Using the new toToml template function crashes tiller

[mattsch]

I'm trying to use toToml to render a simple key/value pair and getting the traceback attached. The template works just fine when using toJson or toYaml, but toToml fails every time.

Template code:

{{ toToml .Values.telegraf.global_tags }}

Relevant values:

telegraf:
  global_tags:
    foo: bar

Traceback:

2017-04-13T13:22:56.286967774Z panic: reflect: call of reflect.Value.NumField on map Value [recovered]
2017-04-13T13:22:56.287034472Z 	panic: reflect: call of reflect.Value.NumField on map Value
2017-04-13T13:22:56.287039565Z 
2017-04-13T13:22:56.287043072Z goroutine 134 [running]:
2017-04-13T13:22:56.287046483Z panic(0x15567c0, 0xc420a14a20)
2017-04-13T13:22:56.287049992Z 	/usr/local/go/src/runtime/panic.go:500 +0x1a1
2017-04-13T13:22:56.287053503Z text/template.errRecover(0xc420b4d100)
2017-04-13T13:22:56.287057143Z 	/usr/local/go/src/text/template/exec.go:146 +0x18e
2017-04-13T13:22:56.287060974Z panic(0x15567c0, 0xc420a14a20)
2017-04-13T13:22:56.287064124Z 	/usr/local/go/src/runtime/panic.go:458 +0x243
2017-04-13T13:22:56.287067615Z reflect.flag.mustBe(0x15, 0x19)
2017-04-13T13:22:56.287070808Z 	/usr/local/go/src/reflect/value.go:201 +0xae
2017-04-13T13:22:56.287084135Z reflect.Value.NumField(0x1576700, 0xc420fa2180, 0x15, 0x2016720)
2017-04-13T13:22:56.287088978Z 	/usr/local/go/src/reflect/value.go:1152 +0x34
2017-04-13T13:22:56.287093279Z k8s.io/helm/vendor/github.com/naoina/toml.marshal(0x0, 0x0, 0x0, 0x0, 0x0, 0x1576700, 0xc420fa2180, 0x15, 0xc420b40000, 0x612041, ...)
2017-04-13T13:22:56.287107048Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/vendor/github.com/naoina/toml/encode.go:77 +0xdc
2017-04-13T13:22:56.287113348Z k8s.io/helm/vendor/github.com/naoina/toml.Marshal(0x1576700, 0xc420fa2180, 0x412815, 0xc420a14a00, 0x10, 0x10, 0xc4204b90e0)
2017-04-13T13:22:56.287116872Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/vendor/github.com/naoina/toml/encode.go:44 +0x95
2017-04-13T13:22:56.287120119Z k8s.io/helm/pkg/chartutil.ToToml(0x1576700, 0xc420fa2180, 0x0, 0x0)
2017-04-13T13:22:56.287123438Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/chartutil/files.go:200 +0x39
2017-04-13T13:22:56.287126761Z reflect.Value.call(0x151a400, 0x17f9508, 0x13, 0x171ddc5, 0x4, 0xc420a149e0, 0x1, 0x1, 0x14ed6a0, 0xc4206522e0, ...)
2017-04-13T13:22:56.287130312Z 	/usr/local/go/src/reflect/value.go:434 +0x5c8
2017-04-13T13:22:56.287133852Z reflect.Value.Call(0x151a400, 0x17f9508, 0x13, 0xc420a149e0, 0x1, 0x1, 0x200f180, 0xc420ac7800, 0x1542a80)
2017-04-13T13:22:56.287137144Z 	/usr/local/go/src/reflect/value.go:302 +0xa4
2017-04-13T13:22:56.287140914Z text/template.(*state).evalCall(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0x151a400, 0x17f9508, 0x13, 0x200f0c0, 0xc420ac7740, 0xc420515846, ...)
2017-04-13T13:22:56.287144164Z 	/usr/local/go/src/text/template/exec.go:658 +0x530
2017-04-13T13:22:56.287147345Z text/template.(*state).evalFunction(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0xc420ac7770, 0x200f0c0, 0xc420ac7740, 0xc42024d840, 0x2, 0x2, ...)
2017-04-13T13:22:56.287150592Z 	/usr/local/go/src/text/template/exec.go:530 +0x195
2017-04-13T13:22:56.287155452Z text/template.(*state).evalCommand(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0xc420ac7740, 0x0, 0x0, 0x0, 0xc420b4cca8, 0x60e262, ...)
2017-04-13T13:22:56.287158772Z 	/usr/local/go/src/text/template/exec.go:427 +0x6f7
2017-04-13T13:22:56.287161969Z text/template.(*state).evalPipeline(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0xc4201353b0, 0x0, 0x0, 0xc420fa2180)
2017-04-13T13:22:56.287165204Z 	/usr/local/go/src/text/template/exec.go:400 +0xee
2017-04-13T13:22:56.287168343Z text/template.(*state).walk(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0x200ef40, 0xc420ac7830)
2017-04-13T13:22:56.287171528Z 	/usr/local/go/src/text/template/exec.go:226 +0x423
2017-04-13T13:22:56.287174572Z text/template.(*state).walk(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0x200f2a0, 0xc420ac76e0)
2017-04-13T13:22:56.287177738Z 	/usr/local/go/src/text/template/exec.go:234 +0x13d
2017-04-13T13:22:56.287180694Z text/template.(*state).walkIfOrWith(0xc420b4d080, 0xa, 0x162c180, 0xc42093de60, 0x15, 0xc420453f90, 0xc420ac76e0, 0x0)
2017-04-13T13:22:56.287183824Z 	/usr/local/go/src/text/template/exec.go:264 +0x1d0
2017-04-13T13:22:56.287186749Z text/template.(*state).walk(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0x200f240, 0xc42025d580)
2017-04-13T13:22:56.287189818Z 	/usr/local/go/src/text/template/exec.go:231 +0x2e8
2017-04-13T13:22:56.287199959Z text/template.(*state).walk(0xc420b4d080, 0x162c180, 0xc42093de60, 0x15, 0x200f2a0, 0xc420ac7140)
2017-04-13T13:22:56.287203312Z 	/usr/local/go/src/text/template/exec.go:234 +0x13d
2017-04-13T13:22:56.287206309Z text/template.(*Template).execute(0xc42025ca80, 0x1ff6d80, 0xc4201ea770, 0x162c180, 0xc42093de60, 0x0, 0x0)
2017-04-13T13:22:56.287209692Z 	/usr/local/go/src/text/template/exec.go:189 +0x204
2017-04-13T13:22:56.287212628Z text/template.(*Template).Execute(0xc42025ca80, 0x1ff6d80, 0xc4201ea770, 0x162c180, 0xc42093de60, 0x0, 0x0)
2017-04-13T13:22:56.287215838Z 	/usr/local/go/src/text/template/exec.go:175 +0x53
2017-04-13T13:22:56.287219069Z text/template.(*Template).ExecuteTemplate(0xc420813300, 0x1ff6d80, 0xc4201ea770, 0xc420fa2630, 0x2e, 0x162c180, 0xc42093de60, 0xc4209b1000, 0x705)
2017-04-13T13:22:56.287222388Z 	/usr/local/go/src/text/template/exec.go:165 +0xb3
2017-04-13T13:22:56.287225381Z k8s.io/helm/pkg/engine.(*Engine).render(0xc4201fc010, 0xc420fa2240, 0xc420fa2240, 0xc42087d085, 0xc420fa4788)
2017-04-13T13:22:56.287228978Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/engine/engine.go:199 +0xbdc
2017-04-13T13:22:56.287232045Z k8s.io/helm/pkg/engine.(*Engine).Render(0xc4201fc010, 0xc420402420, 0xc42093de60, 0xc4201fc010, 0x2066320, 0x454b90)
2017-04-13T13:22:56.287235263Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/engine/engine.go:117 +0x4d
2017-04-13T13:22:56.287238804Z k8s.io/helm/pkg/tiller.(*ReleaseServer).renderResources(0xc4203d98a0, 0xc420402420, 0xc42093de60, 0xc42093dda0, 0xc42000bb60, 0xc420124630, 0x7, 0x100, 0x1, 0xc4202c7420, ...)
2017-04-13T13:22:56.287242184Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/tiller/release_server.go:781 +0x99
2017-04-13T13:22:56.287245254Z k8s.io/helm/pkg/tiller.(*ReleaseServer).prepareRelease(0xc4203d98a0, 0xc420402360, 0xc420af6140, 0x1, 0xc420124730)
2017-04-13T13:22:56.287248448Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/tiller/release_server.go:714 +0x21d
2017-04-13T13:22:56.287251703Z k8s.io/helm/pkg/tiller.(*ReleaseServer).InstallRelease(0xc4203d98a0, 0x7f527efed9d8, 0xc420159710, 0xc420402360, 0x2010860, 0x18, 0x18)
2017-04-13T13:22:56.287254999Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/tiller/release_server.go:647 +0x4d
2017-04-13T13:22:56.287258912Z k8s.io/helm/pkg/proto/hapi/services._ReleaseService_InstallRelease_Handler.func1(0x7f527efed9d8, 0xc420159710, 0x15faf80, 0xc420402360, 0xc420386100, 0xc420124470, 0xc42099ba90, 0x411d48)
2017-04-13T13:22:56.287262324Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/proto/hapi/services/tiller.pb.go:849 +0xa2
2017-04-13T13:22:56.287266343Z k8s.io/helm/pkg/tiller.newUnaryInterceptor.func1(0x7f527efed9d8, 0xc420159710, 0x15faf80, 0xc420402360, 0xc4202e66a0, 0xc4202e66c0, 0x6e26, 0xc4207eab38, 0x0, 0xc4207eab28)
2017-04-13T13:22:56.287269999Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/tiller/server.go:58 +0x18c
2017-04-13T13:22:56.287273195Z k8s.io/helm/pkg/proto/hapi/services._ReleaseService_InstallRelease_Handler(0x16e0640, 0xc4203d98a0, 0x7f527efed9d8, 0xc420159710, 0xc420af60a0, 0x17f96d0, 0x0, 0x0, 0x0, 0x0)
2017-04-13T13:22:56.287279308Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/pkg/proto/hapi/services/tiller.pb.go:851 +0x166
2017-04-13T13:22:56.287282699Z k8s.io/helm/vendor/google.golang.org/grpc.(*Server).processUnaryRPC(0xc4203860c0, 0x2010860, 0xc420808240, 0xc4200b6c30, 0xc42015dd40, 0x2057788, 0xc420159620, 0x0, 0x0)
2017-04-13T13:22:56.287286046Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/vendor/google.golang.org/grpc/server.go:638 +0xc14
2017-04-13T13:22:56.287289483Z k8s.io/helm/vendor/google.golang.org/grpc.(*Server).handleStream(0xc4203860c0, 0x2010860, 0xc420808240, 0xc4200b6c30, 0xc420159620)
2017-04-13T13:22:56.287292829Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/vendor/google.golang.org/grpc/server.go:796 +0x6b0
2017-04-13T13:22:56.287296054Z k8s.io/helm/vendor/google.golang.org/grpc.(*Server).serveStreams.func1.1(0xc42012a580, 0xc4203860c0, 0x2010860, 0xc420808240, 0xc4200b6c30)
2017-04-13T13:22:56.287299374Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/vendor/google.golang.org/grpc/server.go:449 +0xab
2017-04-13T13:22:56.287302535Z created by k8s.io/helm/vendor/google.golang.org/grpc.(*Server).serveStreams.func1
2017-04-13T13:22:56.287306005Z 	/home/ubuntu/.go_workspace/src/k8s.io/helm/vendor/google.golang.org/grpc/server.go:450 +0xa3