From d0ea451bccb473318e13cf23744c402e5466e374 Mon Sep 17 00:00:00 2001
From: Garrison Davis <garrison.davis@featurebase.com>
Date: Wed, 23 Nov 2022 16:30:18 -0700
Subject: [PATCH] Use SOURCE_DATE_EPOCH to make reproducible builds

Reproducible builds are something we should be doing, and we are there
as far as making them in CI is concerned with this change.

The changes to the Dockerfile/Makefile do nothing if the
SOURCE_DATE_EPOCH environment variable is not set before `make build`
happens, or if the build arg is not passed in to docker.

(cherry picked from commit fd93fc99c90b3eeab00bf5118730d212a1c7d98f)
---
 Dockerfile | 3 +++
 Makefile   | 9 ++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/Dockerfile b/Dockerfile
index 0ca6ef677..cf84b9403 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -20,6 +20,8 @@ RUN yarn build
 
 FROM golang:${GO_VERSION} as pilosa-builder
 ARG MAKE_FLAGS
+ARG SOURCE_DATE_EPOCH
+
 WORKDIR /pilosa
 
 RUN go install github.com/rakyll/statik@v0.1.7
@@ -28,6 +30,7 @@ COPY . ./
 COPY --from=lattice-builder /lattice/build /lattice
 RUN /go/bin/statik -src=/lattice -dest=/pilosa
 
+ENV SOURCE_DATE_EPOCH=$SOURCE_DATE_EPOCH
 RUN make build FLAGS="-o build/featurebase" ${MAKE_FLAGS}
 
 #####################
diff --git a/Makefile b/Makefile
index a97dad399..f9b1d1804 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,13 @@ GO=go
 GOOS=$(shell $(GO) env GOOS)
 GOARCH=$(shell $(GO) env GOARCH)
 VERSION_ID=$(if $(TRIAL_DEADLINE),trial-$(TRIAL_DEADLINE)-,)$(VERSION)-$(GOOS)-$(GOARCH)
-BUILD_TIME := $(shell date -u +%FT%T%z)
+DATE_FMT="+%FT%T%z"
+ifdef SOURCE_DATE_EPOCH
+	BUILD_TIME ?= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u "$(DATE_FMT)")
+else
+	BUILD_TIME ?= $(shell date -u "$(DATE_FMT)")
+endif
+SHARD_WIDTH = 20
 COMMIT := $(shell git describe --exact-match >/dev/null 2>&1 || git rev-parse --short HEAD)
 LDFLAGS="-X github.com/featurebasedb/featurebase/v3.Version=$(VERSION) -X github.com/featurebasedb/featurebase/v3.BuildTime=$(BUILD_TIME) -X github.com/featurebasedb/featurebase/v3.Variant=$(VARIANT) -X github.com/featurebasedb/featurebase/v3.Commit=$(COMMIT) -X github.com/featurebasedb/featurebase/v3.TrialDeadline=$(TRIAL_DEADLINE)"
 GO_VERSION=1.19
@@ -177,6 +183,7 @@ docker-build: vendor
 	docker build \
 	    --build-arg GO_VERSION=$(GO_VERSION) \
 	    --build-arg MAKE_FLAGS="TRIAL_DEADLINE=$(TRIAL_DEADLINE) GOOS=$(GOOS) GOARCH=$(GOARCH)" \
+	    --build-arg SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
 	    --target pilosa-builder \
 	    --tag featurebase:build .
 	docker create --name featurebase-build featurebase:build