Make SystemEnvironmentPropertySource origin aware

Closes gh-9252

spring-boot/src/main/java/org/springframework/boot/env/OriginTrackedSystemPropertySource.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2012-2017 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.boot.env;
+
+import java.util.Map;
+
+import org.springframework.boot.origin.Origin;
+import org.springframework.boot.origin.OriginLookup;
+import org.springframework.boot.origin.OriginTrackedValue;
+import org.springframework.core.env.SystemEnvironmentPropertySource;
+
+/**
+ * {@link SystemEnvironmentPropertySource} and {@link OriginLookup} backed by a map
+ * containing {@link OriginTrackedValue OriginTrackedValues}.
+ *
+ * @author Madhura Bhave
+ * @since 2.0.0
+ */
+public class OriginTrackedSystemPropertySource extends SystemEnvironmentPropertySource implements OriginLookup<String> {
+
+	/**
+	 * Create a new {@code OriginTrackedSystemPropertySource} with the given name and
+	 * delegating to the given {@code MapPropertySource}.
+	 * @param name the property name
+	 * @param source the underlying map
+	 */
+	public OriginTrackedSystemPropertySource(String name, Map<String, Object> source) {
+		super(name, source);
+	}
+
+	@Override
+	public Object getProperty(String name) {
+		Object value = super.getProperty(name);
+		if (value instanceof OriginTrackedValue) {
+			return ((OriginTrackedValue) value).getValue();
+		}
+		return value;
+	}
+
+	@Override
+	public Origin getOrigin(String key) {
+		Object value = super.getProperty(key);
+		if (value instanceof OriginTrackedValue) {
+			return ((OriginTrackedValue) value).getOrigin();
+		}
+		return null;
+	}
+}
+

spring-boot/src/main/java/org/springframework/boot/env/SystemEnvironmentPropertySourceEnvironmentPostProcessor.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2012-2017 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.boot.env;
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.origin.OriginTrackedValue;
+import org.springframework.boot.origin.SystemEnvironmentOrigin;
+import org.springframework.core.Ordered;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.PropertySource;
+import org.springframework.core.env.StandardEnvironment;
+import org.springframework.core.env.SystemEnvironmentPropertySource;
+
+/**
+ * An {@link EnvironmentPostProcessor} that replaces the systemEnvironment {@link SystemEnvironmentPropertySource}
+ * with an {@link OriginTrackedSystemPropertySource} that can track the {@link SystemEnvironmentOrigin} for
+ * every system environment property.
+ *
+ * @author Madhura Bhave
+ * @since 2.0.0
+ */
+public class SystemEnvironmentPropertySourceEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered {
+
+	/**
+	 * The default order for the processor.
+	 */
+	public static final int DEFAULT_ORDER = SpringApplicationJsonEnvironmentPostProcessor.DEFAULT_ORDER - 1;
+
+	private int order = DEFAULT_ORDER;
+
+	@Override
+	public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
+		String sourceName = StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME;
+		PropertySource<?> propertySource = environment.getPropertySources().get(sourceName);
+		if (propertySource != null) {
+			replacePropertySource(environment, sourceName, propertySource);
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private void replacePropertySource(ConfigurableEnvironment environment, String sourceName, PropertySource<?> propertySource) {
+		if (propertySource.getSource() instanceof Map) {
+			Map<String, Object> originalSource = (Map<String, Object>) propertySource.getSource();
+			Map<String, Object> originTrackedSource = new LinkedHashMap<>(originalSource);
+			originTrackedSource.entrySet().forEach(e -> e.setValue(OriginTrackedValue.of(e.getValue(),
+					new SystemEnvironmentOrigin(e.getKey()))));
+			OriginTrackedSystemPropertySource source = new OriginTrackedSystemPropertySource(sourceName,
+					Collections.unmodifiableMap(originTrackedSource));
+			environment.getPropertySources().replace(sourceName, source);
+		}
+	}
+
+	@Override
+	public int getOrder() {
+		return this.order;
+	}
+
+	public void setOrder(int order) {
+		this.order = order;
+	}
+
+}
+

spring-boot/src/main/java/org/springframework/boot/origin/SystemEnvironmentOrigin.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2012-2017 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.boot.origin;
+
+import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
+
+/**
+ * {@link Origin} for an item loaded from the system environment. Provides access to the
+ * original property name.
+ *
+ * @author Madhura Bhave
+ * @since 2.0.0
+ */
+public class SystemEnvironmentOrigin implements Origin {
+
+	private final String property;
+
+	public SystemEnvironmentOrigin(String property) {
+		Assert.notNull(property, "Property name must not be null");
+		Assert.hasText(property, "Property name must not be empty");
+		this.property = property;
+	}
+
+	public String getProperty() {
+		return this.property;
+	}
+
+	@Override
+	public String toString() {
+		return "System Environment Property \"" + this.property + "\"";
+	}
+
+	@Override
+	public int hashCode() {
+		int result = ObjectUtils.nullSafeHashCode(this.property);
+		result = 31 * result + ObjectUtils.nullSafeHashCode(this.property);
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj) {
+			return true;
+		}
+		if (obj == null || getClass() != obj.getClass()) {
+			return false;
+		}
+		SystemEnvironmentOrigin other = (SystemEnvironmentOrigin) obj;
+		return ObjectUtils.nullSafeEquals(this.property, other.property);
+	}
+}
+

spring-boot/src/main/resources/META-INF/spring.factories

@@ -33,7 +33,8 @@ org.springframework.boot.liquibase.LiquibaseServiceLocatorApplicationListener
 # Environment Post Processors
 org.springframework.boot.env.EnvironmentPostProcessor=\
 org.springframework.boot.cloud.CloudFoundryVcapEnvironmentPostProcessor,\
-org.springframework.boot.env.SpringApplicationJsonEnvironmentPostProcessor
+org.springframework.boot.env.SpringApplicationJsonEnvironmentPostProcessor,\
+org.springframework.boot.env.SystemEnvironmentPropertySourceEnvironmentPostProcessor
 
 # Failure Analyzers
 org.springframework.boot.diagnostics.FailureAnalyzer=\

spring-boot/src/test/java/org/springframework/boot/env/OriginTrackedSystemPropertySourceTests.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2012-2017 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.boot.env;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.Test;
+
+import org.springframework.boot.origin.Origin;
+import org.springframework.boot.origin.OriginTrackedValue;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link OriginTrackedSystemPropertySource}.
+ *
+ * @author Madhura Bhave
+ */
+public class OriginTrackedSystemPropertySourceTests {
+
+	private Map<String, Object> map = new LinkedHashMap<>();
+
+	private OriginTrackedSystemPropertySource source = new OriginTrackedSystemPropertySource(
+			"test", this.map);
+
+	private Origin origin = mock(Origin.class);
+
+	@Test
+	public void getPropertyWhenMissingShouldReturnNull() throws Exception {
+		assertThat(this.source.getProperty("test")).isNull();
+	}
+
+	@Test
+	public void getPropertyWhenNonTrackedShouldReturnValue() throws Exception {
+		this.map.put("test", "foo");
+		assertThat(this.source.getProperty("test")).isEqualTo("foo");
+	}
+
+	@Test
+	public void getPropertyWhenTrackedShouldReturnValue() throws Exception {
+		this.map.put("test", OriginTrackedValue.of("foo", this.origin));
+		assertThat(this.source.getProperty("test")).isEqualTo("foo");
+	}
+
+	@Test
+	public void getPropertyOriginWhenMissingShouldReturnNull() throws Exception {
+		assertThat(this.source.getOrigin("test")).isNull();
+	}
+
+	@Test
+	public void getPropertyOriginWhenNonTrackedShouldReturnNull() throws Exception {
+		this.map.put("test", "foo");
+		assertThat(this.source.getOrigin("test")).isNull();
+	}
+
+	@Test
+	public void getPropertyOriginWhenTrackedShouldReturnOrigin() throws Exception {
+		this.map.put("test", OriginTrackedValue.of("foo", this.origin));
+		assertThat(this.source.getOrigin("test")).isEqualTo(this.origin);
+	}
+
+}

spring-boot/src/test/java/org/springframework/boot/env/SystemEnvironmentPropertySourceEnvironmentPostProcessorTests.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2012-2017 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.boot.env;
+
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.boot.origin.OriginTrackedValue;
+import org.springframework.boot.origin.SystemEnvironmentOrigin;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.PropertySource;
+import org.springframework.core.env.StandardEnvironment;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link SystemEnvironmentPropertySourceEnvironmentPostProcessor}.
+ *
+ * @author Madhura Bhave
+ */
+public class SystemEnvironmentPropertySourceEnvironmentPostProcessorTests {
+
+	private ConfigurableEnvironment environment;
+
+	@Before
+	public void setUp() throws Exception {
+		this.environment = new StandardEnvironment();
+	}
+
+	@Test
+	public void postProcessShouldReplaceSystemEnviromentPropertySource() throws Exception {
+		SystemEnvironmentPropertySourceEnvironmentPostProcessor postProcessor = new SystemEnvironmentPropertySourceEnvironmentPostProcessor();
+		postProcessor.postProcessEnvironment(this.environment, null);
+		PropertySource<?> replaced = this.environment.getPropertySources().get("systemEnvironment");
+		assertThat(replaced).isInstanceOf(OriginTrackedSystemPropertySource.class);
+	}
+
+	@Test
+	@SuppressWarnings("unchecked")
+	public void replacedPropertySourceShouldHaveOriginTrackedValues() throws Exception {
+		SystemEnvironmentPropertySourceEnvironmentPostProcessor postProcessor = new SystemEnvironmentPropertySourceEnvironmentPostProcessor();
+		PropertySource<?> original = this.environment.getPropertySources().get("systemEnvironment");
+		postProcessor.postProcessEnvironment(this.environment, null);
+		PropertySource<?> replaced = this.environment.getPropertySources().get("systemEnvironment");
+		Map<String, Object> originalMap = (Map<String, Object>) original.getSource();
+		Map<String, OriginTrackedValue> replacedMap = (Map<String, OriginTrackedValue>) replaced.getSource();
+		for (Map.Entry<String, Object> entry : originalMap.entrySet()) {
+			OriginTrackedValue actual = replacedMap.get(entry.getKey());
+			assertThat(actual.getValue()).isEqualTo(entry.getValue());
+			assertThat(actual.getOrigin()).isEqualTo(new SystemEnvironmentOrigin(entry.getKey()));
+		}
+	}
+
+}

spring-boot/src/test/java/org/springframework/boot/origin/SystemEnvironmentOriginTests.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2012-2017 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.boot.origin;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link SystemEnvironmentOrigin}.
+ *
+ * @author Madhura Bhave
+ */
+public class SystemEnvironmentOriginTests {
+
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
+	@Test
+	public void createWhenPropertyIsNullShouldThrowException() throws Exception {
+		this.thrown.expect(IllegalArgumentException.class);
+		new SystemEnvironmentOrigin(null);
+	}
+
+	@Test
+	public void createWhenPropertyNameIsEmptyShouldThrowException() throws Exception {
+		this.thrown.expect(IllegalArgumentException.class);
+		new SystemEnvironmentOrigin("");
+	}
+
+	@Test
+	public void getPropertyShouldReturnProperty() throws Exception {
+		SystemEnvironmentOrigin origin = new SystemEnvironmentOrigin("FOO_BAR");
+		assertThat(origin.getProperty()).isEqualTo("FOO_BAR");
+	}
+
+	@Test
+	public void toStringShouldReturnStringWithDetails() throws Exception {
+		SystemEnvironmentOrigin origin = new SystemEnvironmentOrigin("FOO_BAR");
+		assertThat(origin.toString()).isEqualTo("System Environment Property \"FOO_BAR\"");
+	}
+}