#!/usr/bin/env bash
#
# JbTecWiz Support Centre -- generated fix script
#
# Fault : 413 Request Entity Too Large, or uploads fail silently
# Fix   : Raise every limit in the chain
# Source: https://jbtecwiz.com/support/lnx-web-413
#
# Run as     : Root shell
# Expect     : 25 minutes
# Risk       : low
# Reversible : yes
#
# WHEN THIS IS THE RIGHT FIX
#   Uploads fail above a size.
#
# HOW TO UNDO IT
#   Restore the previous values in nginx.conf and php.ini, then reload
#   both.
#
# Walks the fix one step at a time and asks before each. Steps with no
# command are yours to do -- it prints those and waits. DRYRUN=1 prints
# without executing; UNATTENDED=1 does not ask.
#
# --------------------------------------------------------------------
# NO WARRANTY - USE AT YOUR OWN RISK
#
# This script is provided by JbTecWiz as-is and with no warranty of any
# kind, express or implied. You run it entirely at your own risk.
#
# JbTecWiz accepts no liability for any loss or damage arising from its
# use, including but not limited to data loss, downtime, or configuration
# changes that turn out to be wrong for your system.
#
# You are responsible for reading this script before running it, for
# satisfying yourself that it suits the machine in front of you, and for
# having a working backup first. Some steps cannot be undone.
# --------------------------------------------------------------------

set -uo pipefail
DRYRUN="${DRYRUN:-0}"
UNATTENDED="${UNATTENDED:-0}"
failed=0

if [ "$(id -u)" -ne 0 ]; then
  echo "  This fix is documented as needing root. Re-run with sudo." >&2
  exit 3
fi

rule() { printf "\n%s\n" "$(printf '-%.0s' $(seq 1 70))"; if [ $# -gt 0 ]; then echo "$1"; fi; }
prose() { echo "$1" | fold -s -w 74 | sed "s/^/  /"; }

# Returns 0 when the caller should run the command, 1 when it should not.
# A manual step always returns 1 -- there is nothing for the caller to run.
step() {  # step <n> <do> <why> <manual|cmd> [command lines...]
  local n="$1" dotext="$2" why="$3" mode="$4"; shift 4
  rule "  Step $n of 5"
  prose "$dotext"
  if [ -n "$why" ]; then echo; prose "$why"; fi
  if [ "$mode" = "manual" ]; then
    echo; echo "  -> Do this yourself, then press Enter to carry on."
    if [ "$UNATTENDED" = "0" ] && [ "$DRYRUN" = "0" ]; then read -r _; fi
    return 1
  fi
  echo; printf "    %s\n" "$@"; echo
  if [ "$DRYRUN" = "1" ]; then echo "  (dry run -- not executed)"; return 1; fi
  if [ "$UNATTENDED" = "0" ]; then
    read -r -p "  Run this step? [Y]es / [S]kip / [Q]uit " a
    case "$a" in
      [Qq]*) echo "  Stopped at your request."; exit 0 ;;
      [Ss]*) echo "  Skipped."; return 1 ;;
    esac
  fi
  return 0
}

rule
echo "  413 Request Entity Too Large, or uploads fail silently"
echo "  Raise every limit in the chain"
echo
echo "  Risk: low   Reversible   25 minutes"
echo
prose 'No warranty. Use at your own risk - JbTecWiz accepts no liability. Read it before you run it, and have a backup.'
rule
echo
if [ "$UNATTENDED" = "0" ] && [ "$DRYRUN" = "0" ]; then
  read -r -p "  Ready? [y/N] " go
  case "$go" in [Yy]*) ;; *) echo "  Nothing was changed."; exit 0;; esac
fi

if step 1 'Read the current values at each layer.' 'Setting one and not the others produces a different failure at the next layer down, which is why this often takes three attempts. Reading all three first makes it one change.' cmd 'grep -rn client_max_body_size /etc/nginx/ 2>/dev/null' 'php -i | grep -E '\''upload_max_filesize|post_max_size|memory_limit|max_file_uploads'\'''; then
  grep -rn client_max_body_size /etc/nginx/ 2>/dev/null
  php -i | grep -E 'upload_max_filesize|post_max_size|memory_limit|max_file_uploads'
  if [ $? -ne 0 ]; then
    failed=$((failed+1))
    echo "  Step 1 failed. The rest of the fix may depend on it." >&2
  fi
fi

if step 2 'Raise the nginx limit, in the server or location block that serves the upload path.' '' cmd 'sudo sed -i '\''/http {/a\    client_max_body_size 64M;'\'' /etc/nginx/nginx.conf' 'sudo nginx -t && sudo systemctl reload nginx'; then
  sudo sed -i '/http {/a\    client_max_body_size 64M;' /etc/nginx/nginx.conf
  sudo nginx -t && sudo systemctl reload nginx
  if [ $? -ne 0 ]; then
    failed=$((failed+1))
    echo "  Step 2 failed. The rest of the fix may depend on it." >&2
  fi
fi

if step 3 'Raise the PHP limits. post_max_size must be larger than upload_max_filesize, and memory_limit larger than both.' '' cmd 'sudo sed -i '\''s/^upload_max_filesize.*/upload_max_filesize = 64M/; s/^post_max_size.*/post_max_size = 72M/; s/^memory_limit.*/memory_limit = 256M/'\'' /etc/php/8.2/fpm/php.ini' 'sudo systemctl restart php8.2-fpm'; then
  sudo sed -i 's/^upload_max_filesize.*/upload_max_filesize = 64M/; s/^post_max_size.*/post_max_size = 72M/; s/^memory_limit.*/memory_limit = 256M/' /etc/php/8.2/fpm/php.ini
  sudo systemctl restart php8.2-fpm
  if [ $? -ne 0 ]; then
    failed=$((failed+1))
    echo "  Step 3 failed. The rest of the fix may depend on it." >&2
  fi
fi

step 4 'Check the application'\''s own limit -- most content management systems have one in their settings as well.' '' manual || true

if step 5 'Raise the timeouts to match. A 64MB upload on a slow connection can exceed the read timeout and fail as a 504 instead.' '' cmd 'grep -rn '\''client_body_timeout\|fastcgi_read_timeout'\'' /etc/nginx/'; then
  grep -rn 'client_body_timeout\|fastcgi_read_timeout' /etc/nginx/
  if [ $? -ne 0 ]; then
    failed=$((failed+1))
    echo "  Step 5 failed. The rest of the fix may depend on it." >&2
  fi
fi

rule "  Confirm it worked"
prose 'A file just under the new limit uploads successfully.'
if [ "$DRYRUN" = "0" ]; then
  php -i | grep -E 'upload_max_filesize|post_max_size'
  curl -sI -X POST -F file=@test.bin http://localhost/upload | head -3
fi

rule
if [ "$failed" -gt 0 ]; then
  echo "  Finished with $failed failed step(s)."
  echo "  Read the full write-up at https://jbtecwiz.com/support/lnx-web-413"
else
  echo "  Finished."
fi
echo
prose 'To undo: Restore the previous values in nginx.conf and php.ini, then reload both.'
rule