package task import ( "context" "fmt" "io/fs" "cuelang.org/go/cue" "go.dagger.io/dagger/compiler" "go.dagger.io/dagger/plancontext" "go.dagger.io/dagger/solver" ) func init() { Register("ReadFile", func() Task { return &readFileTask{} }) } type readFileTask struct { } func (t *readFileTask) Run(ctx context.Context, pctx *plancontext.Context, s solver.Solver, v *compiler.Value) (*compiler.Value, error) { path, err := v.Lookup("path").String() if err != nil { return nil, err } input, err := pctx.FS.FromValue(v.Lookup("input")) if err != nil { return nil, err } inputFS := solver.NewBuildkitFS(input.Result()) // FIXME: we should create an intermediate image containing only `path`. // That way, on cache misses, we'll only download the layer with the file contents rather than the entire FS. contents, err := fs.ReadFile(inputFS, path) if err != nil { return nil, fmt.Errorf("ReadFile %s: %w", path, err) } output := compiler.NewValue() if err := output.FillPath(cue.ParsePath("contents"), string(contents)); err != nil { return nil, err } return output, nil }