io.grpc.xds.XdsCredentialsProvider Maven / Gradle / Ivy
/*
* Copyright 2022 The gRPC Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.grpc.xds;
import io.grpc.ChannelCredentials;
import io.grpc.Internal;
import java.util.Map;
/**
* Provider of credentials which can be consumed by clients for xds communications. The actual
* credential to be used for a particular xds communication will be chosen based on the bootstrap
* configuration.
*
* Implementations can be automatically discovered by gRPC via Java's SPI mechanism. For
* automatic discovery, the implementation must have a zero-argument constructor and include
* a resource named {@code META-INF/services/io.grpc.xds.XdsCredentialsProvider} in their JAR. The
* file's contents should be the implementation's class name.
* Implementations that need arguments in their constructor can be manually registered by
* {@link XdsCredentialsRegistry#register}.
*
*
Implementations should not throw. If they do, it may interrupt class loading. If
* exceptions may reasonably occur for implementation-specific reasons, implementations should
* generally handle the exception gracefully and return {@code false} from {@link #isAvailable()}.
*/
@Internal
public abstract class XdsCredentialsProvider {
/**
* Creates a {@link ChannelCredentials} from the given jsonConfig, or
* {@code null} if the given config is invalid. The provider is free to ignore
* the config if it's not needed for producing the channel credentials.
*
* @param jsonConfig json config that can be consumed by the provider to create
* the channel credentials
*
*/
protected abstract ChannelCredentials newChannelCredentials(Map jsonConfig);
/**
* Returns the xDS credential name associated with this provider which makes it selectable
* via {@link XdsCredentialsRegistry#getProvider}. This is called only when the class is loaded.
* It shouldn't change, and there is no point doing so.
*/
protected abstract String getName();
/**
* Whether this provider is available for use, taking the current environment
* into consideration.
* If {@code false}, {@link #newChannelCredentials} is not safe to be called.
*/
public abstract boolean isAvailable();
/**
* A priority, from 0 to 10 that this provider should be used, taking the
* current environment into consideration.
* 5 should be considered the default, and then tweaked based on
* environment detection. A priority of 0 does not imply that the provider
* wouldn't work; just that it should be last in line.
*/
public abstract int priority();
}