From 65b39c1ba92f1e078dd88c8ad94478c05f5999ab Mon Sep 17 00:00:00 2001
From: Victor Marmol <vmarmol@google.com>
Date: Tue, 16 Dec 2014 11:28:42 -0800
Subject: [PATCH] Check HTTP error code in the cAdvisor client.

This will provide more meaningfull errors than the cryptic unmarshalling
ones we've gotten today.

Fixes #362.
---
 client/client.go      |  3 +++
 client/client_test.go | 24 ++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/client/client.go b/client/client.go
index a37266ac..1c57f36d 100644
--- a/client/client.go
+++ b/client/client.go
@@ -153,6 +153,9 @@ func (self *Client) httpGetJsonData(data, postData interface{}, url, infoName st
 		err = fmt.Errorf("unable to read all %q: %v", infoName, err)
 		return err
 	}
+	if resp.StatusCode != 200 {
+		return fmt.Errorf("request failed with error: %q", strings.TrimSpace(string(body)))
+	}
 	if err = json.Unmarshal(body, data); err != nil {
 		err = fmt.Errorf("unable to unmarshal %q (Body: %q) with error: %v", infoName, string(body), err)
 		return err
diff --git a/client/client_test.go b/client/client_test.go
index 67bf3c2b..5b432104 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -116,6 +116,30 @@ func TestGetContainerInfo(t *testing.T) {
 	}
 }
 
+// Test a requesy failing
+func TestRequestFails(t *testing.T) {
+	errorText := "there was an error"
+	// Setup a server that simply fails.
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, errorText, 500)
+	}))
+	client, err := NewClient(ts.URL)
+	if err != nil {
+		ts.Close()
+		t.Fatal(err)
+	}
+	defer ts.Close()
+
+	_, err = client.ContainerInfo("/", &info.ContainerInfoRequest{NumStats: 3})
+	if err == nil {
+		t.Fatalf("Expected non-nil error")
+	}
+	expectedError := fmt.Sprintf("request failed with error: %q", errorText)
+	if err.Error() != expectedError {
+		t.Fatalf("Expected error %q but received %q", expectedError, err)
+	}
+}
+
 func TestGetSubcontainersInfo(t *testing.T) {
 	query := &info.ContainerInfoRequest{
 		NumStats: 3,