engine.
| Variable | Description |
|---|---|
| USING_APPENGINE | Whether the program should use App Engine specific features |
| GOOGLE_CLOUD_PROJECT | The Project ID associated with your application |
| GAE_SERVICE | The service name of your application |
| GAE_VERSION | The version label of the current application |
Go provides a way to set variable values at compile time, this can be used to easily change the default values for variables. This can be done using the -X linker flag during building.
This example will set the default address to 127.0.0.1 and the default port to 8888:
go build -ldflags "-X main.addr=127.0.0.1 -X main.port=8888"
| importpath.name | Description |
|---|---|
| main.addr | The address to listen on |
| main.port | The port to listen on |
| github.com/Hakkin/cddb/cmd/cddb/config.Client | Gracenote Client ID |
| github.com/Hakkin/cddb/cmd/cddb/config.User | Gracenote User ID |
The proxy can be ran as either a standalone program or through Google App Engine.
Simply run go build in the cmd/cddb directory.
Once built, you can start the proxy by running cddb.
You must supply valid Gracenote User and Client IDs (see configuration).
There are multiple configuration files in cmd/cddb you must fill out before deploying to Google App Engine.
| File | Description |
|---|---|
| gracenote.yaml | Contains your Gracenote Client and User IDs |
| appengine.json | Contains your App Engine credentials file in JSON format |
Once these are filled out, you can deploy the proxy using gcloud app deploy from cmd/cddb.
Once running, you can use the proxy by settings the FreeDB server in your client to http://[domain]/cddb, where [domain] is the address or domain the proxy is listening on (see configuration).
Some clients require additional configuration, pages have been created to help configure various clients:
The proxy allows you to set certain parameters using the URL path:
http://[domain]/cddb[/language][/country]
- language
- Specifies the preferred language for the returned metadata.
For the proxy, this only affects the returned genre name.
This should be a 3 character ISO 639-2 code.
- Specifies the preferred language for the returned metadata.
- country
- Specifies the country to use for the "genre hierarchy".
This should be a 3 character ISO 3166-1 alpha-3 code.
Please refer to the examples below and the Gracenote API documentation for the specific use of this parameter.
- Specifies the country to use for the "genre hierarchy".
Examples:
The default response:
http://[domain]/cddb
Genre: Asian Hip-Hop/Rap
Setting the language to German:
http://[domain]/cddb/ger
Genre: Asiatischer Hip-Hop/Rap
This simply translates the genre into the preferred language, but doesn't otherwise modify it.
Setting the language to English and the country to Japan:
http://[domain]/cddb/eng/jpn
Genre: Hip-Hop/Rap
Notice how with the country set to Japan, the genre no longer has the "Asian" specifier.
You can read more about the effects of these parameters on Gracenote's WebAPI Documentation: language + country