feat(configuration): Configuration properties can be overriden by sys…

…tem properties or environment variables

Closes gravitee-io/issues#1042

gravitee-management-api-rest/src/main/java/io/gravitee/management/rest/spring/EnvironmentBeanFactoryPostProcessor.java

@@ -0,0 +1,82 @@
+package io.gravitee.management.rest.spring;
+
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.core.env.Environment;
+import org.springframework.core.env.PropertySource;
+import org.springframework.core.env.StandardEnvironment;
+import org.springframework.core.env.SystemEnvironmentPropertySource;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author David BRASSELY (david.brassely at graviteesource.com)
+ * @author GraviteeSource Team
+ */
+public class EnvironmentBeanFactoryPostProcessor implements BeanFactoryPostProcessor {
+
+    private final static String PROPERTY_PREFIX = "gravitee.";
+
+    @Override
+    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
+        StandardEnvironment environment = (StandardEnvironment) beanFactory.getBean(Environment.class);
+
+        if (environment != null) {
+            Map<String, Object> systemEnvironment = environment.getSystemEnvironment();
+            Map<String, Object> prefixlessSystemEnvironment = new HashMap<>(systemEnvironment.size());
+            systemEnvironment
+                    .keySet()
+                    .forEach(key -> {
+                        String prefixKey = key;
+                        if (key.startsWith(PROPERTY_PREFIX)) {
+                            prefixKey = key.substring(PROPERTY_PREFIX.length());
+                        }
+                        prefixlessSystemEnvironment.put(prefixKey, systemEnvironment.get(key));
+                    });
+            SystemEnvironmentPropertySource systemEnvironmentPropertySource =
+                    new SystemEnvironmentPropertySource(
+                            StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, prefixlessSystemEnvironment);
+
+            environment.getPropertySources().replace(StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME,
+                    new PrefixAwarePropertySource(systemEnvironmentPropertySource));
+        }
+    }
+
+    class PrefixAwarePropertySource extends PropertySource {
+
+
+        private final PropertySource propertySource;
+
+        public PrefixAwarePropertySource(PropertySource propertySource) {
+            super(propertySource.getName());
+            this.propertySource = propertySource;
+        }
+
+        @Override
+        public boolean containsProperty(String name) {
+            removePrefix(name);
+            return propertySource.containsProperty(name);
+        }
+
+        @Override
+        public Object getProperty(String name) {
+            removePrefix(name);
+            return propertySource.getProperty(name);
+        }
+
+        private String removePrefix(String name) {
+            if (name == null) {
+                return null;
+            }
+
+            if (name.startsWith(PROPERTY_PREFIX)) {
+                return name.substring(PROPERTY_PREFIX.length());
+            }
+
+            return name;
+        }
+    }
+}

gravitee-management-api-rest/src/main/java/io/gravitee/management/rest/spring/PropertySourceBeanProcessor.java

@@ -26,15 +26,16 @@
 import java.util.Properties;
 
 /**
- * @author David BRASSELY (brasseld at gmail.com)
+ * @author David BRASSELY (david.brassely at graviteesource.com)
+ * @author GraviteeSource Team
  */
 public class PropertySourceBeanProcessor implements BeanFactoryPostProcessor, Ordered {
 
     private Environment environment;
 
     private Properties properties;
 
-    public PropertySourceBeanProcessor(Properties properties, Environment environment) {
+    PropertySourceBeanProcessor(Properties properties, Environment environment) {
         this.properties = properties;
         this.environment = environment;
     }
@@ -46,7 +47,7 @@ public int getOrder() {
 
     @Override
     public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
-        ((ConfigurableEnvironment) environment).getPropertySources().addFirst(
+        ((ConfigurableEnvironment) environment).getPropertySources().addLast(
                 new PropertiesPropertySource("graviteeConfiguration", properties));
     }
 }

gravitee-management-api-rest/src/main/java/io/gravitee/management/rest/spring/RestConfiguration.java

@@ -30,8 +30,8 @@
 import java.util.Properties;
 
 /**
- *
- * @author David BRASSELY (brasseld at gmail.com)
+ * @author David BRASSELY (david.brassely at graviteesource.com)
+ * @author GraviteeSource Team
  */
 @Configuration
 @ComponentScan({"io.gravitee.management.rest.enhancer"})
@@ -50,6 +50,11 @@ public static PropertySourcesPlaceholderConfigurer properties(@Qualifier("gravit
         return propertySourcesPlaceholderConfigurer;
     }
 
+    @Bean
+    public static EnvironmentBeanFactoryPostProcessor environmentBeanFactoryPostProcessor() {
+        return new EnvironmentBeanFactoryPostProcessor();
+    }
+
     @Bean
     public static PropertySourceBeanProcessor propertySourceBeanProcessor(@Qualifier("graviteeProperties") Properties graviteeProperties,
                                                                           Environment environment) {