Processes

Besides the web server, Lekalao needs two processes, plus one that is optional.

Horizon: the workers

Horizon works the queues. Three supervisors, one per queue:

Queue	Holds	Workers in production	Longest a job may run
`sending`	Every campaign and automation e-mail.	up to 10	150 s
`default`	Outgoing webhooks, the application’s e-mails, short jobs.	3	300 s
`imports`	Contact imports and exports.	2	1 hour

Without Horizon, nothing goes out.

/etc/systemd/system/lekalao-horizon.service

[Unit]
Description=Lekalao Horizon
After=network.target redis-server.service postgresql.service

[Service]
User=lekalao
WorkingDirectory=/var/www/lekalao
ExecStart=/usr/bin/php artisan horizon
ExecStop=/usr/bin/php artisan horizon:terminate
Restart=always
RestartSec=5
KillSignal=SIGTERM
TimeoutStopSec=3600

[Install]
WantedBy=multi-user.target

sudo systemctl enable --now lekalao-horizon

TimeoutStopSec lets an import in progress finish before the stop. The dashboard is at https://lekalao.example.com/horizon, for platform administrators only.

To add sending workers, raise maxProcesses on the sending supervisor in config/horizon.php, then run php artisan horizon:terminate. The real rate is still capped by your providers and by the receiving mailboxes (Sending safety).

The scheduler

One cron line, for the lekalao user:

* * * * * cd /var/www/lekalao && php artisan schedule:run >> /dev/null 2>&1

It sets off:

How often	Work
Every minute	Scheduled campaigns, statistics, A/B test winners, automations, the heartbeat.
Every 10 minutes	Sends that got stuck are queued again.
Every hour	RSS feeds.
Every night	DNS check of the domains (2:30), deleting the unconfirmed (3:00), old exports (3:15) and old provider feedback (3:30), the purge (3:45), retention limits (4:15), engagement scores (4:30).
Every week	List summaries (Monday 8:00), licence check (Tuesday 4:00).

The times are UTC. Every task is listed in Commands.

With Docker or a PaaS without cron, run php artisan schedule:work as one more process.

The SMTP relay

Optional. So that software can send over SMTP through Lekalao (SMTP relay):

/etc/systemd/system/lekalao-smtp.service

[Unit]
Description=Lekalao SMTP relay
After=network.target postgresql.service

[Service]
User=lekalao
WorkingDirectory=/var/www/lekalao
ExecStart=/usr/bin/php artisan lekalao:smtp --host=127.0.0.1 --port=2525 --hostname=smtp.lekalao.example.com
Restart=always

[Install]
WantedBy=multi-user.target

The relay does not speak TLS, and it receives API tokens as passwords. Leave it on 127.0.0.1, or put a TLS terminator in front of it (stunnel, HAProxy). Never expose it as it is on the internet.

So that Settings → Documentation tells the teams about it:

.env

LEKALAO_SMTP_ADVERTISE=true
LEKALAO_SMTP_HOST=smtp.lekalao.example.com
LEKALAO_SMTP_PORT=465

After every deployment

Horizon keeps the old code in memory:

php artisan horizon:terminate

systemd starts it again with the new one. Restart the SMTP relay too, when it runs.

Install

Operate

Selling it

Horizon: the workers

The scheduler

The SMTP relay

After every deployment

​Horizon: the workers

​The scheduler

​The SMTP relay

​After every deployment

Horizon: the workers

The scheduler

The SMTP relay

After every deployment