refactor: no need for the --system flag for buildx.sh

.github/workflows/build_packages.yaml

@@ -262,7 +262,6 @@ jobs:
           --profile "${PROFILE}" \
           --pkgtype "${PACKAGE}" \
           --arch "${ARCH}" \
-          --system "${SYSTEM}" \
           --builder "ghcr.io/emqx/emqx-builder/4.4-19:${OTP}-${SYSTEM}"
     - uses: actions/upload-artifact@v1
       with:

scripts/buildx.sh

@@ -21,7 +21,6 @@ help() {
     echo "--src_dir <SRC_DIR>: EMQ X source ode in this dir, default to PWD"
     echo "--builder <BUILDER>: Builder image to pull"
     echo "                     E.g. ghcr.io/emqx/emqx-builder/4.4-19:24.1.5-3-debian11"
-    echo "--system <SYSTEM>:   The target OS system the package is being built for, ex: debian11"
     echo "--ssh:               Pass ssh agent to the builder."
     echo "                     Also configures git in container to use ssh instead of https to clone deps"
 }
@@ -53,10 +52,6 @@ while [ "$#" -gt 0 ]; do
         ARCH="$2"
         shift 2
         ;;
-    --system)
-        SYSTEM="$2"
-        shift 2
-        ;;
     --ssh)
         USE_SSH='yes'
         shift
@@ -108,8 +103,6 @@ fi
 docker info
 docker run --rm --privileged tonistiigi/binfmt:latest --install "${ARCH}"
 
-# $SYSTEM below is used by the `relup-base-vsns.escript` to correctly
-# output the list of relup base versions.
 # shellcheck disable=SC2086
 docker run -i --rm \
     -v "$(pwd)":$DOCKER_WORKDIR \
@@ -117,7 +110,6 @@ docker run -i --rm \
     --workdir $DOCKER_WORKDIR \
     --platform="linux/$ARCH" \
     --user root \
-    -e SYSTEM="$SYSTEM" \
     $SSH_AGENT_OPTION \
     "$BUILDER" \
     bash -euc "mkdir -p _build && chown -R root:root _build && make ${PROFILE}-${PKGTYPE} && .ci/build_packages/tests.sh $PROFILE $PKGTYPE"

scripts/relup-base-vsns.escript

@@ -160,7 +160,7 @@ fetch_version(Vsn, VsnMap) ->
 
 filter_froms(Froms0, AvailableVersionsIndex) ->
     Froms1 =
-        case os:getenv("SYSTEM") of
+        case get_system() of
             %% we do not support relup for windows
             "windows" ->
                 [];
@@ -178,6 +178,14 @@ filter_froms(Froms0, AvailableVersionsIndex) ->
       fun(V) -> maps:get(V, AvailableVersionsIndex, false) end,
       Froms1).
 
+get_system() ->
+    case os:getenv("SYSTEM") of
+        false ->
+            string:trim(os:cmd("./scripts/get-distro.sh"));
+        System ->
+            System
+    end.
+
 %% assumes that's X.Y.Z, without pre-releases
 parse_vsn(VsnBin) ->
     {match, [Major0, Minor0, Patch0]} = re:run(VsnBin, "([0-9]+)\\.([0-9]+)\\.([0-9]+)",