luci-app-nodered/luasrc/view/nodered/status.htm

<%
local util  = require "luci.util"
local container_status = util.trim(util.exec("/usr/libexec/apps/nodered/nodered.sh status"))
local container_running = string.find(string.lower(container_status), "up") and string.find(string.lower(container_status), "(healthy)")
local port=util.trim(util.exec("/usr/libexec/apps/nodered/nodered.sh port"))
-%>

<div class="cbi-value">
    <div class="cbi-value-field">
        <% if container_running then %>
            <button class="cbi-button cbi-button-success" disabled="true"><%= container_status %></button>
            <%
            if port == "" then
                port="1880"
            end
            -%>
            <input type="button" class="btn cbi-button cbi-button-apply" name="start" value="<%:Open nodered%>" onclick="window.open('http://'+location.hostname+':<%=port%>/', '_blank')">
        <% else %>
            <button class="cbi-button cbi-button-negative" disabled="true"><%= container_status %></button>
        <% end %>
    </div>
</div>