getscreen

#!/usr/bin/env bash
# Capture screenshot from AMI MegaRAC BMC HTML5 KVM
# Usage: getscreen [--wait MS] <bmc-ip> [output.jpg]
# Env: BMC_USER (required), BMC_PASS (required), BMC_DEBUG=1 (optional)
#
# NOTE: ASPEED BMC video encoders can take surprisingly long to deliver the
# first frame after boot, resolution changes, or reconnection. The tool polls
# the KVM canvas for non-black content before capturing. If your screenshot
# comes back black, try increasing --wait (default: 5000ms). In production
# incidents, waiting even 60s is better than getting a false black screen.
set -euo pipefail

# Parse --wait argument
RENDER_WAIT=""
while [[ $# -gt 0 ]]; do
    case "$1" in
        --wait)
            RENDER_WAIT="$2"
            shift 2
            ;;
        --wait=*)
            RENDER_WAIT="${1#--wait=}"
            shift
            ;;
        -*)
            echo "Unknown option: $1" >&2
            echo "Usage: getscreen [--wait MS] <bmc-ip> [output.jpg]" >&2
            exit 1
            ;;
        *)
            break
            ;;
    esac
done

if [[ $# -lt 1 ]]; then
    echo "Usage: getscreen [--wait MS] <bmc-ip> [output.jpg]" >&2
    echo "  --wait MS    Max time to wait for video frame (default: 5000)" >&2
    echo "  Env: BMC_USER, BMC_PASS (required)" >&2
    echo "  Env: BMC_RENDER_WAIT (same as --wait), BMC_DEBUG=1" >&2
    exit 1
fi

HOST="$1"
OUTPUT="${2:-/tmp/bmc-${HOST}.jpg}"

if [[ -z "${BMC_USER:-}" || -z "${BMC_PASS:-}" ]]; then
    echo "ERROR: BMC_USER and BMC_PASS environment variables must be set" >&2
    exit 1
fi

# --wait flag overrides env var
if [[ -n "$RENDER_WAIT" ]]; then
    export BMC_RENDER_WAIT="$RENDER_WAIT"
fi

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
SUPPRESS="${BMC_DEBUG:+/dev/stderr}"

node "${SCRIPT_DIR}/kvm-capture.js" "$HOST" "$BMC_USER" "$BMC_PASS" "$OUTPUT" 2>"${SUPPRESS:-/dev/null}"
EXIT=$?

if [[ $EXIT -eq 0 && -s "$OUTPUT" ]]; then
    echo "${OUTPUT}"
else
    echo "ERROR: Screenshot capture failed for ${HOST}" >&2
    exit 1
fi