Logrotate does not upload to S3

I've spent some hours trying to figure out why logrotate won't successfully upload my logs to S3, so I'm posting my setup here. Here's the thing--logrotate uploads the log file correctly to s3 when I force it like this:

sudo logrotate -f /etc/logrotate.d/haproxy

Starting S3 Log Upload...
WARNING: Module python-magic is not available. Guessing MIME types based on file extensions.
/var/log/haproxy-2014-12-23-044414.gz -> s3://my-haproxy-access-logs/haproxy-2014-12-23-044414.gz  [1 of 1]
 315840 of 315840   100% in    0s     2.23 MB/s  done

But it does not succeed as part of the normal logrotate process. The logs are still compressed by my postrotate script, so I know that it is being run. Here is my setup:

/etc/logrotate.d/haproxy =>

/var/log/haproxy.log {
    size 1k
    rotate 1
    missingok
    copytruncate
    sharedscripts
    su root root
    create 777 syslog adm
    postrotate
        /usr/local/admintools/upload.sh 2>&1 /var/log/upload_errors
    endscript
}

/usr/local/admintools/upload.sh =>

echo "Starting S3 Log Upload..."

BUCKET_NAME="my-haproxy-access-logs"

# Perform Rotated Log File Compression                                                                                                        
filename=/var/log/haproxy-$(date +%F-%H%M%S).gz                                                                                              \

tar -czPf "$filename" /var/log/haproxy.log.1

# Upload log file to Amazon S3 bucket                                                                                                         
/usr/bin/s3cmd put "$filename" s3://"$BUCKET_NAME"

And here is the output of a dry run of logrotate:

sudo logrotate -fd /etc/logrotate.d/haproxy
reading config file /etc/logrotate.d/haproxy

Handling 1 logs

rotating pattern: /var/log/haproxy.log  forced from command line (1 rotations)
empty log files are rotated, old logs are removed
considering log /var/log/haproxy.log
  log needs rotating
rotating log /var/log/haproxy.log, log->rotateCount is 1
dateext suffix '-20141223'
glob pattern '-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
renaming /var/log/haproxy.log.1 to /var/log/haproxy.log.2 (rotatecount 1, logstart 1, i 1), 
renaming /var/log/haproxy.log.0 to /var/log/haproxy.log.1 (rotatecount 1, logstart 1, i 0), 
copying /var/log/haproxy.log to /var/log/haproxy.log.1
truncating /var/log/haproxy.log
running postrotate script
running script with arg /var/log/haproxy.log : "
        /usr/local/admintools/upload.sh 2>&1 /var/log/upload_errors
"
removing old log /var/log/haproxy.log.2

Any insight appreciated.