Serve commands

dpl serve is the long-running process for one base directory.

DPL_BASE=/opt/dpl dpl serve

In production, run it with systemd.

What serve does

dpl serve:

• holds state/serve.pid as a PID file and lock
• starts containers for deployed runtime units
• restarts ready units with backoff if they exit
• stops supervised containers on shutdown
• runs app timers when they are due
• re-reads deploy state and starts newly deployed units when a deploy command sends it SIGHUP

Deploy commands do not act as supervisors. They update state and notify dpl serve.

systemd example

[Unit]
Description=dpl service
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
Environment="DPL_BASE=/opt/dpl"
ExecStart=/usr/local/bin/dpl serve
ExecReload=/bin/kill -s HUP $MAINPID
KillMode=process
TimeoutStopSec=300
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target

One daemon per base directory

Run one dpl serve process for each DPL_BASE.

If another instance is already running for the same base directory, the PID lock stops the second daemon from starting.