Netflix Archaius for property management – Basics
Netflix Archaius provides a neat set of features to load dynamic properties into an application.
This blog post is just a documentation of the extent of Archaius that I have understood, there is much more to it than I have documented here, but this should provide a good start:
Default Behavior
Consider a simple properties file:
stringprop=propvalue listprop=value1, value2, value3 mapprop=key1=value1, key2=value2 longprop=100
If these entries are placed in a config.properties file in the classpath, then the following test demonstrates how each of these properties can be resolved by Archaius in code:
@Test public void testBasicStringProps() { DynamicStringProperty sampleProp = DynamicPropertyFactory.getInstance().getStringProperty("stringprop", ""); assertThat(sampleProp.get(), equalTo("propvalue")); } @Test public void testBasicListProps() { DynamicStringListProperty listProperty = new DynamicStringListProperty("listprop", Collections.emptyList()); assertThat(listProperty.get(), contains("value1", "value2", "value3")); } @Test public void testBasicMapProps() { DynamicStringMapProperty mapProperty = new DynamicStringMapProperty("mapprop", Collections.emptyMap()); assertThat(mapProperty.getMap(), allOf(hasEntry("key1", "value1"), hasEntry("key2", "value2"))); } @Test public void testBasicLongProperty() { DynamicLongProperty longProp = DynamicPropertyFactory.getInstance().getLongProperty("longprop", 1000); assertThat(longProp.get(), equalTo(100L)); }
Loading Properties from a non-default file in classpath
So now, how do we handle a case where the content is to be loaded from a file with a different name, say newconfig.properties but still available in the classpath. The following is one way to do that:
@Before public void setUp() throws Exception{ ConfigurationManager.loadCascadedPropertiesFromResources("newconfig"); }
With this change the previous test will just work.
Another option is to provide a system property to indicate the name of the properties file to load from the classpath:
System.setProperty("archaius.configurationSource.defaultFileName", "newconfig.properties");
Overriding for environments
Now, how do we override the properties for different application environments – Archaius provides a neat feature where a base property file can be loaded up but then overridden based on the context. More details are here. To demonstrate this consider two files, one containing the defaults and one containing overrides for a “test” environment
sample.properties
sampleprop=propvalue @next=sample-${@environment}.properties
sample-test.properties
sampleprop=propvalue-test
See the notation at the end of the default file @next=sample-${@environment}.properties, it is a way to indicate to Archaius that more properties need to be loaded up based on the resolved @environment parameter. This parameter can be injected in a couple of ways and the following test demonstrates this:
@Before public void setUp() throws Exception{ ConfigurationManager.getConfigInstance().setProperty("@environment", "test"); ConfigurationManager.loadCascadedPropertiesFromResources("sample"); } @Test public void testBasicStringPropsInTestEnvironment() throws Exception { DynamicStringProperty sampleProp = DynamicPropertyFactory.getInstance().getStringProperty("sampleprop", ""); assertThat(sampleProp.get(), equalTo("propvalue-test")); }
The base property file itself now has to be loaded in through a call to ConfigurationManager.loadCascadedPropertiesFromResources..
Conclusion
These are essentially the basics of Netflix Archaius, there is much more to it of course which can be gleaned from the wiki on the Archaius github site.
- If you are interested in exploring the samples shown here a little more, they are available in this github project
Reference: | Netflix Archaius for property management – Basics from our JCG partner Biju Kunjummen at the all and sundry blog. |
Thanks Biju. Appreciated. Looking for more on this great framework.
Also add the Spring adapter tutorial towards the end.
I have a question regarding Archaius. We have been using Apache Kafka with 4 nodes and at present to pick any new changes made to the respective properties we are restarting the servers. Archaius is developed for dynamic properties, by using Archaius can we eliminate restarting the servers ?