fix: use TARGETARCH to select the git-credential-github-app artifact (#…

…2002)

cmd/proxy/Dockerfile

@@ -28,6 +28,7 @@ RUN DATE="$(date -u +%Y-%m-%d-%H:%M:%S-%Z)" && \
     -o /bin/athens-proxy ./cmd/proxy
 
 FROM alpine:${ALPINE_VERSION}
+ARG TARGETARCH
 
 ENV GOROOT="/usr/local/go" \
     PATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin \
@@ -44,7 +45,8 @@ RUN chmod 644 /config/config.toml
 RUN apk add --update git git-lfs mercurial openssh-client subversion procps fossil tini
 
 # Add git-credential-github-app for native integration with GitHub Apps
-RUN wget -O git-credential-github-app.tar.gz https://github.com/bdellegrazie/git-credential-github-app/releases/download/v0.3.0/git-credential-github-app_v0.3.0_Linux_x86_64.tar.gz \
+RUN if [ "${TARGETARCH}" = "arm64" ]; then ARCH="arm64"; else ARCH="amd64"; fi \
+  && wget -O git-credential-github-app.tar.gz https://github.com/bdellegrazie/git-credential-github-app/releases/download/v0.3.0/git-credential-github-app_v0.3.0_Linux_${ARCH}.tar.gz \
   && tar xvzf 'git-credential-github-app.tar.gz' git-credential-github-app -C /usr/local/bin \
   && rm git-credential-github-app.tar.gz || true;