install skopeo from source, if missing

Author: cheesesashimi

Makefile

@@ -109,6 +109,18 @@ else
 	GO111MODULE=on go build -o $(GOPATH)/bin/golangci-lint ./vendor/github.com/golangci/golangci-lint/cmd/golangci-lint
 endif
 
+SKOPEO := $(shell command -v skopeo 2> /dev/null)
+install-skopeo:
+ifdef SKOPEO
+	@echo "Found skopeo"
+	skopeo --version
+else
+	@echo "Installing skopeo"
+	./hack/install-skopeo.sh
+endif
+
+# install-skopeo is purposely omitted from this target because it is only
+# needed for a single test target (test-e2e-ocl).
 install-tools: install-golangci-lint install-go-junit-report install-setup-envtest
 
 # Runs golangci-lint
@@ -203,8 +215,9 @@ test-e2e-techpreview: install-go-junit-report
 test-e2e-single-node: install-go-junit-report
 	set -o pipefail; go test -tags=$(GOTAGS) -failfast -timeout 120m -v$${WHAT:+ -run="$$WHAT"} ./test/e2e-single-node/ | ./hack/test-with-junit.sh $(@)
 
-test-e2e-ocl: install-go-junit-report
-	set -o pipefail; go test -tags=$(GOTAGS) -failfast -timeout 190m -v$${WHAT:+ -run="$$WHAT"} ./test/e2e-ocl/ | ./hack/test-with-junit.sh $(@)
+test-e2e-ocl: install-go-junit-report install-skopeo
+	# Temporarily include /tmp/skopeo/bin in our PATH variable so that the test suite can find skopeo.
+	set -o pipefail; PATH="$(PATH):/tmp/skopeo/bin" go test -tags=$(GOTAGS) -failfast -timeout 190m -v$${WHAT:+ -run="$$WHAT"} ./test/e2e-ocl/ | ./hack/test-with-junit.sh $(@)
 
 bootstrap-e2e: install-go-junit-report install-setup-envtest
 	@echo "Setting up KUBEBUILDER_ASSETS"

hack/install-skopeo.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+
+set -xeuo
+
+# This is an isntallation script for skopeo.
+# skopeo is needed by the e2e-gcp-op-ocl test suite since it pushes and pulls images around.
+#
+# I would much rather use a build-root image for this (see:
+# https://docs.ci.openshift.org/docs/architecture/ci-operator/#build-root-image).
+# However, that process is a bit more involved. While it would ultimately pay
+# off, it is not in-scope with the bug I am trying to resolve. Hence the need
+# for this script.
+#
+# Because of limitations within the builder container image and the context it
+# runs in, certain adaptations must be made:
+# - The builder image does not run as a privileged user and is denied privilege
+# escalation. This means that running dnf install -y skopeo cannot be done.
+# - The builder image does not have jq installed, but it does have Python,
+# which has a built-in JSON parser in its stdlib. This means we need to use
+# Python for any JSON parsing we need to perform.
+# - Because this runs as a non-privileged user, we cannot run the make install
+# step for skopeo. Instead, we need to append /tmp/skopeo/bin to the PATH. This
+# is done in the Makefile and only for the go test invocation.
+
+OPENSHIFT_CI="${OPENSHIFT_CI:-""}"
+
+install_skopeo() {
+  # If we've already built skopeo once, check if it works and then return.
+  if [ -f /tmp/skopeo/bin/skopeo ]; then
+    echo "Prebuilt skopeo found at /tmp/skopeo/bin/skopeo, skipping installation"
+    /tmp/skopeo/bin/skopeo --version
+    return 0
+  fi
+
+  # Get the most recent tagged version of skopeo.
+  skopeo_version="$(curl -s https://api.github.com/repos/containers/skopeo/releases/latest | python3 -c 'import sys, json; print(json.load(sys.stdin)["tag_name"])')"
+
+  skopeo_clone_dir="/tmp/skopeo"
+
+  mkdir -p "$skopeo_clone_dir"
+
+  # Shallow-clone the skopeo repo to the local repo dir.
+  git clone --branch "$skopeo_version" --depth 1 https://github.com/containers/skopeo.git "$skopeo_clone_dir"
+
+  cd "$skopeo_clone_dir"
+
+  # Build skopeo
+  make bin/skopeo
+}
+
+# Check if we have skopeo installed first.
+if command -v skopeo >/dev/null 2>&1  ; then
+  # If we do, just output its version.
+  skopeo --version
+else
+  # Check if we're running in CI.
+  if [ "$OPENSHIFT_CI" == "true" ]; then
+    # Only when we're in CI should we install skopeo.
+    install_skopeo
+  else
+    # Otherwise, we should exit with a clear error.
+    echo "Missing required binary 'skopeo'"
+    exit 1
+  fi
+fi