Docker Build: Add ability to detect/set build architecture (#12303)

Clean backport of #12302

This commit adds the ability for the docker build to build artifacts for multiple architectures.
By default, the target architecture is inferred from the architecture of the machine the build is being
run from - running the build from an aarch64 machine will build an aarch64 docker image, while building
from an x86_64 machine will build an x86_64 docker image.

This can be overridden by setting the environment variable DOCKER_ARCHITECTURE to either `x86_64` or
`aarch64`.

This commit also updates the integration tests to test against the architecture from the machine the test
is being run on, and includes the target architecture in the test description.

docker/Makefile

@@ -12,6 +12,12 @@ else
   VERSION_TAG := $(ELASTIC_VERSION)
 endif
 
+ifdef DOCKER_ARCHITECTURE
+  ARCHITECTURE := $(DOCKER_ARCHITECTURE)
+else
+  ARCHITECTURE := $(shell uname -m)
+endif
+
 IMAGE_FLAVORS ?= oss full ubi8
 DEFAULT_IMAGE_FLAVOR ?= full
 
@@ -85,6 +91,7 @@ public-dockerfiles_full: venv templates/Dockerfile.j2 docker_paths $(COPY_FILES)
 	jinja2 \
 	  -D created_date='$(DATE)' \
 	  -D elastic_version='$(ELASTIC_VERSION)' \
+	  -D arch='${ARCHITECTURE}' \
 	  -D version_tag='$(VERSION_TAG)' \
 	  -D image_flavor='full' \
 	  -D local_artifacts='false' \
@@ -98,6 +105,7 @@ public-dockerfiles_oss: venv templates/Dockerfile.j2 docker_paths $(COPY_FILES)
 	jinja2 \
 	  -D created_date='$(DATE)' \
 	  -D elastic_version='$(ELASTIC_VERSION)' \
+	  -D arch='${ARCHITECTURE}' \
 	  -D version_tag='$(VERSION_TAG)' \
 	  -D image_flavor='oss' \
 	  -D local_artifacts='false' \
@@ -111,6 +119,7 @@ public-dockerfiles_ubi8: venv templates/Dockerfile.j2 docker_paths $(COPY_FILES)
 	jinja2 \
 	  -D created_date='$(DATE)' \
 	  -D elastic_version='$(ELASTIC_VERSION)' \
+	  -D arch='${ARCHITECTURE}' \
 	  -D version_tag='$(VERSION_TAG)' \
 	  -D image_flavor='ubi8' \
 	  -D local_artifacts='false' \
@@ -166,6 +175,7 @@ dockerfile: venv templates/Dockerfile.j2
 	  jinja2 \
 	    -D created_date='$(DATE)' \
 	    -D elastic_version='$(ELASTIC_VERSION)' \
+	    -D arch='${ARCHITECTURE}' \
 	    -D version_tag='$(VERSION_TAG)' \
 	    -D image_flavor='$(FLAVOR)' \
 	    -D local_artifacts='true' \

docker/templates/Dockerfile.j2

@@ -6,10 +6,10 @@
 {% endif -%}
 
 {% if image_flavor == 'oss' -%}
-  {% set tarball = 'logstash-oss-%s-linux-x86_64.tar.gz' % elastic_version -%}
+  {% set tarball = 'logstash-oss-%s-linux-%s.tar.gz' % (elastic_version, arch) -%}
   {% set license = 'Apache 2.0' -%}
 {% else -%}
-  {% set tarball = 'logstash-%s-linux-x86_64.tar.gz' % elastic_version -%}
+  {% set tarball = 'logstash-%s-linux-%s.tar.gz' % (elastic_version, arch) -%}
   {% set license = 'Elastic License' -%}
 {% endif -%}
 

qa/docker/shared_examples/image_metadata.rb

@@ -9,8 +9,8 @@ shared_examples_for 'the metadata is set correctly' do |flavor|
     expect(@image_config['WorkingDir']).to eql '/usr/share/logstash'
   end
 
-  it 'should have the correct Architecture' do
-    expect(@image.json['Architecture']).to have_correct_architecture_for_flavor(flavor)
+  it "should have an architecture of #{running_architecture}" do
+    expect(@image.json['Architecture']).to have_correct_architecture
   end
 
   %w(license org.label-schema.license org.opencontainers.image.licenses).each do |label|

qa/docker/spec/spec_helper.rb

@@ -80,10 +80,24 @@ def exec_in_container(container, command)
   container.exec(command.split)[0].join
 end
 
-def architecture_for_flavor(flavor)
-  flavor.match(/aarch64/) ? 'arm64' : 'amd64'
+def running_architecture
+    architecture = ENV['DOCKER_ARCHITECTURE']
+    architecture = normalized_architecture(`uname -m`.strip) if architecture.nil?
+    architecture
 end
 
+def normalized_architecture(cpu)
+  case cpu
+  when 'x86_64'
+    'amd64'
+  when 'aarch64'
+    'arm64'
+  else
+    cpu
+  end
+end
+
+
 RSpec::Matchers.define :have_correct_license_label do |expected|
   match do |actual|
     values_match? license_label_for_flavor(expected), actual
@@ -103,13 +117,12 @@ RSpec::Matchers.define :have_correct_license_agreement do |expected|
   end
 end
 
-RSpec::Matchers.define :have_correct_architecture_for_flavor do |expected|
+RSpec::Matchers.define :have_correct_architecture do
   match do |actual|
-    values_match? architecture_for_flavor(expected), actual
-    true
+    values_match? running_architecture, actual
   end
   failure_message do |actual|
-    "expected Architecture: #{actual} to be #{architecture_for_flavor(expected)}"
+    "expected Architecture: #{actual} to be #{running_architecture}"
   end
 end