fix(builder): Allow custom dockerfile names when building by craciunoiuc · Pull Request #322 · unikraft/cli

craciunoiuc · 2026-05-12T12:16:02Z

Previously, the name was cut from the path, so it used the default 'Dockerfile' name breaking functionality.

~~Depends on: unikraft-cloud/x#253~~
Merged

Closes: TOOL-855

~~TODOs left:~~
* Bump the library after merging
* Update the golden files for tests when they start behaving

jedevc · 2026-05-14T08:19:10Z

This shouldn't be merged as is, it should use the kraftfile dockerfile property.

craciunoiuc · 2026-05-14T09:23:22Z

correct

Copilot

Pull request overview

This PR updates the build pipeline to support building rootfs images from Dockerfiles with non-default filenames by introducing an explicit Rootfs.Dockerfile field, wiring it through Kraftfile parsing, and passing the correct BuildKit frontend attributes for Dockerfile selection.

Changes:

Add FSOpts.Dockerfile and plumb it from Kraftfile (rootfs.source.dockerfile) into builder options.
Update BuildKit LocalDirs/frontend attrs so the Dockerfile frontend can be pointed at a custom filename.
Add integration/E2E test coverage for building with a custom Dockerfile name and bump unikraft.com/x/kraftfile.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
internal/builder/rootfs.go	Adjusts Dockerfile build context wiring to BuildKit; updates dockerfile-path validation/error messages.
internal/builder/rootfs_test.go	Adds integration test for custom Dockerfile filename builds.
internal/builder/kraftfile.go	Adapts to new kraftfile `FSSource` shape and propagates `dockerfile` to `BuildOpts`.
internal/builder/kraftfile_test.go	Updates tests for new kraftfile source structure and adds dockerfile-field cases.
internal/builder/build.go	Extends `FSOpts` with a `Dockerfile` field.
cmd/unikraft/integration/build_test.go	Adds end-to-end test for `rootfs.source.dockerfile` in Kraftfile.
go.mod / go.sum	Bumps `unikraft.com/x/kraftfile` dependency and updates sums.

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jedevc · 2026-05-26T11:11:37Z

+		localDirs["dockerfile"] = filepath.Join(opts.Rootfs.Path, filepath.Dir(opts.Rootfs.Dockerfile))
+		attrs["filename"] = filepath.Base(opts.Rootfs.Dockerfile)
+	} else {
+		localDirs["context"] = filepath.Dir(opts.Rootfs.Path)


👀 Wait why are we changing the context to be the dir here? That's a change from before.

IMO, the source field in the file should now ideally never contain a path to a Dockerfile. We could have a check somewhere that if the path passed is a file, then take the parent directory as the directory, and take the filename as the "filename".

Essentially source: app/foo.Dockerfile (with no dockerfile set) would set context + dockerfile to app/ and would set filename to foo.Dockerfile.

This is worth a little test.

Hmm, I think it's doing just that no? Your comment is on the else case so where dockerfile is empty, but we're in the dockerfile rootfs build.

This means that source points to a Dockerfile and was set to into the path by the library.

This means that the context and the dockerfile fields are correctly extracted.

What is missing is the filename being set to filepath.Base(opts.Rootfs.Path). I will edit.

Now for the tests: basically all the existing tests that build dockerfiles fall in this branch so we have tests. I'll add one more that sets a different Dockerfile name to test that also.

Lemme know if fine now

Previously, the name was cut from the path, so it used the default 'Dockerfile' name breaking functionality. This is fixed in the `x/kraftfile` bump. The dockerfile needs to be in a subfolder in the context. Signed-off-by: Cezar Craciunoiu <cezar@unikraft.io>

craciunoiuc · 2026-05-26T15:08:21Z

Test node dead, needs rerunning

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Pull request overview

Copilot reviewed 8 out of 9 changed files in this pull request and generated 5 comments.

craciunoiuc · 2026-05-27T12:05:27Z

 	for _, rom := range kf.Roms {
-		romPath := filepath.Join(dir, rom.Source)
+		romPath := filepath.Join(dir, rom.Source.Path)
 		romFormat := cmp.Or(rom.Format, kraftfile.FsTypeErofs)
 		romOpt := FSOpts{
 			Path:   romPath,
 			Format: romFormat,
-			Type:   rom.Type,
+			Type:   rom.Source.Type,


not needed, but will do

craciunoiuc · 2026-05-27T12:05:23Z

 	if kf.Rootfs != nil {
-		opts.Rootfs.Path = filepath.Join(dir, kf.Rootfs.Source)
+		opts.Rootfs.Path = filepath.Join(dir, kf.Rootfs.Source.Path)
 		opts.Rootfs.Format = kf.Rootfs.Format
-		opts.Rootfs.Type = kf.Rootfs.Type
-		if opts.Rootfs.Type == "" {
+		opts.Rootfs.Type = kf.Rootfs.Source.Type
+		opts.Rootfs.Dockerfile = kf.Rootfs.Source.Dockerfile
+		if opts.Rootfs.Dockerfile != "" && opts.Rootfs.Type == "" {
+			opts.Rootfs.Type = kraftfile.SourceTypeDockerfile
+		} else if opts.Rootfs.Type == "" {


not needed, but will do

craciunoiuc requested a review from jedevc May 12, 2026 12:16

craciunoiuc force-pushed the craciunoiuc/use-exact-dockerfile-name branch from c271649 to 6b04c57 Compare May 12, 2026 12:42

craciunoiuc marked this pull request as draft May 14, 2026 09:23

craciunoiuc force-pushed the craciunoiuc/use-exact-dockerfile-name branch from 6b04c57 to 689c4aa Compare May 14, 2026 16:03

craciunoiuc force-pushed the craciunoiuc/use-exact-dockerfile-name branch 2 times, most recently from 6be6327 to f0080e3 Compare May 22, 2026 11:03

craciunoiuc requested a review from Copilot May 22, 2026 11:04

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craciunoiuc force-pushed the craciunoiuc/use-exact-dockerfile-name branch from f0080e3 to 5aa4479 Compare May 22, 2026 11:06

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craciunoiuc force-pushed the craciunoiuc/use-exact-dockerfile-name branch 2 times, most recently from 0f1f7c0 to 5bdc9d2 Compare May 22, 2026 11:42

craciunoiuc marked this pull request as ready for review May 22, 2026 11:43

craciunoiuc force-pushed the craciunoiuc/use-exact-dockerfile-name branch from 5bdc9d2 to 6cc644d Compare May 25, 2026 12:06

jedevc reviewed May 26, 2026

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craciunoiuc force-pushed the craciunoiuc/use-exact-dockerfile-name branch from 6cc644d to 428b2d5 Compare May 26, 2026 15:04

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craciunoiuc commented May 12, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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craciunoiuc commented May 12, 2026 •

edited

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