Various improvements to PullImage() + custom registry support by OneBlue · Pull Request #14549 · microsoft/WSL

OneBlue · 2026-03-27T00:03:23Z

Summary of the Pull Request

This change solves two issues with PullImage()

Properly parse and normalize repos so we can correctly pull from outside the library / docker.io registry
Catch errors that are reported after we get the status code back from pull (like the disk being full, or network errors)

Thanks to @kevpar for his help in figuring out the right way to normalize repos.

PR Checklist

Closes: Link to issue #xxx
Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
Tests: Added/updated if needed and all pass
Localization: All end user facing strings can be localized
Dev docs: Added/updated if needed
Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

Copilot

Pull request overview

This PR improves WSLA image pulling by normalizing image repositories to support non-library/ and non-docker.io registries, and by surfacing pull errors that can arrive during the progress stream after an initial HTTP 200 response.

Changes:

Add wslutil::NormalizeRepo() and use it in DockerHTTPClient::PullImage() to construct a fully-qualified pull reference.
Update WSLASession::PullImage() to capture streamed error details from progress JSON and improve HTTP error parsing using response headers.
Expand WSLA test coverage for repo normalization and pulling additional image reference shapes; add a new localized string.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
test/windows/WSLATests.cpp	Adjusts pull tests to cover non-library/custom-registry cases; adds `NormalizeRepo` unit tests.
src/windows/wslasession/WSLASession.cpp	Enhances PullImage streaming/error handling by tracking HTTP response and parsing progress JSON errors.
src/windows/wslasession/DockerHTTPClient.cpp	Uses `NormalizeRepo()` to build the pull `fromImage` parameter for custom registries.
src/windows/inc/docker_schema.h	Extends pull progress schema to include optional `errorDetail`.
src/windows/common/wslutil.h	Declares `NormalizeRepo()` API.
src/windows/common/wslutil.cpp	Implements repo normalization logic aligned with distribution/reference behavior.
localization/strings/en-US/Resources.resw	Adds a new localized string for invalid image repo messaging.

Comments suppressed due to low confidence (1)

test/windows/WSLATests.cpp:5992

In ImageParsing invalid inputs, ParseImage("") is asserted twice. This is redundant and makes the test a bit harder to scan; consider removing the duplicate assertion.

        // Invalid inputs
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":debian:latest"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage("debian:latest@"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":"); }), E_INVALIDARG);

Copilot · 2026-03-27T00:08:49Z

+    if (domain != localhost && domain != legacyDomain && domain.find_first_of(".:") == std::string::npos && !std::ranges::any_of(domain, isupper))
+    {


std::ranges::any_of(domain, isupper) can invoke undefined behavior because isupper expects an unsigned char value (or EOF), but char may be signed and negative for non-ASCII bytes. Use std::isupper(static_cast<unsigned char>(c)) (and qualify with std::) in a lambda predicate to avoid UB.

Copilot

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

test/windows/WSLATests.cpp:5992

ParseImage("") is asserted twice in the invalid-inputs section, which is redundant and makes the test noisier than necessary. Keep only one of the duplicate checks.

        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":debian:latest"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage("debian:latest@"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":"); }), E_INVALIDARG);

…oneblue/repo-parse

Copilot

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Comments suppressed due to low confidence (1)

test/windows/WSLCTests.cpp:1

The ParseImage(\"\") invalid-input assertion is duplicated, which adds noise without increasing coverage. Remove one of the duplicates to keep the test focused.

/*++

Copilot

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

test/windows/WSLCTests.cpp:6013

The invalid-input assertions include ParseImage("") twice, which is redundant and makes it harder to see what’s actually being covered. Remove one of the duplicate checks.

        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":debian:latest"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage("debian:latest@"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":"); }), E_INVALIDARG);

Copilot · 2026-03-27T21:36:08Z

+            auto comError = wsl::windows::common::wslutil::GetCOMErrorInfo();
+            VERIFY_IS_TRUE(comError.has_value());
+
+            // The error message can't be compared directly because it contains an unpredicable path:


Typo in comment: "unpredicable" → "unpredictable".

Suggested change

// The error message can't be compared directly because it contains an unpredicable path:

// The error message can't be compared directly because it contains an unpredictable path:

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

test/windows/WSLCTests.cpp:6013

ParseImage("") is asserted twice in the invalid-inputs section, which is redundant and makes failures noisier. Drop one of the duplicate checks (keep a single assertion for the empty-string case).

        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":debian:latest"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage("debian:latest@"); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(""); }), E_INVALIDARG);
        VERIFY_ARE_EQUAL(wil::ResultFromException([]() { ParseImage(":"); }), E_INVALIDARG);

Copilot · 2026-03-27T21:48:04Z

+        validatePull("pytorch/pytorch", "pytorch/pytorch:latest");
+        validatePull("registry.k8s.io/pause:3.2", "registry.k8s.io/pause:3.2");
+


PullImageAdvanced is still SKIP_TEST_UNSTABLE() and the nearby TODO mentions enabling once custom registries are supported, but this PR adds custom-registry repo normalization and expands coverage for non-docker.io repos. Update the TODO/skip rationale so it matches the current behavior/intent of the test.

OneBlue added 3 commits March 25, 2026 17:02

Save state

8eb1022

Save state

da348e7

Handle issues during pull

ed64898

Copilot AI review requested due to automatic review settings March 27, 2026 00:03

OneBlue changed the title ~~Various improvements to PullImage() adds custom registry support~~ Various improvements to PullImage() + custom registry support Mar 27, 2026

Copilot started reviewing on behalf of OneBlue March 27, 2026 00:04 View session

Copilot AI reviewed Mar 27, 2026

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OneBlue added 3 commits March 26, 2026 17:33

Disable the pull tests

6281307

Update the CLI tests

4cd28a5

Format

982fd9c

Copilot AI review requested due to automatic review settings March 27, 2026 01:26

Copilot started reviewing on behalf of OneBlue March 27, 2026 01:27 View session

Copilot AI reviewed Mar 27, 2026

View reviewed changes

Comment thread src/windows/wslcsession/WSLCSession.cpp

Comment thread src/windows/wslcsession/WSLCSession.cpp Outdated

Comment thread src/windows/common/wslutil.cpp

OneBlue added 2 commits March 26, 2026 18:43

Fix legacy index logic

f59c8a4

Merge remote-tracking branch 'origin/feature/wsl-for-apps' into user/…

c8d42ea

…oneblue/repo-parse

Copilot AI review requested due to automatic review settings March 27, 2026 19:03

Copilot started reviewing on behalf of OneBlue March 27, 2026 19:05 View session

Copilot AI reviewed Mar 27, 2026

View reviewed changes

Comment thread src/windows/wslcsession/WSLCSession.cpp Outdated

Comment thread src/windows/wslcsession/WSLCSession.cpp Outdated

Comment thread src/windows/wslcsession/WSLCSession.cpp Outdated

Comment thread src/windows/common/wslutil.cpp

Comment thread test/windows/WSLCTests.cpp

Add test coverage for failed PullImage()

ddeb16d

OneBlue marked this pull request as ready for review March 27, 2026 21:24

Copilot AI review requested due to automatic review settings March 27, 2026 21:24

Copilot started reviewing on behalf of OneBlue March 27, 2026 21:29 View session

Copilot AI reviewed Mar 27, 2026

View reviewed changes

Update test/windows/WSLCTests.cpp

2ee97ba

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings March 27, 2026 21:37

Copilot started reviewing on behalf of OneBlue March 27, 2026 21:41 View session

Copilot AI reviewed Mar 27, 2026

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benhillis approved these changes Mar 27, 2026

View reviewed changes

benhillis merged commit 7483642 into feature/wsl-for-apps Mar 28, 2026
9 of 11 checks passed

		if (domain != localhost && domain != legacyDomain && domain.find_first_of(".:") == std::string::npos && !std::ranges::any_of(domain, isupper))
		{

	// The error message can't be compared directly because it contains an unpredicable path:
	// The error message can't be compared directly because it contains an unpredictable path:

		validatePull("pytorch/pytorch", "pytorch/pytorch:latest");
		validatePull("registry.k8s.io/pause:3.2", "registry.k8s.io/pause:3.2");

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OneBlue commented Mar 27, 2026

Summary of the Pull Request

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