Do not clear HTTP client config (#4437)

Signed-off-by: Danny Kopping <danny.kopping@grafana.com>

pkg/ruler/registry.go

@@ -227,7 +227,6 @@ func (r *walRegistry) getTenantRemoteWriteConfig(tenant string, base RemoteWrite
 	overrides.Client.Name = fmt.Sprintf("%s-rw", tenant)
 	overrides.Client.SendExemplars = false
 	// TODO(dannyk): configure HTTP client overrides
-	overrides.Client.HTTPClientConfig = promConfig.HTTPClientConfig{}
 	// metadata is only used by prometheus scrape configs
 	overrides.Client.MetadataConfig = config.MetadataConfig{Send: false}
 	overrides.Client.SigV4Config = nil

pkg/ruler/registry_test.go

@@ -96,6 +96,12 @@ func setupRegistry(t *testing.T, dir string) *walRegistry {
 				QueueConfig: config.QueueConfig{
 					Capacity: defaultCapacity,
 				},
+				HTTPClientConfig: promConfig.HTTPClientConfig{
+					BasicAuth: &promConfig.BasicAuth{
+						Password: "bar",
+						Username: "foo",
+					},
+				},
 				Headers: map[string]string{
 					"Base": "value",
 				},
@@ -174,6 +180,20 @@ func TestTenantRemoteWriteConfigDisabled(t *testing.T) {
 	assert.Len(t, tenantCfg.RemoteWrite, 0)
 }
 
+func TestTenantRemoteWriteHTTPConfigMaintained(t *testing.T) {
+	walDir, err := createTempWALDir()
+	require.NoError(t, err)
+	reg := setupRegistry(t, walDir)
+	defer os.RemoveAll(walDir)
+
+	tenantCfg, err := reg.getTenantConfig(enabledRWTenant)
+	require.NoError(t, err)
+
+	// HTTP client config is not currently overrideable, all tenants' configs should inherit base
+	assert.Equal(t, tenantCfg.RemoteWrite[0].HTTPClientConfig.BasicAuth.Username, "foo")
+	assert.Equal(t, tenantCfg.RemoteWrite[0].HTTPClientConfig.BasicAuth.Password, promConfig.Secret("<secret>"))
+}
+
 func TestTenantRemoteWriteHeaderOverride(t *testing.T) {
 	walDir, err := createTempWALDir()
 	require.NoError(t, err)