Move `git/common` to `git`

Signed-off-by: Hidde Beydals <hello@hidde.co>

controllers/gitrepository_controller.go

@@ -44,7 +44,7 @@ import (
 
 	sourcev1 "github.com/fluxcd/source-controller/api/v1beta1"
 	"github.com/fluxcd/source-controller/pkg/git"
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git/strategy"
 )
 
 // +kubebuilder:rbac:groups=source.toolkit.fluxcd.io,resources=gitrepositories,verbs=get;list;watch;create;update;patch;delete
@@ -178,9 +178,9 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 	defer os.RemoveAll(tmpGit)
 
 	// determine auth method
-	auth := &common.Auth{}
+	auth := &git.Auth{}
 	if repository.Spec.SecretRef != nil {
-		authStrategy, err := git.AuthSecretStrategyForURL(repository.Spec.URL, repository.Spec.GitImplementation)
+		authStrategy, err := strategy.AuthSecretStrategyForURL(repository.Spec.URL, repository.Spec.GitImplementation)
 		if err != nil {
 			return sourcev1.GitRepositoryNotReady(repository, sourcev1.AuthenticationFailedReason, err.Error()), err
 		}
@@ -204,7 +204,7 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 		}
 	}
 
-	checkoutStrategy, err := git.CheckoutStrategyForRef(repository.Spec.Reference, repository.Spec.GitImplementation)
+	checkoutStrategy, err := strategy.CheckoutStrategyForRef(repository.Spec.Reference, repository.Spec.GitImplementation)
 	if err != nil {
 		return sourcev1.GitRepositoryNotReady(repository, sourcev1.GitOperationFailedReason, err.Error()), err
 	}

pkg/git/common/common.go

@@ -1,51 +0,0 @@
-/*
-Copyright 2020 The Flux authors
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package common
-
-import (
-	"context"
-
-	"github.com/go-git/go-git/v5/plumbing/transport"
-	git2go "github.com/libgit2/git2go/v31"
-	corev1 "k8s.io/api/core/v1"
-)
-
-const (
-	DefaultOrigin            = "origin"
-	DefaultBranch            = "master"
-	DefaultPublicKeyAuthUser = "git"
-	CAFile                   = "caFile"
-)
-
-type Commit interface {
-	Verify(secret corev1.Secret) error
-	Hash() string
-}
-
-type CheckoutStrategy interface {
-	Checkout(ctx context.Context, path, url string, auth *Auth) (Commit, string, error)
-}
-
-type Auth struct {
-	AuthMethod   transport.AuthMethod
-	CredCallback git2go.CredentialsCallback
-	CertCallback git2go.CertificateCheckCallback
-}
-
-type AuthSecretStrategy interface {
-	Method(secret corev1.Secret) (*Auth, error)
-}

pkg/git/git.go

@@ -17,32 +17,37 @@ limitations under the License.
 package git
 
 import (
-	"fmt"
+	"context"
 
-	sourcev1 "github.com/fluxcd/source-controller/api/v1beta1"
+	"github.com/go-git/go-git/v5/plumbing/transport"
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	git2go "github.com/libgit2/git2go/v31"
-	"github.com/fluxcd/source-controller/pkg/git/gogit"
+	corev1 "k8s.io/api/core/v1"
-	"github.com/fluxcd/source-controller/pkg/git/libgit2"
 )
 
-func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef, gitImplementation string) (common.CheckoutStrategy, error) {
+const (
-	switch gitImplementation {
+	DefaultOrigin            = "origin"
-	case sourcev1.GoGitImplementation:
+	DefaultBranch            = "master"
-		return gogit.CheckoutStrategyForRef(ref), nil
+	DefaultPublicKeyAuthUser = "git"
-	case sourcev1.LibGit2Implementation:
+	CAFile                   = "caFile"
-		return libgit2.CheckoutStrategyForRef(ref), nil
+)
-	default:
+
-		return nil, fmt.Errorf("invalid git implementation %s", gitImplementation)
+type Commit interface {
-	}
+	Verify(secret corev1.Secret) error
+	Hash() string
 }
 
-func AuthSecretStrategyForURL(url string, gitImplementation string) (common.AuthSecretStrategy, error) {
+type CheckoutStrategy interface {
-	switch gitImplementation {
+	Checkout(ctx context.Context, path, url string, auth *Auth) (Commit, string, error)
-	case sourcev1.GoGitImplementation:
-		return gogit.AuthSecretStrategyForURL(url)
-	case sourcev1.LibGit2Implementation:
-		return libgit2.AuthSecretStrategyForURL(url)
-	default:
-		return nil, fmt.Errorf("invalid git implementation %s", gitImplementation)
 }
+
+// TODO(hidde): candidate for refactoring, so that we do not directly
+//  depend on implementation specifics here.
+type Auth struct {
+	AuthMethod   transport.AuthMethod
+	CredCallback git2go.CredentialsCallback
+	CertCallback git2go.CertificateCheckCallback
+}
+
+type AuthSecretStrategy interface {
+	Method(secret corev1.Secret) (*Auth, error)
 }

pkg/git/gogit/checkout.go

@@ -23,19 +23,19 @@ import (
 	"time"
 
 	"github.com/Masterminds/semver/v3"
-	"github.com/go-git/go-git/v5"
+	extgogit "github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
 
 	"github.com/fluxcd/pkg/version"
 
 	sourcev1 "github.com/fluxcd/source-controller/api/v1beta1"
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
-func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef) common.CheckoutStrategy {
+func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef) git.CheckoutStrategy {
 	switch {
 	case ref == nil:
-		return &CheckoutBranch{branch: common.DefaultBranch}
+		return &CheckoutBranch{branch: git.DefaultBranch}
 	case ref.SemVer != "":
 		return &CheckoutSemVer{semVer: ref.SemVer}
 	case ref.Tag != "":
@@ -43,13 +43,13 @@ func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef) common.CheckoutStrat
 	case ref.Commit != "":
 		strategy := &CheckoutCommit{branch: ref.Branch, commit: ref.Commit}
 		if strategy.branch == "" {
-			strategy.branch = common.DefaultBranch
+			strategy.branch = git.DefaultBranch
 		}
 		return strategy
 	case ref.Branch != "":
 		return &CheckoutBranch{branch: ref.Branch}
 	default:
-		return &CheckoutBranch{branch: common.DefaultBranch}
+		return &CheckoutBranch{branch: git.DefaultBranch}
 	}
 }
 
@@ -57,18 +57,18 @@ type CheckoutBranch struct {
 	branch string
 }
 
-func (c *CheckoutBranch) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutBranch) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
-	repo, err := git.PlainCloneContext(ctx, path, false, &git.CloneOptions{
+	repo, err := extgogit.PlainCloneContext(ctx, path, false, &extgogit.CloneOptions{
 		URL:               url,
 		Auth:              auth.AuthMethod,
-		RemoteName:        common.DefaultOrigin,
+		RemoteName:        git.DefaultOrigin,
 		ReferenceName:     plumbing.NewBranchReferenceName(c.branch),
 		SingleBranch:      true,
 		NoCheckout:        false,
 		Depth:             1,
 		RecurseSubmodules: 0,
 		Progress:          nil,
-		Tags:              git.NoTags,
+		Tags:              extgogit.NoTags,
 	})
 	if err != nil {
 		return nil, "", fmt.Errorf("unable to clone '%s', error: %w", url, err)
@@ -88,18 +88,18 @@ type CheckoutTag struct {
 	tag string
 }
 
-func (c *CheckoutTag) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutTag) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
-	repo, err := git.PlainCloneContext(ctx, path, false, &git.CloneOptions{
+	repo, err := extgogit.PlainCloneContext(ctx, path, false, &extgogit.CloneOptions{
 		URL:               url,
 		Auth:              auth.AuthMethod,
-		RemoteName:        common.DefaultOrigin,
+		RemoteName:        git.DefaultOrigin,
 		ReferenceName:     plumbing.NewTagReferenceName(c.tag),
 		SingleBranch:      true,
 		NoCheckout:        false,
 		Depth:             1,
 		RecurseSubmodules: 0,
 		Progress:          nil,
-		Tags:              git.NoTags,
+		Tags:              extgogit.NoTags,
 	})
 	if err != nil {
 		return nil, "", fmt.Errorf("unable to clone '%s', error: %w", url, err)
@@ -120,17 +120,17 @@ type CheckoutCommit struct {
 	commit string
 }
 
-func (c *CheckoutCommit) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutCommit) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
-	repo, err := git.PlainCloneContext(ctx, path, false, &git.CloneOptions{
+	repo, err := extgogit.PlainCloneContext(ctx, path, false, &extgogit.CloneOptions{
 		URL:               url,
 		Auth:              auth.AuthMethod,
-		RemoteName:        common.DefaultOrigin,
+		RemoteName:        git.DefaultOrigin,
 		ReferenceName:     plumbing.NewBranchReferenceName(c.branch),
 		SingleBranch:      true,
 		NoCheckout:        false,
 		RecurseSubmodules: 0,
 		Progress:          nil,
-		Tags:              git.NoTags,
+		Tags:              extgogit.NoTags,
 	})
 	if err != nil {
 		return nil, "", fmt.Errorf("unable to clone '%s', error: %w", url, err)
@@ -143,7 +143,7 @@ func (c *CheckoutCommit) Checkout(ctx context.Context, path, url string, auth *c
 	if err != nil {
 		return nil, "", fmt.Errorf("git commit '%s' not found: %w", c.commit, err)
 	}
-	err = w.Checkout(&git.CheckoutOptions{
+	err = w.Checkout(&extgogit.CheckoutOptions{
 		Hash:  commit.Hash,
 		Force: true,
 	})
@@ -157,21 +157,21 @@ type CheckoutSemVer struct {
 	semVer string
 }
 
-func (c *CheckoutSemVer) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutSemVer) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
 	verConstraint, err := semver.NewConstraint(c.semVer)
 	if err != nil {
 		return nil, "", fmt.Errorf("semver parse range error: %w", err)
 	}
 
-	repo, err := git.PlainCloneContext(ctx, path, false, &git.CloneOptions{
+	repo, err := extgogit.PlainCloneContext(ctx, path, false, &extgogit.CloneOptions{
 		URL:               url,
 		Auth:              auth.AuthMethod,
-		RemoteName:        common.DefaultOrigin,
+		RemoteName:        git.DefaultOrigin,
 		NoCheckout:        false,
 		Depth:             1,
 		RecurseSubmodules: 0,
 		Progress:          nil,
-		Tags:              git.AllTags,
+		Tags:              extgogit.AllTags,
 	})
 	if err != nil {
 		return nil, "", fmt.Errorf("unable to clone '%s', error: %w", url, err)
@@ -238,7 +238,7 @@ func (c *CheckoutSemVer) Checkout(ctx context.Context, path, url string, auth *c
 		return nil, "", fmt.Errorf("git worktree error: %w", err)
 	}
 
-	err = w.Checkout(&git.CheckoutOptions{
+	err = w.Checkout(&extgogit.CheckoutOptions{
 		Branch: plumbing.NewTagReferenceName(t),
 	})
 	if err != nil {

pkg/git/gogit/checkout_test.go

@@ -22,11 +22,11 @@ import (
 	"os"
 	"testing"
 
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
 func TestCheckoutTagSemVer_Checkout(t *testing.T) {
-	auth := &common.Auth{}
+	auth := &git.Auth{}
 	tag := CheckoutTag{
 		tag: "v1.7.0",
 	}

pkg/git/gogit/transport.go

@@ -26,10 +26,10 @@ import (
 
 	"github.com/fluxcd/pkg/ssh/knownhosts"
 
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
-func AuthSecretStrategyForURL(URL string) (common.AuthSecretStrategy, error) {
+func AuthSecretStrategyForURL(URL string) (git.AuthSecretStrategy, error) {
 	u, err := url.Parse(URL)
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse URL to determine auth strategy: %w", err)
@@ -47,8 +47,8 @@ func AuthSecretStrategyForURL(URL string) (common.AuthSecretStrategy, error) {
 
 type BasicAuth struct{}
 
-func (s *BasicAuth) Method(secret corev1.Secret) (*common.Auth, error) {
+func (s *BasicAuth) Method(secret corev1.Secret) (*git.Auth, error) {
-	if _, ok := secret.Data[common.CAFile]; ok {
+	if _, ok := secret.Data[git.CAFile]; ok {
 		return nil, fmt.Errorf("found caFile key in secret '%s' but go-git HTTP transport does not support custom certificates", secret.Name)
 	}
 
@@ -62,18 +62,17 @@ func (s *BasicAuth) Method(secret corev1.Secret) (*common.Auth, error) {
 	if auth.Username == "" || auth.Password == "" {
 		return nil, fmt.Errorf("invalid '%s' secret data: required fields 'username' and 'password'", secret.Name)
 	}
-	return &common.Auth{AuthMethod: auth}, nil
+	return &git.Auth{AuthMethod: auth}, nil
 }
 
 type PublicKeyAuth struct {
 	user string
 }
 
-func (s *PublicKeyAuth) Method(secret corev1.Secret) (*common.Auth, error) {
+func (s *PublicKeyAuth) Method(secret corev1.Secret) (*git.Auth, error) {
-	if _, ok := secret.Data[common.CAFile]; ok {
+	if _, ok := secret.Data[git.CAFile]; ok {
 		return nil, fmt.Errorf("found caFile key in secret '%s' but go-git SSH transport does not support custom certificates", secret.Name)
 	}
-
 	identity := secret.Data["identity"]
 	knownHosts := secret.Data["known_hosts"]
 	if len(identity) == 0 || len(knownHosts) == 0 {
@@ -82,7 +81,7 @@ func (s *PublicKeyAuth) Method(secret corev1.Secret) (*common.Auth, error) {
 
 	user := s.user
 	if user == "" {
-		user = common.DefaultPublicKeyAuthUser
+		user = git.DefaultPublicKeyAuthUser
 	}
 
 	pk, err := ssh.NewPublicKeys(user, identity, "")
@@ -95,5 +94,5 @@ func (s *PublicKeyAuth) Method(secret corev1.Secret) (*common.Auth, error) {
 		return nil, err
 	}
 	pk.HostKeyCallback = callback
-	return &common.Auth{AuthMethod: pk}, nil
+	return &git.Auth{AuthMethod: pk}, nil
 }

pkg/git/gogit/transport_test.go

@@ -23,7 +23,7 @@ import (
 	"github.com/go-git/go-git/v5/plumbing/transport/http"
 	corev1 "k8s.io/api/core/v1"
 
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
 const (
@@ -69,7 +69,7 @@ func TestAuthSecretStrategyForURL(t *testing.T) {
 	tests := []struct {
 		name    string
 		url     string
-		want    common.AuthSecretStrategy
+		want    git.AuthSecretStrategy
 		wantErr bool
 	}{
 		{"HTTP", "http://git.example.com/org/repo.git", &BasicAuth{}, false},
@@ -97,10 +97,10 @@ func TestBasicAuthStrategy_Method(t *testing.T) {
 		name    string
 		secret  corev1.Secret
 		modify  func(secret *corev1.Secret)
-		want    *common.Auth
+		want    *git.Auth
 		wantErr bool
 	}{
-		{"username and password", basicAuthSecretFixture, nil, &common.Auth{AuthMethod: &http.BasicAuth{Username: "git", Password: "password"}}, false},
+		{"username and password", basicAuthSecretFixture, nil, &git.Auth{AuthMethod: &http.BasicAuth{Username: "git", Password: "password"}}, false},
 		{"without username", basicAuthSecretFixture, func(s *corev1.Secret) { delete(s.Data, "username") }, nil, true},
 		{"without password", basicAuthSecretFixture, func(s *corev1.Secret) { delete(s.Data, "password") }, nil, true},
 		{"empty", corev1.Secret{}, nil, nil, true},

pkg/git/libgit2/checkout.go

@@ -24,13 +24,13 @@ import (
 	git2go "github.com/libgit2/git2go/v31"
 
 	sourcev1 "github.com/fluxcd/source-controller/api/v1beta1"
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
-func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef) common.CheckoutStrategy {
+func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef) git.CheckoutStrategy {
 	switch {
 	case ref == nil:
-		return &CheckoutBranch{branch: common.DefaultBranch}
+		return &CheckoutBranch{branch: git.DefaultBranch}
 	case ref.SemVer != "":
 		return &CheckoutSemVer{semVer: ref.SemVer}
 	case ref.Tag != "":
@@ -38,13 +38,13 @@ func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef) common.CheckoutStrat
 	case ref.Commit != "":
 		strategy := &CheckoutCommit{branch: ref.Branch, commit: ref.Commit}
 		if strategy.branch == "" {
-			strategy.branch = common.DefaultBranch
+			strategy.branch = git.DefaultBranch
 		}
 		return strategy
 	case ref.Branch != "":
 		return &CheckoutBranch{branch: ref.Branch}
 	default:
-		return &CheckoutBranch{branch: common.DefaultBranch}
+		return &CheckoutBranch{branch: git.DefaultBranch}
 	}
 }
 
@@ -52,7 +52,7 @@ type CheckoutBranch struct {
 	branch string
 }
 
-func (c *CheckoutBranch) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutBranch) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
 	repo, err := git2go.Clone(url, path, &git2go.CloneOptions{
 		FetchOptions: &git2go.FetchOptions{
 			DownloadTags: git2go.DownloadTagsNone,
@@ -81,7 +81,7 @@ type CheckoutTag struct {
 	tag string
 }
 
-func (c *CheckoutTag) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutTag) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
 	repo, err := git2go.Clone(url, path, &git2go.CloneOptions{
 		FetchOptions: &git2go.FetchOptions{
 			DownloadTags: git2go.DownloadTagsAll,
@@ -118,7 +118,7 @@ type CheckoutCommit struct {
 	commit string
 }
 
-func (c *CheckoutCommit) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutCommit) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
 	repo, err := git2go.Clone(url, path, &git2go.CloneOptions{
 		FetchOptions: &git2go.FetchOptions{
 			DownloadTags: git2go.DownloadTagsNone,
@@ -158,7 +158,7 @@ type CheckoutSemVer struct {
 	semVer string
 }
 
-func (c *CheckoutSemVer) Checkout(ctx context.Context, path, url string, auth *common.Auth) (common.Commit, string, error) {
+func (c *CheckoutSemVer) Checkout(ctx context.Context, path, url string, auth *git.Auth) (git.Commit, string, error) {
 	rng, err := semver.ParseRange(c.semVer)
 	if err != nil {
 		return nil, "", fmt.Errorf("semver parse range error: %w", err)

pkg/git/libgit2/checkout_test.go

@@ -22,15 +22,16 @@ import (
 	"os"
 	"testing"
 
-	"github.com/fluxcd/source-controller/pkg/git/common"
 	git2go "github.com/libgit2/git2go/v31"
+
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
 func TestCheckoutTagSemVer_Checkout(t *testing.T) {
 	certCallback := func(cert *git2go.Certificate, valid bool, hostname string) git2go.ErrorCode {
 		return 0
 	}
-	auth := &common.Auth{CertCallback: certCallback}
+	auth := &git.Auth{CertCallback: certCallback}
 
 	tag := CheckoutTag{
 		tag: "v1.7.0",

pkg/git/libgit2/transport.go

@@ -30,10 +30,10 @@ import (
 	git2go "github.com/libgit2/git2go/v31"
 	corev1 "k8s.io/api/core/v1"
 
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
-func AuthSecretStrategyForURL(URL string) (common.AuthSecretStrategy, error) {
+func AuthSecretStrategyForURL(URL string) (git.AuthSecretStrategy, error) {
 	u, err := url.Parse(URL)
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse URL to determine auth strategy: %w", err)
@@ -51,7 +51,7 @@ func AuthSecretStrategyForURL(URL string) (common.AuthSecretStrategy, error) {
 
 type BasicAuth struct{}
 
-func (s *BasicAuth) Method(secret corev1.Secret) (*common.Auth, error) {
+func (s *BasicAuth) Method(secret corev1.Secret) (*git.Auth, error) {
 	var credCallback git2go.CredentialsCallback
 	var username string
 	if d, ok := secret.Data["username"]; ok {
@@ -72,7 +72,7 @@ func (s *BasicAuth) Method(secret corev1.Secret) (*common.Auth, error) {
 	}
 
 	var certCallback git2go.CertificateCheckCallback
-	if caFile, ok := secret.Data[common.CAFile]; ok {
+	if caFile, ok := secret.Data[git.CAFile]; ok {
 		certCallback = func(cert *git2go.Certificate, valid bool, hostname string) git2go.ErrorCode {
 			roots := x509.NewCertPool()
 			ok := roots.AppendCertsFromPEM(caFile)
@@ -92,18 +92,17 @@ func (s *BasicAuth) Method(secret corev1.Secret) (*common.Auth, error) {
 		}
 	}
 
-	return &common.Auth{CredCallback: credCallback, CertCallback: certCallback}, nil
+	return &git.Auth{CredCallback: credCallback, CertCallback: certCallback}, nil
 }
 
 type PublicKeyAuth struct {
 	user string
 }
 
-func (s *PublicKeyAuth) Method(secret corev1.Secret) (*common.Auth, error) {
+func (s *PublicKeyAuth) Method(secret corev1.Secret) (*git.Auth, error) {
-	if _, ok := secret.Data[common.CAFile]; ok {
+	if _, ok := secret.Data[git.CAFile]; ok {
 		return nil, fmt.Errorf("found caFile key in secret '%s' but libgit2 SSH transport does not support custom certificates", secret.Name)
 	}
-
 	identity := secret.Data["identity"]
 	knownHosts := secret.Data["known_hosts"]
 	if len(identity) == 0 || len(knownHosts) == 0 {
@@ -124,7 +123,7 @@ func (s *PublicKeyAuth) Method(secret corev1.Secret) (*common.Auth, error) {
 
 	user := s.user
 	if user == "" {
-		user = common.DefaultPublicKeyAuthUser
+		user = git.DefaultPublicKeyAuthUser
 	}
 
 	credCallback := func(url string, username_from_url string, allowed_types git2go.CredType) (*git2go.Cred, error) {
@@ -143,7 +142,7 @@ func (s *PublicKeyAuth) Method(secret corev1.Secret) (*common.Auth, error) {
 		return git2go.ErrGeneric
 	}
 
-	return &common.Auth{CredCallback: credCallback, CertCallback: certCallback}, nil
+	return &git.Auth{CredCallback: credCallback, CertCallback: certCallback}, nil
 }
 
 type knownKey struct {

pkg/git/libgit2/transport_test.go

@@ -22,7 +22,7 @@ import (
 
 	corev1 "k8s.io/api/core/v1"
 
-	"github.com/fluxcd/source-controller/pkg/git/common"
+	"github.com/fluxcd/source-controller/pkg/git"
 )
 
 const (
@@ -68,7 +68,7 @@ func TestAuthSecretStrategyForURL(t *testing.T) {
 	tests := []struct {
 		name    string
 		url     string
-		want    common.AuthSecretStrategy
+		want    git.AuthSecretStrategy
 		wantErr bool
 	}{
 		{"HTTP", "http://git.example.com/org/repo.git", &BasicAuth{}, false},

pkg/git/strategy/strategy.go

@@ -0,0 +1,48 @@
+/*
+Copyright 2020 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package strategy
+
+import (
+	"fmt"
+
+	sourcev1 "github.com/fluxcd/source-controller/api/v1beta1"
+	"github.com/fluxcd/source-controller/pkg/git"
+	"github.com/fluxcd/source-controller/pkg/git/gogit"
+	"github.com/fluxcd/source-controller/pkg/git/libgit2"
+)
+
+func CheckoutStrategyForRef(ref *sourcev1.GitRepositoryRef, gitImplementation string) (git.CheckoutStrategy, error) {
+	switch gitImplementation {
+	case sourcev1.GoGitImplementation:
+		return gogit.CheckoutStrategyForRef(ref), nil
+	case sourcev1.LibGit2Implementation:
+		return libgit2.CheckoutStrategyForRef(ref), nil
+	default:
+		return nil, fmt.Errorf("invalid git implementation %s", gitImplementation)
+	}
+}
+
+func AuthSecretStrategyForURL(url string, gitImplementation string) (git.AuthSecretStrategy, error) {
+	switch gitImplementation {
+	case sourcev1.GoGitImplementation:
+		return gogit.AuthSecretStrategyForURL(url)
+	case sourcev1.LibGit2Implementation:
+		return libgit2.AuthSecretStrategyForURL(url)
+	default:
+		return nil, fmt.Errorf("invalid git implementation %s", gitImplementation)
+	}
+}