tests/e2e: allow option E2E_DIND_VERSION to test with different Docker versions

Dockerfile

@@ -1,3 +1,4 @@
+ARG DOCKER_VERSION=20.10
 ############################################################
 # builder                                                  #
 # -> golang image used solely for building the k3d binary  #
@@ -14,12 +15,13 @@ RUN make build -e GIT_TAG_OVERRIDE=${GIT_TAG_OVERRIDE} && bin/k3d version
 # -> k3d + some tools in a docker-in-docker container #
 # -> used e.g. in our CI pipelines for testing        #
 #######################################################
-FROM docker:20.10-dind as dind
+FROM docker:$DOCKER_VERSION-dind as dind
 ARG OS=linux
 ARG ARCH=amd64
 
 # install some basic packages needed for testing, etc.
-RUN echo "building for ${OS}/${ARCH}" && \
+RUN docker version; \
+    echo ">>> building for ${OS}/${ARCH}" && \
     apk update && \
     apk add bash curl sudo jq git make netcat-openbsd
 

Makefile

@@ -53,6 +53,7 @@ E2E_RUNNER_START_TIMEOUT ?= 10
 E2E_HELPER_IMAGE_TAG ?=
 E2E_KEEP ?=
 E2E_PARALLEL ?=
+E2E_DIND_VERSION ?=
 
 ########## Go Build Options ##########
 # Build targets
@@ -127,18 +128,18 @@ build-cross:
 # build a specific docker target ( '%' matches the target as specified in the Dockerfile)
 build-docker-%:
 	@echo "Building Docker image k3d:$(K3D_IMAGE_TAG)-$*"
-	DOCKER_BUILDKIT=1 docker build . --no-cache -t k3d:$(K3D_IMAGE_TAG)-$* --target $*
+	DOCKER_BUILDKIT=1 docker build . --quiet --no-cache -t k3d:$(K3D_IMAGE_TAG)-$* --target $*
 
 # build helper images
 build-helper-images: build-proxy-image build-tools-image
 
 build-proxy-image:
 	@echo "Building docker image rancher/k3d-proxy:$(K3D_IMAGE_TAG)"
-	DOCKER_BUILDKIT=1 docker build --no-cache proxy/ -f proxy/Dockerfile -t rancher/k3d-proxy:$(K3D_IMAGE_TAG)
+	DOCKER_BUILDKIT=1 docker build --quiet --no-cache proxy/ -f proxy/Dockerfile -t rancher/k3d-proxy:$(K3D_IMAGE_TAG)
 
 build-tools-image:
 	@echo "Building docker image rancher/k3d-tools:$(K3D_IMAGE_TAG)"
-	DOCKER_BUILDKIT=1 docker build --no-cache tools/ -f tools/Dockerfile -t rancher/k3d-tools:$(K3D_IMAGE_TAG) --build-arg GIT_TAG=$(GIT_TAG)
+	DOCKER_BUILDKIT=1 docker build --quiet --no-cache tools/ -f tools/Dockerfile -t rancher/k3d-tools:$(K3D_IMAGE_TAG) --build-arg GIT_TAG=$(GIT_TAG)
 
 ##############################
 ########## Cleaning ##########
@@ -175,9 +176,9 @@ check: check-fmt lint
 test:
 	$(GO) test $(TESTS) $(TESTFLAGS)
 
-e2e: build-docker-dind
-	@echo "Running e2e tests in k3d:$(K3D_IMAGE_TAG)"
-	LOG_LEVEL="$(E2E_LOG_LEVEL)" E2E_INCLUDE="$(E2E_INCLUDE)" E2E_EXCLUDE="$(E2E_EXCLUDE)" E2E_EXTRA="$(E2E_EXTRA)" E2E_RUNNER_START_TIMEOUT=$(E2E_RUNNER_START_TIMEOUT) E2E_HELPER_IMAGE_TAG="$(E2E_HELPER_IMAGE_TAG)" E2E_KEEP="$(E2E_KEEP)" E2E_PARALLEL="$(E2E_PARALLEL)" tests/dind.sh "${K3D_IMAGE_TAG}-dind"
+e2e:
+	@echo "Running e2e tests"
+	LOG_LEVEL="$(E2E_LOG_LEVEL)" E2E_INCLUDE="$(E2E_INCLUDE)" E2E_EXCLUDE="$(E2E_EXCLUDE)" E2E_EXTRA="$(E2E_EXTRA)" E2E_RUNNER_START_TIMEOUT=$(E2E_RUNNER_START_TIMEOUT) E2E_HELPER_IMAGE_TAG="$(E2E_HELPER_IMAGE_TAG)" E2E_KEEP="$(E2E_KEEP)" E2E_PARALLEL="$(E2E_PARALLEL)" E2E_DIND_VERSION="$(E2E_DIND_VERSION)" tests/dind.sh "${K3D_IMAGE_TAG}"
 
 ci-tests: fmt check e2e
 

tests/dind.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 K3D_EXE=${EXE:-/bin/k3d}
-K3D_IMAGE_TAG=$1
+K3D_IMAGE_TAG="$1-dind"
 
 # define E2E_KEEP to non-empty for keeping the e2e runner container after running the tests
 E2E_KEEP=${E2E_KEEP:-}
@@ -12,6 +12,9 @@ E2E_PARALLEL=${E2E_PARALLEL:-}
 # Max. time to wait for the runner container to be up
 RUNNER_START_TIMEOUT=${E2E_RUNNER_START_TIMEOUT:-10}
 
+# Override Docker-in-Docker version
+E2E_DIND_VERSION=${E2E_DIND_VERSION:-}
+
 ####################################################################################
 
 CURR_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
@@ -28,9 +31,19 @@ source "$CURR_DIR/common.sh"
 
 ####################################################################################
 
+info "Building container image k3d:${K3D_IMAGE_TAG}"
+# Extra Image Build Arg
+: "${EXTRA_BUILD_FLAG:=""}"
+if [[ -n "$E2E_DIND_VERSION" ]]; then
+  info "Testing with Docker version $E2E_DIND_VERSION"
+  EXTRA_BUILD_FLAG="--build-arg DOCKER_VERSION=$E2E_DIND_VERSION"
+fi
+DOCKER_BUILDKIT=1 docker build . --quiet --no-cache $EXTRA_BUILD_FLAG --tag "k3d:${K3D_IMAGE_TAG}" --target "dind" || failed "Build failed"
+
 # Start the runner container
 TIMESTAMP=$(date "+%y%m%d%H%M%S")
 container_name="k3d-e2e-runner-$TIMESTAMP"
+info "Starting E2E Test Runner container ${container_name}"
 k3de2e=$(docker run -d \
           -v "$(pwd):/src" \
           --privileged \