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Systemd忽略LD_PRELOAD变量和服务可以启动

发布于 2025-02-12 18:40:05 字数 8690 浏览 0 评论 0原文

我在预加载图书馆时有问题。

但是首先，我要解释我打算做什么。 我已经使用Un4Seen低音音频库开发了一款Blazor Web应用程序。该应用程序托管在Kestrel Web服务器上，我想将应用程序部署为服务（SystemD）。

该应用程序可完美地工作，旨在在Ubuntu和Windows系统上运行。正如我所说，它可以按照我想要的方式工作。只是不是作为服务。

如前所述，执行需要的Un4Seen Audio库是所需的，这些库存储在项目结构中，如下所示。

[AppRoot]
¦
+---....
¦
+---Bass.Net.dll
¦
+---....
¦   
+---libs
    +---unix
    ¦   +---x64
    ¦   ¦       libbass.so
    ¦   ¦       libbassalac.so
    ¦   ¦       libbassenc.so
    ¦   ¦       libbassenc_flac.so
    ¦   ¦       libbassenc_mp3.so
    ¦   ¦       libbassenc_opus.so
    ¦   ¦       libbassflac.so
    ¦   ¦       libbassmix.so
    ¦   ¦       libbassopus.so
    ¦   ¦       libbasswebm.so
    ¦   ¦       libbass_aac.so
    ¦   ¦       libbass_ac3.so
    ¦   ¦       
    ¦   +---x86
    ¦           libbass.so
    ¦           libbassalac.so
    ¦           libbassenc.so
    ¦           libbassenc_flac.so
    ¦           libbassenc_mp3.so
    ¦           libbassenc_opus.so
    ¦           libbassflac.so
    ¦           libbassmix.so
    ¦           libbassopus.so
    ¦           libbasswebm.so
    ¦           libbass_aac.so
    ¦           libbass_ac3.so
    ¦           
    +---Win32NT
        +---x64
        ¦       bass.dll
        ¦       bassalac.dll
        ¦       bassenc.dll
        ¦       bassenc_flac.dll
        ¦       bassenc_mp3.dll
        ¦       bassenc_opus.dll
        ¦       bassflac.dll
        ¦       bassmix.dll
        ¦       bassopus.dll
        ¦       basswebm.dll
        ¦       bass_aac.dll
        ¦       bass_ac3.dll
        ¦       
        +---x86
                bass.dll
                bassalac.dll
                bassenc.dll
                bassenc_flac.dll
                bassenc_mp3.dll
                bassenc_opus.dll
                bassflac.dll
                bassmix.dll
                bassopus.dll
                basswebm.dll
                bass_aac.dll
                bass_ac3.dll

使用以下方法，我初始化了低音库：

private bool InitializeBassLibrary()
{
    var appPath = new Uri(Assembly.GetEntryAssembly()?.GetName().CodeBase ?? throw new NullReferenceException())
        .LocalPath;
    appPath = Path.GetDirectoryName(appPath);
    if (string.IsNullOrEmpty(appPath))
    {
        return false;
    }

    var librariesPath = appPath;

    var osPlatform = Environment.OSVersion.Platform;

    switch (osPlatform)
    {
        case PlatformID.Win32NT:
        {
            librariesPath += Environment.Is64BitProcess ? "\\libs\\win32nt\\x64\\" : "\\libs\\win32nt\\x86\\";
            break;
        }
        case PlatformID.Unix:
        {
            // Add following paths to search path for libs of your linux distribution.
            // e.g. for Ubuntu
            //      ldconfig /full/path/to/libs/unix/x64
            //      ldconfig /full/path/to/libs/unix/x86
            break;
        }
    }

    BassNet.Registration("[email protected]", "X123456789012345");

    if (osPlatform == PlatformID.Win32NT)
    {
        var libLoadIsOk = Bass.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassAac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassAc3.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassAlac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassFlac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassOpus.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc_Flac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc_Mp3.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc_Opus.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassMix.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }
    }

    if (osPlatform == PlatformID.Unix)
    {
        // For preloading BASS libs execute creation of fake streams or execute GetVersion() Methods if exists.
        Bass.BASS_GetVersion(4);
        _ = BassAc3.BASS_AC3_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        _ = BassAlac.BASS_ALAC_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        _ = BassFlac.BASS_FLAC_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        _ = BassOpus.BASS_OPUS_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        BassEnc.BASS_Encode_GetVersion();
        BassEnc_Flac.BASS_Encode_FLAC_GetVersion();
        BassEnc_Mp3.BASS_Encode_MP3_GetVersion();
        BassEnc_Opus.BASS_Encode_OPUS_GetVersion();
        BassMix.BASS_Mixer_GetVersion();
    }
    
    Bass.BASS_Init(AudioDevice, AudioDeviceSamplingRate, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero);
    if (Bass.BASS_ErrorGetCode() != BASSError.BASS_OK)
    {
        return false;
    }

    return true;
}

该应用程序的Ubuntu版本是针对Linux-X64发布的，然后将其复制到Ubuntu机器。

因此，库分配在Ubuntu下正常工作，我创建了文件/etc/ld.so.conf.d/app_name.conf。

/etc/ld.so.conf.d/app_name.conf

/usr/share/nginx/html/dds-audio-transcoder-service/libs/unix/x64
/usr/share/nginx/html/dds-audio-transcoder-service/libs/unix/x86

此LD配置文件通过sudo> sudo ldconfig -v成功应用。

无论出于何种原因，要使它起作用，我都必须预努加载libbass.so带有ld_preload库，尽管它已经在/etc/ld.so.conf中.d/app_name.conf应该可以发现。我输入了ld_preload通过/etc/code>和值/usr/share/nginx/nginx/html/app_name/libs/unix/x64/x64/x64/ libbass.so设置。 对于那些不知道低音音频库的人：libbass.o是主要库。其他文件是插件。

If I don't set the LD_PRELOAD variable the application won't start and gives the error: symbol lookup error: /usr/share/nginx/html/dds-audio-transcoder-service /libs/unix/x64/libbass_ac3.so：不确定的符号：bass_getversion。这是完全误导的，因为该方法根本没有调用。至少不在libbass_ac3.so上。花了一点时间来弄清楚这是从libbass.o中弄清楚的。

如果我然后以：sudo [app_file_name] - environment [custom_environment]该应用程序按预期工作。

现在终于出现了问题

我将此Kestrel托管应用程序配置为SystemD中的服务。为此目的创建了以下服务文件。

/etc/systemd/system/app_name.service

[Unit]
Description=DDS-Audio-Transcoder for transcoding audio files to different audio formats

[Service]
WorkingDirectory=/usr/share/nginx/html/app-name
ExecStart=/usr/share/nginx/html/app-name/app-name-start-binary --environment TestInstance3Unix
Restart=always
RestartSec=150
KillSignal=SIGINT
SyslogIdentifier=bit-dds-transcoder
User=www-data
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false
Environment="LD_PRELOAD=libbass.so"
Environment="LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/share/nginx/html/dds-transcoder-service/libs/unix/x64:/usr/share/nginx/html/dds-transcoder-service/libs/unix/x86"

[Install]
WantedBy=multi-user.target

启用了服务：sudo systemctl enable app_name.service

然后我尝试了：sudo systemctl start app_name.service.service.service.service.service.service.service.service.service.service.service.service.service.service.service.service.name开始服务，什么也不会发生。

Syslog说以下内容：

Jul  4 23:04:49 l01-v-s-0081 systemd[1]: app_name.service: Scheduled restart job, restart counter is at 21.
Jul  4 23:04:49 l01-v-s-0081 systemd[1]: Stopped app_name.
Jul  4 23:04:49 l01-v-s-0081 systemd[1]: Started app_name.
Jul  4 23:04:50 l01-v-s-0081 app_name[2241]: /usr/share/nginx/html/app_name/app-name-start-binary: symbol lookup error: /usr/share/nginx/html/dds-audio-transcoder-service/libs/unix/x64/libbass_ac3.so: undefined symbol: BASS_GetVersion
Jul  4 23:04:50 l01-v-s-0081 systemd[1]: dds-audio-transcoder.service: Main process exited, code=exited, status=127/n/a
Jul  4 23:04:50 l01-v-s-0081 systemd[1]: dds-audio-transcoder.service: Failed with result 'exit-code'.

系统信息

esx虚拟Mashine with ubuntu 20.04 .net 5.0

我缺少什么或我做错了什么？

记得！没有SystemD，它可以正常工作。

我真的很感激每个小费。

许多问候

马库斯

原文

i have a problem with preloading a library.

But first I'll explain what I intend to do.
I've developed a Blazor web application using the Un4Seen Bass Audio libraries. The application is hosted on the Kestrel Web Server and I wanted to deploy the application as a service (systemd).

The application works flawlessly and is designed to run on both Ubuntu and Windows systems. As I said, it works the way I want it to. Just not as a service.

As already mentioned, the Un4Seen audio libraries are required for execution, which are stored in the project structure as follows.

[AppRoot]
¦
+---....
¦
+---Bass.Net.dll
¦
+---....
¦   
+---libs
    +---unix
    ¦   +---x64
    ¦   ¦       libbass.so
    ¦   ¦       libbassalac.so
    ¦   ¦       libbassenc.so
    ¦   ¦       libbassenc_flac.so
    ¦   ¦       libbassenc_mp3.so
    ¦   ¦       libbassenc_opus.so
    ¦   ¦       libbassflac.so
    ¦   ¦       libbassmix.so
    ¦   ¦       libbassopus.so
    ¦   ¦       libbasswebm.so
    ¦   ¦       libbass_aac.so
    ¦   ¦       libbass_ac3.so
    ¦   ¦       
    ¦   +---x86
    ¦           libbass.so
    ¦           libbassalac.so
    ¦           libbassenc.so
    ¦           libbassenc_flac.so
    ¦           libbassenc_mp3.so
    ¦           libbassenc_opus.so
    ¦           libbassflac.so
    ¦           libbassmix.so
    ¦           libbassopus.so
    ¦           libbasswebm.so
    ¦           libbass_aac.so
    ¦           libbass_ac3.so
    ¦           
    +---Win32NT
        +---x64
        ¦       bass.dll
        ¦       bassalac.dll
        ¦       bassenc.dll
        ¦       bassenc_flac.dll
        ¦       bassenc_mp3.dll
        ¦       bassenc_opus.dll
        ¦       bassflac.dll
        ¦       bassmix.dll
        ¦       bassopus.dll
        ¦       basswebm.dll
        ¦       bass_aac.dll
        ¦       bass_ac3.dll
        ¦       
        +---x86
                bass.dll
                bassalac.dll
                bassenc.dll
                bassenc_flac.dll
                bassenc_mp3.dll
                bassenc_opus.dll
                bassflac.dll
                bassmix.dll
                bassopus.dll
                basswebm.dll
                bass_aac.dll
                bass_ac3.dll

With the following method i initialize the Bass Libraries:

private bool InitializeBassLibrary()
{
    var appPath = new Uri(Assembly.GetEntryAssembly()?.GetName().CodeBase ?? throw new NullReferenceException())
        .LocalPath;
    appPath = Path.GetDirectoryName(appPath);
    if (string.IsNullOrEmpty(appPath))
    {
        return false;
    }

    var librariesPath = appPath;

    var osPlatform = Environment.OSVersion.Platform;

    switch (osPlatform)
    {
        case PlatformID.Win32NT:
        {
            librariesPath += Environment.Is64BitProcess ? "\\libs\\win32nt\\x64\\" : "\\libs\\win32nt\\x86\\";
            break;
        }
        case PlatformID.Unix:
        {
            // Add following paths to search path for libs of your linux distribution.
            // e.g. for Ubuntu
            //      ldconfig /full/path/to/libs/unix/x64
            //      ldconfig /full/path/to/libs/unix/x86
            break;
        }
    }

    BassNet.Registration("[email protected]", "X123456789012345");

    if (osPlatform == PlatformID.Win32NT)
    {
        var libLoadIsOk = Bass.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassAac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassAc3.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassAlac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassFlac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassOpus.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc_Flac.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc_Mp3.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassEnc_Opus.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }

        libLoadIsOk = BassMix.LoadMe(librariesPath);
        if (!libLoadIsOk)
        {
            return false;
        }
    }

    if (osPlatform == PlatformID.Unix)
    {
        // For preloading BASS libs execute creation of fake streams or execute GetVersion() Methods if exists.
        Bass.BASS_GetVersion(4);
        _ = BassAc3.BASS_AC3_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        _ = BassAlac.BASS_ALAC_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        _ = BassFlac.BASS_FLAC_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        _ = BassOpus.BASS_OPUS_StreamCreateFile("", 0, 0, BASSFlag.BASS_DEFAULT);
        BassEnc.BASS_Encode_GetVersion();
        BassEnc_Flac.BASS_Encode_FLAC_GetVersion();
        BassEnc_Mp3.BASS_Encode_MP3_GetVersion();
        BassEnc_Opus.BASS_Encode_OPUS_GetVersion();
        BassMix.BASS_Mixer_GetVersion();
    }
    
    Bass.BASS_Init(AudioDevice, AudioDeviceSamplingRate, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero);
    if (Bass.BASS_ErrorGetCode() != BASSError.BASS_OK)
    {
        return false;
    }

    return true;
}

The Ubuntu version of the application is released for linux-x64 and is then copied to an Ubuntu machine.

So that the library assignment works correctly under Ubuntu, I created the file /etc/ld.so.conf.d/app_name.conf.

/etc/ld.so.conf.d/app_name.conf

/usr/share/nginx/html/dds-audio-transcoder-service/libs/unix/x64
/usr/share/nginx/html/dds-audio-transcoder-service/libs/unix/x86

This LD configuration file was then successfully applied with sudo ldconfig -v.

Whatever the reason, to get it working I had to preload the libbass.so library with LD_PRELOAD although it already has it in /etc/ld.so.conf.d/app_name.conf should be discoverable. I entered the LD_PRELOAD variable system-wide via /etc/environment and the value /usr/share/nginx/html/app_name/libs/unix/x64/libbass.so set.
For those who don't know the bass audio libraries: libbass.so is the main library. The other files are plugins.

If I don't set the LD_PRELOAD variable the application won't start and gives the error: symbol lookup error: /usr/share/nginx/html/dds-audio-transcoder-service/libs/unix/ x64/libbass_ac3.so: undefined symbol: BASS_GetVersion. This is completely misleading because the method is not called at all. At least not on libbass_ac3.so. Took a bit to figure out it's from libbass.so.

If I then start the application with: sudo [app_file_name] --environment [custom_environment] the app works as expected.

Now finally comes the problem

I configured this Kestrel hosted application as a service in systemd. The following service file was created for this purpose.

/etc/systemd/system/app_name.service

[Unit]
Description=DDS-Audio-Transcoder for transcoding audio files to different audio formats

[Service]
WorkingDirectory=/usr/share/nginx/html/app-name
ExecStart=/usr/share/nginx/html/app-name/app-name-start-binary --environment TestInstance3Unix
Restart=always
RestartSec=150
KillSignal=SIGINT
SyslogIdentifier=bit-dds-transcoder
User=www-data
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false
Environment="LD_PRELOAD=libbass.so"
Environment="LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/share/nginx/html/dds-transcoder-service/libs/unix/x64:/usr/share/nginx/html/dds-transcoder-service/libs/unix/x86"

[Install]
WantedBy=multi-user.target

The service was enabled with: sudo systemctl enable app_name.service

Then I tried with: sudo systemctl start app_name.service to start the service and nothing happens.

The syslog says the following:

Jul  4 23:04:49 l01-v-s-0081 systemd[1]: app_name.service: Scheduled restart job, restart counter is at 21.
Jul  4 23:04:49 l01-v-s-0081 systemd[1]: Stopped app_name.
Jul  4 23:04:49 l01-v-s-0081 systemd[1]: Started app_name.
Jul  4 23:04:50 l01-v-s-0081 app_name[2241]: /usr/share/nginx/html/app_name/app-name-start-binary: symbol lookup error: /usr/share/nginx/html/dds-audio-transcoder-service/libs/unix/x64/libbass_ac3.so: undefined symbol: BASS_GetVersion
Jul  4 23:04:50 l01-v-s-0081 systemd[1]: dds-audio-transcoder.service: Main process exited, code=exited, status=127/n/a
Jul  4 23:04:50 l01-v-s-0081 systemd[1]: dds-audio-transcoder.service: Failed with result 'exit-code'.

System Informations

esx Virtual Mashine with Ubuntu 20.04
.Net 5.0

What i'm missing or what i have done wrong?

Remember! Without systemd it works fine.

I'm really grateful for every tip.

Many greetings

Marcus

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