feat: extend AgentType vars with runtime configuration [NR-428549] (#1438)

* chore: remove unneeded clone

* refactor: add support for runtime info in variables

* chore: restrict variants to string type

* feat: add support for variants in config

* chore: update docs

* chore: address old TODO

* improve docs

* fix unused imports

---------

Co-authored-by: Guillermo Sanchez Gavier <gsanchez@newrelic.com>

Author: sigilioso

agent-control/src/agent_control/run.rs

@@ -7,6 +7,7 @@ use super::error::AgentError;
 use super::http_server::config::ServerConfig;
 use crate::agent_control::http_server::runner::Runner;
 use crate::agent_type::embedded_registry::EmbeddedRegistry;
+use crate::agent_type::variable::constraints::VariableConstraints;
 use crate::event::broadcaster::unbounded::UnboundedBroadcast;
 
 use crate::event::{AgentControlEvent, ApplicationEvent, SubAgentEvent, channel::EventConsumer};
@@ -71,6 +72,7 @@ pub struct AgentControlRunConfig {
     pub base_paths: BasePaths,
     pub proxy: ProxyConfig,
     pub k8s_config: K8sConfig,
+    pub agent_type_var_constraints: VariableConstraints,
 }
 
 /// Structure with all the data required to run the agent control.
@@ -93,6 +95,7 @@ pub struct AgentControlRunner {
     runtime: Arc<Runtime>,
 
     http_server_runner: Option<Runner>,
+    agent_type_var_constraints: VariableConstraints,
 }
 
 impl AgentControlRunner {
@@ -172,6 +175,7 @@ impl AgentControlRunner {
             sub_agent_publisher,
             base_paths: config.base_paths,
             signature_validator,
+            agent_type_var_constraints: config.agent_type_var_constraints,
         })
     }
 

agent-control/src/agent_control/run/k8s.rs

@@ -14,7 +14,7 @@ use crate::agent_control::resource_cleaner::k8s_garbage_collector::K8sGarbageCol
 use crate::agent_control::run::AgentControlRunner;
 use crate::agent_control::version_updater::k8s::K8sACUpdater;
 use crate::agent_type::render::renderer::TemplateRenderer;
-use crate::agent_type::variable::definition::VariableDefinition;
+use crate::agent_type::variable::Variable;
 #[cfg_attr(test, mockall_double::double)]
 use crate::k8s::client::SyncK8sClient;
 use crate::opamp::effective_config::loader::DefaultEffectiveConfigLoaderBuilder;
@@ -121,13 +121,11 @@ impl AgentControlRunner {
         let agent_control_variables = HashMap::from([
             (
                 NAMESPACE_VARIABLE_NAME.to_string(),
-                VariableDefinition::new_final_string_variable(self.k8s_config.namespace.clone()),
+                Variable::new_final_string_variable(self.k8s_config.namespace.clone()),
             ),
             (
                 NAMESPACE_AGENTS_VARIABLE_NAME.to_string(),
-                VariableDefinition::new_final_string_variable(
-                    self.k8s_config.namespace_agents.clone(),
-                ),
+                Variable::new_final_string_variable(self.k8s_config.namespace_agents.clone()),
             ),
         ]);
 
@@ -137,6 +135,7 @@ impl AgentControlRunner {
         let agents_assembler = Arc::new(LocalEffectiveAgentsAssembler::new(
             self.agent_type_registry.clone(),
             template_renderer,
+            self.agent_type_var_constraints,
         ));
 
         let supervisor_builder =

agent-control/src/agent_control/run/on_host.rs

@@ -12,7 +12,7 @@ use crate::agent_control::run::AgentControlRunner;
 use crate::agent_control::version_updater::updater::NoOpUpdater;
 use crate::agent_type::render::persister::config_persister_file::ConfigurationPersisterFile;
 use crate::agent_type::render::renderer::TemplateRenderer;
-use crate::agent_type::variable::definition::VariableDefinition;
+use crate::agent_type::variable::Variable;
 use crate::health::noop::NoOpHealthChecker;
 use crate::http::client::HttpClient;
 use crate::http::config::{HttpConfig, ProxyConfig};
@@ -90,7 +90,7 @@ impl AgentControlRunner {
 
         let agent_control_variables = HashMap::from([(
             HOST_ID_VARIABLE_NAME.to_string(),
-            VariableDefinition::new_final_string_variable(identifiers.host_id.clone()),
+            Variable::new_final_string_variable(identifiers.host_id.clone()),
         )]);
 
         let instance_id_storer = Storer::new(
@@ -142,6 +142,7 @@ impl AgentControlRunner {
         let agents_assembler = Arc::new(LocalEffectiveAgentsAssembler::new(
             self.agent_type_registry.clone(),
             template_renderer,
+            self.agent_type_var_constraints,
         ));
 
         let supervisor_builder =

agent-control/src/agent_type/agent_attributes.rs

@@ -1,6 +1,6 @@
 use std::collections::HashMap;
 
-use super::variable::{definition::VariableDefinition, namespace::Namespace};
+use super::variable::{Variable, namespace::Namespace};
 
 /// contains any attribute from the sub-agent that is used to build or modify variables used to template the AgentType.
 #[derive(Debug, PartialEq, Clone, Default)]
@@ -13,10 +13,10 @@ impl AgentAttributes {
     const VARIABLE_SUB_AGENT_ID: &'static str = "agent_id";
 
     /// returns the variables from the sub-agent attributes source 'nr-sub'.
-    pub fn sub_agent_variables(&self) -> HashMap<String, VariableDefinition> {
+    pub fn sub_agent_variables(&self) -> HashMap<String, Variable> {
         HashMap::from([(
             Namespace::SubAgent.namespaced_name(Self::VARIABLE_SUB_AGENT_ID),
-            VariableDefinition::new_final_string_variable(self.agent_id.clone()),
+            Variable::new_final_string_variable(self.agent_id.clone()),
         )])
     }
 }