From 7ef8d4b846a6245258a23503862e8f95a2985d81 Mon Sep 17 00:00:00 2001
From: Jef Roosens <roosensjef@gmail.com>
Date: Mon, 12 Dec 2022 21:50:34 +0100
Subject: [PATCH] feat(agent): wrote ImageManager

---
 src/agent/cli.v    |  2 +-
 src/agent/daemon.v |  4 +--
 src/agent/images.v | 73 ++++++++++++++++++++++++++--------------------
 3 files changed, 45 insertions(+), 34 deletions(-)

diff --git a/src/agent/cli.v b/src/agent/cli.v
index a0a249cc..063d9607 100644
--- a/src/agent/cli.v
+++ b/src/agent/cli.v
@@ -13,7 +13,7 @@ pub:
 	polling_frequency     int = 30
 	// Architecture of agent
 	// arch string
-	// image_rebuild_frequency int    = 1440
+	image_rebuild_frequency int = 1440
 }
 
 // cmd returns the cli module that handles the cron daemon.
diff --git a/src/agent/daemon.v b/src/agent/daemon.v
index 71f47804..0508790d 100644
--- a/src/agent/daemon.v
+++ b/src/agent/daemon.v
@@ -14,8 +14,7 @@ const (
 struct AgentDaemon {
 	logger shared log.Log
 	conf   Config
-	// List of last built builder images
-	builder_images          []string
+	images ImageManager
 	// Which builds are currently running; length is same as
 	// conf.max_concurrent_builds
 	builds []BuildConfig
@@ -30,6 +29,7 @@ fn agent_init(logger log.Log, conf Config) AgentDaemon {
 		logger: logger
 		client: client.new(conf.address, conf.api_key)
 		conf: conf
+		images: new_image_manager(conf.image_rebuild_frequency)
 		builds: []BuildConfig{len: conf.max_concurrent_builds}
 		atomics: []u64{len: conf.max_concurrent_builds}
 	}
diff --git a/src/agent/images.v b/src/agent/images.v
index 454f85f9..aee2be0d 100644
--- a/src/agent/images.v
+++ b/src/agent/images.v
@@ -2,48 +2,59 @@ module agent
 
 import time
 import docker
+import build
 
 struct ImageManager {
-	images map[string]string
-	timestamps map[string]time.Time
+mut:
+	refresh_frequency int
+	images            map[string][]string  [required]
+	timestamps        map[string]time.Time [required]
 }
 
-// clean_old_base_images tries to remove any old but still present builder
-// images.
-fn (mut d AgentDaemon) clean_old_base_images() {
-	mut i := 0
+fn new_image_manager(refresh_frequency int) ImageManager {
+	return ImageManager{
+		refresh_frequency: refresh_frequency
+		images: map[string][]string{}
+		timestamps: map[string]time.Time{}
+	}
+}
 
-	mut dd := docker.new_conn() or {
-		d.lerror('Failed to connect to Docker socket.')
+fn (mut m ImageManager) refresh_image(base_image string) ! {
+	// No need to refresh the image if the previous one is still new enough
+	if base_image in m.timestamps
+		&& m.timestamps[base_image].add_seconds(m.refresh_frequency) > time.now() {
 		return
 	}
 
+	// TODO use better image tags for built images
+	new_image := build.create_build_image(base_image) or {
+		return error('Failed to build builder image from base image $base_image')
+	}
+
+	m.images[base_image] << new_image
+	m.timestamps[base_image] = time.now()
+}
+
+// clean_old_images tries to remove any old but still present builder images.
+fn (mut m ImageManager) clean_old_images() {
+	mut dd := docker.new_conn() or { return }
+
 	defer {
 		dd.close() or {}
 	}
 
-	for i < d.builder_images.len - 1 {
-		// For each builder image, we try to remove it by calling the Docker
-		// API. If the function returns an error or false, that means the image
-		// wasn't deleted. Therefore, we move the index over. If the function
-		// returns true, the array's length has decreased by one so we don't
-		// move the index.
-		dd.remove_image(d.builder_images[i]) or { i += 1 }
+	mut i := 0
+
+	for image in m.images.keys() {
+		i = 0
+
+		for i < m.images[image].len - 1 {
+			// For each builder image, we try to remove it by calling the Docker
+			// API. If the function returns an error or false, that means the image
+			// wasn't deleted. Therefore, we move the index over. If the function
+			// returns true, the array's length has decreased by one so we don't
+			// move the index.
+			dd.remove_image(m.images[image][i]) or { i += 1 }
+		}
 	}
 }
-
-// rebuild_base_image builds a builder image from the given base image.
-/* fn (mut d AgentDaemon) build_base_image(base_image string) bool { */
-/* 	d.linfo('Rebuilding builder 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 */
-/* } */