PublishPlugin.cs

public class PublishPlugin : IPlugin
{
    public void Execute(IServiceProvider serviceProvider)
    {
        IPluginExecutionContext context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
        IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
        IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);

        if (context.MessageName != "Publish" && context.MessageName != "PublishAll")
            return;

        string parameterXml = string.Empty;
        if (context.MessageName == "Publish")
        {
            if (context.InputParameters.Contains("ParameterXml"))
            {
                parameterXml = (string)context.InputParameters["ParameterXml"];
            }
        }

        CreatePublishAuditRecord(service, context.MessageName, context.InitiatingUserId, parameterXml);
    }

    private void CreatePublishAuditRecord(IOrganizationService service, string messageName, Guid userId, string parameterXml)
    {
        Entity auditRecord = new Entity("fjo_publishaudit");
        auditRecord["fjo_message"] = messageName;
        auditRecord["fjo_publishbyid"] = new EntityReference("systemuser", userId);
        auditRecord["fjo_publishon"] = DateTime.Now;
        auditRecord["fjo_parameterxml"] = parameterXml;

        service.Create(auditRecord);
    }
}