From 403620e5f72c259e3c7ecd1f8c2a9934d611d6fd Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Thu, 16 Jul 2026 17:45:15 -0400
Subject: [PATCH] Pass substituters in so local builds aren't trying to hit the
 in-kubernetes cache.

---
 .webhook_bridge/pipeline-build-homepage-staging.yaml | 2 ++
 docker/server/Dockerfile                             | 6 +++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/.webhook_bridge/pipeline-build-homepage-staging.yaml b/.webhook_bridge/pipeline-build-homepage-staging.yaml
index 657f2e1..bbe1da2 100644
--- a/.webhook_bridge/pipeline-build-homepage-staging.yaml
+++ b/.webhook_bridge/pipeline-build-homepage-staging.yaml
@@ -142,6 +142,8 @@ spec:
               - "type=registry,ref=$(params.image-name):buildcache,mode=max,compression=zstd,compression-level=22,rewrite-timestamp=true,image-manifest=true,oci-mediatypes=true"
               - --opt
               - build-arg:SOURCE_DATE_EPOCH=$(tasks.get-git-commit-time.results.unix-time)
+              - --opt
+              - "build-arg:NIX_SUBSTITUTERS=http://ncps.nix-pull-through-cache.svc.cluster.local:80 https://cache.nixos.org"
           - name: BUILDKITD_TOML
             value: |
               debug = true
diff --git a/docker/server/Dockerfile b/docker/server/Dockerfile
index 49f6160..a831bc0 100644
--- a/docker/server/Dockerfile
+++ b/docker/server/Dockerfile
@@ -2,15 +2,15 @@
 #
 # Builder
 #
+ARG NIX_SUBSTITUTERS=https://cache.nixos.org
 
 FROM nixos/nix:2.31.3 AS builder
 
+ARG NIX_SUBSTITUTERS
 RUN tee -a /etc/nix/nix.conf <<EOF
 extra-experimental-features = nix-command flakes
 filter-syscalls = false
-substituters = http://ncps.nix-pull-through-cache.svc.cluster.local:80 https://cache.nixos.org
-download-attempts = 1
-connect-timeout = 3
+substituters = $NIX_SUBSTITUTERS
 EOF
 
 RUN cp "$(nix build nixpkgs#cacert --print-out-paths)/etc/ssl/certs/ca-bundle.crt" /tmp/ca-bundle.crt