org.springframework.vault.authentication.AuthenticationStepsExecutor.java Source code

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Here is the source code for org.springframework.vault.authentication.AuthenticationStepsExecutor.java

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/*
 * Copyright 2017 the original author or 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 org.springframework.vault.authentication;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.http.HttpEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.vault.VaultException;
import org.springframework.vault.authentication.AuthenticationSteps.HttpRequest;
import org.springframework.vault.authentication.AuthenticationSteps.HttpRequestNode;
import org.springframework.vault.authentication.AuthenticationSteps.MapStep;
import org.springframework.vault.authentication.AuthenticationSteps.Node;
import org.springframework.vault.authentication.AuthenticationSteps.OnNextStep;
import org.springframework.vault.authentication.AuthenticationSteps.SupplierStep;
import org.springframework.vault.client.VaultResponses;
import org.springframework.vault.support.VaultResponse;
import org.springframework.vault.support.VaultToken;
import org.springframework.web.client.HttpStatusCodeException;
import org.springframework.web.client.RestOperations;

/**
 * Synchronous executor for {@link AuthenticationSteps} using {@link RestOperations} to
 * login using authentication flows.
 *
 * @author Mark Paluch
 * @since 2.0
 * @see AuthenticationSteps
 */
public class AuthenticationStepsExecutor implements ClientAuthentication {

    private static final Log logger = LogFactory.getLog(AppIdAuthentication.class);

    private final AuthenticationSteps chain;

    private final RestOperations restOperations;

    /**
     * Create a new {@link AuthenticationStepsExecutor} given {@link AuthenticationSteps}
     * and {@link RestOperations}.
     *
     * @param steps must not be {@literal null}.
     * @param restOperations must not be {@literal null}.
     */
    public AuthenticationStepsExecutor(AuthenticationSteps steps, RestOperations restOperations) {

        Assert.notNull(steps, "AuthenticationSteps must not be null");
        Assert.notNull(restOperations, "RestOperations must not be null");

        this.chain = steps;
        this.restOperations = restOperations;
    }

    @Override
    @SuppressWarnings("unchecked")
    public VaultToken login() throws VaultException {

        Object state = null;

        for (Node<?> o : chain.steps) {

            if (logger.isDebugEnabled()) {
                logger.debug(String.format("Executing %s with current state %s", o, state));
            }

            try {
                if (o instanceof HttpRequestNode) {
                    state = doHttpRequest((HttpRequestNode<Object>) o, state);
                }

                if (o instanceof AuthenticationSteps.MapStep) {
                    state = doMapStep((MapStep<Object, Object>) o, state);
                }

                if (o instanceof OnNextStep) {
                    state = doOnNext((OnNextStep<Object>) o, state);
                }

                if (o instanceof AuthenticationSteps.SupplierStep<?>) {
                    state = doSupplierStep((SupplierStep<Object>) o);
                }

                if (logger.isDebugEnabled()) {
                    logger.debug(String.format("Executed %s with current state %s", o, state));
                }
            } catch (HttpStatusCodeException e) {
                throw new VaultException(
                        String.format("HTTP request %s in state %s failed with Status %s and body %s", o, state,
                                e.getStatusCode(), VaultResponses.getError(e.getResponseBodyAsString())));
            } catch (RuntimeException e) {
                throw new VaultException(String.format("Authentication execution failed in %s", o), e);
            }
        }

        if (state instanceof VaultToken) {
            return (VaultToken) state;
        }

        if (state instanceof VaultResponse) {

            VaultResponse response = (VaultResponse) state;
            Assert.state(response.getAuth() != null, "Auth field must not be null");
            return LoginTokenUtil.from(response.getAuth());
        }

        throw new IllegalStateException(
                String.format("Cannot retrieve VaultToken from authentication chain. Got instead %s", state));
    }

    private static Object doSupplierStep(SupplierStep<Object> supplierStep) {
        return supplierStep.get();
    }

    private static Object doMapStep(MapStep<Object, Object> o, Object state) {
        return o.apply(state);
    }

    private static Object doOnNext(OnNextStep<Object> o, Object state) {
        return o.apply(state);
    }

    @SuppressWarnings("ConstantConditions")
    @Nullable
    private Object doHttpRequest(HttpRequestNode<Object> step, @Nullable Object state) {

        HttpRequest<Object> definition = step.getDefinition();

        if (definition.getUri() == null) {

            ResponseEntity<?> exchange = restOperations.exchange(definition.getUriTemplate(),
                    definition.getMethod(), getEntity(definition.getEntity(), state), definition.getResponseType(),
                    (Object[]) definition.getUrlVariables());

            return exchange.getBody();
        }
        ResponseEntity<?> exchange = restOperations.exchange(definition.getUri(), definition.getMethod(),
                getEntity(definition.getEntity(), state), definition.getResponseType());

        return exchange.getBody();

    }

    private static HttpEntity<?> getEntity(HttpEntity<?> entity, @Nullable Object state) {

        if (entity == null) {
            return state == null ? HttpEntity.EMPTY : new HttpEntity<>(state);
        }

        if (entity.getBody() == null && state != null) {
            return new HttpEntity<>(state, entity.getHeaders());
        }

        return entity;
    }
}