Revert "docker: add multi-platform support"

Didn't mean to push this yet.

This reverts commit 43b75b0ba2.

.github/workflows/docker.yml

@@ -49,10 +49,6 @@ jobs:
         push: ${{ github.event_name != 'pull_request' }}
         tags: ${{ steps.meta.outputs.tags }}
         labels: ${{ steps.meta.outputs.labels }}
-        platforms:
-        - linux/amd64
-        - linux/arm64
-        - linux/arm/v7
 
     # Sign the Docker image
     - name: Install cosign

Dockerfile

@@ -1,21 +1,26 @@
-# syntax=docker/dockerfile:1.4
-FROM --platform=$BUILDPLATFORM cgr.dev/chainguard/go:latest as build
+FROM golang:1.17 as build
 LABEL maintainer="Will Norris <will@willnorris.com>"
 
+RUN useradd -u 1001 go
+
 WORKDIR /app
+
 COPY go.mod go.sum ./
 RUN go mod download
 
 COPY . .
 
-ARG TARGETOS
-ARG TARGETARCH
-RUN CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=$TARGETARCH go build -v ./cmd/imageproxy
+RUN CGO_ENABLED=0 GOOS=linux go build -v ./cmd/imageproxy
 
-FROM cgr.dev/chainguard/static:latest
+FROM scratch
 
+COPY --from=build /etc/passwd /etc/passwd
+COPY --from=build /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 COPY --from=build /app/imageproxy /app/imageproxy
 
+USER go
+
 CMD ["-addr", "0.0.0.0:8080"]
 ENTRYPOINT ["/app/imageproxy"]