A shell script to select the fastest freebsd-update mirror

best-mirror.sh

#!/bin/sh

# best-mirror.sh
#
# Domesticaed for FreeBSD by Babak Farrokhi (farrokhi@FreeBSD.org)
#
# This script finds the fastest freebsd-update mirror based on 
# data transfer rates from cURL.
#
# Note: I used a static list of mirrors, which is not the best way to 
#       get the list. You may want to try following command to get a 
#       list of active mirrors:
#
#       dig +short  -t srv _http._tcp.update.freebsd.org
#

# Originally taken from: 
#
# mirror_test.sh
# benchmarks closest ubuntu mirrors and outputs them in speed order
# bash -c "$(curl -fsSL https://gist.githubusercontent.com/lox/9152137/raw/mirror_test.sh)"

MIRRORS="update1.freebsd.org update2.freebsd.org update3.freebsd.org update4.freebsd.org update5.freebsd.org"
TESTFILE="/to-12.0-RC1/amd64/bp/0cfaf7bd9064730d8df2839f0ecfdd1b8311946b95315917c2e6832d4b5ac0e0-35c52504b158099f3b7eb9426ef0fdf7f3d626e528298de4f8b6e89565936b3e"
TIMEOUT=10
SAMPLES=3
BYTES=300000 # 300KB

# tests the provided mirror, outputs times
test_mirror() {
    if [ -z ${HTTP_PROXY} ]; then
        PROXY_SETTINGS=""
    else
        PROXY_SETTINGS="-x ${HTTP_PROXY}"
    fi
    for s in $(seq 1 $SAMPLES) ; do
        time=$(curl -r 0-$BYTES --max-time $TIMEOUT ${PROXY_SETTINGS} --fail --silent --output /dev/null --write-out %{time_total} ${1}${TESTFILE})
        if [ $? -eq 0 ]; then
            echo $time
        else
            echo "nan"
        fi
    done
}

# tests all the mirrors, outputs mirror and average time
test_all_mirrors() {
    for MIRROR in $MIRRORS; do
        results=$(test_mirror $MIRROR)
        mean=$(mean $results)
        if [ "$mean" != "nan" ] ; then
            printf '%-25s %.5f\n' $MIRROR $mean
        else
            printf '%-25s failed, ignoring\n' $MIRROR 1>&2
        fi
    done
}

# calculates the mean of all arguments
mean() {
    len=$#
    echo $* | tr " " "\n" | sort -n | head -n $(((len+1)/2)) | tail -n 1
}

# print mirrors in order of time
test_all_mirrors | sort -n -k 2