diff --git a/engine/auth/auth.go b/engine/auth/auth.go
deleted file mode 100644
index 997bb12..0000000
--- a/engine/auth/auth.go
+++ /dev/null
@@ -1,122 +0,0 @@
-// Copyright 2019 Drone.IO Inc. All rights reserved.
-// Use of this source code is governed by the Polyform License
-// that can be found in the LICENSE file.
-
-package auth
-
-import (
-	"encoding/base64"
-	"encoding/json"
-	"io"
-	"net/url"
-	"os"
-	"strings"
-
-	"github.com/drone-runners/drone-runner-docker/engine"
-)
-
-// config represents the Docker client configuration,
-// typically located at ~/.docker/config.json
-type config struct {
-	Auths map[string]auths `json:"auths"`
-}
-
-type auths struct {
-	Auth string `json:"auth"`
-}
-
-// Parse parses the registry credential from the reader.
-func Parse(r io.Reader) ([]*engine.Auth, error) {
-	c := new(config)
-	err := json.NewDecoder(r).Decode(c)
-	if err != nil {
-		return nil, err
-	}
-	var auths []*engine.Auth
-	for k, v := range c.Auths {
-		username, password := decode(v.Auth)
-		auths = append(auths, &engine.Auth{
-			Address:  hostname(k),
-			Username: username,
-			Password: password,
-		})
-	}
-	return auths, nil
-}
-
-// ParseFile parses the registry credential file.
-func ParseFile(filepath string) ([]*engine.Auth, error) {
-	f, err := os.Open(filepath)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	return Parse(f)
-}
-
-// ParseString parses the registry credential file.
-func ParseString(s string) ([]*engine.Auth, error) {
-	return Parse(strings.NewReader(s))
-}
-
-// encode returns the encoded credentials.
-func encode(username, password string) string {
-	return base64.StdEncoding.EncodeToString(
-		[]byte(username + ":" + password),
-	)
-}
-
-// decode returns the decoded credentials.
-func decode(s string) (username, password string) {
-	d, err := base64.StdEncoding.DecodeString(s)
-	if err != nil {
-		return
-	}
-	parts := strings.SplitN(string(d), ":", 2)
-	if len(parts) > 0 {
-		username = parts[0]
-	}
-	if len(parts) > 1 {
-		password = parts[1]
-	}
-	return
-}
-
-func hostname(s string) string {
-	uri, _ := url.Parse(s)
-	if uri.Host != "" {
-		s = uri.Host
-	}
-	return s
-}
-
-// Encode returns the json marshaled, base64 encoded
-// credential string that can be passed to the docker
-// registry authentication header.
-func Encode(username, password string) string {
-	v := struct {
-		Username string `json:"username,omitempty"`
-		Password string `json:"password,omitempty"`
-	}{
-		Username: username,
-		Password: password,
-	}
-	buf, _ := json.Marshal(&v)
-	return base64.URLEncoding.EncodeToString(buf)
-}
-
-// Marshal marshals the Auth credentials to a
-// .docker/config.json file.
-func Marshal(list []*engine.Auth) ([]byte, error) {
-	out := &config{}
-	out.Auths = map[string]auths{}
-	for _, item := range list {
-		out.Auths[item.Address] = auths{
-			Auth: encode(
-				item.Username,
-				item.Password,
-			),
-		}
-	}
-	return json.Marshal(out)
-}
diff --git a/engine/auth/auth_test.go b/engine/auth/auth_test.go
deleted file mode 100644
index 6b94d72..0000000
--- a/engine/auth/auth_test.go
+++ /dev/null
@@ -1,143 +0,0 @@
-// Copyright 2019 Drone.IO Inc. All rights reserved.
-// Use of this source code is governed by the Polyform License
-// that can be found in the LICENSE file.
-
-package auth
-
-import (
-	"bytes"
-	"encoding/base64"
-	"os"
-	"testing"
-
-	"github.com/drone-runners/drone-runner-docker/engine"
-
-	"github.com/google/go-cmp/cmp"
-)
-
-func TestParse(t *testing.T) {
-	got, err := ParseString(sample)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-	want := []*engine.Auth{
-		{
-			Address:  "index.docker.io",
-			Username: "octocat",
-			Password: "correct-horse-battery-staple",
-		},
-	}
-	if diff := cmp.Diff(got, want); diff != "" {
-		t.Errorf(diff)
-	}
-}
-
-func TestParseGCR(t *testing.T) {
-	got, err := ParseFile("testdata/config_gcr.json")
-	if err != nil {
-		t.Error(err)
-		return
-	}
-	want := []*engine.Auth{
-		{
-			Address:  "gcr.io",
-			Username: "_json_key",
-			Password: "xxx:bar\n",
-		},
-	}
-	if diff := cmp.Diff(got, want); diff != "" {
-		t.Errorf(diff)
-	}
-}
-
-func TestParseErr(t *testing.T) {
-	_, err := ParseString("")
-	if err == nil {
-		t.Errorf("Expect unmarshal error")
-	}
-}
-
-func TestParseFile(t *testing.T) {
-	got, err := ParseFile("./testdata/config.json")
-	if err != nil {
-		t.Error(err)
-		return
-	}
-	want := []*engine.Auth{
-		{
-			Address:  "index.docker.io",
-			Username: "octocat",
-			Password: "correct-horse-battery-staple",
-		},
-	}
-	if diff := cmp.Diff(got, want); diff != "" {
-		t.Errorf(diff)
-	}
-}
-
-func TestParseFileErr(t *testing.T) {
-	_, err := ParseFile("./testdata/x.json")
-	if _, ok := err.(*os.PathError); !ok {
-		t.Errorf("Expect error when file does not exist")
-	}
-}
-
-func Test_encodeDecode(t *testing.T) {
-	username := "octocat"
-	password := "correct-horse-battery-staple"
-
-	encoded := encode(username, password)
-	decodedUsername, decodedPassword := decode(encoded)
-	if got, want := decodedUsername, username; got != want {
-		t.Errorf("Want decoded username %s, got %s", want, got)
-	}
-	if got, want := decodedPassword, password; got != want {
-		t.Errorf("Want decoded password %s, got %s", want, got)
-	}
-}
-
-func Test_decodeInvalid(t *testing.T) {
-	username, password := decode("b2N0b2NhdDp==")
-	if username != "" || password != "" {
-		t.Errorf("Expect decoding error")
-	}
-}
-
-func TestEncode(t *testing.T) {
-	username := "octocat"
-	password := "correct-horse-battery-staple"
-	result := Encode(username, password)
-	got, err := base64.URLEncoding.DecodeString(result)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-	want := []byte(`{"username":"octocat","password":"correct-horse-battery-staple"}`)
-	if bytes.Equal(got, want) == false {
-		t.Errorf("Could not decode credential header")
-	}
-}
-
-func TestMarshal(t *testing.T) {
-	auths := []*engine.Auth{
-		{
-			Address:  "index.docker.io",
-			Username: "octocat",
-			Password: "correct-horse-battery-staple",
-		},
-	}
-	got, _ := Marshal(auths)
-	want := []byte(`{"auths":{"index.docker.io":{"auth":"b2N0b2NhdDpjb3JyZWN0LWhvcnNlLWJhdHRlcnktc3RhcGxl"}}}`)
-	if bytes.Equal(got, want) == false {
-		t.Errorf("Could not decode credential header")
-	}
-}
-
-var sample = `{
-	"auths": {
-		"https://index.docker.io/v1/": {
-			"auth": "b2N0b2NhdDpjb3JyZWN0LWhvcnNlLWJhdHRlcnktc3RhcGxl"
-		}
-	}
-}`
diff --git a/engine/auth/testdata/config.json b/engine/auth/testdata/config.json
deleted file mode 100644
index 382c690..0000000
--- a/engine/auth/testdata/config.json
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-	"auths": {
-		"https://index.docker.io/v1/": {
-			"auth": "b2N0b2NhdDpjb3JyZWN0LWhvcnNlLWJhdHRlcnktc3RhcGxl"
-		}
-	}
-}
\ No newline at end of file
diff --git a/engine/auth/testdata/config_gcr.json b/engine/auth/testdata/config_gcr.json
deleted file mode 100644
index 259907a..0000000
--- a/engine/auth/testdata/config_gcr.json
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-    "auths": {
-        "gcr.io": {
-            "auth": "X2pzb25fa2V5Onh4eDpiYXIK"
-        }
-    }
-}
\ No newline at end of file