Makefile: Don't always build kolet for all architectures

The reason we build kolet for other architectures is so that we
can mix architectures with test initiators and test runners. i.e.
i.e. x86_64 kola running in the pipeline testing against an aarch64
EC2 instance.

This use case isn't too common so let's just not build kolet for
all the different architectures on every architecture. We'll special
case for x86_64 here and let it build for them all, but for the rest
we just build for the architecture that the container build is for.

Author: dustymabe

Makefile

@@ -12,7 +12,8 @@ PYIGNORE ?= E128,E241,E402,E501,E722,W503,W504
 .PHONY: all check shellcheck flake8 pycheck unittest clean mantle mantle-check install
 
 MANTLE_BINARIES := ore kola plume
-KOLET_ARCHES := aarch64 ppc64le s390x x86_64
+# Typically just build kolet for the architecture we are on.
+export KOLET_ARCHES:=$(shell uname -m)
 
 all: bin/coreos-assembler mantle
 
@@ -26,9 +27,14 @@ cwd_checked:=$(patsubst ./%,.%.shellchecked,${cwd})
 GOARCH:=$(shell uname -m)
 export COSA_META_SCHEMA:=$(shell pwd)/src/v1.json
 ifeq ($(GOARCH),x86_64)
-        GOARCH="amd64"
+	GOARCH="amd64"
+	# On x86_64 only we'll build kolet for all the other architectures.
+	# This is mainly so we can initiate tests against a remote that is
+	# a different architecture. i.e. x86_64 kola testing against an
+	# aarch64 EC2 instance.
+	export KOLET_ARCHES := aarch64 ppc64le s390x x86_64
 else ifeq ($(GOARCH),aarch64)
-        GOARCH="arm64"
+	GOARCH="arm64"
 endif
 
 bin/coreos-assembler:

mantle/build

@@ -11,7 +11,8 @@ if [[ $# -eq 0 ]]; then
 fi
 
 declare -A BASEARCH_TO_GOARCH=([s390x]=s390x [x86_64]=amd64 [aarch64]=arm64 [ppc64le]=ppc64le)
-KOLET_ARCHES="${KOLET_ARCHES:-s390x x86_64 aarch64 ppc64le}"
+ARCH=$(arch)
+KOLET_ARCHES="${KOLET_ARCHES:-${ARCH}}"
 
 race=
 if [ -n "${ENABLE_GO_RACE_DETECTOR:-}" ] && [[ ! "$(uname -m)" =~ "s390" ]]; then