feat: allow for no agents in config (#180)

* feat: allow for no agents in config

Signed-off-by: David Sánchez <[email protected]>

* test: check default agent config

Signed-off-by: David Sánchez <[email protected]>

---------

Signed-off-by: David Sánchez <[email protected]>

Author: DavSanchez

build/package/config.yaml

@@ -3,7 +3,7 @@
 #  headers:
 #    api-key: API_KEY_HERE
 
-agents:
+# agents:
 #  nr_infra_agent:
 #    agent_type: "newrelic/com.newrelic.infrastructure_agent:0.0.1"
 #  nr_otel_collector:

src/agent/mod.rs

@@ -559,4 +559,23 @@ deployment:
         };
         assert_eq!("license_key: abc123\nstaging: true\n", f.content);
     }
+
+    #[test]
+    fn empty_load_agent_cfgs_test() {
+        let local_agent_type_repository = LocalRepository::new();
+        let file_reader_mock = MockFileReaderMock::new();
+        let agent_config = SuperAgentConfig {
+            agents: Default::default(),
+            opamp: None,
+        };
+
+        let effective_agent_repository = load_agent_cfgs(
+            &local_agent_type_repository,
+            &file_reader_mock,
+            &agent_config,
+        )
+        .unwrap();
+
+        assert_eq!(local_agent_type_repository, effective_agent_repository);
+    }
 }

src/agent/supervisor_group.rs

@@ -297,6 +297,21 @@ pub mod tests {
         Ok(SupervisorGroup(group))
     }
 
+    #[test]
+    fn run_stop_without_opamp_nor_agents() {
+        let supervisor_group: SupervisorGroup<MockOpAMPClientMock, Stopped> =
+            SupervisorGroup(HashMap::new());
+        let running_supervisor_group = supervisor_group.run();
+        assert!(
+            running_supervisor_group.is_ok(),
+            "unable to run supervisor_group without opamp"
+        );
+        assert!(
+            running_supervisor_group.unwrap().stop().is_ok(),
+            "unable to stop supervisor_group without opamp"
+        );
+    }
+
     #[test]
     fn run_stop_without_opamp() {
         let (tx, _) = std::sync::mpsc::channel();

src/config/agent_configs.rs

@@ -22,6 +22,7 @@ impl Display for AgentID {
 #[serde(deny_unknown_fields)]
 pub struct SuperAgentConfig {
     /// agents is a map of agent types to their specific configuration (if any).
+    #[serde(default)]
     pub agents: HashMap<AgentID, AgentSupervisorConfig>,
 
     /// opamp contains the OpAMP client configuration

src/config/agent_type_registry.rs

@@ -23,7 +23,7 @@ pub trait AgentRepository {
     fn store_with_key(&mut self, key: String, agent: Agent) -> Result<(), AgentRepositoryError>;
 }
 
-#[derive(Debug, Default, Clone)]
+#[derive(Debug, Default, Clone, PartialEq)]
 pub struct LocalRepository(HashMap<String, Agent>);
 
 impl AgentRepository for LocalRepository {