Expose Environment in AbstractVaultConfiguration.

Accessing Environment when providing a VaultPropertySource in bean bootstrapping requires a class to implement ApplicationContextAware. This is, because autowiring didn't happen yet and the exposed method provides Environment in the appropriate way.

See gh-26.

spring-vault-core/src/main/java/org/springframework/vault/config/AbstractVaultConfiguration.java

@@ -15,10 +15,14 @@
  */
 package org.springframework.vault.config;
 
+import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.DisposableBean;
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
 import org.springframework.core.task.AsyncTaskExecutor;
 import org.springframework.core.task.SimpleAsyncTaskExecutor;
 import org.springframework.http.client.ClientHttpRequestFactory;
@@ -41,7 +45,9 @@ import org.springframework.vault.support.SslConfiguration;
  * @author Mark Paluch
  */
 @Configuration
-public abstract class AbstractVaultConfiguration {
+public abstract class AbstractVaultConfiguration implements ApplicationContextAware {
+
+	private ApplicationContext applicationContext;
 
 	/**
 	 * @return Vault endpoint coordinates for HTTP/HTTPS communication, must not be
@@ -164,6 +170,28 @@ public abstract class AbstractVaultConfiguration {
 		return new VaultTemplate(vaultClientFactory(), sessionManager());
 	}
 
+	/**
+	 * Return the {@link Environment} to access property sources during Spring Vault
+	 * bootstrapping. Requires {@link #setApplicationContext(ApplicationContext)
+	 * ApplicationContext} to be set.
+	 * 
+	 * @return the {@link Environment} to access property sources during Spring Vault
+	 * bootstrapping.
+	 */
+	protected Environment getEnvironment() {
+
+		Assert.state(applicationContext != null,
+				"ApplicationContext must be set before accessing getEnvironment()");
+
+		return applicationContext.getEnvironment();
+	}
+
+	@Override
+	public void setApplicationContext(ApplicationContext applicationContext)
+			throws BeansException {
+		this.applicationContext = applicationContext;
+	}
+
 	/**
 	 * Wrapper for {@link ClientHttpRequestFactory} to not expose the bean globally.
 	 */

spring-vault-core/src/test/java/org/springframework/vault/demo/SecurePropertyUsage.java

@@ -18,16 +18,12 @@ package org.springframework.vault.demo;
 import java.util.HashMap;
 import java.util.Map;
 
-import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.annotation.Value;
-import org.springframework.context.ApplicationContext;
-import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.PropertySource;
 import org.springframework.context.annotation.PropertySources;
-import org.springframework.core.env.Environment;
 import org.springframework.stereotype.Component;
 import org.springframework.vault.annotation.VaultPropertySource;
 import org.springframework.vault.authentication.ClientAuthentication;
@@ -82,20 +78,11 @@ public class SecurePropertyUsage {
 	@VaultPropertySource({ "secret/secure-introduction" })
 	@Configuration
 	@ComponentScan
-	static class Config extends VaultIntegrationTestConfiguration implements
-			ApplicationContextAware {
-
-		private Environment environment;
+	static class Config extends VaultIntegrationTestConfiguration {
 
 		@Override
 		public ClientAuthentication clientAuthentication() {
-			return new TokenAuthentication(environment.getProperty("vault.token"));
-		}
-
-		@Override
-		public void setApplicationContext(ApplicationContext applicationContext)
-				throws BeansException {
-			environment = applicationContext.getEnvironment();
+			return new TokenAuthentication(getEnvironment().getProperty("vault.token"));
 		}
 	}
 

src/main/asciidoc/reference/authentication.adoc

@@ -26,25 +26,18 @@ OS access levels.
 ----
 @PropertySource("configuration.properties"),
 @Configuration
-static class Config extends VaultIntegrationTestConfiguration implements
-    ApplicationContextAware {
-
-    private Environment environment;
+public class Config extends AbstractVaultConfiguration {
 
     @Override
     public ClientAuthentication clientAuthentication() {
-        return new TokenAuthentication(environment.getProperty("vault.token"));
+        return new TokenAuthentication(getEnvironment().getProperty("vault.token"));
     }
-
-    @Override
-    public void setApplicationContext(ApplicationContext applicationContext)
-            throws BeansException {
-        environment = applicationContext.getEnvironment();
-        }
 }
 ----
 ====
 
+NOTE: Spring allows multiple ways to obtain `Environment`. When using `VaultPropertySource`, injection via `@Autowired Environment environment` will not provide the `Environment` as the environment bean is still in construction and autowiring comes at a later stage. Your configuration class should rather implement `ApplicationContextAware` and obtain the `Environment` from `ApplicationContext`.
+
 See https://github.com/spring-projects/spring-vault/blob/master/spring-vault-core/src/test/java/org/springframework/vault/demo/SecurePropertyUsage.java[`SecurePropertyUsage.java`] 
 for a sample on referencing properties in components and other property sources.