From 9f7c1804b2935db85e3ea64d373153c12c4f36c8 Mon Sep 17 00:00:00 2001
From: Daniel Aloni <daniel@globekeeper.com>
Date: Wed, 15 Mar 2023 16:19:22 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=9A=80=20CD=20build.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .cloudbuild/dev.yaml |  2 +-
 Dockerfile           | 19 +++++++++++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/.cloudbuild/dev.yaml b/.cloudbuild/dev.yaml
index 8af553094..4f1b6c96c 100644
--- a/.cloudbuild/dev.yaml
+++ b/.cloudbuild/dev.yaml
@@ -1,6 +1,6 @@
 steps:
   - name: gcr.io/cloud-builders/docker
-    args: ['build', '-t', 'gcr.io/$PROJECT_ID/dendrite-monolith:$COMMIT_SHA', '-f', 'Dockerfile', '.']
+    args: ['build', '--build-arg', 'BUILDPLATFORM=linux/amd64', '-t', 'gcr.io/$PROJECT_ID/dendrite-monolith:$COMMIT_SHA', '-f', 'Dockerfile', '.']
   - name: gcr.io/cloud-builders/kubectl
     args: ['-n', 'dendrite', 'set', 'image', 'deployment/dendrite', 'dendrite=gcr.io/$PROJECT_ID/dendrite-monolith:$COMMIT_SHA']
     env:
diff --git a/Dockerfile b/Dockerfile
index d0db9de49..76c7b7785 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,8 +4,23 @@
 FROM --platform=${BUILDPLATFORM} docker.io/golang:1.20-alpine AS base
 RUN apk --update --no-cache add bash build-base curl
 
-WORKDIR /build
-COPY . /build
+#
+# build creates all needed binaries
+#
+FROM --platform=${BUILDPLATFORM} base AS build
+WORKDIR /src
+ARG TARGETOS
+ARG TARGETARCH
+ARG FLAGS
+RUN --mount=target=. \
+    --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=cache,target=/go/pkg/mod \
+    USERARCH=`go env GOARCH` \
+    GOARCH="$TARGETARCH" \
+    GOOS="linux" \
+    CGO_ENABLED=$([ "$TARGETARCH" = "$USERARCH" ] && echo "1" || echo "0") \
+    go build -v -ldflags="${FLAGS}" -trimpath -o /out/ ./cmd/...
+
 
 #
 # Builds the Dendrite image containing all required binaries