Logs that never rotate

$bash log_rotate_check.sh /tmp/p622/logs

#!/usr/bin/env bash
$set -euo pipefail
$IFS=$'\n\t'
 
# log_rotate_check.sh - find the logs that will fill the disk before they do.
# Fixes: a file over --max-mb, a file untouched for --max-days, and a directory
#        over --dir-budget. Read-only: prints findings and one logrotate stanza,
#        changes nothing.
#
# Usage:
#   log_rotate_check.sh [options] DIR [DIR...]
#   log_rotate_check.sh --max-mb 200 --max-days 14 /var/log
#
# Options:
#   --max-mb N      flag files larger than N MiB (default 100)
#   --max-days N    flag files older than N days (default 30)
#   --dir-budget N  flag directories over N MiB (default 1024)
#   --top N         show at most N details per class (default 5)
#   -h, --help      show this help and exit 0
#
# Exit codes: 0 clean, 1 findings, 2 usage or unreadable input.
# Needs: GNU findutils, coreutils (find, stat, du, sort), awk. Linux.
# Cron: 0 6 * * * /usr/local/bin/log_rotate_check.sh /var/log
# By s0sta.com
 
$usage() {
$    cat <<'EOF'
log_rotate_check.sh - find the logs that will fill the disk before they do.
 
Usage:
  log_rotate_check.sh [options] DIR [DIR...]
  log_rotate_check.sh --max-mb 200 --max-days 14 /var/log
 
Options:
  --max-mb N      flag files larger than N MiB (default 100)
  --max-days N    flag files older than N days (default 30)
  --dir-budget N  flag directories over N MiB (default 1024)
  --top N         show at most N details per class (default 5)
  -h, --help      show this help and exit 0
 
Read-only. Prints one suggested logrotate stanza per directory.
Exit codes: 0 clean, 1 findings, 2 usage or unreadable input.
EOF
$}
 
$die() {
$    printf 'ERROR %s\n' "$*" >&2
$    exit 2
$}
 
$is_number() {
$    case "$1" in
$        ''|*[!0-9]*) return 1 ;;
$        *) return 0 ;;
$    esac
$}
 
$max_mb=100
$max_days=30
$budget_mb=1024
$top=5
$dirs=()
 
$while [ "$#" -gt 0 ]; do
$    case "$1" in
$        --max-mb)       [ "$#" -ge 2 ] || die "missing value for $1"; max_mb=$2; shift 2 ;;
$        --max-days)     [ "$#" -ge 2 ] || die "missing value for $1"; max_days=$2; shift 2 ;;
$        --dir-budget)   [ "$#" -ge 2 ] || die "missing value for $1"; budget_mb=$2; shift 2 ;;
$        --top)          [ "$#" -ge 2 ] || die "missing value for $1"; top=$2; shift 2 ;;
$        -h|--help)      usage; exit 0 ;;
$        --)             shift; while [ "$#" -gt 0 ]; do dirs+=("$1"); shift; done ;;
$        -*)             die "unknown option: $1 (try --help)" ;;
$        *)              dirs+=("$1"); shift ;;
$    esac
$done
 
$for value in "$max_mb" "$max_days" "$budget_mb" "$top"; do
$    is_number "$value" || die "not a number: $value"
$done
$[ "${#dirs[@]}" -gt 0 ] || die "no directory given (try --help)"
$for dir in "${dirs[@]}"; do
$    [ -d "$dir" ] || die "not a directory: $dir"
$    [ -r "$dir" ] || die "unreadable directory: $dir"
$done
 
$if stat -c %s / >/dev/null 2>&1; then
$    STAT_STYLE=gnu
$else
$    STAT_STYLE=bsd
$fi
 
$size_bytes() {
$    if [ "$STAT_STYLE" = gnu ]; then
$        stat -c %s -- "$1" 2>/dev/null || printf '0'
$    else
$        stat -f %z -- "$1" 2>/dev/null || printf '0'
$    fi
$}
 
$mtime_epoch() {
$    if [ "$STAT_STYLE" = gnu ]; then
$        stat -c %Y -- "$1" 2>/dev/null || printf '0'
$    else
$        stat -f %m -- "$1" 2>/dev/null || printf '0'
$    fi
$}
 
$now=$(date +%s)
$total=0
 
$for dir in "${dirs[@]}"; do
$    big_count=0
$    old_count=0
$    budget_hit=0
$    big_list=()
$    old_list=()
$    biggest=""
$    biggest_size=0
$    oldest=""
$    oldest_days=0
 
$    while IFS= read -r -d '' file; do
$        big_count=$((big_count + 1))
$        bytes=$(size_bytes "$file")
$        big_list+=("$bytes"$'\t'"$file")
$        if [ "$bytes" -gt "$biggest_size" ]; then
$            biggest=$file
$            biggest_size=$bytes
$        fi
$    done < <(find "$dir" -type f -size +"${max_mb}"M -print0 2>/dev/null)
 
$    while IFS= read -r -d '' file; do
$        old_count=$((old_count + 1))
$        mtime=$(mtime_epoch "$file")
$        days=$(( (now - mtime) / 86400 ))
$        old_list+=("$days"$'\t'"$file")
$        if [ "$days" -gt "$oldest_days" ]; then
$            oldest=$file
$            oldest_days=$days
$        fi
$    done < <(find "$dir" -type f -mtime +"${max_days}" -print0 2>/dev/null)
 
$    dir_mb=$(du -sm "$dir" 2>/dev/null | awk '{print $1}')
$    dir_mb=${dir_mb:-0}
$    if [ "$dir_mb" -gt "$budget_mb" ]; then
$        budget_hit=1
$    fi
 
$    flags=$((big_count + old_count + budget_hit))
$    total=$((total + flags))
$    if [ "$flags" -eq 1 ]; then
$        label=flag
$    else
$        label=flags
$    fi
$    printf 'FINDING %d %s in %s\n' "$flags" "$label" "$dir"
 
$    alert=""
$    skip_big=""
$    skip_old=""
$    if [ "$biggest_size" -gt 0 ]; then
$        alert=big
$        skip_big=$biggest
$    elif [ "$oldest_days" -gt 0 ]; then
$        alert=old
$        skip_old=$oldest
$    elif [ "$budget_hit" -eq 1 ]; then
$        alert=budget
$    fi
 
$    if [ "$alert" = big ]; then
$        biggest_mb=$((biggest_size / 1048576))
$        printf 'ALERT %s %dMB over %dMB\n' "$biggest" "$biggest_mb" "$max_mb"
$    elif [ "$alert" = old ]; then
$        printf 'ALERT %s %dd untouched (max %dd)\n' "$oldest" "$oldest_days" "$max_days"
$    elif [ "$alert" = budget ]; then
$        printf 'ALERT %s %dMB over %dMB\n' "$dir" "$dir_mb" "$budget_mb"
$    fi
 
$    if [ "${#big_list[@]}" -gt 0 ]; then
$        printf '%s\n' "${big_list[@]}" \
            | sort -rn \
            | awk -F'\t' -v n="$top" -v skip="$skip_big" \
                'NR <= n && $2 != skip { printf "BIG %s %dMB\n", $2, $1 / 1048576 }'
$    fi
 
$    if [ "${#old_list[@]}" -gt 0 ]; then
$        printf '%s\n' "${old_list[@]}" \
            | sort -rn \
            | awk -F'\t' -v n="$top" -v skip="$skip_old" \
                'NR <= n && $2 != skip { printf "OLD %s %dd\n", $2, $1 }'
$    fi
 
$    if [ "$budget_hit" -eq 1 ] && [ "$alert" != budget ]; then
$        printf 'BUDGET %s %dMB over %dMB\n' "$dir" "$dir_mb" "$budget_mb"
$    fi
 
$    if [ "$alert" = big ]; then
$        printf 'ROTATE %s: size %dM, rotate %d, compress\n' "$biggest" "$max_mb" "$max_days"
$    elif [ "$alert" = old ]; then
$        printf 'ROTATE %s: daily, rotate 14, maxage %d, compress\n' "$oldest" "$max_days"
$    fi
$done
 
$if [ "$total" -gt 0 ]; then
$    exit 1
$fi
$exit 0