fix(cron): made Daemon.run infallible

src/cron/cron.v

@@ -25,5 +25,5 @@ pub fn cron(conf Config) ? {
 	mut d := daemon.init_daemon(logger, conf.address, conf.api_key, conf.base_image, ce,
 		conf.max_concurrent_builds, conf.api_update_frequency, conf.image_rebuild_frequency) ?
 
-	d.run() ?
+	d.run()
 }

src/cron/daemon/build.v

@@ -12,7 +12,7 @@ const build_done = 2
 
 // clean_finished_builds removes finished builds from the build slots & returns
 // them.
-fn (mut d Daemon) clean_finished_builds() ?[]ScheduledBuild {
+fn (mut d Daemon) clean_finished_builds() []ScheduledBuild {
 	mut out := []ScheduledBuild{}
 
 	for i in 0 .. d.atomics.len {
@@ -26,12 +26,22 @@ fn (mut d Daemon) clean_finished_builds() ?[]ScheduledBuild {
 }
 
 // update_builds starts as many builds as possible.
-fn (mut d Daemon) start_new_builds() ? {
+fn (mut d Daemon) start_new_builds() {
 	now := time.now()
 
 	for d.queue.len() > 0 {
-		if d.queue.peek() ?.timestamp < now {
-			sb := d.queue.pop() ?
+		elem := d.queue.peek() or {
+			d.lerror("queue.peek() unexpectedly returned an error. This shouldn't happen.")
+
+			break
+		}
+
+		if elem.timestamp < now {
+			sb := d.queue.pop() or {
+				d.lerror("queue.pop() unexpectedly returned an error. This shouldn't happen.")
+
+				break
+			}
 
 			// If this build couldn't be scheduled, no more will be possible.
 			if !d.start_build(sb) {
@@ -61,10 +71,19 @@ fn (mut d Daemon) start_build(sb ScheduledBuild) bool {
 }
 
 // run_build actually starts the build process for a given repo.
-fn (mut d Daemon) run_build(build_index int, sb ScheduledBuild) ? {
+fn (mut d Daemon) run_build(build_index int, sb ScheduledBuild) {
 	d.linfo('started build: $sb.repo.url $sb.repo.branch')
 
-	build.build_repo(d.address, d.api_key, d.builder_images.last(), &sb.repo) ?
+	// 0 means success, 1 means failure
+	mut status := 0
+
+	build.build_repo(d.address, d.api_key, d.builder_images.last(), &sb.repo) or { status = 1 }
+
+	if status == 0 {
+		d.linfo('finished build: $sb.repo.url $sb.repo.branch')
+	} else {
+		d.linfo('failed build: $sb.repo.url $sb.repo.branch')
+	}
 
 	stdatomic.store_u64(&d.atomics[build_index], daemon.build_done)
 }

src/cron/daemon/daemon.v

@@ -9,6 +9,12 @@ import math
 import build
 import docker
 
+// How many seconds to wait before retrying to update API if failed
+const api_update_retry_timeout = 5
+
+// How many seconds to wait before retrying to rebuild image if failed
+const rebuild_base_image_retry_timout = 30
+
 struct ScheduledBuild {
 pub:
 	repo_id   string
@@ -60,29 +66,31 @@ pub fn init_daemon(logger log.Log, address string, api_key string, base_image st
 	}
 
 	// Initialize the repos & queue
-	d.renew_repos() ?
-	d.renew_queue() ?
-	d.rebuild_base_image() ?
+	d.renew_repos()
+	d.renew_queue()
+	if !d.rebuild_base_image() {
+		return error('The base image failed to build. The Vieter cron daemon cannot run without an initial builder image.')
+	}
 
 	return d
 }
 
 // run starts the actual daemon process. It runs builds when possible &
 // periodically refreshes the list of repositories to ensure we stay in sync.
-pub fn (mut d Daemon) run() ? {
+pub fn (mut d Daemon) run() {
 	for {
-		finished_builds := d.clean_finished_builds() ?
+		finished_builds := d.clean_finished_builds()
 
 		// Update the API's contents if needed & renew the queue
 		if time.now() >= d.api_update_timestamp {
-			d.renew_repos() ?
-			d.renew_queue() ?
+			d.renew_repos()
+			d.renew_queue()
 		}
 		// The finished builds should only be rescheduled if the API contents
 		// haven't been renewed.
 		else {
 			for sb in finished_builds {
-				d.schedule_build(sb.repo_id, sb.repo) ?
+				d.schedule_build(sb.repo_id, sb.repo)
 			}
 		}
 
@@ -93,14 +101,14 @@ pub fn (mut d Daemon) run() ? {
 		// keep track of a list or something & remove an image once we have
 		// made sure it isn't being used anymore.
 		if time.now() >= d.image_build_timestamp {
-			d.rebuild_base_image() ?
+			d.rebuild_base_image()
 			// In theory, executing this function here allows an old builder
 			// image to exist for at most image_rebuild_frequency minutes.
 			d.clean_old_base_images()
 		}
 
 		// Schedules new builds when possible
-		d.start_new_builds() ?
+		d.start_new_builds()
 
 		// If there are builds currently running, the daemon should refresh
 		// every second to clean up any finished builds & start new ones.
@@ -113,7 +121,17 @@ pub fn (mut d Daemon) run() ? {
 			delay = d.api_update_timestamp - now
 
 			if d.queue.len() > 0 {
-				time_until_next_job := d.queue.peek() ?.timestamp - now
+				elem := d.queue.peek() or {
+					d.lerror("queue.peek() unexpectedly returned an error. This shouldn't happen.")
+
+					// This is just a fallback option. In theory, queue.peek()
+					// should *never* return an error or none, because we check
+					// its len beforehand.
+					time.sleep(1)
+					continue
+				}
+
+				time_until_next_job := elem.timestamp - now
 
 				delay = math.min(delay, time_until_next_job)
 			}
@@ -131,7 +149,7 @@ pub fn (mut d Daemon) run() ? {
 }
 
 // schedule_build adds the next occurence of the given repo build to the queue.
-fn (mut d Daemon) schedule_build(repo_id string, repo git.GitRepo) ? {
+fn (mut d Daemon) schedule_build(repo_id string, repo git.GitRepo) {
 	ce := if repo.schedule != '' {
 		parse_expression(repo.schedule) or {
 			// TODO This shouldn't return an error if the expression is empty.
@@ -144,7 +162,10 @@ fn (mut d Daemon) schedule_build(repo_id string, repo git.GitRepo) ? {
 	}
 
 	// A repo that can't be scheduled will just be skipped for now
-	timestamp := ce.next_from_now() ?
+	timestamp := ce.next_from_now() or {
+		d.lerror("Couldn't calculate next timestamp from '$repo.schedule'; skipping")
+		return
+	}
 
 	d.queue.insert(ScheduledBuild{
 		repo_id: repo_id
@@ -155,9 +176,15 @@ fn (mut d Daemon) schedule_build(repo_id string, repo git.GitRepo) ? {
 
 // renew_repos requests the newest list of Git repos from the server & replaces
 // the old one.
-fn (mut d Daemon) renew_repos() ? {
+fn (mut d Daemon) renew_repos() {
 	d.linfo('Renewing repos...')
-	mut new_repos := git.get_repos(d.address, d.api_key) ?
+
+	mut new_repos := git.get_repos(d.address, d.api_key) or {
+		d.lerror('Failed to renew repos. Retrying in ${daemon.api_update_retry_timeout}s...')
+		d.api_update_timestamp = time.now().add_seconds(daemon.api_update_retry_timeout)
+
+		return
+	}
 
 	d.repos_map = new_repos.move()
 
@@ -166,7 +193,7 @@ fn (mut d Daemon) renew_repos() ? {
 
 // renew_queue replaces the old queue with a new one that reflects the newest
 // values in repos_map.
-fn (mut d Daemon) renew_queue() ? {
+fn (mut d Daemon) renew_queue() {
 	d.linfo('Renewing queue...')
 	mut new_queue := MinHeap<ScheduledBuild>{}
 
@@ -181,8 +208,13 @@ fn (mut d Daemon) renew_queue() ? {
 	// here causes the function to prematurely just exit, without any errors or anything, very weird
 	// https://github.com/vlang/v/issues/14042
 	for d.queue.len() > 0 {
-		if d.queue.peek() ?.timestamp < now {
-			new_queue.insert(d.queue.pop() ?)
+		elem := d.queue.pop() or {
+			d.lerror("queue.pop() returned an error. This shouldn't happen.")
+			continue
+		}
+
+		if elem.timestamp < now {
+			new_queue.insert(elem)
 		} else {
 			break
 		}
@@ -193,16 +225,24 @@ fn (mut d Daemon) renew_queue() ? {
 	// For each repository in repos_map, parse their cron expression (or use
 	// the default one if not present) & add them to the queue
 	for id, repo in d.repos_map {
-		d.schedule_build(id, repo) ?
+		d.schedule_build(id, repo)
 	}
 }
 
 // rebuild_base_image recreates the builder image.
-fn (mut d Daemon) rebuild_base_image() ? {
+fn (mut d Daemon) rebuild_base_image() bool {
 	d.linfo('Rebuilding builder image....')
 
-	d.builder_images << build.create_build_image(d.base_image) ?
+	d.builder_images << build.create_build_image(d.base_image) or {
+		d.lerror('Failed to rebuild base image. Retrying in ${daemon.rebuild_base_image_retry_timout}s...')
+		d.image_build_timestamp = time.now().add_seconds(daemon.rebuild_base_image_retry_timout)
+
+		return false
+	}
+
 	d.image_build_timestamp = time.now().add_seconds(60 * d.image_rebuild_frequency)
+
+	return true
 }
 
 // clean_old_base_images tries to remove any old but still present builder