例外の先で、判定が開いたままになる — Web 2025 の新項目 A10

async function authzFailOpen(user) {
try {
  const r = await pool.query("SELECT role FROM users WHERE name = $1", [user]);
  if (r.rows[0]?.role !== "admin") return { allow: false, status: 403, why: "role is not admin" };
} catch (e) {
  // "don't let a DB hiccup break the page" -- swallow and continue
  log(...);
}
return { allow: true, status: 200, why: "allowed" };
}
 
async function authzFailClosed(user) {
try {
  const r = await pool.query("SELECT role FROM users WHERE name = $1", [user]);
  if (r.rows[0]?.role !== "admin") return { allow: false, status: 403, why: "role is not admin" };
  return { allow: true, status: 200, why: "allowed" };
} catch (e) {
  log(...);
  return { allow: false, status: 503, why: "authorization unavailable" };
}
}

## phase A: DB up
$ curl -s -w " => HTTP %{http_code}\n" -H "x-user: bob" http://localhost:18080/open/admin
role is not admin
=> HTTP 403
## phase B: docker stop l4-pg
l4-pg
$ curl -s -w " => HTTP %{http_code}\n" -H "x-user: bob" http://localhost:18080/open/admin
ADMIN REPORT (secret dummy data) for bob
=> HTTP 200
$ curl -s -w " => HTTP %{http_code}\n" -H "x-user: bob" http://localhost:18080/closed/admin
authorization unavailable
=> HTTP 503
## app log since 2026-09-28T10:16:41Z
2026-09-28T10:16:44.457Z [open]   authz lookup failed: ENOTFOUND -- continuing
2026-09-28T10:16:44.457Z [open]   GET /open/admin user=bob -> 200 (allowed)
2026-09-28T10:16:44.484Z [closed] authz lookup failed: ENOTFOUND -- denying
2026-09-28T10:16:44.484Z [closed] GET /closed/admin user=bob -> 503 (authorization unavailable)

## phase B: reset, interrupt /transfer/plain (no transaction)
$ curl -s http://localhost:18080/balances
alice=1000 bob=0 ledger_rows=0
$ curl -s -w " => HTTP %{http_code}\n" "http://localhost:18080/transfer/plain?slow=1&amount=100" &   # runs in background
$ docker stop l4-pg   # 2s later, while the app is between debit and credit
transfer failed: 57P01
=> HTTP 500
l4-pg
$ docker start l4-pg
l4-pg
$ curl -s http://localhost:18080/balances
alice=900 bob=0 ledger_rows=0
## phase C: reset, interrupt /transfer/tx (BEGIN ... COMMIT)
$ curl -s http://localhost:18080/balances
alice=1000 bob=0 ledger_rows=0
$ curl -s -w " => HTTP %{http_code}\n" "http://localhost:18080/transfer/tx?slow=1&amount=100" &   # runs in background
$ docker stop l4-pg   # 2s later, while the app is between debit and credit
transfer failed: 57P01
=> HTTP 500
l4-pg
$ docker start l4-pg
l4-pg
$ curl -s http://localhost:18080/balances
alice=1000 bob=0 ledger_rows=0

## app log since 2026-09-28T10:19:22Z
2026-09-28T10:19:30.777Z [tx]     debit done (uncommitted)
2026-09-28T10:19:32.828Z [tx]     client 'error' event: Connection terminated unexpectedly
2026-09-28T10:19:32.828Z [tx]     ROLLBACK failed: Connection terminated unexpectedly
2026-09-28T10:19:32.828Z [tx] GET /transfer/tx?slow=1 -> 500 (57P01)
## postgres log since 2026-09-28T10:19:22Z (grep shutdown|terminat|ready)
2026-09-28 10:19:32.823 UTC [1] LOG:  received fast shutdown request
2026-09-28 10:19:32.825 UTC [36] FATAL:  terminating connection due to administrator command