From 5cdab7933f52cd930bf067e306c2884cea53c62c Mon Sep 17 00:00:00 2001
From: Simon Pasquier <spasquie@redhat.com>
Date: Tue, 5 Nov 2024 11:50:31 +0100
Subject: [PATCH] chore: optimize build layers

Signed-off-by: Simon Pasquier <spasquie@redhat.com>
---
 Dockerfile                                | 7 +++++--
 cmd/admission-webhook/Dockerfile          | 7 +++++--
 cmd/prometheus-config-reloader/Dockerfile | 7 +++++--
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index a8d6cefb7..977e3cd3d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,16 +1,19 @@
 ARG ARCH=amd64
 ARG OS=linux
 ARG GOLANG_BUILDER=1.23
+
 FROM quay.io/prometheus/golang-builder:${GOLANG_BUILDER}-base AS builder
 WORKDIR /workspace
 
-# Copy source files
 COPY . .
 
+# Download Go dependencies to reuse the Go cache in subsequent builds.
+RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build go mod download -x && go mod verify
+
 # Build
 ARG GOARCH
 ENV GOARCH=${GOARCH}
-RUN make operator
+RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build make operator
 
 FROM quay.io/prometheus/busybox-${OS}-${ARCH}:latest
 
diff --git a/cmd/admission-webhook/Dockerfile b/cmd/admission-webhook/Dockerfile
index c51474115..d3a037527 100644
--- a/cmd/admission-webhook/Dockerfile
+++ b/cmd/admission-webhook/Dockerfile
@@ -1,16 +1,19 @@
 ARG ARCH=amd64
 ARG OS=linux
 ARG GOLANG_BUILDER=1.23
+
 FROM quay.io/prometheus/golang-builder:${GOLANG_BUILDER}-base AS builder
 WORKDIR /workspace
 
-# Copy source files
 COPY . .
 
+# Download Go dependencies to reuse the Go cache in subsequent builds.
+RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build go mod download -x && go mod verify
+
 # Build
 ARG GOARCH
 ENV GOARCH=${GOARCH}
-RUN make admission-webhook
+RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build make admission-webhook
 
 FROM quay.io/prometheus/busybox-${OS}-${ARCH}:latest
 
diff --git a/cmd/prometheus-config-reloader/Dockerfile b/cmd/prometheus-config-reloader/Dockerfile
index 48a79a282..d8cd404b9 100644
--- a/cmd/prometheus-config-reloader/Dockerfile
+++ b/cmd/prometheus-config-reloader/Dockerfile
@@ -1,16 +1,19 @@
 ARG ARCH=amd64
 ARG OS=linux
 ARG GOLANG_BUILDER=1.23
+
 FROM quay.io/prometheus/golang-builder:${GOLANG_BUILDER}-base AS builder
 WORKDIR /workspace
 
-# Copy source files
 COPY . .
 
+# Download Go dependencies to reuse the Go cache in subsequent builds.
+RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build go mod download -x && go mod verify
+
 # Build
 ARG GOARCH
 ENV GOARCH=${GOARCH}
-RUN make prometheus-config-reloader
+RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build make prometheus-config-reloader
 
 FROM quay.io/prometheus/busybox-${OS}-${ARCH}:latest