Merge pull request #50 from dora-rs/python-operator-alias

Add support for single operator nodes in YAML dataflow specification

apis/rust/node/src/config.rs

@@ -6,7 +6,7 @@ use std::{
     str::FromStr,
 };
 
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct NodeRunConfig {
     #[serde(default)]

binaries/coordinator/examples/mini-dataflow.yml

@@ -54,5 +54,14 @@ nodes:
         python: ../runtime/examples/python-operator/op.py
         inputs:
           time: timer/time
+          test: python-operator/counter
         outputs:
           - counter
+
+  - id: python-operator
+    operator:
+      python: ../runtime/examples/python-operator/op.py
+      inputs:
+        time: timer/time
+      outputs:
+        - counter

binaries/coordinator/src/main.rs

@@ -1,4 +1,4 @@
-use dora_core::descriptor::{self, Descriptor, NodeKind};
+use dora_core::descriptor::{self, CoreNodeKind, Descriptor};
 use dora_node_api::config::NodeId;
 use eyre::{bail, eyre, WrapErr};
 use futures::{stream::FuturesUnordered, StreamExt};
@@ -49,17 +49,21 @@ async fn main() -> eyre::Result<()> {
 }
 
 async fn run_dataflow(dataflow_path: PathBuf, runtime: &Path) -> eyre::Result<()> {
-    let Descriptor {
-        mut communication,
-        nodes,
-    } = read_descriptor(&dataflow_path).await.wrap_err_with(|| {
+    let descriptor = read_descriptor(&dataflow_path).await.wrap_err_with(|| {
         format!(
             "failed to read dataflow descriptor at {}",
             dataflow_path.display()
         )
     })?;
 
-    if nodes.iter().any(|n| matches!(n.kind, NodeKind::Runtime(_))) && !runtime.is_file() {
+    let nodes = descriptor.resolve_aliases();
+    let mut communication = descriptor.communication;
+
+    if nodes
+        .iter()
+        .any(|n| matches!(n.kind, CoreNodeKind::Runtime(_)))
+        && !runtime.is_file()
+    {
         bail!(
             "There is no runtime at {}, or it is not a file",
             runtime.display()
@@ -74,12 +78,12 @@ async fn run_dataflow(dataflow_path: PathBuf, runtime: &Path) -> eyre::Result<()
         let node_id = node.id.clone();
 
         match node.kind {
-            descriptor::NodeKind::Custom(node) => {
+            descriptor::CoreNodeKind::Custom(node) => {
                 let result = spawn_custom_node(node_id.clone(), &node, &communication)
                     .wrap_err_with(|| format!("failed to spawn custom node {node_id}"))?;
                 tasks.push(result);
             }
-            descriptor::NodeKind::Runtime(node) => {
+            descriptor::CoreNodeKind::Runtime(node) => {
                 if !node.operators.is_empty() {
                     let result =
                         spawn_runtime_node(runtime, node_id.clone(), &node, &communication)

binaries/runtime/src/main.rs

@@ -1,6 +1,6 @@
 #![warn(unsafe_op_in_unsafe_fn)]
 
-use dora_core::descriptor::OperatorConfig;
+use dora_core::descriptor::OperatorDefinition;
 use dora_node_api::{
     self,
     communication::{self, CommunicationLayer},
@@ -37,7 +37,7 @@ async fn main() -> eyre::Result<()> {
             .wrap_err("env variable DORA_COMMUNICATION_CONFIG must be set")?;
         serde_yaml::from_str(&raw).context("failed to deserialize communication config")?
     };
-    let operators: Vec<OperatorConfig> = {
+    let operators: Vec<OperatorDefinition> = {
         let raw =
             std::env::var("DORA_OPERATORS").wrap_err("env variable DORA_OPERATORS must be set")?;
         serde_yaml::from_str(&raw).context("failed to deserialize operator config")?
@@ -107,7 +107,7 @@ async fn main() -> eyre::Result<()> {
                     .ok_or_else(|| eyre!("received event from unknown operator {id}"))?;
                 match event {
                     OperatorEvent::Output { id: data_id, value } => {
-                        if !operator.config().outputs.contains(&data_id) {
+                        if !operator.definition().config.outputs.contains(&data_id) {
                             eyre::bail!("unknown output {data_id} for operator {id}");
                         }
                         publish(&node_id, id, data_id, &value, communication.as_ref())
@@ -154,7 +154,7 @@ async fn main() -> eyre::Result<()> {
 }
 
 async fn subscribe<'a>(
-    operators: &'a [OperatorConfig],
+    operators: &'a [OperatorDefinition],
     communication: &'a dyn CommunicationLayer,
 ) -> eyre::Result<impl futures::Stream<Item = SubscribeEvent> + 'a> {
     let mut streams = Vec::new();
@@ -168,11 +168,11 @@ async fn subscribe<'a>(
 }
 
 async fn subscribe_operator<'a>(
-    operator: &'a OperatorConfig,
+    operator: &'a OperatorDefinition,
     communication: &'a dyn CommunicationLayer,
 ) -> Result<impl futures::Stream<Item = SubscribeEvent> + 'a, eyre::Error> {
     let stop_messages = FuturesUnordered::new();
-    for input in operator.inputs.values() {
+    for input in operator.config.inputs.values() {
         let InputMapping {
             source, operator, ..
         } = input;
@@ -189,7 +189,7 @@ async fn subscribe_operator<'a>(
     let finished = Box::pin(stop_messages.all(|_| async { true }).shared());
 
     let mut streams = Vec::new();
-    for (input, mapping) in &operator.inputs {
+    for (input, mapping) in &operator.config.inputs {
         let InputMapping {
             source,
             operator: source_operator,

binaries/runtime/src/operator/mod.rs

@@ -1,4 +1,4 @@
-use dora_core::descriptor::{OperatorConfig, OperatorSource};
+use dora_core::descriptor::{OperatorDefinition, OperatorSource};
 use dora_node_api::config::DataId;
 use eyre::{eyre, Context};
 use std::any::Any;
@@ -9,28 +9,31 @@ mod shared_lib;
 
 pub struct Operator {
     operator_task: Sender<OperatorInput>,
-    config: OperatorConfig,
+    definition: OperatorDefinition,
 }
 
 impl Operator {
     pub async fn init(
-        operator_config: OperatorConfig,
+        operator_definition: OperatorDefinition,
         events_tx: Sender<OperatorEvent>,
     ) -> eyre::Result<Self> {
         let (operator_task, operator_rx) = mpsc::channel(10);
 
-        match &operator_config.source {
+        match &operator_definition.config.source {
             OperatorSource::SharedLibrary(path) => {
                 shared_lib::spawn(path, events_tx, operator_rx).wrap_err_with(|| {
                     format!(
                         "failed ot spawn shared library operator for {}",
-                        operator_config.id
+                        operator_definition.id
                     )
                 })?;
             }
             OperatorSource::Python(path) => {
                 python::spawn(path, events_tx, operator_rx).wrap_err_with(|| {
-                    format!("failed ot spawn Python operator for {}", operator_config.id)
+                    format!(
+                        "failed ot spawn Python operator for {}",
+                        operator_definition.id
+                    )
                 })?;
             }
             OperatorSource::Wasm(path) => {
@@ -39,7 +42,7 @@ impl Operator {
         }
         Ok(Self {
             operator_task,
-            config: operator_config,
+            definition: operator_definition,
         })
     }
 
@@ -52,10 +55,10 @@ impl Operator {
             })
     }
 
-    /// Get a reference to the operator's config.
+    /// Get a reference to the operator's definition.
     #[must_use]
-    pub fn config(&self) -> &OperatorConfig {
-        &self.config
+    pub fn definition(&self) -> &OperatorDefinition {
+        &self.definition
     }
 }
 

libraries/core/src/descriptor/mod.rs

@@ -2,6 +2,7 @@ use dora_node_api::config::{
     CommunicationConfig, DataId, InputMapping, NodeId, NodeRunConfig, OperatorId,
 };
 use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
 use std::fmt;
 use std::{
     collections::{BTreeMap, BTreeSet},
@@ -18,14 +19,68 @@ pub struct Descriptor {
 }
 
 impl Descriptor {
+    pub fn resolve_aliases(&self) -> Vec<ResolvedNode> {
+        let default_op_id = OperatorId::from("op".to_string());
+
+        let single_operator_nodes: HashMap<_, _> = self
+            .nodes
+            .iter()
+            .filter_map(|n| match &n.kind {
+                NodeKind::Operator(op) => Some((&n.id, op.id.as_ref().unwrap_or(&default_op_id))),
+                _ => None,
+            })
+            .collect();
+
+        let mut resolved = vec![];
+        for mut node in self.nodes.clone() {
+            // adjust input mappings
+            let input_mappings: Vec<_> = match &mut node.kind {
+                NodeKind::Runtime(node) => node
+                    .operators
+                    .iter_mut()
+                    .flat_map(|op| op.config.inputs.values_mut())
+                    .collect(),
+                NodeKind::Custom(node) => node.run_config.inputs.values_mut().collect(),
+                NodeKind::Operator(operator) => operator.config.inputs.values_mut().collect(),
+            };
+            for mapping in input_mappings {
+                if let Some(op_name) = single_operator_nodes.get(&mapping.source).copied() {
+                    if mapping.operator.is_none() {
+                        mapping.operator = Some(op_name.to_owned());
+                    }
+                }
+            }
+
+            // resolve nodes
+            let kind = match node.kind {
+                NodeKind::Custom(node) => CoreNodeKind::Custom(node),
+                NodeKind::Runtime(node) => CoreNodeKind::Runtime(node),
+                NodeKind::Operator(op) => CoreNodeKind::Runtime(RuntimeNode {
+                    operators: vec![OperatorDefinition {
+                        id: op.id.unwrap_or_else(|| default_op_id.clone()),
+                        config: op.config,
+                    }],
+                }),
+            };
+            resolved.push(ResolvedNode {
+                id: node.id,
+                name: node.name,
+                description: node.description,
+                kind,
+            });
+        }
+        resolved
+    }
+
     pub fn visualize_as_mermaid(&self) -> eyre::Result<String> {
-        let flowchart = visualize::visualize_nodes(&self.nodes);
+        let resolved = self.resolve_aliases();
+        let flowchart = visualize::visualize_nodes(&resolved);
 
         Ok(flowchart)
     }
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Node {
     pub id: NodeId,
     pub name: Option<String>,
@@ -35,24 +90,58 @@ pub struct Node {
     pub kind: NodeKind,
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "lowercase")]
 pub enum NodeKind {
     /// Dora runtime node
     #[serde(rename = "operators")]
     Runtime(RuntimeNode),
     Custom(CustomNode),
+    Operator(SingleOperatorDefinition),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ResolvedNode {
+    pub id: NodeId,
+    pub name: Option<String>,
+    pub description: Option<String>,
+
+    #[serde(flatten)]
+    pub kind: CoreNodeKind,
 }
 
 #[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum CoreNodeKind {
+    /// Dora runtime node
+    #[serde(rename = "operators")]
+    Runtime(RuntimeNode),
+    Custom(CustomNode),
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(transparent)]
 pub struct RuntimeNode {
-    pub operators: Vec<OperatorConfig>,
+    pub operators: Vec<OperatorDefinition>,
 }
 
 #[derive(Debug, Serialize, Deserialize, Clone)]
-pub struct OperatorConfig {
+pub struct OperatorDefinition {
     pub id: OperatorId,
+    #[serde(flatten)]
+    pub config: OperatorConfig,
+}
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct SingleOperatorDefinition {
+    /// ID is optional if there is only a single operator.
+    pub id: Option<OperatorId>,
+    #[serde(flatten)]
+    pub config: OperatorConfig,
+}
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct OperatorConfig {
     pub name: Option<String>,
     pub description: Option<String>,
 
@@ -73,7 +162,16 @@ pub enum OperatorSource {
     Wasm(PathBuf),
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct PythonOperatorConfig {
+    pub path: PathBuf,
+    #[serde(default)]
+    pub inputs: BTreeMap<DataId, InputMapping>,
+    #[serde(default)]
+    pub outputs: BTreeSet<DataId>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct CustomNode {
     pub run: String,
     pub env: Option<BTreeMap<String, EnvValue>>,
@@ -83,7 +181,7 @@ pub struct CustomNode {
     pub run_config: NodeRunConfig,
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(untagged)]
 pub enum EnvValue {
     Bool(bool),