Add support for using env vars to override cassandra datastax driver configuration properties

cassandra/build.gradle

@@ -15,4 +15,11 @@ dependencies {
     testImplementation(libs.testcontainers.cassandra)
     testImplementation(mn.micronaut.management)
     testImplementation(mnMicrometer.micronaut.micrometer.core)
+    testImplementation(libs.system.stubs)
+    testRuntimeOnly(mn.snakeyaml)
+}
+
+tasks.withType(Test) {
+    // this is needed by libs.system.stubs
+    jvmArgs = ["--add-opens", "java.base/java.util=ALL-UNNAMED"]
 }

cassandra/src/main/java/io/micronaut/cassandra/CassandraSessionFactory.java

@@ -21,13 +21,13 @@
 import com.typesafe.config.ConfigFactory;
 import io.micronaut.context.annotation.EachBean;
 import io.micronaut.context.annotation.Factory;
-import io.micronaut.core.naming.conventions.StringConvention;
 import io.micronaut.core.value.PropertyResolver;
 import jakarta.annotation.PreDestroy;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
@@ -37,6 +37,7 @@
  *
  * @author Nirav Assar
  * @author Michael Pollind
+ * @author Dean Wette
  * @since 1.0
  */
 @Factory
@@ -67,10 +68,11 @@ public CqlSessionBuilder session(CassandraConfiguration configuration) {
             return CqlSession.builder().withConfigLoader(new DefaultDriverConfigLoader(() -> {
                 ConfigFactory.invalidateCaches();
                 String prefix = configuration.getName();
-                Map<String, Object> properties = this.resolver.getProperties(CassandraConfiguration.PREFIX + "." + prefix, StringConvention.RAW);
+                Map<String, Object> properties = this.resolver.getProperties(CassandraConfiguration.PREFIX + "." + prefix);
                 // translate indexed properties for list values from Micronaut array index notation (i.e. foo[0]=bar)
                 // to Datastax driver decimal notation (i.e. foo.0=bar)
                 properties = properties.entrySet().stream()
+                    .filter(e -> !(e.getValue() instanceof Collection<?>))
                     .collect((Collectors.toMap(e -> e.getKey().replaceAll("\\[(\\d+)]", ".$1"), Map.Entry::getValue)));
                 return ConfigFactory.parseMap(properties).withFallback(ConfigFactory.load().getConfig(DefaultDriverConfigLoader.DEFAULT_ROOT_PATH));
             }));

cassandra/src/test/groovy/io/micronaut/cassandra/metrics/CassandraMetricsSpec.groovy

@@ -4,12 +4,13 @@ import com.datastax.oss.driver.api.core.CqlSession
 import io.micrometer.core.instrument.Meter
 import io.micrometer.core.instrument.MeterRegistry
 import io.micronaut.context.ApplicationContext
-import io.micronaut.context.DefaultApplicationContext
-import io.micronaut.context.env.MapPropertySource
+import io.micronaut.core.value.PropertyResolver
 import io.micronaut.inject.qualifiers.Qualifiers
 import org.testcontainers.containers.CassandraContainer
 import org.testcontainers.utility.DockerImageName
+import spock.lang.Issue
 import spock.lang.Specification
+import uk.org.webcompere.systemstubs.environment.EnvironmentVariables
 
 class CassandraMetricsSpec extends Specification {
 
@@ -55,4 +56,41 @@ class CassandraMetricsSpec extends Specification {
         cassandra.stop()
         applicationContext.close()
     }
+
+    @Issue("https://github.com/micronaut-projects/micronaut-cassandra/issues/240")
+    void "test metrics with overriding #configStyle with env vars"() {
+        given:
+        CassandraContainer cassandra = new CassandraContainer(DockerImageName.parse('cassandra:latest'))
+        cassandra.start()
+
+        // override: cassandra.default.basic.session-name=defaultSession
+        def env = new EnvironmentVariables(
+                "CASSANDRA_DEFAULT_BASIC_SESSION_NAME", "envSession",
+                "CASSANDRA_PORT", "${cassandra.firstMappedPort}"
+        )
+        env.setup()
+
+        ApplicationContext applicationContext = ApplicationContext.run("env$configStyle")
+
+        when:
+        CqlSession defaultCluster = applicationContext.getBean(CqlSession)
+        PropertyResolver resolver = applicationContext.getBean(PropertyResolver)
+        MeterRegistry meterRegistry = applicationContext.getBean(MeterRegistry)
+
+        then:
+        resolver.getRequiredProperty("configuration", String) == configStyle
+        defaultCluster
+        meterRegistry
+
+        and:
+        meterRegistry.meters.id.name.findAll { it.contains("envSession") } ==~ ['envSession.connected-nodes', 'envSession.cql-requests']
+
+        cleanup:
+        env.teardown()
+        cassandra.stop()
+        applicationContext.close()
+
+        where:
+        configStyle << ['props', 'yaml']
+    }
 }

cassandra/src/test/resources/application-envprops.properties

@@ -0,0 +1,8 @@
+configuration=props
+micronaut.metrics.enabled=true
+cassandra.default.basic.contact-points[0]=localhost:${cassandra.port}
+cassandra.default.basic.session-name=defaultSession
+cassandra.default.advanced.metrics.factory.class=MicrometerMetricsFactory
+cassandra.default.advanced.metrics.session.enabled[0]=connected-nodes
+cassandra.default.advanced.metrics.session.enabled[1]=cql-requests
+cassandra.default.basic.load-balancing-policy.local-datacenter=datacenter1

cassandra/src/test/resources/application-envyaml.yaml

@@ -0,0 +1,17 @@
+micronaut:
+  metrics:
+    enabled: true
+configuration: yaml
+cassandra:
+  default:
+    basic:
+      contact-points: ["localhost:${cassandra.port}"]
+      session-name: defaultSession
+      load-balancing-policy:
+        local-datacenter: datacenter1
+    advanced:
+      metrics:
+        factory:
+          class: MicrometerMetricsFactory
+        session:
+          enabled: [connected-nodes, cql-requests]

gradle/libs.versions.toml

@@ -12,6 +12,7 @@ managed-datastax-cassandra-driver = "4.17.0"
 groovy = "4.0.14"
 spock = "2.3-groovy-4.0"
 testcontainers = "1.19.1"
+system-stubs = "1.2.0"
 
 [libraries]
 # Core
@@ -22,6 +23,7 @@ managed-datastax-cassandra-driver-core = { module = "com.datastax.oss:java-drive
 managed-datastax-cassandra-driver-mapper-processor = { module = "com.datastax.oss:java-driver-mapper-processor", version.ref = "managed-datastax-cassandra-driver" }
 managed-datastax-cassandra-driver-metrics-micrometer = { module = "com.datastax.oss:java-driver-metrics-micrometer", version.ref = "managed-datastax-cassandra-driver" }
 
+system-stubs = { module = "uk.org.webcompere:system-stubs-core", version.ref = "system-stubs" }
 testcontainers-cassandra = { module = "org.testcontainers:cassandra", version.ref = "testcontainers" }
 testcontainers-spock = { module = "org.testcontainers:spock", version.ref = "testcontainers" }
 

src/main/docs/guide/additional.adoc

@@ -14,8 +14,8 @@ datastax-java-driver {
     }
 }
 ----
-.micronaut bean configuration - application.yml
-[source,yaml]
+.micronaut bean configuration - application configuration
+[configuration]
 ----
 cassandra:
   default:
@@ -26,3 +26,8 @@ cassandra:
       load-balancing-policy:
         local-datacenter: datacenter1
 ----
+
+Micronaut Framework is very flexible with how application configuration is specified. Configuration properties can be overridden with environment variables. However, the Cassandra Datastax driver is not tolerant and fails fast when it encounters what it considers malformed/illegal configuration properties. Micronaut Cassandra handles this automatically for most cases, but if you want to use environment variables to override Cassandra application configuration the following rules apply:
+
+1. Must be uppercase camelcase, e.g. MY_UPPER_CAMEL_CASE_ENV
+2. Where https://docs.datastax.com/en/developer/java-driver/latest/manual/core/configuration/reference/[DataStax driver configuration] specifies hyphenated configuration keys, the hyphens must be preserved, e.g. `cassandra.default.basic.session-name` is overridden with `CASSANDRA_DEFAULT_BASIC_SESSION-NAME`.