Initial commit for EELF Logger

Issue-ID: DCAEGEN2-633
Change-Id: I108929219d2d6570080d2fe7792cbc5a6530bb59
Signed-off-by: Singla, Rajiv (rs153v) <rs153v@att.com>

4 files changed, 199 insertions, 0 deletions

diff --git a/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/CompositePropertyResolver.java b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/CompositePropertyResolver.java
new file mode 100644
index 0000000..e5f1bc1
--- /dev/null
+++ b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/CompositePropertyResolver.java
@@ -0,0 +1,53 @@
+/*
+ * ================================================================================
+ * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ *
+ */
+
+package org.onap.dcae.utils.eelf.logger.logback.resolver;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * A composite property resolver can look under different resolvers in order of given property resolvers
+ *
+ * @author Rajiv Singla
+ */
+public class CompositePropertyResolver implements PropertyResolver {
+
+    private static final long serialVersionUID = 1L;
+
+    private final List<PropertyResolver> propertyResolvers;
+
+    public CompositePropertyResolver(PropertyResolver... propertyResolvers) {
+        this.propertyResolvers = Arrays.asList(propertyResolvers);
+    }
+
+    @Override
+    public String resolve(final List<String> propertyNames) {
+        // resolver property in given resolvers in the same order they are defined
+        for (PropertyResolver propertyResolver : propertyResolvers) {
+            final String propertyValue = propertyResolver.resolve(propertyNames);
+            if (propertyValue != null) {
+                return propertyValue;
+            }
+        }
+
+        return null;
+    }
+
+}
diff --git a/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/EnvironmentPropertyResolver.java b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/EnvironmentPropertyResolver.java
new file mode 100644
index 0000000..8f3d59f
--- /dev/null
+++ b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/EnvironmentPropertyResolver.java
@@ -0,0 +1,46 @@
+/*
+ * ================================================================================
+ * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ *
+ */
+
+package org.onap.dcae.utils.eelf.logger.logback.resolver;
+
+import java.util.List;
+
+/**
+ * Looks up Property values inside HOST environment variables
+ *
+ * @author Rajiv Singla
+ */
+public class EnvironmentPropertyResolver implements PropertyResolver {
+
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public String resolve(final List<String> propertyNames) {
+
+        // check if system environment variables have property names set
+        for (final String propertyName : propertyNames) {
+            final String propertyValue = System.getenv(propertyName);
+            if (propertyValue != null) {
+                return propertyValue;
+            }
+        }
+
+        return null;
+    }
+}
diff --git a/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/PropertyResolver.java b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/PropertyResolver.java
new file mode 100644
index 0000000..758de61
--- /dev/null
+++ b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/PropertyResolver.java
@@ -0,0 +1,41 @@
+/*
+ * ================================================================================
+ * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ *
+ */
+
+package org.onap.dcae.utils.eelf.logger.logback.resolver;
+
+import java.io.Serializable;
+import java.util.List;
+
+/**
+ * A resolver is used to resolve properties
+ *
+ * @author Rajiv Singla
+ */
+public interface PropertyResolver extends Serializable {
+
+    /**
+     * Returns resolved property value
+     *
+     * @param propertyNames names under which property can be found
+     *
+     * @return property value
+     */
+    String resolve(List<String> propertyNames);
+
+}
diff --git a/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/SystemPropertyResolver.java b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/SystemPropertyResolver.java
new file mode 100644
index 0000000..674b00b
--- /dev/null
+++ b/eelf-logger/eelf-logger-logback-impl/src/main/java/org/onap/dcae/utils/eelf/logger/logback/resolver/SystemPropertyResolver.java
@@ -0,0 +1,59 @@
+/*
+ * ================================================================================
+ * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ *
+ */
+
+package org.onap.dcae.utils.eelf.logger.logback.resolver;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+
+/**
+ * Resolve System Properties passed in by -DpropertyName=propertyValue when invoking
+ * via java command line arguments
+ *
+ * @author Rajiv Singla
+ */
+public class SystemPropertyResolver implements PropertyResolver {
+
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public String resolve(final List<String> propertyNames) {
+
+        // Get all system Properties
+        final Properties systemProperties = System.getProperties();
+
+        for (Map.Entry<Object, Object> systemEntries : systemProperties.entrySet()) {
+
+            if (systemEntries.getKey() instanceof String) {
+                final String systemKey = (String) systemEntries.getKey();
+
+                // if system properties contain any of the property names - ignoring case then return its value
+                for (String propertyName : propertyNames) {
+                    if (propertyName.equalsIgnoreCase(systemKey)) {
+                        return (String) systemEntries.getValue();
+                    }
+                }
+
+            }
+        }
+
+        return null;
+    }
+}