name: 'Refresh BuildKit Builder'
description: 'Ensure a BuildKit builder is healthy; re-initialize it if the connection has been lost'

# This action guards against the remote BuildKit connection going stale between
# build steps in the same job (e.g. after a long primary build the TCP connection
# to the remote daemon can time out before the test-image build starts).
#
# How it works:
#   1. Runs `docker buildx inspect --bootstrap` to check whether the builder is
#      still reachable.  If it succeeds the action exits immediately — no extra
#      work is done.
#   2. If the inspect/bootstrap fails the builder is considered stale and
#      init-dynamo-builder is called with the same flavor/arch/cuda_version that
#      were used when the builder was first created, effectively re-routing
#      workers and re-registering the builder from scratch.

inputs:
  builder_name:
    description: 'Name of the buildx builder to check'
    required: true
  flavor:
    description: 'Buildkit flavor used to route workers on re-init (vllm, sglang, trtllm, general)'
    required: true
  arch:
    description: 'Docker platform string used on re-init (e.g. linux/amd64, linux/arm64, linux/amd64,linux/arm64)'
    required: false
    default: 'linux/amd64'
  cuda_version:
    description: 'CUDA version used on re-init (e.g. 12.9, 13.0). Leave empty for general flavor.'
    required: false
    default: ''

  # Kubernetes fallback passthrough inputs (forwarded to init-dynamo-builder)
  ephemeral_storage:
    description: 'Ephemeral storage request for Kubernetes fallback driver'
    required: false
    default: '400Gi'
  namespace:
    description: 'Kubernetes namespace for buildkit fallback pods'
    required: false
    default: 'buildkit'
  replicas:
    description: 'Number of buildkit fallback replicas'
    required: false
    default: '1'
  requests_cpu:
    description: 'CPU requests for buildkit fallback pods'
    required: false
    default: '12'
  requests_memory:
    description: 'Memory requests for buildkit fallback pods'
    required: false
    default: '26Gi'
  limits_memory:
    description: 'Memory limits for buildkit fallback pods'
    required: false
    default: '29Gi'
  tolerations:
    description: 'Tolerations for buildkit fallback pods'
    required: false
    default: "key=buildkit-fallback-worker,value=true,operator=Equal,effect=NoSchedule"

runs:
  using: "composite"
  steps:
    - name: Check builder health
      id: check-health
      continue-on-error: true
      shell: bash
      run: |
        echo "Checking BuildKit builder '${{ inputs.builder_name }}'..."
        docker buildx inspect "${{ inputs.builder_name }}" --bootstrap
        echo "Builder is healthy."

    - name: Remove stale builder (if unhealthy)
      if: steps.check-health.outcome == 'failure'
      shell: bash
      run: |
        echo "::warning::Builder '${{ inputs.builder_name }}' is unhealthy. Removing and re-initializing..."
        docker buildx rm "${{ inputs.builder_name }}" || true

    - name: Re-initialize builder (if unhealthy)
      if: steps.check-health.outcome == 'failure'
      uses: ./.github/actions/init-dynamo-builder
      with:
        builder_name: ${{ inputs.builder_name }}
        flavor: ${{ inputs.flavor }}
        arch: ${{ inputs.arch }}
        cuda_version: ${{ inputs.cuda_version }}
        ephemeral_storage: ${{ inputs.ephemeral_storage }}
        namespace: ${{ inputs.namespace }}
        replicas: ${{ inputs.replicas }}
        requests_cpu: ${{ inputs.requests_cpu }}
        requests_memory: ${{ inputs.requests_memory }}
        limits_memory: ${{ inputs.limits_memory }}
        tolerations: ${{ inputs.tolerations }}