Files
mesh-catalog/modules/mesh-build-go/buildstep/narrow.go
T
jschoubben 9c57f7afb3 mesh-build-go publishes the build runner as its own package, so the other build modules share it without mesh-sdk (ADR 0593 §1)
The runner, the toolchain guard, the fetch, the parsers, buildcpu, the conformance kit and mesh-pack move from mesh-sdk's
buildstep into modules/mesh-build-go/buildstep (own go.mod). mesh-build-go, mesh-build-node and mesh-build-image require it
by a same-repository replace; what the delivery parts read (the failure contract, the fetch request, the stale sweep, the
module tree shape, NewID, CapacitySetting) stays imported from mesh-sdk as sdkstep.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL
2026-11-02 18:22:41 +01:00

73 lines
2.4 KiB
Go

package buildstep
import (
"fmt"
sdkstep "git.novox.be/novox/mesh-sdk/go/buildstep"
"os"
"path"
"path/filepath"
"strings"
)
// narrowKept are the files of a module's directory a narrowed build keeps beside its named paths: its manifest and
// its lock files, each an input of the module's key (ModuleTree's Manifest and Locks). package.json and go.mod are
// not kept: neither is in the named tree, so a build that needs one names it among its artifact's paths, which puts
// it in the key (novox/hq ADR 0499 clause 4).
var narrowKept = append([]string{"module.json"}, lockFiles...)
// Narrow leaves in the fetched tree only what a build of an artifact that names its paths may see (novox/hq ADR 0499
// clause 4): r.Dir's named paths, its manifest and lock files, and .git; everything else is removed, so a file outside
// them cannot change what is built without changing its key. A named path absent at the tree is an error naming it,
// and nothing is removed then. With no paths in r it changes nothing. Both build modules' fetch steps call it.
func Narrow(tree string, r sdkstep.FetchRequest) error {
if len(r.Paths) == 0 {
return nil
}
keep := map[string]bool{".git": true}
for _, p := range r.Paths {
rel := path.Join(r.Dir, p)
if strings.HasPrefix(rel, "../") || rel == ".." || path.IsAbs(p) {
return fmt.Errorf("the named path %q leaves the module's directory", p)
}
if _, err := os.Lstat(filepath.Join(tree, filepath.FromSlash(rel))); err != nil {
return fmt.Errorf("the named path %q is not in the fetched tree: %w", p, err)
}
keep[rel] = true
}
for _, f := range narrowKept {
keep[path.Join(r.Dir, f)] = true
}
return prune(tree, "", keep)
}
// prune removes from dir (rel within the tree) every entry that is neither kept nor on the way to one.
func prune(root, rel string, keep map[string]bool) error {
entries, err := os.ReadDir(filepath.Join(root, filepath.FromSlash(rel)))
if err != nil {
return err
}
for _, e := range entries {
p := path.Join(rel, e.Name())
if keep[p] {
continue
}
ancestor := false
for k := range keep {
if strings.HasPrefix(k, p+"/") {
ancestor = true
break
}
}
if ancestor && e.IsDir() {
if err := prune(root, p, keep); err != nil {
return err
}
continue
}
if err := os.RemoveAll(filepath.Join(root, filepath.FromSlash(p))); err != nil {
return err
}
}
return nil
}