Validate runner paths at startup and improve diagnostics; bump version to 0.1.10

- Add validation for `RUNNER_LINUX_PATH` and `RUNNER_ILLUMOS_PATH` with detailed warnings and diagnostics for misconfigurations.
- Log fallback to default paths and warn if binaries are missing.
- Increment orchestrator version to 0.1.10.

Signed-off-by: Till Wegmueller <toasterson@gmail.com>

crates/orchestrator/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "orchestrator"
-version = "0.1.9"
+version = "0.1.10"
 edition = "2024"
 build = "build.rs"
 

crates/orchestrator/src/main.rs

@@ -119,6 +119,57 @@ async fn main() -> Result<()> {
     let opts = Opts::parse();
     info!(db = %opts.database_url, amqp = %opts.amqp_url, "orchestrator starting");
 
+    // Validate runner binary paths early and explain source of values
+    {
+        const DEFAULT_LINUX: &str = "./target/release/solstice-runner-linux";
+        const DEFAULT_ILLUMOS: &str = "./target/release/solstice-runner-illumos";
+        let env_linux = std::env::var("RUNNER_LINUX_PATH").ok();
+        let env_illumos = std::env::var("RUNNER_ILLUMOS_PATH").ok();
+
+        // Linux runner diagnostics
+        if opts.runner_linux_path == DEFAULT_LINUX {
+            match env_linux {
+                Some(ref v) if v == DEFAULT_LINUX => {
+                    // Env explicitly set to default; still log info
+                    debug!(runner_linux_env = %v, "RUNNER_LINUX_PATH provided but equals default");
+                }
+                Some(ref v) => {
+                    // Clap should have picked env; if not, operator likely used wrong syntax in EnvironmentFile
+                    warn!(expected_env = %v, actual = %opts.runner_linux_path, "environment contained RUNNER_LINUX_PATH but CLI value did not reflect it; ensure EnvironmentFile uses KEY=VALUE syntax and restart the service");
+                }
+                None => {
+                    warn!(using_default = %opts.runner_linux_path, "RUNNER_LINUX_PATH not set; using default Linux runner path");
+                }
+            }
+        } else {
+            info!(runner_linux_path = %opts.runner_linux_path, "using Linux runner path from CLI/env");
+        }
+        // Existence check
+        if std::fs::metadata(&opts.runner_linux_path).is_err() {
+            warn!(path = %opts.runner_linux_path, "Linux runner binary not found at path; job execution will fail until this is corrected");
+        }
+
+        // Illumos runner diagnostics
+        if opts.runner_illumos_path == DEFAULT_ILLUMOS {
+            match env_illumos {
+                Some(ref v) if v == DEFAULT_ILLUMOS => {
+                    debug!(runner_illumos_env = %v, "RUNNER_ILLUMOS_PATH provided but equals default");
+                }
+                Some(ref v) => {
+                    warn!(expected_env = %v, actual = %opts.runner_illumos_path, "environment contained RUNNER_ILLUMOS_PATH but CLI value did not reflect it; ensure EnvironmentFile uses KEY=VALUE syntax and restart the service");
+                }
+                None => {
+                    debug!(using_default = %opts.runner_illumos_path, "RUNNER_ILLUMOS_PATH not set; using default illumos runner path");
+                }
+            }
+        } else {
+            info!(runner_illumos_path = %opts.runner_illumos_path, "using illumos runner path from CLI/env");
+        }
+        if std::fs::metadata(&opts.runner_illumos_path).is_err() {
+            debug!(path = %opts.runner_illumos_path, "Illumos runner binary not found (only relevant for illumos labels)");
+        }
+    }
+
     // Load orchestrator config (image map) and ensure images are present locally
     let cfg = OrchestratorConfig::load(opts.config.as_deref()).await?;
     config::ensure_images(&cfg).await?;