Weave context through lokiClient methods

internals/overlord/logstate/loki.go

@@ -16,6 +16,7 @@ package logstate
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -35,16 +36,19 @@ type lokiClient struct {
 	entries map[string][]lokiEntry
 }
 
-func newLokiClient(target *plan.LogTarget) *lokiClient {
+func newLokiClient(target *plan.LogTarget) logClient {
 	return &lokiClient{
 		target:    target,
 		remoteURL: target.Location,
 		entries:   map[string][]lokiEntry{},
 	}
 }
 
-func (c *lokiClient) Write(entry servicelog.Entry) error {
+func (c *lokiClient) Write(ctx context.Context, entry servicelog.Entry) error {
 	c.entries[entry.Service] = append(c.entries[entry.Service], asLokiEntry(entry))
+	if len(c.entries) >= 10 {
+		return c.Flush(ctx)
+	}
 	return nil
 }
 
@@ -55,7 +59,11 @@ func asLokiEntry(entry servicelog.Entry) lokiEntry {
 	}
 }
 
-func (c *lokiClient) Flush() error {
+func (c *lokiClient) Flush(ctx context.Context) error {
+	defer func() {
+		// TODO: clear entries
+	}()
+
 	// Build request
 	req := lokiRequest{}
 	for service, entries := range c.entries {
@@ -70,10 +78,16 @@ func (c *lokiClient) Flush() error {
 
 	jsonReq, err := json.Marshal(req)
 	if err != nil {
-		return err
+		return fmt.Errorf("encoding request to JSON: %v", err)
+	}
+
+	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, c.remoteURL, bytes.NewReader(jsonReq))
+	if err != nil {
+		return fmt.Errorf("creating HTTP request: %v", err)
 	}
+	httpReq.Header.Set("Content-Type", "application/json")
 
-	resp, err := http.Post(c.remoteURL, "application/json", bytes.NewReader(jsonReq))
+	resp, err := http.DefaultClient.Do(httpReq)
 	if err != nil {
 		return err
 	}