From c948af2e1865c9cfb1d0423186270e8c16a8f3ec Mon Sep 17 00:00:00 2001
From: Erik Arvstedt <erik.arvstedt@gmail.com>
Date: Sat, 21 Jan 2023 13:14:27 +0100
Subject: [PATCH 1/2] dev/dev-features: add `enter_service` helper

---
 dev/dev-features.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/dev/dev-features.sh b/dev/dev-features.sh
index 8eba0e8..b06ce4f 100644
--- a/dev/dev-features.sh
+++ b/dev/dev-features.sh
@@ -53,6 +53,15 @@ ls -al /var/lib/nixos-containers/nb-test
 # The container root filesystem on NixOS systems with stateVersion < 22.05
 ls -al /var/lib/containers/nb-test
 
+# Start a shell in the context of a service process.
+# Must be run inside the container (enter with cmd `c`).
+enter_service() {
+    local name=$1
+    nsenter --all -t "$(systemctl show -p MainPID --value "$name")" \
+      --setuid "$(id -u "$name")" --setgid "$(id -g "$name")" bash
+}
+enter_service clightning
+
 #―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
 # bitcoind
 run-tests.sh -s bitcoind container

From 86dc7e2669004d4abeeff4fae0817d7a06d40e00 Mon Sep 17 00:00:00 2001
From: Erik Arvstedt <erik.arvstedt@gmail.com>
Date: Sat, 21 Jan 2023 13:14:28 +0100
Subject: [PATCH 2/2] fulcrum: allow access to `/proc/meminfo`

This still hides the proc subdirectories for other processes.

Without this setting, fulcrum fails when the config value of
`fast-sync` is greater than 2^31 bytes.
---
 modules/fulcrum.nix | 1 +
 1 file changed, 1 insertion(+)

diff --git a/modules/fulcrum.nix b/modules/fulcrum.nix
index 0cbb87d..592757a 100644
--- a/modules/fulcrum.nix
+++ b/modules/fulcrum.nix
@@ -126,6 +126,7 @@ in {
         Restart = "on-failure";
         RestartSec = "10s";
         ReadWritePaths = cfg.dataDir;
+        ProcSubset = "all"; # Fulcrum requires read access to /proc/meminfo
       } // nbLib.allowedIPAddresses cfg.tor.enforce;
     };