feat: add picodata yaml config render

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 
 ### Added
 
+- Add Liquid template rendering support for `picodata.yaml` config files (see [picodata.yaml](README.md#picodatayaml))
 - Add configurable manifest.yaml.template path for build helper
 
 ### Changed

README.md

@@ -169,6 +169,17 @@ PICODATA_HTTP_LISTEN = "127.0.0.1:{{ 8000 | plus: instance_id }}"
 
 Пайк позволяет использовать файл конфигурации Пикодаты вместе с запущенным кластером. Пример файла сразу генерируется командами `new` и `init`. Документацию к параметрам можно найти в [документации к Пикодате](https://docs.picodata.io/picodata/stable/reference/config/).
 
+Файл `picodata.yaml` поддерживает [Liquid-шаблоны](https://shopify.dev/docs/api/liquid). При запуске кластера Пайк рендерит конфиг для каждого инстанса отдельно, подставляя переменные из контекста. Доступные переменные:
+
+- `instance_id` — порядковый номер инстанса (начиная с 1)
+
+Пример использования:
+
+```yaml
+instance:
+  name: "my-instance-{{ instance_id }}"
+```
+
 #### Настройка нескольких тиров
 
 Для настройки необходимо указать нужные тиры в файле топологии topology.toml.

src/commands/run.rs

@@ -414,9 +414,12 @@ impl PicodataInstance {
 
         let config_path = run_params.plugin_path.join(&run_params.config_path);
         if config_path.exists() {
+            // Template the config file with instance_id
+            let instance_config_path =
+                Self::template_config(&config_path, &instance_data_dir, &env_templates_ctx)?;
             child.args([
                 "--config",
-                config_path.to_str().unwrap_or("./picodata.yaml"),
+                instance_config_path.to_str().unwrap_or("./picodata.yaml"),
             ]);
         } else {
             warn!(
@@ -538,6 +541,49 @@ impl PicodataInstance {
             .collect()
     }
 
+    /// Templates a picodata.yaml config file with Liquid variables (e.g., `instance_id`).
+    /// Returns the path to the templated config file in the instance data directory.
+    fn template_config(
+        config_path: &Path,
+        instance_data_dir: &Path,
+        ctx: &liquid::Object,
+    ) -> Result<PathBuf> {
+        let config_content = fs::read_to_string(config_path).with_context(|| {
+            format!(
+                "failed to read picodata config at {}",
+                config_path.display()
+            )
+        })?;
+
+        let parser = liquid::ParserBuilder::with_stdlib()
+            .build()
+            .context("failed to build Liquid parser")?;
+
+        let template = parser.parse(&config_content).with_context(|| {
+            format!(
+                "failed to parse picodata config as Liquid template at {}",
+                config_path.display()
+            )
+        })?;
+
+        let rendered = template.render(ctx).with_context(|| {
+            format!(
+                "failed to render picodata config template at {}",
+                config_path.display()
+            )
+        })?;
+
+        let instance_config_path = instance_data_dir.join("picodata.yaml");
+        fs::write(&instance_config_path, &rendered).with_context(|| {
+            format!(
+                "failed to write templated picodata config to {}",
+                instance_config_path.display()
+            )
+        })?;
+
+        Ok(instance_config_path)
+    }
+
     fn capture_logs(&mut self) -> Result<()> {
         let mut rnd = rand::rng();
         let instance_name_color = colored::CustomColor::new(

tests/plugin_pack.rs

@@ -35,9 +35,8 @@ fn find_archive(dir: &Path, name: &str, version: &str) -> PathBuf {
     }
     assert!(
         !matches.is_empty(),
-        "No archive found in {} with prefix {}",
-        dir.display(),
-        prefix
+        "No archive found in {} with prefix {prefix}",
+        dir.display()
     );
     assert_eq!(
         matches.len(),

tests/plugin_template.rs

@@ -59,3 +59,81 @@ fn test_plugin_run_tests() {
         String::from_utf8_lossy(&output.stderr)
     );
 }
+
+#[test]
+fn test_picodata_config_template_rendering() {
+    let plugin_path = Path::new("./tests/tmp/plugin-template-config-test");
+    init_plugin("plugin-template-config-test");
+
+    // Create a picodata.yaml config template with Liquid variables
+    let config_path = plugin_path.join("picodata.yaml");
+    let template_content = r#"cluster:
+  name: "test-cluster"
+  tier:
+    default:
+      can_vote: true
+  default_replication_factor: 2
+
+instance:
+  name: "instance-{{ instance_id }}"
+  log:
+    level: warn
+    format: plain
+  memtx:
+    memory: 67108864
+"#;
+
+    fs::write(&config_path, template_content).expect("Failed to write templated picodata.yaml");
+
+    let config_content = fs::read_to_string(&config_path).expect("Failed to read picodata.yaml");
+
+    // Verify that the template contains Liquid template variables
+    assert!(
+        config_content.contains("{{ instance_id }}"),
+        "picodata.yaml should contain {{ instance_id }} template variable"
+    );
+
+    // Test template rendering with Liquid
+    let parser = liquid::ParserBuilder::with_stdlib()
+        .build()
+        .expect("Failed to build Liquid parser");
+
+    let template = parser
+        .parse(&config_content)
+        .expect("Failed to parse picodata.yaml as Liquid template");
+
+    // Render with instance_id = 1
+    let ctx = liquid::object!({
+        "instance_id": 1,
+    });
+    let rendered = template
+        .render(&ctx)
+        .expect("Failed to render template with instance_id=1");
+
+    // Verify that the rendered output contains the substituted value
+    assert!(
+        rendered.contains("instance-1"),
+        "Rendered config should contain 'instance-1', got:\n{rendered}"
+    );
+    assert!(
+        !rendered.contains("{{ instance_id }}"),
+        "Rendered config should not contain template variable, got:\n{rendered}"
+    );
+
+    // Render with instance_id = 42
+    let ctx = liquid::object!({
+        "instance_id": 42,
+    });
+    let rendered = template
+        .render(&ctx)
+        .expect("Failed to render template with instance_id=42");
+
+    assert!(
+        rendered.contains("instance-42"),
+        "Rendered config should contain 'instance-42', got:\n{rendered}"
+    );
+    assert!(
+        !rendered.contains("{{ instance_id }}"),
+        "Rendered config should not contain template variable, got:\n{rendered}"
+    );
+}

tests/run.rs

@@ -43,9 +43,8 @@ fn find_os_suffixed_archive(dir: &Path, name: &str, version: &str) -> PathBuf {
     }
     assert!(
         !matches.is_empty(),
-        "No archive found in {} with prefix {}",
-        dir.display(),
-        prefix
+        "No archive found in {} with prefix {prefix}",
+        dir.display()
     );
     assert_eq!(
         matches.len(),