feat(entrypoint): add support for RUNNER_LABELS env var

[lauralex]

Summary

This PR updates the entrypoint.sh script to check for the RUNNER_LABELS environment variable before falling back to LABELS or the default value.

Motivation

The official Actions Runner Controller (ARC) Helm charts inject runner labels using the environment variable RUNNER_LABELS, whereas this image currently expects LABELS.

By prioritizing RUNNER_LABELS, we improve compatibility for users attempting to use this Docker image with the official ARC deployment manifests without needing to manually map environment variables.

Changes

• Modified entrypoint.sh to set _LABELS using the logic: RUNNER_LABELS -> LABELS -> default.

Testing

• Verified that passing RUNNER_LABELS correctly sets the runner labels.
• Verified that passing LABELS (legacy method) still works as a fallback.
• Verified that omitting both still results in default.

[lauralex]

Successful tests:

Tests script:

#!/bin/bash

# 1. Create a dummy script representing the logic in your entrypoint.sh
# We are testing specifically this line: _LABELS=${RUNNER_LABELS:-${LABELS:-default}}
cat << 'EOF' > mock_entrypoint.sh
#!/bin/bash
_LABELS=${RUNNER_LABELS:-${LABELS:-default}}
echo "$_LABELS"
EOF

chmod +x mock_entrypoint.sh

# Helper function to print results
check_result() {
    TEST_NAME=$1
    EXPECTED=$2
    ACTUAL=$3

    if [ "$ACTUAL" == "$EXPECTED" ]; then
        echo -e "✅ \033[0;32mPASS: $TEST_NAME\033[0m (Got: '$ACTUAL')"
    else
        echo -e "❌ \033[0;31mFAIL: $TEST_NAME\033[0m"
        echo "   Expected: '$EXPECTED'"
        echo "   Got:      '$ACTUAL'"
    fi
}

echo "--- Starting Tests ---"

# --- SCENARIO 1: RUNNER_LABELS is set (Should take priority) ---
# Input: RUNNER_LABELS="priority-label", LABELS="legacy-label"
export RUNNER_LABELS="priority-label"
export LABELS="legacy-label"
RESULT=$(./mock_entrypoint.sh)
check_result "Scenario 1 (RUNNER_LABELS set)" "priority-label" "$RESULT"

# Cleanup vars
unset RUNNER_LABELS
unset LABELS

# --- SCENARIO 2: RUNNER_LABELS is unset, LABELS is set (Legacy fallback) ---
# Input: RUNNER_LABELS=(unset), LABELS="legacy-label"
export LABELS="legacy-label"
RESULT=$(./mock_entrypoint.sh)
check_result "Scenario 2 (LABELS fallback)" "legacy-label" "$RESULT"

# Cleanup vars
unset RUNNER_LABELS
unset LABELS

# --- SCENARIO 3: Both are unset (Default fallback) ---
# Input: RUNNER_LABELS=(unset), LABELS=(unset)
RESULT=$(./mock_entrypoint.sh)
check_result "Scenario 3 (Default fallback)" "default" "$RESULT"

echo "--- Tests Complete ---"

# Cleanup the mock file
rm mock_entrypoint.sh

[myoung34]

Thanks, seems good