Docker container fails to render in OSR from CEF v76

[zerodefect]

Up until now, I have been running CEF v75.1.14 with OSR all in a Docker container (Ubuntu 18.03 flavour). It has been fine but my motivation to upgrade is because of issue #2732

I have now upgraded to v76.1.13, but upon running my Docker container, I now receive the following errors:

[0902/091723.692398:ERROR:sandbox_linux.cc(369)] InitializeSandbox() called with multiple threads in process gpu-process.
[0902/091723.738778:WARNING:ipc_message_attachment_set.cc(49)] MessageAttachmentSet destroyed with unconsumed attachments: 0/1

Now if I run that exact same code outside a container on my Linux VM (Ubuntu Linux 18.04.3), there are no errors. The issues only arise within the confines of a Docker container. Am I missing some required libraries? Lastly, I noticed that there is a new 'CefRequestContext' to the 'CreateBrowserSync' function which I set to 'nullptr'. Could that be causing issues?

Any tips/suggestions would be much appreciated.

[Czarek]

Could be a configuration issue on your OS. Does Chromium headless work fine in that container? You can disable sandbox through CefSettings.no_sandbox = true and see if it makes any difference. If you Google the error message you will find some suggestions e.g. to disable GPU.

[zerodefect]

Thanks Czarek for your reply.

I've not tried Chromium headless before. I'll need to research how that is done (and also how to containerize).

I had disabled sandboxing but it appears to be ignoring my request! I'm assuming that is occurring from Chromium or below. In addition (and for anybody elses benefit), I had also tried:

• --headless
• --no-sandbox
• --disable-gpu
• --disable-gpu-sandbox
• --disable-software-rasterizer

[Czarek]

Have you tested cefclient sample application with the --off-screen-rendering-enabled flag?

[zerodefect]

That sounds like the best route. I'll look to give that a go.

Without hijacking the original topic, I notice that there is a cefsimple but no cefclient executable in the automated builds for Linux 64-bit. Is that how it should be? I was hoping not to have to go away and build it .

[Czarek]

You have to build cefclient yourself on Linux. It's not included with Sample Application. See the CMakeLists.txt file for instructions.