Pre-receive hook to block commits by size under 50MB #259

mzzmjd · 2019-08-06T14:09:22Z

Pre-receive hook to block commits smaller than repo Maximum Object Size setting.

We had a requirement from a user to block any file and any commit that was over 100000 bytes in size.

Obviously the Maximum Object Size setting would be useful for this:

Set the maximum size of Git objects that can be pushed to this repository.
Allowing large objects to be pushed into Git can degrade performance, consider other options
(e.g. git-lfs) before increasing this value.

However, as the minimum value that can be set is 50 MB this was not the way forward.

So knocked up this pre-receive hook. Not sure that it is the most efficient way of doing things, but it seems to work OK.


        Pre-receive hook to block commits smaller than repo Maximum Object Si…

…ze setting

stoe · 2019-08-07T07:19:07Z

Cool addition, @mzzmjd.

Currently it will not work for newly created branches, when e.g. doing a git push -u origin HEAD.

Feel free to take a look at one of the other scripts on how to also capture new branches, for example

platform-samples/pre-receive-hooks/block_file_extensions.sh

Lines 11 to 36 in fd0818b

    
           zero_commit="0000000000000000000000000000000000000000" 
        
           # Do not traverse over commits that are already in the repository 
        
           # (e.g. in a different branch) 
        
           # This prevents funny errors if pre-receive hooks got enabled after some 
        
           # commits got already in and then somebody tries to create a new branch 
        
           # If this is unwanted behavior, just set the variable to empty 
        
           excludeExisting="--not --all" 
        
           while read oldrev newrev refname; do 
        
             # echo "payload" 
        
             echo $refname $oldrev $newrev 
        
             # branch or tag get deleted 
        
             if [ "$newrev" = "$zero_commit" ]; then 
        
               continue 
        
             fi 
        
             # Check for new branch or tag 
        
             if [ "$oldrev" = "$zero_commit" ]; then 
        
               span=`git rev-list $newrev $excludeExisting` 
        
             else 
        
               span=`git rev-list $oldrev..$newrev $excludeExisting` 
        
             fi 
        
             for COMMIT in $span;

jonico · 2020-03-20T13:02:24Z

@mzzmjd: GitHub.com and GitHub Enterprise Server (since version 2.20) now have an ability to restrict the commit size per repository to values smaller than 50 MB,, e.g. 1 MB:
https://help.github.com/en/enterprise/2.20/admin/installation/setting-git-push-limits

I will close this pull request because of this. Feel free to reopen if you believe there is still a reason for a pre-receive hook.

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…ze setting

jonico closed this Mar 20, 2020

github / platform-samples

Pre-receive hook to block commits by size under 50MB #259

Pre-receive hook to block commits by size under 50MB #259

mzzmjd commented Aug 6, 2019

stoe commented Aug 7, 2019

jonico commented Mar 20, 2020

github / platform-samples

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Pre-receive hook to block commits by size under 50MB #259

Pre-receive hook to block commits by size under 50MB #259

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mzzmjd commented Aug 6, 2019

stoe commented Aug 7, 2019

jonico commented Mar 20, 2020