Initial implementation of garage.AdminClient

go-workspace/src/garage/admin_client.go

@@ -0,0 +1,84 @@
+package garage
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+// AdminClient is a helper type for performing actions against the garage admin
+// interface.
+type AdminClient struct {
+	c          *http.Client
+	addr       string
+	adminToken string
+}
+
+// NewAdminClient initializes and returns an AdminClient which will use the
+// given address and adminToken for all requests made.
+func NewAdminClient(addr, adminToken string) *AdminClient {
+	return &AdminClient{
+		c: &http.Client{
+			Transport: http.DefaultTransport.(*http.Transport).Clone(),
+		},
+		addr:       addr,
+		adminToken: adminToken,
+	}
+}
+
+// Do performs an HTTP request with the given method (GET, POST) and path, and
+// using the json marshaling of the given body as the request body (unless body
+// is nil). It will JSON unmarshal the response into rcv, unless rcv is nil.
+func (c *AdminClient) Do(
+	ctx context.Context, rcv interface{}, method, path string, body interface{},
+) error {
+
+	var bodyR io.Reader
+
+	if body != nil {
+		bodyBuf := new(bytes.Buffer)
+		bodyR = bodyBuf
+
+		if err := json.NewEncoder(bodyBuf).Encode(body); err != nil {
+			return fmt.Errorf("json marshaling body: %w", err)
+		}
+	}
+
+	urlStr := fmt.Sprintf("http://%s%s", c.addr, path)
+
+	req, err := http.NewRequestWithContext(ctx, method, urlStr, bodyR)
+	if err != nil {
+		return fmt.Errorf("initializing request: %w", err)
+	}
+
+	req.Header.Set("Authorization", "Bearer "+c.adminToken)
+
+	res, err := c.c.Do(req)
+	if err != nil {
+		return fmt.Errorf("performing http request: %w", err)
+	}
+
+	defer res.Body.Close()
+
+	if res.StatusCode != 200 {
+		return fmt.Errorf("unexpected %s response returned", res.Status)
+	}
+
+	if rcv == nil {
+
+		if _, err := io.Copy(io.Discard, res.Body); err != nil {
+			return fmt.Errorf("discarding response body: %w", err)
+		}
+
+		return nil
+	}
+
+	if err := json.NewDecoder(res.Body).Decode(rcv); err != nil {
+		return fmt.Errorf("decoding json response body: %w", err)
+	}
+
+	return nil
+}