feat(web): initialize Next.js project with Tailwind CSS and TypeScript setup

pkg/orchestrator/admin.go

@@ -0,0 +1,73 @@
+package orchestrator
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+// HealthCheckRestate verifies the Restate ingress is reachable. The flow
+// binary fails fast at startup if this returns an error.
+func HealthCheckRestate(ingressURL string) error {
+	client := &http.Client{Timeout: 3 * time.Second}
+	r, err := client.Get(ingressURL + "/restate/health")
+	if err != nil {
+		return fmt.Errorf("restate ingress unreachable at %s: %w", ingressURL, err)
+	}
+	defer r.Body.Close()
+	if r.StatusCode != http.StatusOK {
+		return fmt.Errorf("restate ingress returned %d at %s", r.StatusCode, ingressURL)
+	}
+	return nil
+}
+
+// RegisterDeployment registers this service with the Restate admin API so
+// Restate knows where to call back for the WorkflowExecutor handler.
+//
+// adminURL  — Restate admin endpoint (default http://localhost:9070)
+// deployURI — how Restate reaches this service (e.g. http://flow:9080)
+func RegisterDeployment(ctx context.Context, adminURL, deployURI string) error {
+	body, _ := json.Marshal(map[string]any{"uri": deployURI, "force": true})
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, adminURL+"/deployments", bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("build admin request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	client := &http.Client{Timeout: 10 * time.Second}
+	r, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("restate admin call failed: %w", err)
+	}
+	defer r.Body.Close()
+	if r.StatusCode >= 300 {
+		respBody, _ := io.ReadAll(r.Body)
+		return fmt.Errorf("restate admin returned %d: %s", r.StatusCode, string(respBody))
+	}
+	return nil
+}
+
+// RegisterDeploymentWithRetry retries registration until it succeeds or ctx
+// is cancelled. Used at startup because the Restate cluster may take a moment
+// to become ready relative to flow.
+func RegisterDeploymentWithRetry(ctx context.Context, adminURL, deployURI string, maxAttempts int, interval time.Duration) error {
+	var last error
+	for i := 0; i < maxAttempts; i++ {
+		if err := RegisterDeployment(ctx, adminURL, deployURI); err == nil {
+			return nil
+		} else {
+			last = err
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-time.After(interval):
+		}
+	}
+	return fmt.Errorf("registration failed after %d attempts: %w", maxAttempts, last)
+}