disable configsource if no host or hosts are set

.gitignore

@@ -4,3 +4,4 @@
 target/
 
 .idea/
+*.iml

README.md

@@ -19,21 +19,23 @@ The eclipse microprofile config framework is a simple yet powerful configuration
         <dependency>
             <groupId>ch.carve</groupId>
             <artifactId>mp-config-consul</artifactId>
-            <version>0.8</version>
+            <version>0.9</version>
         </dependency>
 ```
 
 ## Configuration
 Currently there are 6 values you can configure, either through Java system properties or environment variables:
-* **configsource.consul.host** url of your consul agent instance, e.g. "192.168.99.100", default value is "localhost", variable substitution available.
+* **configsource.consul.host** url of your consul agent instance, e.g. "192.168.99.100", default empty, variable substitution available.
 * **configsource.consul.hosts** list of consul servers, e.g. "192.168.99.100,192.168.99.101", default empty, variable substitution available.
 * **configsource.consul.port** port of consul, e.g. "8500", default value is "8500", variable substitution available.
 * **configsource.consul.validity** how long to cache values (in seconds), default is 30s
 * **configsource.consul.prefix** key prefix to search value in consul, variable substitution available
 * **configsource.consul.list-all** whether getProperties() should query consul for all kv pairs, default is false
 * **configsource.consul.token** token that will be used to retrieve key/values from consul. Default is empty and retrieval is done without token.
 
-Note: these config values cannot be set in Quarkus application.properties, you need to pass them as JVM arguments like this `-Dconfigsource.consul.host=consul.mycompany.com`
+> Note: these config values cannot be set in Quarkus application.properties, you need to pass them as JVM arguments like this `-Dconfigsource.consul.host=consul.mycompany.com` or through environment variables.
+
+> Note: if both host and hosts are empty, this configsource is disabled!
 
 ## Ordinal
 Config sources have priorities called ordinal. This config source has ordinal 550, but can be overriden with setting 'config_ordinal' in this source (including prefix if defined)

src/main/java/ch/carve/microprofile/config/consul/Configuration.java

@@ -12,7 +12,7 @@ public class Configuration {
             .build();
 
     private StringSubstitutor substitutor = new StringSubstitutor(s -> getConfigValue(s, ""));
-    private String consulHost = substitutor.replace(getConfigValue("configsource.consul.host", "localhost"));
+    private String consulHost = substitutor.replace(getConfigValue("configsource.consul.host", ""));
     private String consulHostList = substitutor.replace(getConfigValue("configsource.consul.hosts", ""));
     private int consulPort = Integer.valueOf(substitutor.replace(getConfigValue("configsource.consul.port", "8500")));
     private long validity = Long.valueOf(getConfigValue("configsource.consul.validity", "30")) * 1000L;

src/main/java/ch/carve/microprofile/config/consul/ConsulConfigSource.java

@@ -17,13 +17,13 @@ public class ConsulConfigSource implements ConfigSource {
 
     Configuration config = new Configuration();
     ExpiringMap<String, String> cache = new ExpiringMap<>(config.getValidity());
-
+    boolean isDisabled = config.getConsulHost().isEmpty() && config.getConsulHostList().isEmpty();
     ConsulClientWrapper client = new ConsulClientWrapper(config.getConsulHost(), config.getConsulHostList(), config.getConsulPort(), config.getToken());
 
     @Override
     public Map<String, String> getProperties() {
         // only query for values if explicitly enabled
-        if (config.listAll()) {
+        if (!isDisabled && config.listAll()) {
             List<Entry<String, String>> values = client.getKeyValuePairs(config.getPrefix());
             values.forEach(v -> cache.put(v.getKey(), v.getValue()));
         }
@@ -37,6 +37,9 @@ public Map<String, String> getProperties() {
 
     @Override
     public String getValue(String propertyName) {
+        if (isDisabled) {
+            return null;
+        }
         String value = cache.getOrCompute(propertyName,
                 p -> client.getValue(config.getPrefix() + propertyName),
                 p -> logger.debug("consul getKV failed for key {}", p));

src/test/java/ch/carve/microprofile/config/consul/ConfigurationTest.java

@@ -6,7 +6,7 @@
 import org.junit.jupiter.api.Test;
 
 public class ConfigurationTest {
-    
+
     @Test
     public void testGetValidity() throws Exception {
         Configuration config = new Configuration();
@@ -48,7 +48,7 @@ public void testGetPrefix_withSubstitution() throws Exception {
     @Test
     public void testGetConsulHost() throws Exception {
         Configuration config = new Configuration();
-        assertEquals("localhost", config.getConsulHost());
+        assertEquals("", config.getConsulHost());
     }
 
     @Test

src/test/java/ch/carve/microprofile/config/consul/ConsulClientWrapperTest.java

@@ -32,7 +32,8 @@ public void init(ClientAndServer client) {
         clientServer.when(request().withPath("/v1/status/leader")).respond(response().withBody("localhost"));
         clientServer.when(request().withPath("/v1/status/peers")).respond(response().withBody("[\"localhost:8300\"]"));
         clientServer.when(request().withPath("/v1/kv/test")).respond(response().withBody("[{\"LockIndex\":0,\"Key\":\"test\",\"Flags\":0,\"Value\":\"aGVsbG8=\",\"CreateIndex\":1,\"ModifyIndex\":2}]"));
-        clientServer.when(request().withPath("/v1/kv/testFromToken").withQueryStringParameter("token", "tokenValue")).respond(response().withBody("[{\"LockIndex\":0,\"Key\":\"testFromToken\",\"Flags\":0,\"Value\":\"aGVsbG8=\",\"CreateIndex\":1,\"ModifyIndex\":2}]"));
+        clientServer.when(request().withPath("/v1/kv/testFromToken").withQueryStringParameter("token", "tokenValue"))
+                .respond(response().withBody("[{\"LockIndex\":0,\"Key\":\"testFromToken\",\"Flags\":0,\"Value\":\"aGVsbG8=\",\"CreateIndex\":1,\"ModifyIndex\":2}]"));
         clientServer.when(request().withPath("/v1/kv/myapp")).respond(response().withBody("[{\"LockIndex\":0,\"Key\":\"test\",\"Flags\":0,\"Value\":\"aGVsbG8=\",\"CreateIndex\":1,\"ModifyIndex\":2}]"));
         clientWrapper = new ConsulClientWrapper("localhost", null, clientServer.getLocalPort(), null);
     }
@@ -85,7 +86,7 @@ public void testGetValue_force_reconnect() {
         clientServer.when(request().withPath("/v1/kv/test")).respond(response().withStatusCode(503));
         assertThrows(OperationException.class, () -> clientWrapper.getValue("test"));
         clientServer.clear(request().withPath("/v1/kv/test"));
-        clientServer.when(request().withPath("/v1/kv/test")).respond(response().withBody("[{\"LockIndex\":0,\"Key\":\"test\",\"Flags\":0,\"Value\":\"aGVsbG8=\",\"CreateIndex\":1,\"ModifyIndex\":2}]"));        
+        clientServer.when(request().withPath("/v1/kv/test")).respond(response().withBody("[{\"LockIndex\":0,\"Key\":\"test\",\"Flags\":0,\"Value\":\"aGVsbG8=\",\"CreateIndex\":1,\"ModifyIndex\":2}]"));
         String value = clientWrapper.getValue("test");
         assertEquals("hello", value);
     }

src/test/java/ch/carve/microprofile/config/consul/ConsulConfigSourceTest.java

@@ -3,7 +3,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -21,6 +21,7 @@ class ConsulConfigSourceTest {
 
     @BeforeEach
     public void init() {
+        System.setProperty("configsource.consul.host", "localhost");
         configSource = new ConsulConfigSource();
         configSource.config = new Configuration();
         configSource.client = mock(ConsulClientWrapper.class);
@@ -51,6 +52,7 @@ void testGetProperties_from_consul() {
     @Test
     void testGetProperties_with_null() {
         when(configSource.client.getValue(anyString())).thenReturn(null);
+        configSource.getValue("test");
         assertEquals(0, configSource.getProperties().size());
     }