From 31c00cd65a2438a8244250fa74b3538fe969a425 Mon Sep 17 00:00:00 2001
From: Anthony Ettinger <anthony@chovy.com>
Date: Sun, 14 Jun 2026 10:31:29 +0000
Subject: [PATCH] setup.sh: persistent Go cache + HOME so timer deploys build
 instead of OOM/erroring
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The self-update timer runs setup.sh as a systemd oneshot with no $HOME, so
`go build` aborted with "module cache not found: neither GOMODCACHE nor GOPATH
is set" before compiling — auto-deploys silently pulled new code but never
rebuilt or restarted. On top of that, a cold cache made the 458MB droplet
OOM-kill the compiler.

Set explicit, root-owned, persistent Go caches (/var/cache/agentbbs/{go,go-build})
plus HOME and GOMAXPROCS=1 in setup.sh, and add HOME=/root to the generated
agentbbs-update.service. A warm persistent cache means incremental redeploys
recompile almost nothing, keeping peak memory within RAM+swap; combined with
the existing `go build -p=1` the compiler no longer gets OOM-killed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 setup.sh | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/setup.sh b/setup.sh
index 6d8d986..26d1d8a 100755
--- a/setup.sh
+++ b/setup.sh
@@ -111,6 +111,21 @@ if [ "$("$GO_ROOT/bin/go" version 2>/dev/null | awk '{print $3}')" != "go${GO_VE
 fi
 export PATH="$GO_ROOT/bin:$PATH"
 
+# Persistent, root-owned Go caches. Two reasons this matters on this box:
+#  1. The self-update timer runs setup.sh as a systemd oneshot with no $HOME, so
+#     a bare `go build` aborts with "module cache not found: neither GOMODCACHE
+#     nor GOPATH is set" before it compiles a thing. Setting these explicitly
+#     (not relying on $HOME) fixes timer-driven redeploys.
+#  2. A warm cache means an incremental redeploy recompiles only what changed, so
+#     the 458MB droplet stops OOM-killing the compiler on every build. Combined
+#     with GOMAXPROCS=1 + `go build -p=1`, peak memory stays within RAM+swap.
+export HOME="${HOME:-/root}"
+export GOPATH="${GOPATH:-/var/cache/agentbbs/go}"
+export GOMODCACHE="${GOMODCACHE:-$GOPATH/pkg/mod}"
+export GOCACHE="${GOCACHE:-/var/cache/agentbbs/go-build}"
+export GOMAXPROCS=1
+mkdir -p "$GOPATH" "$GOCACHE"
+
 # ---- 3. service user + rootless podman prerequisites -----------------------
 if ! id "$SVC_USER" >/dev/null 2>&1; then
   log "creating service user $SVC_USER"
@@ -304,6 +319,9 @@ Wants=network-online.target
 
 [Service]
 Type=oneshot
+# systemd oneshots start with no HOME; set one so git (and Go, via setup.sh)
+# behave the same as an interactive root deploy instead of erroring.
+Environment=HOME=/root
 Environment=REPO=${REPO}
 Environment=BRANCH=${BRANCH}
 Environment=SRC_DIR=${SRC_DIR}