repo init

internal/apiclient/apiclient.go

@@ -0,0 +1,65 @@
+// Package apiclient is a thin HTTP client for the Control API's /api/v1
+// surface, shared by the validator-agent and prober binaries. Neither
+// binary talks to the database directly — this is their only channel to
+// shared state, keeping both genuinely stateless.
+package apiclient
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+type Client struct {
+	BaseURL    string
+	HTTPClient *http.Client
+}
+
+func New(baseURL string, timeout time.Duration) *Client {
+	return &Client{BaseURL: baseURL, HTTPClient: &http.Client{Timeout: timeout}}
+}
+
+// Do issues a JSON request and decodes a JSON response into out (if
+// non-nil). A 204 response is treated as "no content" and out is left
+// untouched, with ok=false — used for the assignment poll's empty case.
+func (c *Client) Do(ctx context.Context, method, path string, body, out interface{}) (ok bool, err error) {
+	var reader io.Reader
+	if body != nil {
+		b, err := json.Marshal(body)
+		if err != nil {
+			return false, fmt.Errorf("marshal request: %w", err)
+		}
+		reader = bytes.NewReader(b)
+	}
+	req, err := http.NewRequestWithContext(ctx, method, c.BaseURL+path, reader)
+	if err != nil {
+		return false, fmt.Errorf("build request: %w", err)
+	}
+	if body != nil {
+		req.Header.Set("Content-Type", "application/json")
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return false, fmt.Errorf("%s %s: %w", method, path, err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusNoContent {
+		return false, nil
+	}
+	respBody, _ := io.ReadAll(resp.Body)
+	if resp.StatusCode >= 300 {
+		return false, fmt.Errorf("%s %s: status %d: %s", method, path, resp.StatusCode, string(respBody))
+	}
+	if out != nil && len(respBody) > 0 {
+		if err := json.Unmarshal(respBody, out); err != nil {
+			return false, fmt.Errorf("%s %s: decode response: %w", method, path, err)
+		}
+	}
+	return true, nil
+}