use drone env to set GITREV_BUILD

.drone.yml

@@ -7,6 +7,7 @@ steps:
   network_mode: bridge
   settings:
     repo: sneak/mfer
+    build_args_from_env: [ DRONE_COMMIT_SHA ]
     dry_run: true
     custom_dns: [ 116.202.204.30 ]
     tags:

Dockerfile

@@ -4,7 +4,6 @@
 FROM sneak/builder:2022-12-08 AS builder
 ENV DEBIAN_FRONTEND noninteractive
 WORKDIR /build
-COPY ./.git /build/.git
 COPY ./Makefile ./.golangci.yml ./go.mod ./go.sum /build/
 COPY ./vendor.tzst /build/vendor.tzst
 COPY ./modcache.tzst /build/modcache.tzst
@@ -13,6 +12,7 @@ COPY ./bin/gitrev.sh ./bin/gitrev.sh
 COPY ./mfer ./mfer
 COPY ./cmd ./cmd
 ARG GITREV unknown
+ARG DRONE_COMMIT_SHA unknown
 
 RUN mkdir -p "$(go env GOMODCACHE)" && cd "$(go env GOMODCACHE)" && \
     zstdmt -d --stdout /build/modcache.tzst | tar xf - && \

bin/gitrev.sh

@@ -1,4 +1,10 @@
 #!/bin/bash
+#
+if [[ ! -z "$DRONE_COMMIT_SHA" ]]; then
+    echo "${DRONE_COMMIT_SHA:0:7}"
+    exit 0
+fi
+
 if [[ ! -z "$GITREV" ]]; then
     echo $GITREV
 else