Switch to using a persistent folder for RAUC bundle downloads

Author: yfyf

base/default.nix

@@ -62,11 +62,25 @@ with lib;
         User = "root";
         RestartSec = "10s";
         Restart = "always";
+        ExecStartPre = "-${pkgs.writeShellScript "clear-state" ''
+            rm -rf /var/lib/playos-controller/*
+            rm -rf /var/lib/playos-controller/.*
+        ''}";
+        StateDirectory = "playos-controller";
       };
       wantedBy = [ "multi-user.target" ];
       requires = [ "connman.service" ];
       after = [ "rauc.service" "connman.service" ];
     };
 
+    # Use the persistent partition for storing controller state only to avoid
+    # storing the RAUC bundles in memory (tmpfs)
+    playos.storage.persistentFolders."/var/lib/playos-controller" = {
+      mode = "0755";
+      user = "root";
+      group = "root";
+    };
+
+
   };
 }

controller/server/update_client.ml

@@ -16,14 +16,20 @@ module type UpdateClientDeps = sig
   val get_proxy : unit -> Uri.t option Lwt.t
 end
 
-let make_deps ?(download_dir = "/tmp") get_proxy base_url :
-    (module UpdateClientDeps) =
+let make_deps ?download_dir get_proxy base_url : (module UpdateClientDeps) =
   (module struct
     let base_url = base_url
 
     let get_proxy = get_proxy
 
-    let download_dir = download_dir
+    let download_dir =
+      let fallback_download_dir = "/tmp" in
+      (* STATE_DIRECTORY is set by systemd when running controller as a service *)
+      let state_dir = Sys.getenv_opt "STATE_DIRECTORY" in
+      let state_or_fallback =
+        state_dir |> Option.value ~default:fallback_download_dir
+      in
+      download_dir |> Option.value ~default:state_or_fallback
   end
 )
 

testing/disk/default.nix

@@ -8,8 +8,9 @@
 , rescueSystem
 , systemImage
 
-, # Size of data partition in MiB
-  dataPartSizeMiB ? 400
+, # The data partition needs to be big enough to store at least a single RAUC
+  # bundle, which currently is ~1.4GB, + other cached/persisted stuff
+  dataPartSizeMiB ? 2000
 }:
 with lib;
 let

testing/release-validation.nix

@@ -139,9 +139,6 @@ pkgs.testers.runNixOSTest {
         virtualisation.qemu.networkingOptions = lib.mkOverride 0 [ ];
         virtualisation.sharedDirectories = lib.mkOverride 0 { };
 
-        # Note: this has to be at least 2x bundle size, otherwise
-        # the bundle download will not fit into /tmp (which is defined
-        # as 50% of RAM)!
         virtualisation.memorySize = lib.mkForce 4096;
 
         virtualisation.vlans = [ 1 ];