Complete Overhaul of install script - improvements and added functionality: user input flow, clarified prompt messages. Cloudflare Zero-Trust Tunnel support, Cloudflare DNS-01 SSL cert option, adaptive performance tuning, general reliability and hardening

[zoltan151]

### Quick Overview:

• Added guided interactive UX + unattended flags capabilities
• Added new SSL cert method: Cloudflare DNS-01
• Added support and optimization for hosting behind a Cloudflare Zero-Trust Tunnel, rather than directly via public IP
• Added safe reruns with cleanup/backup behavior
• Added optional php-fpm+mpm_event “high performance” profile
• Added boot-time autotune for (MariaDB/PHP-FPM/OPcache/Apache/system limits) for vertical scaling/future-proofing and maximal performance optimization
• Improved logging, validation, and post-install diagnostics + reboot prompt

### Detailed Breakdown:

1) Safety & reliability (fail-fast + predictable)

Auto-elevation to root (sudo self-elevate, hard stop if unavailable)
Why: Prevents partial installs and permission-based weirdness; avoids “script ran but nothing happened.”

set -euo pipefail and consistent error handling/logging (die, warn, say)
Why: Fewer silent failures, faster debugging, safer automation.

Non-interactive apt-get update && apt-get upgrade at the beginning
Why: Reduces dependency conflicts and runtime surprises; aligns with “clean base image” installs.

2) Dependencies installed up front (ensures that clean installs reliably work)

Explicit prerequisites installed at start, assuming a fresh OS:

Apache, MariaDB, PHP + extensions, certbot, cron, dnsutils, ufw, openssl, git, python3 bits, python3-certbot-dns-cloudflare
Why: Prevents mid-script failures and reduces “works on my server” scenarios.

3) Cleaner, lower-error UX (interactive + unattended)

Number-based menus for option-style prompts:

Access mode, performance profile, timezone handling, branch selection, TLS method, cleanup options
Why: Less user input error than free-form strings; faster and more approachable for non-experts.

Timezone prompt improved:

Offers detected TZ, UTC, or manual entry with examples (e.g., America/Denver)
Why: Users often don’t know tz database formats; detection can be wrong.

FQDN prompt clarified:

Explicit example (itflow.example.com)
Why: Reduces invalid domain input and confusion.

4) SSL/TLS improvements (adds options, doesn’t break the old path)

Preserves original classic Let’s Encrypt behavior as default (letsencrypt via HTTP-01 / apache plugin)
Why: Keeps the “common case” intact and avoids breaking expectations.

Adds Cloudflare DNS-01 option (letsencrypt-dns-cloudflare) using API token credentials
Why: Enables installs behind Cloudflare Tunnel / no inbound ports. DNS-01 works in locked-down network environments.

Certificate reuse support (--reuse-cert-name or auto-detect existing cert under /etc/letsencrypt/live/)
Why: Avoids needless re-issuance; supports re-runs and pre-provisioned cert flows.

UFW checks for classic HTTP-01 (ports 80/443):

If UFW active and ports blocked, prompt to open them, or fail clearly in unattended mode
Why: Classic LE fails silently otherwise; this makes the failure mode explicit and fixable.

Certbot renewal dry-run included (non-fatal)
Why: Verifies automation health up front so renewal failures don’t show up 60 days later.

5) Apache hardening & correctness improvements

Global Apache ServerName set (/etc/apache2/conf-available/servername.conf)
Why: Removes the common FQDN warning and prevents edge-case vhost behavior.

Vhost generation improved:

Proper HTTP vhost + optional HTTPS redirect (when TLS enabled)

Explicit Directory block with AllowOverride All to support .htaccess
Why: More consistent behavior across environments; avoids incomplete defaults.

6) Performance profile option (opt-in, controlled)

Balanced (default): classic mod_php with prefork (matches original behavior)
Why: Lowest-risk default. Minimizes potential compatibility surprises.

High performance (opt-in): php-fpm + mpm_event + proxy_fcgi
Why: Better concurrency and memory efficiency at scale (lots of simultaneous users / background jobs) - especially with heavy customer portal and API traffic. Introducing this as a manual opt-in feature to avoid surprises.

7) Idempotent reruns + cleanup (ops-friendly)

Cleanup options added:

Web only: vhosts/webroot/cron for the domain

DB only: drop itflow DB + itflow@localhost user (destructive)

All: both web + DB
Why: Fixes the “previous failed attempts” problem caused by remnants from abandoned or failed previous installs, and supports clean re-install loops.

Safe webroot behavior:

If non-empty webroot exists, move to timestamped .bak-YYYYMMDD-HHMMSS instead of clobbering
Why: Prevents accidental data loss while still allowing reruns.

8) Database improvements (stability + repeatability)

MariaDB startup + readiness checks (mysqladmin ping) before DB actions
Why: Avoids race conditions that cause intermittent failures.

User creation logic made re-run safe:

Creates user if missing, then ALTER USER sets password to a fresh random value
Why: Prevents “Access denied” and broken state after partial installs.

Credential generation improved:

Uses openssl rand (replaces tr | head patterns)
Why: More robust and consistent across distros; avoids subtle shell/pipeline edge cases.

9) Adaptive “autotune at boot” for dynamic scalability

Adds a dedicated tool + systemd unit:

/usr/local/sbin/itflow-autotune.sh

itflow-autotune.service enabled at boot

It automatically tunes based on detected RAM/CPU, and safely re-applies on boot.

Tuning includes:

MariaDB: InnoDB buffer pool sizing, connections, tmp table sizes, slow query logging
Why: Out-of-box MariaDB defaults are not MSP-scale friendly; this reduces latency and improves throughput.

OPcache: memory sizing and file cache sizing based on resources
Why: Huge win for PHP app responsiveness under load.

PHP-FPM pool tuning (high profile): pm.max_children, spares, pm.max_requests, timeouts
Why: Avoids worker starvation, prevents memory creep, adapts when resources change.

Apache MPM tuning: Event/prefork worker limits based on resources/profile
Why: Prevents thrash and handles concurrency.

System limits: LimitNOFILE=65535 for Apache + MariaDB
Why: Helps at higher concurrency, avoids file descriptor exhaustion.

Sysctl baseline: somaxconn, swappiness, etc.
Why: Reasonable baseline for server workloads.

First-run force apply marker
Creates /var/lib/itflow-autotune/first_run_done after first successful apply.
Why: Ensures the first run actually writes configs and restarts services, even if identical files existed; prevents the “it did nothing” confusion.

Autotune status output
Prints active MPM, php-fpm state, and file mtimes for the tuned configs
Why: Reviewers/operators can verify changes quickly without digging.

10) Cloudflare Tunnel guidance only when relevant

If access mode = cloudflare-tunnel, prints recommended tunnel origin settings:

• Match SNI to Host
• Origin Server Name
• HTTP Host Header
• Optional notes on Cloudflare SSL modes (Full strict recommended, but not mandatory)

Why: Prevents misconfiguration and avoids adding tunnel-specific noise for non-tunnel users.

11) Post-install reboot prompt (clean UX)

Recommends reboot and prompts interactively:

Enter defaults to YES

Only n/N rejects; other input re-prompts

Exit immediately after calling reboot

Why: Applies service changes cleanly and avoids SSH disconnect artifacts / weird repeated prompts.