From 3c17144fb54c155310a9855e35c00fd715a745b3 Mon Sep 17 00:00:00 2001 From: Mitchell Hashimoto Date: Wed, 13 Jun 2018 11:03:28 +0100 Subject: [PATCH] agent/structs: JSON marshal the configuration for a managed proxy --- agent/structs/service_definition.go | 175 ++++++++++++++++++++++- agent/structs/service_definition_test.go | 84 +++++++++++ 2 files changed, 256 insertions(+), 3 deletions(-) diff --git a/agent/structs/service_definition.go b/agent/structs/service_definition.go index c02ea67710..ef51ebc06d 100644 --- a/agent/structs/service_definition.go +++ b/agent/structs/service_definition.go @@ -1,9 +1,14 @@ package structs import ( + "encoding/json" "fmt" + "reflect" "github.com/hashicorp/go-multierror" + "github.com/mitchellh/copystructure" + "github.com/mitchellh/mapstructure" + "github.com/mitchellh/reflectwalk" ) // ServiceDefinition is used to JSON decode the Service definitions. For @@ -130,7 +135,171 @@ func (s *ServiceDefinition) CheckTypes() (checks CheckTypes, err error) { // registration. Note this is duplicated in config.ServiceConnectProxy and needs // to be kept in sync. type ServiceDefinitionConnectProxy struct { - Command []string - ExecMode string - Config map[string]interface{} + Command []string `json:",omitempty"` + ExecMode string `json:",omitempty"` + Config map[string]interface{} `json:",omitempty"` +} + +func (p *ServiceDefinitionConnectProxy) MarshalJSON() ([]byte, error) { + type typeCopy ServiceDefinitionConnectProxy + copy := typeCopy(*p) + + // If we have config, then we want to run it through our proxyConfigWalker + // which is a reflectwalk implementation that attempts to turn arbitrary + // interface{} values into JSON-safe equivalents (more or less). This + // should always work because the config input is either HCL or JSON and + // both are JSON compatible. + if copy.Config != nil { + configCopyRaw, err := copystructure.Copy(copy.Config) + if err != nil { + return nil, err + } + configCopy, ok := configCopyRaw.(map[string]interface{}) + if !ok { + // This should never fail because we KNOW the input type, + // but we don't ever want to risk the panic. + return nil, fmt.Errorf("internal error: config copy is not right type") + } + if err := reflectwalk.Walk(configCopy, &proxyConfigWalker{}); err != nil { + return nil, err + } + + copy.Config = configCopy + } + + return json.Marshal(©) +} + +var typMapIfaceIface = reflect.TypeOf(map[interface{}]interface{}{}) + +// proxyConfigWalker implements interfaces for the reflectwalk package +// (github.com/mitchellh/reflectwalk) that can be used to automatically +// make the proxy configuration safe for JSON usage. +// +// Most of the implementation here is just keeping track of where we are +// in the reflectwalk process, so that we can replace values. The key logic +// is in Slice() and SliceElem(). +// +// In particular we're looking to replace two cases HCL causes: +// +// 1.) String values get turned into byte slices. JSON will base64-encode +// this and we don't want that, so we convert them back to strings. +// +// 2.) Nested maps turn into map[interface{}]interface{}. JSON cannot +// encode this, so we need to turn it back into map[string]interface{}. +// +// This is tested via the TestServiceDefinitionConnectProxy_json test. +type proxyConfigWalker struct { + lastValue reflect.Value // lastValue of map, required for replacement + loc, lastLoc reflectwalk.Location // locations + cs []reflect.Value // container stack + csKey []reflect.Value // container keys (maps) stack + csData interface{} // current container data + sliceIndex []int // slice index stack (one for each slice in cs) +} + +func (w *proxyConfigWalker) Enter(loc reflectwalk.Location) error { + w.lastLoc = w.loc + w.loc = loc + return nil +} + +func (w *proxyConfigWalker) Exit(loc reflectwalk.Location) error { + w.loc = reflectwalk.None + w.lastLoc = reflectwalk.None + + switch loc { + case reflectwalk.Map: + w.cs = w.cs[:len(w.cs)-1] + case reflectwalk.MapValue: + w.csKey = w.csKey[:len(w.csKey)-1] + case reflectwalk.Slice: + // Split any values that need to be split + w.cs = w.cs[:len(w.cs)-1] + case reflectwalk.SliceElem: + w.csKey = w.csKey[:len(w.csKey)-1] + w.sliceIndex = w.sliceIndex[:len(w.sliceIndex)-1] + } + + return nil +} + +func (w *proxyConfigWalker) Map(m reflect.Value) error { + w.cs = append(w.cs, m) + return nil +} + +func (w *proxyConfigWalker) MapElem(m, k, v reflect.Value) error { + w.csData = k + w.csKey = append(w.csKey, k) + + w.lastValue = v + return nil +} + +func (w *proxyConfigWalker) Slice(v reflect.Value) error { + // If we find a []byte slice, it is an HCL-string converted to []byte. + // Convert it back to a Go string and replace the value so that JSON + // doesn't base64-encode it. + if v.Type() == reflect.TypeOf([]byte{}) { + resultVal := reflect.ValueOf(string(v.Interface().([]byte))) + switch w.lastLoc { + case reflectwalk.MapKey: + m := w.cs[len(w.cs)-1] + + // Delete the old value + var zero reflect.Value + m.SetMapIndex(w.csData.(reflect.Value), zero) + + // Set the new key with the existing value + m.SetMapIndex(resultVal, w.lastValue) + + // Set the key to be the new key + w.csData = resultVal + case reflectwalk.MapValue: + // If we're in a map, then the only way to set a map value is + // to set it directly. + m := w.cs[len(w.cs)-1] + mk := w.csData.(reflect.Value) + m.SetMapIndex(mk, resultVal) + case reflectwalk.Slice: + s := w.cs[len(w.cs)-1] + s.Index(w.sliceIndex[len(w.sliceIndex)-1]).Set(resultVal) + default: + return fmt.Errorf("cannot convert []byte") + } + } + + w.cs = append(w.cs, v) + return nil +} + +func (w *proxyConfigWalker) SliceElem(i int, elem reflect.Value) error { + w.csKey = append(w.csKey, reflect.ValueOf(i)) + w.sliceIndex = append(w.sliceIndex, i) + + // We're looking specifically for map[interface{}]interface{}, but the + // values in a slice are wrapped up in interface{} so we need to unwrap + // that first. Therefore, we do three checks: 1.) is it valid? so we + // don't panic, 2.) is it an interface{}? so we can unwrap it and 3.) + // after unwrapping the interface do we have the map we expect? + if !elem.IsValid() { + return nil + } + + if elem.Kind() != reflect.Interface { + return nil + } + + if inner := elem.Elem(); inner.Type() == typMapIfaceIface { + // map[interface{}]interface{}, attempt to weakly decode into string keys + var target map[string]interface{} + if err := mapstructure.WeakDecode(inner.Interface(), &target); err != nil { + return err + } + + elem.Set(reflect.ValueOf(target)) + } + + return nil } diff --git a/agent/structs/service_definition_test.go b/agent/structs/service_definition_test.go index 3beefc28f3..07846dbb56 100644 --- a/agent/structs/service_definition_test.go +++ b/agent/structs/service_definition_test.go @@ -1,6 +1,7 @@ package structs import ( + "encoding/json" "fmt" "strings" "testing" @@ -120,3 +121,86 @@ func TestServiceDefinitionValidate(t *testing.T) { }) } } + +func TestServiceDefinitionConnectProxy_json(t *testing.T) { + cases := []struct { + Name string + Input *ServiceDefinitionConnectProxy + Expected string + Err string + }{ + { + "no config", + &ServiceDefinitionConnectProxy{ + Command: []string{"foo"}, + ExecMode: "bar", + }, + ` +{ + "Command": [ + "foo" + ], + "ExecMode": "bar" +} + `, + "", + }, + + { + "basic config", + &ServiceDefinitionConnectProxy{ + Config: map[string]interface{}{ + "foo": "bar", + }, + }, + ` +{ + "Config": { + "foo": "bar" + } +} + `, + "", + }, + + { + "config with upstreams", + &ServiceDefinitionConnectProxy{ + Config: map[string]interface{}{ + "upstreams": []interface{}{ + map[interface{}]interface{}{ + "key": []byte("value"), + }, + }, + }, + }, + ` +{ + "Config": { + "upstreams": [ + { + "key": "value" + } + ] + } +} + `, + "", + }, + } + + for _, tc := range cases { + t.Run(tc.Name, func(t *testing.T) { + require := require.New(t) + result, err := json.MarshalIndent(tc.Input, "", "\t") + t.Logf("error: %s", err) + require.Equal(err != nil, tc.Err != "") + if err != nil { + require.Contains(strings.ToLower(err.Error()), strings.ToLower(tc.Err)) + return + } + + require.Equal(strings.TrimSpace(tc.Expected), strings.TrimSpace(string(result))) + }) + } +}