Preflight

Preflight checks that a node has everything it needs before it starts: its settings, the services it must connect to, and the database Migrations. Preflight only reads and changes nothing, so you can run it on a site people are using. A node runs Preflight by itself every time it starts, and awhere setup and awhere upgrade always run it first.

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awhere preflight

The output has one row per node, then every check that did not pass, with the fix. The last line is Preflight passed or Preflight failed. If no node fails a check, the command ends with exit code 0. To check one node, give its name, such as awhere preflight core-services.

Run Preflight before the first deploy, after you change settings, and when a node will not start. You see all the problems at once.

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This is the result for logging-services with nothing set (some rows cut).

preflight: logging-services
  FAIL  env.TRANSPORTER           TRANSPORTER is not set
                                  fix: Set TRANSPORTER to the broker every node of this site shares (nats://<host>:4222, or TCP on a single host): without it this node cannot see the others.
  PASS  env.PORT                  PORT is not set (optional)
  WARN  release                   this image has no Release number (APP_VERSION is unset): it was not built by CI
preflight: logging-services: 1 passed, 1 warning, 1 failed

Each row is one check. It starts with the result, then the name of the check and what it found. When the result is WARN or FAIL, the next line starts with fix: and says what to change. The output never shows passwords. For the name of every check, see All Preflight checks.