Logging – Get Msiexec to Echo to Stdout Instead of Logging to File

loggingmsistderrstdout

As part of a continuous delivery pipeline I'd like to install an msi on a given machine. msiexec plus psexec does this perfectly, but it seems that msiexec can only log to a file and I need it to log to stdout/stderr.

Right now, to get the output back into our CI software I'll have to add a second step to echo the contents of the log, which seems a bit pointless.

Has anybody faced this issue before (and overcome it?)

Thanks in advance for any help here.

Mark

Best Answer

I checked this again, and here is some updated information:

It is possible to suppress the MSI GUI and set an external GUI implemented by a third party. This external GUI is able to receive messages from msiexec.exe as it performs the installation. This is mostly to implement a custom progress bar, but it seems you can also intercept most other error messages and status messages: MsiSetExternalUI function.

The interesting parameter is the dwMessageFilter. By setting this you can, for example, receive only the error messages that occur during the installation - or so it would seem. I suppose this can be enough for most purposes.

INSTALLUI_HANDLER MsiSetExternalUI(
  _In_  INSTALLUI_HANDLER puiHandler,
  _In_  DWORD dwMessageFilter,
  _In_  LPVOID pvContext
);

Regrettably I do not have sample code for this at the moment. I will test this later, when I get my system set up properly. The MsiEnableLog function is a related function call that will enable logging to file. Update: Here is what looks like a working SDK example.

At the command line interface level, you can also set logging to flush its buffer immediately to file by adding the ! parameter:

msiexec.exe /I "IsWiX.msi" /QN /L*V! "C:\msilog.log"

This means the log file is written continuously so no log buffer is lost if msiexec.exe crashes. The cost is a significantly slower installer due to the IO overhead.

Related Solutions

Way to redirect output to a file without buffering on unix/linux

You can explicitly set the buffering options of the standard streams using a setvbuf call in C (see this link), but if you're trying to modify the behaviour of an existing program try stdbuf (part of coreutils starting with version 7.5 apparently).

This buffers stdout up to a line:

stdbuf -oL command > output

This disables stdout buffering altogether:

stdbuf -o0 command > output

How to make SCP on Linux output “success” to stdout instead of stderr

I don't think you can redirect STDERR output selectively without rewriting the program to write those particular messages to STDOUT instead of STDERR. What you can do, however, is write a wrapper script that filters out the unwanted message, and run that script in the cron job.

#!/bin/bash

(ssh USER@LOCAL-SERVER ... 3>&1 1>&2- 2>&3-) 2>> ~/log/some.log \
  | grep -v "Connection .* succeeded" 1>&2

exit $?

Out of curiosity, why aren't you running a cron job with the scp command directly on LOCAL-SERVER?

Edit: You want to filter out some of the STDERR output while redirecting all STDOUT output to a file, but the pipe can connect STDOUT of one process to STDIN of another process. |& or 2>&1 | won't work, because STDOUT is already is redirected to ~/log/some.log, so there'd be nothing going into the pipe, and a lot of unwanted output in your log file.

However, it's possible to swap the descriptors, so that STDOUT actually goes to STDERR and STDERR actually goes to STDOUT. Then you can redirect all STDERR output to your log file and filter the STDOUT output via grep. Someone over at stackoverflow posted this neat little trick. The 1>&2 returns the filtered output back to STDERR.

Best Answer

Related Solutions

Way to redirect output to a file without buffering on unix/linux

How to make SCP on Linux output “success” to stdout instead of stderr

Related Topic