Chapter 12. Configuring providers
The server is built with extensibility in mind and for that it provides a number of Service Provider Interfaces or SPIs, each one responsible for providing a specific capability to the server. In this chapter, you are going to understand the core concepts around the configuration of SPIs and their respective providers.
After reading this chapter, you should be able to use the concepts and the steps herein explained to install, uninstall, enable, disable, and configure any provider, including those you have implemented to extend the server capabilities in order to better fulfill your requirements.
12.1. Configuration option format
Providers can be configured by using a specific configuration format. The format consists of:
spi-<spi-id>-<provider-id>-<property>=<value>
The <spi-id> is the name of the SPI you want to configure.
The <provider-id> is the id of the provider you want to configure. This is the id set to the corresponding provider factory implementation.
The <property> is the actual name of the property you want to set for a given provider.
All those names (for spi, provider, and property) should be in lower case and if the name is in camel-case such as myKeycloakProvider, it should include dashes (-) before upper-case letters as follows: my-keycloak-provider.
Taking the HttpClientSpi SPI as an example, the name of the SPI is connectionsHttpClient and one of the provider implementations available is named default. In order to set the connectionPoolSize property you would use a configuration option as follows:
spi-connections-http-client-default-connection-pool-size=10
12.2. Setting a provider configuration option
Provider configuration options are provided when starting the server, as shown in the following example:
Setting the connection-pool-size for the default provider of the connections-http-client SPI
bin/kc.[sh|bat] start --spi-connections-http-client-default-connection-pool-size=10
12.3. Configuring a default provider
Depending on the SPI, multiple provider implementations can co-exist but only one of them is going to be used at runtime. For these SPIs, a default provider is the primary implementation that is going to be active and used at runtime.
To configure a provider as the default you should run the build command as follows:
Marking the mycustomprovider provider as the default provider for the email-template SPI
bin/kc.[sh|bat] build --spi-email-template-provider=mycustomprovider
In the example above, we are using the provider property to set the id of the provider we want to mark as the default.
12.4. Enabling and disabling a provider
To enable or disable a provider you should run the build command as follows:
Enabling a provider
bin/kc.[sh|bat] build --spi-email-template-mycustomprovider-enabled=true
To disable a provider, use the same command and set the enabled property to false.
12.5. Installing and uninstalling a provider
Custom providers should be packaged in a Java Archive (JAR) file and copied to the providers directory of the distribution. After that, you must run the build command in order to update the server’s provider registry with the implementations from the JAR file.
This step is needed in order to optimize the server runtime so that all providers are known ahead-of-time rather than discovered only when starting the server or at runtime.
To uninstall a provider, you should remove the JAR file from the providers directory and run the build command again.
12.6. Using third-party dependencies
When implementing a provider you might need to use some third-party dependency that is not available from the server distribution.
In this case, you should copy any additional dependency to the providers directory and run the build command. Once you do that, the server is going to make these additional dependencies available at runtime for any provider that depends on them.
