Fix deprecated Kibana APIs

internal/agentdeployer/kubernetes.go

@@ -221,11 +221,12 @@ func readCACertBase64(profile *profile.Profile) (string, error) {
 	return base64.StdEncoding.EncodeToString(d), nil
 }
 
-// getTokenPolicyName function returns the policy name for the 8.x Elastic stack. The agent's policy
-// is predefined in the Kibana configuration file. The logic is not present in older stacks.
+// getTokenPolicyName function returns the policy name for the >= 8.x Elastic stacks. The agent's policy
+// is predefined in the Kibana configuration file. The logic is not present in older stacks and it uses
+// the default policy in Kibana (empty string).
 func getTokenPolicyName(stackVersion, policyName string) string {
-	if strings.HasPrefix(stackVersion, "8.") {
-		return policyName
+	if strings.HasPrefix(stackVersion, "7.") {
+		return ""
 	}
-	return ""
+	return policyName
 }

internal/kibana/agents.go

@@ -59,22 +59,36 @@ func (c *Client) ListAgents(ctx context.Context) ([]Agent, error) {
 	}
 
 	var resp struct {
-		List []Agent `json:"list"`
+		List  []Agent `json:"list"`
+		Items []Agent `json:"items"`
 	}
 
 	if err := json.Unmarshal(respBody, &resp); err != nil {
 		return nil, fmt.Errorf("could not convert list agents (response) to JSON: %w", err)
 	}
 
-	return resp.List, nil
+	switch {
+	case c.semver.Major() < 9:
+		return resp.List, nil
+	default:
+		return resp.Items, nil
+	}
 }
 
 // AssignPolicyToAgent assigns the given Policy to the given Agent.
 func (c *Client) AssignPolicyToAgent(ctx context.Context, a Agent, p Policy) error {
 	reqBody := `{ "policy_id": "` + p.ID + `" }`
-
 	path := fmt.Sprintf("%s/agents/%s/reassign", FleetAPI, a.ID)
-	statusCode, respBody, err := c.put(ctx, path, []byte(reqBody))
+
+	var statusCode int
+	var err error
+	var respBody []byte
+	switch {
+	case c.semver.Major() < 9:
+		statusCode, respBody, err = c.put(ctx, path, []byte(reqBody))
+	default:
+		statusCode, respBody, err = c.post(ctx, path, []byte(reqBody))
+	}
 	if err != nil {
 		return fmt.Errorf("could not assign policy to agent: %w", err)
 	}