publishing with intentional architecture

crates/common/src/models.rs

@@ -444,13 +444,55 @@ pub mod runtime {
 
         /// Optional environment variables to set during action execution.
         ///
-        /// Values support the same template variables as other fields:
+        /// Entries support the same template variables as other fields:
         /// `{pack_dir}`, `{env_dir}`, `{interpreter}`, `{manifest_path}`.
         ///
-        /// Example: `{"NODE_PATH": "{env_dir}/node_modules"}` ensures Node.js
-        /// can find packages installed in the isolated runtime environment.
+        /// The shorthand string form replaces the variable entirely:
+        /// `{"NODE_PATH": "{env_dir}/node_modules"}`
+        ///
+        /// The object form supports declarative merge semantics:
+        /// `{"PYTHONPATH": {"value": "{pack_dir}/lib", "operation": "prepend"}}`
         #[serde(default)]
-        pub env_vars: HashMap<String, String>,
+        pub env_vars: HashMap<String, RuntimeEnvVarConfig>,
+    }
+
+    /// Declarative configuration for a single runtime environment variable.
+    ///
+    /// The string form is shorthand for `{ "value": "...", "operation": "set" }`.
+    #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+    #[serde(untagged)]
+    pub enum RuntimeEnvVarConfig {
+        Value(String),
+        Spec(RuntimeEnvVarSpec),
+    }
+
+    /// Full configuration for a runtime environment variable.
+    #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+    pub struct RuntimeEnvVarSpec {
+        /// Template value to resolve for this variable.
+        pub value: String,
+
+        /// How the resolved value should be merged with any existing value.
+        #[serde(default)]
+        pub operation: RuntimeEnvVarOperation,
+
+        /// Separator used for prepend/append operations.
+        #[serde(default = "default_env_var_separator")]
+        pub separator: String,
+    }
+
+    /// Merge behavior for runtime-provided environment variables.
+    #[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Default)]
+    #[serde(rename_all = "snake_case")]
+    pub enum RuntimeEnvVarOperation {
+        #[default]
+        Set,
+        Prepend,
+        Append,
+    }
+
+    fn default_env_var_separator() -> String {
+        ":".to_string()
     }
 
     /// Controls how inline code is materialized before execution.
@@ -768,6 +810,43 @@ pub mod runtime {
         }
     }
 
+    impl RuntimeEnvVarConfig {
+        /// Resolve this environment variable against the current template
+        /// variables and any existing value already present in the process env.
+        pub fn resolve(
+            &self,
+            vars: &HashMap<&str, String>,
+            existing_value: Option<&str>,
+        ) -> String {
+            match self {
+                Self::Value(value) => RuntimeExecutionConfig::resolve_template(value, vars),
+                Self::Spec(spec) => {
+                    let resolved = RuntimeExecutionConfig::resolve_template(&spec.value, vars);
+                    match spec.operation {
+                        RuntimeEnvVarOperation::Set => resolved,
+                        RuntimeEnvVarOperation::Prepend => {
+                            join_env_var_values(&resolved, existing_value, &spec.separator)
+                        }
+                        RuntimeEnvVarOperation::Append => join_env_var_values(
+                            existing_value.unwrap_or_default(),
+                            Some(&resolved),
+                            &spec.separator,
+                        ),
+                    }
+                }
+            }
+        }
+    }
+
+    fn join_env_var_values(left: &str, right: Option<&str>, separator: &str) -> String {
+        match (left.is_empty(), right.unwrap_or_default().is_empty()) {
+            (true, true) => String::new(),
+            (false, true) => left.to_string(),
+            (true, false) => right.unwrap_or_default().to_string(),
+            (false, false) => format!("{}{}{}", left, separator, right.unwrap_or_default()),
+        }
+    }
+
     #[derive(Debug, Clone, Serialize, Deserialize, FromRow)]
     pub struct Runtime {
         pub id: Id,
@@ -1640,3 +1719,68 @@ pub mod entity_history {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::runtime::{
+        RuntimeEnvVarConfig, RuntimeEnvVarOperation, RuntimeEnvVarSpec, RuntimeExecutionConfig,
+    };
+    use serde_json::json;
+    use std::collections::HashMap;
+
+    #[test]
+    fn runtime_execution_config_env_vars_accept_string_and_object_forms() {
+        let config: RuntimeExecutionConfig = serde_json::from_value(json!({
+            "env_vars": {
+                "NODE_PATH": "{env_dir}/node_modules",
+                "PYTHONPATH": {
+                    "value": "{pack_dir}/lib",
+                    "operation": "prepend",
+                    "separator": ":"
+                }
+            }
+        }))
+        .expect("runtime execution config should deserialize");
+
+        assert!(matches!(
+            config.env_vars.get("NODE_PATH"),
+            Some(RuntimeEnvVarConfig::Value(value)) if value == "{env_dir}/node_modules"
+        ));
+
+        assert!(matches!(
+            config.env_vars.get("PYTHONPATH"),
+            Some(RuntimeEnvVarConfig::Spec(RuntimeEnvVarSpec {
+                value,
+                operation: RuntimeEnvVarOperation::Prepend,
+                separator,
+            })) if value == "{pack_dir}/lib" && separator == ":"
+        ));
+    }
+
+    #[test]
+    fn runtime_env_var_config_resolves_prepend_and_append_against_existing_values() {
+        let mut vars = HashMap::new();
+        vars.insert("pack_dir", "/packs/example".to_string());
+        vars.insert("env_dir", "/runtime_envs/example/python".to_string());
+
+        let prepend = RuntimeEnvVarConfig::Spec(RuntimeEnvVarSpec {
+            value: "{pack_dir}/lib".to_string(),
+            operation: RuntimeEnvVarOperation::Prepend,
+            separator: ":".to_string(),
+        });
+        assert_eq!(
+            prepend.resolve(&vars, Some("/already/set")),
+            "/packs/example/lib:/already/set"
+        );
+
+        let append = RuntimeEnvVarConfig::Spec(RuntimeEnvVarSpec {
+            value: "{env_dir}/node_modules".to_string(),
+            operation: RuntimeEnvVarOperation::Append,
+            separator: ":".to_string(),
+        });
+        assert_eq!(
+            append.resolve(&vars, Some("/base/modules")),
+            "/base/modules:/runtime_envs/example/python/node_modules"
+        );
+    }
+}

crates/sensor/src/sensor_manager.rs

@@ -27,6 +27,37 @@ use tracing::{debug, error, info, warn};
 
 use crate::api_client::ApiClient;
 
+fn existing_command_env(cmd: &Command, key: &str) -> Option<String> {
+    cmd.as_std()
+        .get_envs()
+        .find_map(|(env_key, value)| {
+            if env_key == key {
+                value.map(|value| value.to_string_lossy().into_owned())
+            } else {
+                None
+            }
+        })
+        .or_else(|| std::env::var(key).ok())
+}
+
+fn apply_runtime_env_vars(
+    cmd: &mut Command,
+    exec_config: &RuntimeExecutionConfig,
+    pack_dir: &std::path::Path,
+    env_dir: Option<&std::path::Path>,
+) {
+    if exec_config.env_vars.is_empty() {
+        return;
+    }
+
+    let vars = exec_config.build_template_vars_with_env(pack_dir, env_dir);
+    for (key, env_var_config) in &exec_config.env_vars {
+        let resolved = env_var_config.resolve(&vars, existing_command_env(cmd, key).as_deref());
+        debug!("Setting sensor runtime env var: {}={}", key, resolved);
+        cmd.env(key, resolved);
+    }
+}
+
 /// Sensor manager that coordinates all sensor instances
 #[derive(Clone)]
 pub struct SensorManager {
@@ -502,20 +533,7 @@ impl SensorManager {
             .env("ATTUNE_MQ_EXCHANGE", "attune.events")
             .env("ATTUNE_LOG_LEVEL", "info");
 
-        if !exec_config.env_vars.is_empty() {
-            let vars = exec_config.build_template_vars_with_env(&pack_dir, env_dir_opt);
-            for (key, value_template) in &exec_config.env_vars {
-                let resolved = attune_common::models::RuntimeExecutionConfig::resolve_template(
-                    value_template,
-                    &vars,
-                );
-                debug!(
-                    "Setting sensor runtime env var: {}={} (template: {})",
-                    key, resolved, value_template
-                );
-                cmd.env(key, resolved);
-            }
-        }
+        apply_runtime_env_vars(&mut cmd, &exec_config, &pack_dir, env_dir_opt);
 
         let mut child = cmd
             .stdin(Stdio::null())
@@ -904,6 +922,10 @@ pub struct SensorStatus {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use attune_common::models::runtime::{
+        RuntimeEnvVarConfig, RuntimeEnvVarOperation, RuntimeEnvVarSpec,
+    };
+    use std::collections::HashMap;
 
     #[test]
     fn test_sensor_status_default() {
@@ -913,4 +935,46 @@ mod tests {
         assert_eq!(status.failure_count, 0);
         assert!(status.last_poll.is_none());
     }
+
+    #[test]
+    fn test_apply_runtime_env_vars_prepends_to_existing_command_env() {
+        let mut env_vars = HashMap::new();
+        env_vars.insert(
+            "PYTHONPATH".to_string(),
+            RuntimeEnvVarConfig::Spec(RuntimeEnvVarSpec {
+                value: "{pack_dir}/lib".to_string(),
+                operation: RuntimeEnvVarOperation::Prepend,
+                separator: ":".to_string(),
+            }),
+        );
+
+        let exec_config = RuntimeExecutionConfig {
+            env_vars,
+            ..RuntimeExecutionConfig::default()
+        };
+
+        let mut cmd = Command::new("python3");
+        cmd.env("PYTHONPATH", "/existing/pythonpath");
+
+        apply_runtime_env_vars(
+            &mut cmd,
+            &exec_config,
+            std::path::Path::new("/packs/testpack"),
+            None,
+        );
+
+        let resolved = cmd
+            .as_std()
+            .get_envs()
+            .find_map(|(key, value)| {
+                if key == "PYTHONPATH" {
+                    value.map(|value| value.to_string_lossy().into_owned())
+                } else {
+                    None
+                }
+            })
+            .expect("PYTHONPATH should be set");
+
+        assert_eq!(resolved, "/packs/testpack/lib:/existing/pythonpath");
+    }
 }

crates/worker/src/runtime/process.rs

@@ -830,12 +830,9 @@ impl Runtime for ProcessRuntime {
         // resolved against the current pack/env directories.
         if !effective_config.env_vars.is_empty() {
             let vars = effective_config.build_template_vars_with_env(&pack_dir, env_dir_opt);
-            for (key, value_template) in &effective_config.env_vars {
-                let resolved = RuntimeExecutionConfig::resolve_template(value_template, &vars);
-                debug!(
-                    "Setting runtime env var: {}={} (template: {})",
-                    key, resolved, value_template
-                );
+            for (key, env_var_config) in &effective_config.env_vars {
+                let resolved = env_var_config.resolve(&vars, env.get(key).map(String::as_str));
+                debug!("Setting runtime env var: {}={}", key, resolved);
                 env.insert(key.clone(), resolved);
             }
         }
@@ -1062,7 +1059,8 @@ mod tests {
     use super::*;
     use attune_common::models::runtime::{
         DependencyConfig, EnvironmentConfig, InlineExecutionConfig, InlineExecutionStrategy,
-        InterpreterConfig, RuntimeExecutionConfig,
+        InterpreterConfig, RuntimeEnvVarConfig, RuntimeEnvVarOperation, RuntimeEnvVarSpec,
+        RuntimeExecutionConfig,
     };
     use attune_common::models::{OutputFormat, ParameterDelivery, ParameterFormat};
     use std::collections::HashMap;
@@ -1377,6 +1375,88 @@ mod tests {
         assert!(result.stdout.contains("hello from python process runtime"));
     }
 
+    #[tokio::test]
+    async fn test_execute_python_file_with_pack_lib_on_pythonpath() {
+        let temp_dir = TempDir::new().unwrap();
+        let packs_dir = temp_dir.path().join("packs");
+        let pack_dir = packs_dir.join("testpack");
+        let actions_dir = pack_dir.join("actions");
+        let lib_dir = pack_dir.join("lib");
+        std::fs::create_dir_all(&actions_dir).unwrap();
+        std::fs::create_dir_all(&lib_dir).unwrap();
+
+        std::fs::write(
+            lib_dir.join("helper.py"),
+            "def message():\n    return 'hello from pack lib'\n",
+        )
+        .unwrap();
+        std::fs::write(
+            actions_dir.join("hello.py"),
+            "import helper\nimport os\nprint(helper.message())\nprint(os.environ['PYTHONPATH'])\n",
+        )
+        .unwrap();
+
+        let mut env_vars = HashMap::new();
+        env_vars.insert(
+            "PYTHONPATH".to_string(),
+            RuntimeEnvVarConfig::Spec(RuntimeEnvVarSpec {
+                value: "{pack_dir}/lib".to_string(),
+                operation: RuntimeEnvVarOperation::Prepend,
+                separator: ":".to_string(),
+            }),
+        );
+
+        let runtime = ProcessRuntime::new(
+            "python".to_string(),
+            RuntimeExecutionConfig {
+                interpreter: InterpreterConfig {
+                    binary: "python3".to_string(),
+                    args: vec![],
+                    file_extension: Some(".py".to_string()),
+                },
+                inline_execution: InlineExecutionConfig::default(),
+                environment: None,
+                dependencies: None,
+                env_vars,
+            },
+            packs_dir,
+            temp_dir.path().join("runtime_envs"),
+        );
+
+        let mut env = HashMap::new();
+        env.insert("PYTHONPATH".to_string(), "/existing/pythonpath".to_string());
+
+        let context = ExecutionContext {
+            execution_id: 3,
+            action_ref: "testpack.hello".to_string(),
+            parameters: HashMap::new(),
+            env,
+            secrets: HashMap::new(),
+            timeout: Some(10),
+            working_dir: None,
+            entry_point: "hello.py".to_string(),
+            code: None,
+            code_path: Some(actions_dir.join("hello.py")),
+            runtime_name: Some("python".to_string()),
+            runtime_config_override: None,
+            runtime_env_dir_suffix: None,
+            selected_runtime_version: None,
+            max_stdout_bytes: 1024 * 1024,
+            max_stderr_bytes: 1024 * 1024,
+            parameter_delivery: ParameterDelivery::default(),
+            parameter_format: ParameterFormat::default(),
+            output_format: OutputFormat::default(),
+            cancel_token: None,
+        };
+
+        let result = runtime.execute(context).await.unwrap();
+        assert_eq!(result.exit_code, 0);
+        assert!(result.stdout.contains("hello from pack lib"));
+        assert!(result
+            .stdout
+            .contains(&format!("{}/lib:/existing/pythonpath", pack_dir.display())));
+    }
+
     #[tokio::test]
     async fn test_execute_inline_code() {
         let temp_dir = TempDir::new().unwrap();