support older versions of docker and docker-compose (#414)

docker/Dockerfile

@@ -13,8 +13,8 @@ ARG SHA256
 
 ENV PORT=34197 \
     RCON_PORT=27015 \
-    VERSION=${VERSION:?} \
-    SHA256=${SHA256:?} \
+    VERSION=${VERSION} \
+    SHA256=${SHA256} \
     SAVES=/factorio/saves \
     CONFIG=/factorio/config \
     MODS=/factorio/mods \
@@ -25,6 +25,14 @@ ENV PORT=34197 \
 
 SHELL ["/bin/ash", "-eo", "pipefail", "-c"]
 RUN set -ox pipefail \
+    && if [[ "${VERSION}" == "" ]]; then \
+        echo "build-arg VERSION is required" \
+        && exit 1; \
+    fi \
+    && if [[ "${SHA256}" == "" ]]; then \
+        echo "build-arg SHA256 is required" \
+        && exit 1; \
+    fi \
     && archive="/tmp/factorio_headless_x64_$VERSION.tar.xz" \
     && mkdir -p /opt /factorio \
     && apk add --update --no-cache --no-progress bash binutils curl file gettext jq libintl pwgen shadow su-exec \

docker/docker-compose.yml

@@ -1,7 +1,13 @@
 version: '2'
 services:
   factorio:
-    build: .
+    build:
+      context: .
+      args:
+      # Check buildinfo.json for supported versions and SHAs
+      # https://github.com/factoriotools/factorio-docker/blob/master/buildinfo.json
+      - VERSION=1.1.39
+      - SHA256=5528b8e23ac5d3a13e3328a0c64fee71f4a321792afe7b2fe46f95e62b7ed119
     ports:
      - "34197:34197/udp"
      - "27015:27015/tcp"