io.pivotal.spring.cloud.service.config.VaultTokenRenewalAutoConfiguration.java Source code

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Here is the source code for io.pivotal.spring.cloud.service.config.VaultTokenRenewalAutoConfiguration.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 io.pivotal.spring.cloud.service.config;

import java.util.HashMap;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.cloud.config.client.ConfigClientProperties;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.security.oauth2.client.OAuth2RestTemplate;
import org.springframework.web.client.RestTemplate;

/**
 * Configuration for a periodic Vault token renewer. Conditionally configured if there
 * is a {@link ConfigClientProperties} bean and if there is a `spring.cloud.config.token`
 * property set.
 * 
 * By default, the token is renewed every 60 seconds and is renewed with a 5 minute time-to-live.
 * The renew rate can be configured by setting `vault.token.renew.rate` to some value that is the 
 * renewal rate in milliseconds. The renewal time-to-live can be specified with by setting
 * `vault.token.ttl` to some value indicating the time-to-live in milliseconds.
 * 
 * @author cwalls
 */
@Configuration
@ConditionalOnBean(ConfigClientProperties.class)
@ConditionalOnProperty(name = "spring.cloud.config.token")
public class VaultTokenRenewalAutoConfiguration {

    private static final Logger logger = LoggerFactory.getLogger(VaultTokenRenewalAutoConfiguration.class);

    private final RestTemplate rest;
    private final String refreshUri;
    private final HttpEntity<Map<String, Long>> request;
    private final String obscuredToken;
    private final long renewTTL;

    @Autowired
    public VaultTokenRenewalAutoConfiguration(ConfigClientOAuth2ResourceDetails configClientOAuth2ResourceDetails,
            ConfigClientProperties configClientProps, @Value("${spring.cloud.config.token}") String vaultToken,
            @Value("${vault.token.ttl:300000}") long renewTTL) { // <-- Default to a 300 second (5 minute) TTL
        this.rest = new OAuth2RestTemplate(configClientOAuth2ResourceDetails);
        this.refreshUri = configClientProps.getRawUri() + "/vault/v1/auth/token/renew-self";
        long renewTTLInMS = renewTTL / 1000; // convert to seconds, since that's what Vault wants
        this.request = buildTokenRenewRequest(vaultToken, renewTTLInMS);
        this.obscuredToken = vaultToken.substring(0, 4) + "[*]" + vaultToken.substring(vaultToken.length() - 4);
        this.renewTTL = renewTTL;
    }

    @Scheduled(fixedRateString = "${vault.token.renew.rate:60000}") // <-- Default to renew token every 60 seconds
    public void refreshVaultToken() {
        try {
            logger.info("Renewing Vault token " + obscuredToken + " for " + renewTTL + " milliseconds.");
            rest.postForObject(refreshUri, request, String.class);
        } catch (Exception e) {
            logger.error("Unable to renew Vault token " + obscuredToken + ". Is the token invalid or expired?");
        }
    }

    private HttpEntity<Map<String, Long>> buildTokenRenewRequest(String vaultToken, long renewTTL) {
        Map<String, Long> requestBody = new HashMap<>();
        requestBody.put("increment", renewTTL);
        HttpHeaders headers = new HttpHeaders();
        headers.set("X-Vault-Token", vaultToken);
        HttpEntity<Map<String, Long>> request = new HttpEntity<Map<String, Long>>(requestBody, headers);
        return request;
    }

}