From Inside a .netcore application running in a docker container, logs are not reaching to GrayLog server

Question

I have built an asp.net core based application. while running the application directly from VS, I am able to receive the logs in the graylog server. But after building the docker container logs are not reaching to the server.

I have tried with both Http and UDP configuration. but it's not sending the logs. I am using Gelf Extension.

    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        ConfigurationSettings.InitConfig(Configuration.GetSection("ConfigurationSettings"));
        loggerFactory.AddGelf(new GelfLoggerOptions
        {
            Host = ConfigurationSettings.LogHost,
            Port = ConfigurationSettings.LogPort,
            Protocol = GelfProtocol.Http,
            LogSource = ConfigurationSettings.LoggerName,
            LogLevel = LogLevel.Information
        });
    }