Migrating agents from Elastic

# Define keys to ignore at root level
ignored_keys = ["@metadata"]

# Define resource key prefixes
resource_keys = ["host", "cloud", "agent", "service"]

# Create separate objects for resource and log record fields
resource_obj = {}
log_record_obj = {}

# Copy all non-ignored root keys to appropriate objects
root_keys = keys(.)
for_each(root_keys) -> |_index, key| {
    if !includes(ignored_keys, key) {
        val, err = get(., [key])
        if err == null {
            # Check if this is a resource field
            is_resource = false
            if includes(resource_keys, key) {
                is_resource = true
            }

            # Add to appropriate object
            if is_resource {
                resource_obj = set(resource_obj, [key], val) ?? resource_obj
            } else {
                log_record_obj = set(log_record_obj, [key], val) ?? log_record_obj
            }
        }
    }
}

# Flatten both objects separately
flattened_resources = flatten(resource_obj, separator: ".")
flattened_logs = flatten(log_record_obj, separator: ".")

# Process resource attributes
resource_attributes = []
resource_keys_list = keys(flattened_resources)
for_each(resource_keys_list) -> |_index, field_key| {
    field_value, err = get(flattened_resources, [field_key])
    if err == null && field_value != null {
        attribute, err = {
            "key": field_key,
            "value": {
                "stringValue": to_string(field_value)
            }
        }
        if (err == null) {
            resource_attributes = push(resource_attributes, attribute)
        }
    }
}

# Process log record attributes
log_attributes = []
log_keys_list = keys(flattened_logs)
for_each(log_keys_list) -> |_index, field_key| {
    field_value, err = get(flattened_logs, [field_key])
    if err == null && field_value != null {
        attribute, err = {
            "key": field_key,
            "value": {
                "stringValue": to_string(field_value)
            }
        }
        if (err == null) {
            log_attributes = push(log_attributes, attribute)
        }
    }
}

# Get timestamp for timeUnixNano (convert to nanoseconds)
timestamp_nano = if exists(.@timestamp) {
    to_unix_timestamp!(parse_timestamp!(.@timestamp, format: "%Y-%m-%dT%H:%M:%S%.3fZ"), unit: "nanoseconds")
} else {
    to_unix_timestamp(now(), unit: "nanoseconds")
}

# Get message/body field
body_value = if exists(.message) {
    to_string!(.message)
} else if exists(.body) {
    to_string!(.body)
} else {
    ""
}

# Create the OpenTelemetry structure
. = {
    "resourceLogs": [
        {
            "resource": {
                "attributes": resource_attributes
            },
            "scopeLogs": [
                {
                    "scope": {},
                    "logRecords": [
                        {
                            "timeUnixNano": to_string(timestamp_nano),
                            "severityNumber": 9,
                            "severityText": "info",
                            "body": {
                                "stringValue": body_value
                            },
                            "attributes": log_attributes
                        }
                    ]
                }
            ]
        }
    ]
}