#!/usr/bin/env bash
# Reads what knotless logs on the host (deploy/README.md, Logs):
#
#   deploy/logs.sh [serve|run|runner|pages|deploys] [--since 30m] [--follow] [jq filter]
#
#   deploy/logs.sh serve 'select(.duration_ms > 1000)'
#   deploy/logs.sh serve --since 2h 'select(.level == "WARN" or .level == "ERROR")'
#   deploy/logs.sh runner --since 1h 'select(.message == "batch started")'
#   deploy/logs.sh deploys
#
# They are read from the host's journal, so a container a rollout removed
# is read too. serve and the runners log JSON lines, each run through the
# jq filter (`.` if none); lines that are not JSON are left out. pages
# logs plain text, and deploys is the host's /var/log/knotless-deploy.log,
# each shown as is.
# The host is KNOTLESS_HOST, from deploy/local.env, else knotless.dev: run
# is a runner there. runner is the runner host's instead
# (deploy/runner-host): KNOTLESS_RUNNER_HOST, else runner.knotless.dev,
# its runner named by KNOTLESS_RUNNER_NAME (knotless-runner). As
# deploy/runner-host/deploy.sh does, KNOTLESS_RUNNER_ENV names a file
# read in place of deploy/local.env, for another runner such as the
# trusted one: `KNOTLESS_RUNNER_ENV=deploy/ci.env deploy/logs.sh runner`.

set -euo pipefail
cd "$(dirname "$0")/.."
SVC="${1:-serve}"
if [ "$SVC" = runner ] && [ -n "${KNOTLESS_RUNNER_ENV:-}" ]; then
  set -a; . "$KNOTLESS_RUNNER_ENV"; set +a
elif [ -f deploy/local.env ]; then
  set -a; . deploy/local.env; set +a
fi
DEST="${KNOTLESS_HOST:-root@knotless.dev}"
if [ "$SVC" = runner ]; then
  DEST="${KNOTLESS_RUNNER_HOST:-root@runner.knotless.dev}"
fi
[ $# -eq 0 ] || shift
SINCE=30m
FOLLOW=
while [ $# -gt 0 ]; do
  case "$1" in
    --since) SINCE=$2 && shift 2 ;;
    --follow) FOLLOW=--follow && shift ;;
    *) break ;;
  esac
done
FILTER="${1:-.}"
SSH="ssh -o StrictHostKeyChecking=accept-new $DEST"
# This project's lines, as written, since then: journalctl takes `-30m`.
JOURNAL="journalctl --no-pager -o cat --since '-$SINCE' ${FOLLOW:+--follow} COM_DOCKER_COMPOSE_PROJECT=knotless"

case "$SVC" in
  deploys)
    # shellcheck disable=SC2029
    $SSH "tail -n 100 $FOLLOW /var/log/knotless-deploy.log"
    ;;
  serve | run)
    # Every container of the service, gone or running, both while a
    # rollout overlaps them.
    # shellcheck disable=SC2029
    $SSH "$JOURNAL COM_DOCKER_COMPOSE_SERVICE='$SVC'" |
      jq -R -c --unbuffered "fromjson? | $FILTER"
    ;;
  runner)
    # The runner host tags each line with its container's name, which a
    # deploy that replaces the container keeps, and the host's clock may
    # not be in UTC: `--since` is relative, so it reads the same anywhere.
    # shellcheck disable=SC2029
    $SSH "journalctl --no-pager -o cat --since '-$SINCE' ${FOLLOW:+--follow} CONTAINER_TAG='${KNOTLESS_RUNNER_NAME:-knotless-runner}-run-1'" |
      jq -R -c --unbuffered "fromjson? | $FILTER"
    ;;
  pages)
    # shellcheck disable=SC2029
    $SSH "$JOURNAL COM_DOCKER_COMPOSE_SERVICE=pages"
    ;;
  *)
    sed -n '4p' "$0" >&2
    exit 2
    ;;
esac