support multi-image (docker) archives

Support loading and saving tarballs with more than one image.
Add a new `/libpod/images/export` endpoint to the rest API to
allow for exporting/saving multiple images into an archive.

Note that a non-release version of containers/image is vendored.
A release version must be vendored before cutting a new Podman
release.  We force the containers/image version via a replace in
the go.mod file; this way go won't try to match the versions.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

7 files changed, 328 insertions, 191 deletions

diff --git a/vendor/github.com/imdario/mergo/README.md b/vendor/github.com/imdario/mergo/README.md
index 02fc81e06..876abb500 100644
--- a/vendor/github.com/imdario/mergo/README.md
+++ b/vendor/github.com/imdario/mergo/README.md
@@ -1,44 +1,54 @@
 # Mergo
 
-A helper to merge structs and maps in Golang. Useful for configuration default values, avoiding messy if-statements.
-
-Also a lovely [comune](http://en.wikipedia.org/wiki/Mergo) (municipality) in the Province of Ancona in the Italian region of Marche.
-
-## Status
-
-It is ready for production use. [It is used in several projects by Docker, Google, The Linux Foundation, VMWare, Shopify, etc](https://github.com/imdario/mergo#mergo-in-the-wild).
 
 [![GoDoc][3]][4]
-[![GoCard][5]][6]
+[![GitHub release][5]][6]
+[![GoCard][7]][8]
 [![Build Status][1]][2]
-[![Coverage Status][7]][8]
-[![Sourcegraph][9]][10]
-[![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fimdario%2Fmergo.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Fimdario%2Fmergo?ref=badge_shield)
+[![Coverage Status][9]][10]
+[![Sourcegraph][11]][12]
+[![FOSSA Status][13]][14]
+
+[![GoCenter Kudos][15]][16]
 
 [1]: https://travis-ci.org/imdario/mergo.png
 [2]: https://travis-ci.org/imdario/mergo
 [3]: https://godoc.org/github.com/imdario/mergo?status.svg
 [4]: https://godoc.org/github.com/imdario/mergo
-[5]: https://goreportcard.com/badge/imdario/mergo
-[6]: https://goreportcard.com/report/github.com/imdario/mergo
-[7]: https://coveralls.io/repos/github/imdario/mergo/badge.svg?branch=master
-[8]: https://coveralls.io/github/imdario/mergo?branch=master
-[9]: https://sourcegraph.com/github.com/imdario/mergo/-/badge.svg
-[10]: https://sourcegraph.com/github.com/imdario/mergo?badge
+[5]: https://img.shields.io/github/release/imdario/mergo.svg
+[6]: https://github.com/imdario/mergo/releases
+[7]: https://goreportcard.com/badge/imdario/mergo
+[8]: https://goreportcard.com/report/github.com/imdario/mergo
+[9]: https://coveralls.io/repos/github/imdario/mergo/badge.svg?branch=master
+[10]: https://coveralls.io/github/imdario/mergo?branch=master
+[11]: https://sourcegraph.com/github.com/imdario/mergo/-/badge.svg
+[12]: https://sourcegraph.com/github.com/imdario/mergo?badge
+[13]: https://app.fossa.io/api/projects/git%2Bgithub.com%2Fimdario%2Fmergo.svg?type=shield
+[14]: https://app.fossa.io/projects/git%2Bgithub.com%2Fimdario%2Fmergo?ref=badge_shield
+[15]: https://search.gocenter.io/api/ui/badge/github.com%2Fimdario%2Fmergo
+[16]: https://search.gocenter.io/github.com/imdario/mergo
 
-### Latest release
+A helper to merge structs and maps in Golang. Useful for configuration default values, avoiding messy if-statements.
 
-[Release v0.3.7](https://github.com/imdario/mergo/releases/tag/v0.3.7).
+Mergo merges same-type structs and maps by setting default values in zero-value fields. Mergo won't merge unexported (private) fields. It will do recursively any exported one. It also won't merge structs inside maps (because they are not addressable using Go reflection).
+
+Also a lovely [comune](http://en.wikipedia.org/wiki/Mergo) (municipality) in the Province of Ancona in the Italian region of Marche.
+
+## Status
+
+It is ready for production use. [It is used in several projects by Docker, Google, The Linux Foundation, VMWare, Shopify, etc](https://github.com/imdario/mergo#mergo-in-the-wild).
 
 ### Important note
 
-Please keep in mind that in [0.3.2](//github.com/imdario/mergo/releases/tag/0.3.2) Mergo changed `Merge()`and `Map()` signatures to support [transformers](#transformers). An optional/variadic argument has been added, so it won't break existing code.
+Please keep in mind that a problematic PR broke [0.3.9](//github.com/imdario/mergo/releases/tag/0.3.9). I reverted it in [0.3.10](//github.com/imdario/mergo/releases/tag/0.3.10), and I consider it stable but not bug-free. Also, this version adds suppot for go modules.
 
-If you were using Mergo **before** April 6th 2015, please check your project works as intended after updating your local copy with ```go get -u github.com/imdario/mergo```. I apologize for any issue caused by its previous behavior and any future bug that Mergo could cause (I hope it won't!) in existing projects after the change (release 0.2.0).
+Keep in mind that in [0.3.2](//github.com/imdario/mergo/releases/tag/0.3.2), Mergo changed `Merge()`and `Map()` signatures to support [transformers](#transformers). I added an optional/variadic argument so that it won't break the existing code.
+
+If you were using Mergo before April 6th, 2015, please check your project works as intended after updating your local copy with ```go get -u github.com/imdario/mergo```. I apologize for any issue caused by its previous behavior and any future bug that Mergo could cause in existing projects after the change (release 0.2.0).
 
 ### Donations
 
-If Mergo is useful to you, consider buying me a coffee, a beer or making a monthly donation so I can keep building great free software. :heart_eyes:
+If Mergo is useful to you, consider buying me a coffee, a beer, or making a monthly donation to allow me to keep building great free software. :heart_eyes:
 
 <a href='https://ko-fi.com/B0B58839' target='_blank'><img height='36' style='border:0px;height:36px;' src='https://az743702.vo.msecnd.net/cdn/kofi1.png?v=0' border='0' alt='Buy Me a Coffee at ko-fi.com' /></a>
 [![Beerpay](https://beerpay.io/imdario/mergo/badge.svg)](https://beerpay.io/imdario/mergo)
@@ -87,8 +97,9 @@ If Mergo is useful to you, consider buying me a coffee, a beer or making a month
 - [mantasmatelis/whooplist-server](https://github.com/mantasmatelis/whooplist-server)
 - [jnuthong/item_search](https://github.com/jnuthong/item_search)
 - [bukalapak/snowboard](https://github.com/bukalapak/snowboard)
+- [janoszen/containerssh](https://github.com/janoszen/containerssh)
 
-## Installation
+## Install
 
     go get github.com/imdario/mergo
 
@@ -99,7 +110,7 @@ If Mergo is useful to you, consider buying me a coffee, a beer or making a month
 
 ## Usage
 
-You can only merge same-type structs with exported fields initialized as zero value of their type and same-types maps. Mergo won't merge unexported (private) fields but will do recursively any exported one. It won't merge empty structs value as [they are not considered zero values](https://golang.org/ref/spec#The_zero_value) either. Also maps will be merged recursively except for structs inside maps (because they are not addressable using Go reflection).
+You can only merge same-type structs with exported fields initialized as zero value of their type and same-types maps. Mergo won't merge unexported (private) fields but will do recursively any exported one. It won't merge empty structs value as [they are zero values](https://golang.org/ref/spec#The_zero_value) too. Also, maps will be merged recursively except for structs inside maps (because they are not addressable using Go reflection).
 
 ```go
 if err := mergo.Merge(&dst, src); err != nil {
@@ -125,9 +136,7 @@ if err := mergo.Map(&dst, srcMap); err != nil {
 
 Warning: if you map a struct to map, it won't do it recursively. Don't expect Mergo to map struct members of your struct as `map[string]interface{}`. They will be just assigned as values.
 
-More information and examples in [godoc documentation](http://godoc.org/github.com/imdario/mergo).
-
-### Nice example
+Here is a nice example:
 
 ```go
 package main
@@ -175,10 +184,10 @@ import (
         "time"
 )
 
-type timeTransfomer struct {
+type timeTransformer struct {
 }
 
-func (t timeTransfomer) Transformer(typ reflect.Type) func(dst, src reflect.Value) error {
+func (t timeTransformer) Transformer(typ reflect.Type) func(dst, src reflect.Value) error {
 	if typ == reflect.TypeOf(time.Time{}) {
 		return func(dst, src reflect.Value) error {
 			if dst.CanSet() {
@@ -202,7 +211,7 @@ type Snapshot struct {
 func main() {
 	src := Snapshot{time.Now()}
 	dest := Snapshot{}
-	mergo.Merge(&dest, src, mergo.WithTransformers(timeTransfomer{}))
+	mergo.Merge(&dest, src, mergo.WithTransformers(timeTransformer{}))
 	fmt.Println(dest)
 	// Will print
 	// { 2018-01-12 01:15:00 +0000 UTC m=+0.000000001 }
diff --git a/vendor/github.com/imdario/mergo/doc.go b/vendor/github.com/imdario/mergo/doc.go
index 6e9aa7baf..fcd985f99 100644
--- a/vendor/github.com/imdario/mergo/doc.go
+++ b/vendor/github.com/imdario/mergo/doc.go
@@ -4,41 +4,140 @@
 // license that can be found in the LICENSE file.
 
 /*
-Package mergo merges same-type structs and maps by setting default values in zero-value fields.
+A helper to merge structs and maps in Golang. Useful for configuration default values, avoiding messy if-statements.
 
-Mergo won't merge unexported (private) fields but will do recursively any exported one. It also won't merge structs inside maps (because they are not addressable using Go reflection).
+Mergo merges same-type structs and maps by setting default values in zero-value fields. Mergo won't merge unexported (private) fields. It will do recursively any exported one. It also won't merge structs inside maps (because they are not addressable using Go reflection).
+
+Status
+
+It is ready for production use. It is used in several projects by Docker, Google, The Linux Foundation, VMWare, Shopify, etc.
+
+Important note
+
+Please keep in mind that a problematic PR broke 0.3.9. We reverted it in 0.3.10. We consider 0.3.10 as stable but not bug-free. . Also, this version adds suppot for go modules.
+
+Keep in mind that in 0.3.2, Mergo changed Merge() and Map() signatures to support transformers. We added an optional/variadic argument so that it won't break the existing code.
+
+If you were using Mergo before April 6th, 2015, please check your project works as intended after updating your local copy with go get -u github.com/imdario/mergo. I apologize for any issue caused by its previous behavior and any future bug that Mergo could cause in existing projects after the change (release 0.2.0).
+
+Install
+
+Do your usual installation procedure:
+
+    go get github.com/imdario/mergo
+
+    // use in your .go code
+    import (
+        "github.com/imdario/mergo"
+    )
 
 Usage
 
-From my own work-in-progress project:
+You can only merge same-type structs with exported fields initialized as zero value of their type and same-types maps. Mergo won't merge unexported (private) fields but will do recursively any exported one. It won't merge empty structs value as they are zero values too. Also, maps will be merged recursively except for structs inside maps (because they are not addressable using Go reflection).
+
+	if err := mergo.Merge(&dst, src); err != nil {
+		// ...
+	}
+
+Also, you can merge overwriting values using the transformer WithOverride.
+
+	if err := mergo.Merge(&dst, src, mergo.WithOverride); err != nil {
+		// ...
+	}
+
+Additionally, you can map a map[string]interface{} to a struct (and otherwise, from struct to map), following the same restrictions as in Merge(). Keys are capitalized to find each corresponding exported field.
+
+	if err := mergo.Map(&dst, srcMap); err != nil {
+		// ...
+	}
+
+Warning: if you map a struct to map, it won't do it recursively. Don't expect Mergo to map struct members of your struct as map[string]interface{}. They will be just assigned as values.
+
+Here is a nice example:
+
+	package main
+
+	import (
+		"fmt"
+		"github.com/imdario/mergo"
+	)
 
-	type networkConfig struct {
-		Protocol string
-		Address string
-		ServerType string `json: "server_type"`
-		Port uint16
+	type Foo struct {
+		A string
+		B int64
 	}
 
-	type FssnConfig struct {
-		Network networkConfig
+	func main() {
+		src := Foo{
+			A: "one",
+			B: 2,
+		}
+		dest := Foo{
+			A: "two",
+		}
+		mergo.Merge(&dest, src)
+		fmt.Println(dest)
+		// Will print
+		// {two 2}
 	}
 
-	var fssnDefault = FssnConfig {
-		networkConfig {
-			"tcp",
-			"127.0.0.1",
-			"http",
-			31560,
-		},
+Transformers
+
+Transformers allow to merge specific types differently than in the default behavior. In other words, now you can customize how some types are merged. For example, time.Time is a struct; it doesn't have zero value but IsZero can return true because it has fields with zero value. How can we merge a non-zero time.Time?
+
+	package main
+
+	import (
+		"fmt"
+		"github.com/imdario/mergo"
+			"reflect"
+			"time"
+	)
+
+	type timeTransformer struct {
 	}
 
-	// Inside a function [...]
+	func (t timeTransformer) Transformer(typ reflect.Type) func(dst, src reflect.Value) error {
+		if typ == reflect.TypeOf(time.Time{}) {
+			return func(dst, src reflect.Value) error {
+				if dst.CanSet() {
+					isZero := dst.MethodByName("IsZero")
+					result := isZero.Call([]reflect.Value{})
+					if result[0].Bool() {
+						dst.Set(src)
+					}
+				}
+				return nil
+			}
+		}
+		return nil
+	}
+
+	type Snapshot struct {
+		Time time.Time
+		// ...
+	}
 
-	if err := mergo.Merge(&config, fssnDefault); err != nil {
-		log.Fatal(err)
+	func main() {
+		src := Snapshot{time.Now()}
+		dest := Snapshot{}
+		mergo.Merge(&dest, src, mergo.WithTransformers(timeTransformer{}))
+		fmt.Println(dest)
+		// Will print
+		// { 2018-01-12 01:15:00 +0000 UTC m=+0.000000001 }
 	}
 
-	// More code [...]
+Contact me
+
+If I can help you, you have an idea or you are using Mergo in your projects, don't hesitate to drop me a line (or a pull request): https://twitter.com/im_dario
+
+About
+
+Written by Dario Castañé: https://da.rio.hn
+
+License
+
+BSD 3-Clause license, as Go language.
 
 */
 package mergo
diff --git a/vendor/github.com/imdario/mergo/go.mod b/vendor/github.com/imdario/mergo/go.mod
new file mode 100644
index 000000000..3d689d93e
--- /dev/null
+++ b/vendor/github.com/imdario/mergo/go.mod
@@ -0,0 +1,5 @@
+module github.com/imdario/mergo
+
+go 1.13
+
+require gopkg.in/yaml.v2 v2.3.0
diff --git a/vendor/github.com/imdario/mergo/go.sum b/vendor/github.com/imdario/mergo/go.sum
new file mode 100644
index 000000000..168980da5
--- /dev/null
+++ b/vendor/github.com/imdario/mergo/go.sum
@@ -0,0 +1,4 @@
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/vendor/github.com/imdario/mergo/map.go b/vendor/github.com/imdario/mergo/map.go
index d83258b4d..a13a7ee46 100644
--- a/vendor/github.com/imdario/mergo/map.go
+++ b/vendor/github.com/imdario/mergo/map.go
@@ -99,11 +99,11 @@ func deepMap(dst, src reflect.Value, visited map[uintptr]*visit, depth int, conf
 				continue
 			}
 			if srcKind == dstKind {
-				if _, err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil {
+				if err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil {
 					return
 				}
 			} else if dstKind == reflect.Interface && dstElement.Kind() == reflect.Interface {
-				if _, err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil {
+				if err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil {
 					return
 				}
 			} else if srcKind == reflect.Map {
@@ -141,6 +141,9 @@ func MapWithOverwrite(dst, src interface{}, opts ...func(*Config)) error {
 }
 
 func _map(dst, src interface{}, opts ...func(*Config)) error {
+	if dst != nil && reflect.ValueOf(dst).Kind() != reflect.Ptr {
+		return ErrNonPointerAgument
+	}
 	var (
 		vDst, vSrc reflect.Value
 		err        error
@@ -157,8 +160,7 @@ func _map(dst, src interface{}, opts ...func(*Config)) error {
 	// To be friction-less, we redirect equal-type arguments
 	// to deepMerge. Only because arguments can be anything.
 	if vSrc.Kind() == vDst.Kind() {
-		_, err := deepMerge(vDst, vSrc, make(map[uintptr]*visit), 0, config)
-		return err
+		return deepMerge(vDst, vSrc, make(map[uintptr]*visit), 0, config)
 	}
 	switch vSrc.Kind() {
 	case reflect.Struct:
diff --git a/vendor/github.com/imdario/mergo/merge.go b/vendor/github.com/imdario/mergo/merge.go
index 3332c9c2a..afa84a1e2 100644
--- a/vendor/github.com/imdario/mergo/merge.go
+++ b/vendor/github.com/imdario/mergo/merge.go
@@ -11,26 +11,26 @@ package mergo
 import (
 	"fmt"
 	"reflect"
-	"unsafe"
 )
 
-func hasExportedField(dst reflect.Value) (exported bool) {
+func hasMergeableFields(dst reflect.Value) (exported bool) {
 	for i, n := 0, dst.NumField(); i < n; i++ {
 		field := dst.Type().Field(i)
-		if isExportedComponent(&field) {
-			return true
+		if field.Anonymous && dst.Field(i).Kind() == reflect.Struct {
+			exported = exported || hasMergeableFields(dst.Field(i))
+		} else if isExportedComponent(&field) {
+			exported = exported || len(field.PkgPath) == 0
 		}
 	}
 	return
 }
 
 func isExportedComponent(field *reflect.StructField) bool {
-	name := field.Name
 	pkgPath := field.PkgPath
 	if len(pkgPath) > 0 {
 		return false
 	}
-	c := name[0]
+	c := field.Name[0]
 	if 'a' <= c && c <= 'z' || c == '_' {
 		return false
 	}
@@ -44,6 +44,8 @@ type Config struct {
 	Transformers                 Transformers
 	overwriteWithEmptyValue      bool
 	overwriteSliceWithEmptyValue bool
+	sliceDeepCopy                bool
+	debug                        bool
 }
 
 type Transformers interface {
@@ -53,17 +55,16 @@ type Transformers interface {
 // Traverses recursively both values, assigning src's fields values to dst.
 // The map argument tracks comparisons that have already been seen, which allows
 // short circuiting on recursive types.
-func deepMerge(dstIn, src reflect.Value, visited map[uintptr]*visit, depth int, config *Config) (dst reflect.Value, err error) {
-	dst = dstIn
+func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, config *Config) (err error) {
 	overwrite := config.Overwrite
 	typeCheck := config.TypeCheck
 	overwriteWithEmptySrc := config.overwriteWithEmptyValue
 	overwriteSliceWithEmptySrc := config.overwriteSliceWithEmptyValue
+	sliceDeepCopy := config.sliceDeepCopy
 
 	if !src.IsValid() {
 		return
 	}
-
 	if dst.CanAddr() {
 		addr := dst.UnsafeAddr()
 		h := 17 * addr
@@ -71,7 +72,7 @@ func deepMerge(dstIn, src reflect.Value, visited map[uintptr]*visit, depth int,
 		typ := dst.Type()
 		for p := seen; p != nil; p = p.next {
 			if p.ptr == addr && p.typ == typ {
-				return dst, nil
+				return nil
 			}
 		}
 		// Remember, remember...
@@ -85,126 +86,154 @@ func deepMerge(dstIn, src reflect.Value, visited map[uintptr]*visit, depth int,
 		}
 	}
 
-	if dst.IsValid() && src.IsValid() && src.Type() != dst.Type() {
-		err = fmt.Errorf("cannot append two different types (%s, %s)", src.Kind(), dst.Kind())
-		return
-	}
-
 	switch dst.Kind() {
 	case reflect.Struct:
-		if hasExportedField(dst) {
-			dstCp := reflect.New(dst.Type()).Elem()
+		if hasMergeableFields(dst) {
 			for i, n := 0, dst.NumField(); i < n; i++ {
-				dstField := dst.Field(i)
-				structField := dst.Type().Field(i)
-				// copy un-exported struct fields
-				if !isExportedComponent(&structField) {
-					rf := dstCp.Field(i)
-					rf = reflect.NewAt(rf.Type(), unsafe.Pointer(rf.UnsafeAddr())).Elem() //nolint:gosec
-					dstRF := dst.Field(i)
-					if !dst.Field(i).CanAddr() {
-						continue
-					}
-
-					dstRF = reflect.NewAt(dstRF.Type(), unsafe.Pointer(dstRF.UnsafeAddr())).Elem() //nolint:gosec
-					rf.Set(dstRF)
-					continue
-				}
-				dstField, err = deepMerge(dstField, src.Field(i), visited, depth+1, config)
-				if err != nil {
+				if err = deepMerge(dst.Field(i), src.Field(i), visited, depth+1, config); err != nil {
 					return
 				}
-				dstCp.Field(i).Set(dstField)
 			}
-
-			if dst.CanSet() {
-				dst.Set(dstCp)
-			} else {
-				dst = dstCp
-			}
-			return
 		} else {
 			if (isReflectNil(dst) || overwrite) && (!isEmptyValue(src) || overwriteWithEmptySrc) {
-				dst = src
+				dst.Set(src)
 			}
 		}
-
 	case reflect.Map:
 		if dst.IsNil() && !src.IsNil() {
-			if dst.CanSet() {
-				dst.Set(reflect.MakeMap(dst.Type()))
-			} else {
-				dst = src
-				return
+			dst.Set(reflect.MakeMap(dst.Type()))
+		}
+
+		if src.Kind() != reflect.Map {
+			if overwrite {
+				dst.Set(src)
 			}
+			return
 		}
+
 		for _, key := range src.MapKeys() {
 			srcElement := src.MapIndex(key)
-			dstElement := dst.MapIndex(key)
 			if !srcElement.IsValid() {
 				continue
 			}
-			if dst.MapIndex(key).IsValid() {
-				k := dstElement.Interface()
-				dstElement = reflect.ValueOf(k)
-			}
-			if isReflectNil(srcElement) {
-				if overwrite || isReflectNil(dstElement) {
-					dst.SetMapIndex(key, srcElement)
+			dstElement := dst.MapIndex(key)
+			switch srcElement.Kind() {
+			case reflect.Chan, reflect.Func, reflect.Map, reflect.Interface, reflect.Slice:
+				if srcElement.IsNil() {
+					if overwrite {
+						dst.SetMapIndex(key, srcElement)
+					}
+					continue
+				}
+				fallthrough
+			default:
+				if !srcElement.CanInterface() {
+					continue
+				}
+				switch reflect.TypeOf(srcElement.Interface()).Kind() {
+				case reflect.Struct:
+					fallthrough
+				case reflect.Ptr:
+					fallthrough
+				case reflect.Map:
+					srcMapElm := srcElement
+					dstMapElm := dstElement
+					if srcMapElm.CanInterface() {
+						srcMapElm = reflect.ValueOf(srcMapElm.Interface())
+						if dstMapElm.IsValid() {
+							dstMapElm = reflect.ValueOf(dstMapElm.Interface())
+						}
+					}
+					if err = deepMerge(dstMapElm, srcMapElm, visited, depth+1, config); err != nil {
+						return
+					}
+				case reflect.Slice:
+					srcSlice := reflect.ValueOf(srcElement.Interface())
+
+					var dstSlice reflect.Value
+					if !dstElement.IsValid() || dstElement.IsNil() {
+						dstSlice = reflect.MakeSlice(srcSlice.Type(), 0, srcSlice.Len())
+					} else {
+						dstSlice = reflect.ValueOf(dstElement.Interface())
+					}
+
+					if (!isEmptyValue(src) || overwriteWithEmptySrc || overwriteSliceWithEmptySrc) && (overwrite || isEmptyValue(dst)) && !config.AppendSlice && !sliceDeepCopy {
+						if typeCheck && srcSlice.Type() != dstSlice.Type() {
+							return fmt.Errorf("cannot override two slices with different type (%s, %s)", srcSlice.Type(), dstSlice.Type())
+						}
+						dstSlice = srcSlice
+					} else if config.AppendSlice {
+						if srcSlice.Type() != dstSlice.Type() {
+							return fmt.Errorf("cannot append two slices with different type (%s, %s)", srcSlice.Type(), dstSlice.Type())
+						}
+						dstSlice = reflect.AppendSlice(dstSlice, srcSlice)
+					} else if sliceDeepCopy {
+						i := 0
+						for ; i < srcSlice.Len() && i < dstSlice.Len(); i++ {
+							srcElement := srcSlice.Index(i)
+							dstElement := dstSlice.Index(i)
+
+							if srcElement.CanInterface() {
+								srcElement = reflect.ValueOf(srcElement.Interface())
+							}
+							if dstElement.CanInterface() {
+								dstElement = reflect.ValueOf(dstElement.Interface())
+							}
+
+							if err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil {
+								return
+							}
+						}
+
+					}
+					dst.SetMapIndex(key, dstSlice)
 				}
-				continue
 			}
-			if !srcElement.CanInterface() {
+			if dstElement.IsValid() && !isEmptyValue(dstElement) && (reflect.TypeOf(srcElement.Interface()).Kind() == reflect.Map || reflect.TypeOf(srcElement.Interface()).Kind() == reflect.Slice) {
 				continue
 			}
 
-			if srcElement.CanInterface() {
-				srcElement = reflect.ValueOf(srcElement.Interface())
-				if dstElement.IsValid() {
-					dstElement = reflect.ValueOf(dstElement.Interface())
+			if srcElement.IsValid() && ((srcElement.Kind() != reflect.Ptr && overwrite) || !dstElement.IsValid() || isEmptyValue(dstElement)) {
+				if dst.IsNil() {
+					dst.Set(reflect.MakeMap(dst.Type()))
 				}
+				dst.SetMapIndex(key, srcElement)
 			}
-			dstElement, err = deepMerge(dstElement, srcElement, visited, depth+1, config)
-			if err != nil {
-				return
-			}
-			dst.SetMapIndex(key, dstElement)
-
 		}
 	case reflect.Slice:
-		newSlice := dst
-		if (!isEmptyValue(src) || overwriteWithEmptySrc || overwriteSliceWithEmptySrc) && (overwrite || isEmptyValue(dst)) && !config.AppendSlice {
-			if typeCheck && src.Type() != dst.Type() {
-				return dst, fmt.Errorf("cannot override two slices with different type (%s, %s)", src.Type(), dst.Type())
-			}
-			newSlice = src
-		} else if config.AppendSlice {
-			if typeCheck && src.Type() != dst.Type() {
-				err = fmt.Errorf("cannot append two slice with different type (%s, %s)", src.Type(), dst.Type())
-				return
-			}
-			newSlice = reflect.AppendSlice(dst, src)
-		}
-		if dst.CanSet() {
-			dst.Set(newSlice)
-		} else {
-			dst = newSlice
-		}
-	case reflect.Ptr, reflect.Interface:
-		if isReflectNil(src) {
+		if !dst.CanSet() {
 			break
 		}
+		if (!isEmptyValue(src) || overwriteWithEmptySrc || overwriteSliceWithEmptySrc) && (overwrite || isEmptyValue(dst)) && !config.AppendSlice && !sliceDeepCopy {
+			dst.Set(src)
+		} else if config.AppendSlice {
+			if src.Type() != dst.Type() {
+				return fmt.Errorf("cannot append two slice with different type (%s, %s)", src.Type(), dst.Type())
+			}
+			dst.Set(reflect.AppendSlice(dst, src))
+		} else if sliceDeepCopy {
+			for i := 0; i < src.Len() && i < dst.Len(); i++ {
+				srcElement := src.Index(i)
+				dstElement := dst.Index(i)
+				if srcElement.CanInterface() {
+					srcElement = reflect.ValueOf(srcElement.Interface())
+				}
+				if dstElement.CanInterface() {
+					dstElement = reflect.ValueOf(dstElement.Interface())
+				}
 
-		if dst.Kind() != reflect.Ptr && src.Type().AssignableTo(dst.Type()) {
-			if dst.IsNil() || overwrite {
-				if overwrite || isEmptyValue(dst) {
-					if dst.CanSet() {
-						dst.Set(src)
-					} else {
-						dst = src
-					}
+				if err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil {
+					return
 				}
 			}
+		}
+	case reflect.Ptr:
+		fallthrough
+	case reflect.Interface:
+		if isReflectNil(src) {
+			if overwriteWithEmptySrc && dst.CanSet() && src.Type().AssignableTo(dst.Type()) {
+				dst.Set(src)
+			}
 			break
 		}
 
@@ -214,33 +243,35 @@ func deepMerge(dstIn, src reflect.Value, visited map[uintptr]*visit, depth int,
 					dst.Set(src)
 				}
 			} else if src.Kind() == reflect.Ptr {
-				if dst, err = deepMerge(dst.Elem(), src.Elem(), visited, depth+1, config); err != nil {
+				if err = deepMerge(dst.Elem(), src.Elem(), visited, depth+1, config); err != nil {
 					return
 				}
-				dst = dst.Addr()
 			} else if dst.Elem().Type() == src.Type() {
-				if dst, err = deepMerge(dst.Elem(), src, visited, depth+1, config); err != nil {
+				if err = deepMerge(dst.Elem(), src, visited, depth+1, config); err != nil {
 					return
 				}
 			} else {
-				return dst, ErrDifferentArgumentsTypes
+				return ErrDifferentArgumentsTypes
 			}
 			break
 		}
+
 		if dst.IsNil() || overwrite {
-			if (overwrite || isEmptyValue(dst)) && (overwriteWithEmptySrc || !isEmptyValue(src)) {
-				if dst.CanSet() {
-					dst.Set(src)
-				} else {
-					dst = src
-				}
+			if dst.CanSet() && (overwrite || isEmptyValue(dst)) {
+				dst.Set(src)
 			}
-		} else if _, err = deepMerge(dst.Elem(), src.Elem(), visited, depth+1, config); err != nil {
-			return
+			break
+		}
+
+		if dst.Elem().Kind() == src.Elem().Kind() {
+			if err = deepMerge(dst.Elem(), src.Elem(), visited, depth+1, config); err != nil {
+				return
+			}
+			break
 		}
 	default:
-		overwriteFull := (!isEmptyValue(src) || overwriteWithEmptySrc) && (overwrite || isEmptyValue(dst))
-		if overwriteFull {
+		mustSet := (isEmptyValue(dst) || overwrite) && (!isEmptyValue(src) || overwriteWithEmptySrc)
+		if mustSet {
 			if dst.CanSet() {
 				dst.Set(src)
 			} else {
@@ -281,6 +312,7 @@ func WithOverride(config *Config) {
 
 // WithOverwriteWithEmptyValue will make merge override non empty dst attributes with empty src attributes values.
 func WithOverwriteWithEmptyValue(config *Config) {
+	config.Overwrite = true
 	config.overwriteWithEmptyValue = true
 }
 
@@ -299,7 +331,16 @@ func WithTypeCheck(config *Config) {
 	config.TypeCheck = true
 }
 
+// WithSliceDeepCopy will merge slice element one by one with Overwrite flag.
+func WithSliceDeepCopy(config *Config) {
+	config.sliceDeepCopy = true
+	config.Overwrite = true
+}
+
 func merge(dst, src interface{}, opts ...func(*Config)) error {
+	if dst != nil && reflect.ValueOf(dst).Kind() != reflect.Ptr {
+		return ErrNonPointerAgument
+	}
 	var (
 		vDst, vSrc reflect.Value
 		err        error
@@ -314,14 +355,10 @@ func merge(dst, src interface{}, opts ...func(*Config)) error {
 	if vDst, vSrc, err = resolveValues(dst, src); err != nil {
 		return err
 	}
-	if !vDst.CanSet() {
-		return fmt.Errorf("cannot set dst, needs reference")
-	}
 	if vDst.Type() != vSrc.Type() {
 		return ErrDifferentArgumentsTypes
 	}
-	_, err = deepMerge(vDst, vSrc, make(map[uintptr]*visit), 0, config)
-	return err
+	return deepMerge(vDst, vSrc, make(map[uintptr]*visit), 0, config)
 }
 
 // IsReflectNil is the reflect value provided nil
diff --git a/vendor/github.com/imdario/mergo/mergo.go b/vendor/github.com/imdario/mergo/mergo.go
index a82fea2fd..3cc926c7f 100644
--- a/vendor/github.com/imdario/mergo/mergo.go
+++ b/vendor/github.com/imdario/mergo/mergo.go
@@ -20,6 +20,7 @@ var (
 	ErrNotSupported                = errors.New("only structs and maps are supported")
 	ErrExpectedMapAsDestination    = errors.New("dst was expected to be a map")
 	ErrExpectedStructAsDestination = errors.New("dst was expected to be a struct")
+	ErrNonPointerAgument           = errors.New("dst must be a pointer")
 )
 
 // During deepMerge, must keep track of checks that are
@@ -75,23 +76,3 @@ func resolveValues(dst, src interface{}) (vDst, vSrc reflect.Value, err error) {
 	}
 	return
 }
-
-// Traverses recursively both values, assigning src's fields values to dst.
-// The map argument tracks comparisons that have already been seen, which allows
-// short circuiting on recursive types.
-func deeper(dst, src reflect.Value, visited map[uintptr]*visit, depth int) (err error) {
-	if dst.CanAddr() {
-		addr := dst.UnsafeAddr()
-		h := 17 * addr
-		seen := visited[h]
-		typ := dst.Type()
-		for p := seen; p != nil; p = p.next {
-			if p.ptr == addr && p.typ == typ {
-				return nil
-			}
-		}
-		// Remember, remember...
-		visited[h] = &visit{addr, typ, seen}
-	}
-	return // TODO refactor
-}