ported op.#FetchGit to engine.#GitPull

Signed-off-by: Richard Jones <richard@dagger.io>

plan/task/gitPull.go

@@ -0,0 +1,80 @@
+package task
+
+import (
+	"context"
+	"net/url"
+
+	"github.com/moby/buildkit/client/llb"
+	"go.dagger.io/dagger/compiler"
+	"go.dagger.io/dagger/plancontext"
+	"go.dagger.io/dagger/solver"
+)
+
+func init() {
+	Register("GitPull", func() Task { return &gitPullTask{} })
+}
+
+type gitPullTask struct {
+}
+
+func (c gitPullTask) Run(ctx context.Context, pctx *plancontext.Context, s solver.Solver, v *compiler.Value) (*compiler.Value, error) {
+	remote, err := v.Lookup("remote").String()
+	if err != nil {
+		return nil, err
+	}
+	ref, err := v.Lookup("ref").String()
+	if err != nil {
+		return nil, err
+	}
+
+	remoteRedacted := remote
+	if u, err := url.Parse(remote); err == nil {
+		remoteRedacted = u.Redacted()
+	}
+
+	gitOpts := []llb.GitOption{}
+	var opts struct {
+		KeepGitDir bool
+	}
+
+	if err := v.Decode(&opts); err != nil {
+		return nil, err
+	}
+
+	if opts.KeepGitDir {
+		gitOpts = append(gitOpts, llb.KeepGitDir())
+	}
+	// Secret
+	if authToken := v.Lookup("auth.token"); authToken.Exists() {
+		authTokenSecret, err := pctx.Secrets.FromValue(authToken)
+		if err != nil {
+			return nil, err
+		}
+		gitOpts = append(gitOpts, llb.AuthTokenSecret(authTokenSecret.ID()))
+	}
+	if authHeader := v.Lookup("auth.header"); authHeader.Exists() {
+		authHeaderSecret, err := pctx.Secrets.FromValue(authHeader)
+		if err != nil {
+			return nil, err
+		}
+		gitOpts = append(gitOpts, llb.AuthHeaderSecret(authHeaderSecret.ID()))
+	}
+
+	gitOpts = append(gitOpts, withCustomName(v, "FetchGit %s@%s", remoteRedacted, ref))
+
+	st := llb.Git(
+		remote,
+		ref,
+		gitOpts...,
+	)
+
+	result, err := s.Solve(ctx, st, pctx.Platform.Get())
+	if err != nil {
+		return nil, err
+	}
+
+	fs := pctx.FS.New(result)
+	return compiler.NewValue().FillFields(map[string]interface{}{
+		"contents": fs.MarshalCUE(),
+	})
+}