Docker + TTY CRLF Behavior

Question

There's a known issue/behavior around docker run -t

• stdout stderr streams both go to stdout
• LF(\n) replaced -> CRLF (\r\n)

There're explanation in the net that CRLF replacements is the matter of an allocated tty it self.

With this in mind

There's an app that under the hood wraps calls to docker run -t bypassing stdio completely as is. It runs it own logs under stderr and LF driven

As a result (combination of docker stdout:CRLF and logs stderr:LF) the output in the terminal differs depending on another option docker run -I For docker run -t it is

[err] regular app logs LF
[err] regular app logs LF
[out] docker related outputs CRLF
[out] docker related outputs CRLF
[err] regular app logs LF
[err] regular app logs LF

But for docker run -it the terminal output starts being displayed corrupted just after the first CRLF occurrence (yet in byte representation content looks very similar for run -t outputs)

[err] regular app logs LF
[err] regular app logs LF
[out] docker related outputs CRLF
[out] docker related outputs CRLF
[err] regular app logs LF
[err]                    regular app logs LF
[err]                                       regular app logs LF

It looks like terminal automatically switches to CRLF mode ofter the first appearance and for the LF simply changes the line without turn the carriage back.

So what is not clear

• Actually for what reason the docker (it looks like) glues stdout+stderr
• Once CRLF replacement is the matter of terminal it self why doesn't it do this in consistent way both for stdout and stderr as well
• Why for (seems to be) similar output content on a same terminal the view of logs differs for -t and -it runs (the commands actually don't rely in stdin at all)

And for the following it maybe should to be asked in a standalone question but mainly this is more about are these related to the root problem cause at all

• At least would it be proper to turn CRLF behavior for the terminal (it is macOS)
• in iterm I didn't find CRLF related option neither on Text nor Terminal section
• How stty and iterm settings relate each other

Thanks