[CI/CD] Ping code owners does not work on some components that share base names

[crobert-1]

Component(s)

No response

Describe the issue you're reporting

Problem

Our current workflow requires github-actions to ping code owners adding labels to issues and PRs. However, there's a bug currently that is hit for a label of a base component when there are multiple sub-components that share the same name, but the base name does not end in its component type.

Places where no pings are happening but should be:
#29082
#18491
#27046
(There are more)

Example Components

The extension/encoding label will not ping code owners, but the rest will. So in the terminology I'm using, extension/encoding is the base component, extension/encoding/zipkinencodingextension would be a sub-component, and the component type is extension.

extension/encoding/                                                     @open-telemetry/collector-contrib-approvers @atoulme @dao-jun @dmitryax @MovieStoreGuy @VihasMakwana
extension/encoding/jaegerencodingextension/                             @open-telemetry/collector-contrib-approvers @MovieStoreGuy @atoulme
extension/encoding/jsonlogencodingextension/                            @open-telemetry/collector-contrib-approvers @VihasMakwana @atoulme
extension/encoding/otlpencodingextension/                               @open-telemetry/collector-contrib-approvers @dao-jun @VihasMakwana
extension/encoding/textencodingextension/                               @open-telemetry/collector-contrib-approvers @MovieStoreGuy @atoulme
extension/encoding/zipkinencodingextension/                             @open-telemetry/collector-contrib-approvers @MovieStoreGuy @dao-jun

The extension/observer label will not ping code owners, but the rest will.

extension/observer/                                                     @open-telemetry/collector-contrib-approvers @dmitryax @rmfitzpatrick
extension/observer/dockerobserver/                                      @open-telemetry/collector-contrib-approvers @MovieStoreGuy
extension/observer/ecsobserver/                                         @open-telemetry/collector-contrib-approvers @dmitryax @rmfitzpatrick
extension/observer/ecstaskobserver/                                     @open-telemetry/collector-contrib-approvers @rmfitzpatrick
extension/observer/hostobserver/                                        @open-telemetry/collector-contrib-approvers @MovieStoreGuy
extension/observer/k8sobserver/                                         @open-telemetry/collector-contrib-approvers @rmfitzpatrick @dmitryax

Problem code

The problem is in get-codeowners.sh here:

# there may be more than 1 component matching a label
# if so, try to narrow things down by appending the component
# type to the label
if [[ ${RESULT} != 1 ]]; then
    COMPONENT_TYPE=$(echo "${COMPONENT}" | cut -f 1 -d '/')
    COMPONENT="${COMPONENT}${COMPONENT_TYPE}"
fi

RESULT is the number of lines matched by grepping the component passed in. In the case of COMPONENT=extension/encoding, RESULT is set to 6. The script then appends the COMPONENT_TYPE, extension in this case, to the COMPONENT and attempts to parse code owners from this component. However, there's no COMPONENT in the code owners file extension/encodingextension. This results in no pings being sent and the script ends "successfully"

This code is in place for some components that have labels that don't match their code owner entry name. One example is the resource detection processor. The label is processor/resourcedetection, but the code owners line is processor/resourcedetectionprocessor.

Solution

There are a few possible solutions here:

1. Add another case in get-codeowners.sh that simply appends a / to the original component, before appending component type. Check if there are any results for this component, if so, return code owners as we know we matched the full path. In my given examples, the script would then search the CODEOWNERS file for extension/encoding/ or processor/resourcedetection/. At worst, no owners would be returned. Otherwise, it would properly find the entry and return owners in a determinate way. This seems like the best solution.
2. Remove the functionality of appending COMPONENT_TYPE entirely. This would technically work today for all components as all of the base components are listed before their sub-components. This would work because the get-codeowners.sh script returns the first line in the file that matches the COMPONENT. The downside here is it would be order dependent in the CODEOWNERS file. This would introduce some level of instability though, so it's not a perfect solution. This would not work as processor/resourcedetectionprocessor is before processor/resourceprocessor alphabetically. If we removed append, the label processor/resource would ping processor/resourcedetection code owners incorrectly, as it comes before the resource processor alphabetically.
3. Rename base components to end with their type. I don't think this is a good solution as there's no requirement that I'm seeing that requires components to end in their type. If components are required to end in their type, we should fix component directories and names which would be a big impacting and breaking change, and it should be done in its own issue.

[crobert-1]

I'll work on implementing solution 1.

[crobert-1]

Seems to be working: #29082 (comment)