Image name not sanitized when default repo is unset

[halvards]

Expected behavior

Skaffold can build images where the image name in skaffold.yaml is a ko:// scheme-prefixed Go import path that may contain uppercase characters, e.g., ko://github.com/GoogleContainerTools/skaffold/cmd/skaffold.

This should work regardless of whether the Skaffold default repo is set or not.

Sanitization (see #4952) removes the ko:// prefix and lowercases the Go import path, e.g., ko://github.com/GoogleContainerTools/skaffold/cmd/skaffold -> github.com/googlecontainertools/skaffold/cmd/skaffold

Actual behavior

Builds of images with the ko:// prefix and Go import paths with uppercase characters fail if the Skaffold default repo is not set.

See steps to reproduce below for details on the error.

Information

• Skaffold version: v1.32.0
• Operating system: Linux Debian 5.10.46
• Installed via: GitHub release
• Contents of skaffold.yaml:

apiVersion: skaffold/v2beta23
kind: Config
build:
  artifacts:
  - image: ko://github.com/GoogleContainerTools/skaffold/examples/custom
    custom:
      buildCommand: ./build.sh
      dependencies:
        paths:
        - "go.mod"
        - "**.go"
  tagPolicy:
    sha256: {}

Steps to reproduce the behavior

git clone https://github.com/GoogleContainerTools/skaffold.git
cd skaffold
git checkout v1.32.0
cd examples/custom
unset SKAFFOLD_DEFAULT_REPO
skaffold build --cache-artifacts=false --push=false

Output:

Generating tags...
 - ko://github.com/GoogleContainerTools/skaffold/examples/custom -> ko://github.com/GoogleContainerTools/skaffold/examples/custom:latest
Starting build...
Building [ko://github.com/GoogleContainerTools/skaffold/examples/custom]...
2021/10/05 22:17:14 Using base gcr.io/distroless/static:nonroot for github.com/GoogleContainerTools/skaffold/examples/custom
2021/10/05 22:17:18 Building github.com/GoogleContainerTools/skaffold/examples/custom for linux/amd64
2021/10/05 22:17:18 Loading ko.local/github.com/googlecontainertools/skaffold/examples/custom:f3d25bf00e3dc061e3f130d284317c8599fcb80775418a559c0acfe9f98a6177
2021/10/05 22:17:18 Loaded ko.local/github.com/googlecontainertools/skaffold/examples/custom:f3d25bf00e3dc061e3f130d284317c8599fcb80775418a559c0acfe9f98a6177
Error parsing reference: "ko://github.com/GoogleContainerTools/skaffold/examples/custom:latest" is not a valid repository/tag: invalid reference format: repository name must be lowercase
exit status 1

Related

This issue was uncovered by this failed build of #6614: https://github.com/GoogleContainerTools/skaffold/pull/6614/checks?check_run_id=3799415059