From 3781696316a200a886924b136b50e6c12f845ec9 Mon Sep 17 00:00:00 2001
From: Quentin Dufour <quentin@deuxfleurs.fr>
Date: Fri, 24 Mar 2023 16:46:31 +0100
Subject: [PATCH] working garbage collector

---
 hcl/builder.hcl | 32 ++++++++++++++++++++++++++++++++
 hcl/pin.sh      |  7 ++++++-
 main.go         |  2 +-
 3 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/hcl/builder.hcl b/hcl/builder.hcl
index 3b1252e..9d541a0 100644
--- a/hcl/builder.hcl
+++ b/hcl/builder.hcl
@@ -125,6 +125,38 @@ job "builder" {
         memory = 4000
     }
   }
+  task "garbage-collect-cache" {
+    driver = "docker"
+    config {
+      image = "nixpkgs/nix:nixos-22.11"
+      args = [ "/tmp/gc.sh" ]
+      volumes = [ 
+        "local/gc.sh:/tmp/gc.sh",
+        "local/nix.conf:/etc/nix/nix.conf",
+        "/var/cache/albatros/nix:/nix",
+      ]
+    }
+
+    lifecycle {
+      hook = "poststop"
+      sidecar = false
+    }
+
+    template {
+      data = file("./nix.conf")
+      destination = "local/nix.conf"
+    }
+
+    template {
+      data = file("./gc.sh")
+      destination = "local/gc.sh"
+      perms = "555"
+    }
+
+    restart {
+      attempts = 0
+    }
+  }
   }
 }
 
diff --git a/hcl/pin.sh b/hcl/pin.sh
index eca04cb..085186f 100644
--- a/hcl/pin.sh
+++ b/hcl/pin.sh
@@ -1,4 +1,9 @@
 #!/usr/bin/env bash
 set -euxo pipefail
+set -f # disable globbing
 
-echo "hook on $DRV_PATH"
+mkdir -p /nix/var/nix/gcroots/albatros
+DRV_NAME=$(echo $DRV_PATH | cut -d '/' -f 4)
+GCROOT=/nix/var/nix/gcroots/albatros/$DRV_NAME
+rm -f $GCROOT
+ln -s $DRV_PATH $GCROOT
diff --git a/main.go b/main.go
index a0e3486..5f30691 100644
--- a/main.go
+++ b/main.go
@@ -413,7 +413,7 @@ func main() {
 	http.HandleFunc("/build", build)
 
 	// launch
-	log.Println("Listen on :8080")
+	log.Println("Albatros listen on :8080")
 	if err = http.ListenAndServe(":8080", nil); err != nil {
 		log.Fatal("Can't start HTTP server")
 	}