syz-cluster: don't use envsubst

It's not available in gcr.io/google.com/cloudsdktool/cloud-sdk.
Use sed instead.

Author: a-nogikh

syz-cluster/Makefile

@@ -64,8 +64,6 @@ restart-spanner: build-db-mgmt
 	minikube addons enable cloud-spanner;
 	./run-local.sh db-mgmt migrate
 
-SUBSTITUTE_VARS := '$$IMAGE_PREFIX $$IMAGE_TAG $$SPANNER_DATABASE_URI $$BLOB_STORAGE_GCS_BUCKET $$WORKFLOW_ARTIFACTS_BUCKET'
-
 # It takes some time for K8S to set up Argo CRDs, so if we `kubectl apply` everything at once, it will not
 # work on the first attempt.
 # The following two targets facilitate CI/CD:
@@ -78,14 +76,29 @@ k8s-config-argo-wait:
 	@kubectl wait --for condition=established --timeout=60s crd/cronworkflows.argoproj.io
 	@kubectl wait --for condition=established --timeout=60s crd/workflows.argoproj.io
 
+escape_sed_replacement = \
+    $(shell printf '%s' '$(subst ','\'',$(1))' | \
+    sed -e 's~\\~\\\\~g' \
+        -e 's~&~\\&~g' \
+        -e 's~\$$~\\$$~g' \
+        -e 's~/~\\/~g' \
+    )
+
+SED_EXPRESSIONS := \
+    -e "s~\$${IMAGE_PREFIX}~$(call escape_sed_replacement,${IMAGE_PREFIX})~g" \
+    -e "s~\$${IMAGE_TAG}~$(call escape_sed_replacement,${IMAGE_TAG})~g" \
+    -e "s~\$${SPANNER_DATABASE_URI}~$(call escape_sed_replacement,${SPANNER_DATABASE_URI})~g" \
+    -e "s~\$${WORKFLOW_ARTIFACTS_BUCKET}~$(call escape_sed_replacement,${WORKFLOW_ARTIFACTS_BUCKET})~g" \
+    -e "s~\$${BLOB_STORAGE_GCS_BUCKET}~$(call escape_sed_replacement,${BLOB_STORAGE_GCS_BUCKET})~g" \
+
 k8s-config-dev:
-	@kubectl kustomize ./overlays/minikube/ | IMAGE_PREFIX=${IMAGE_PREFIX} IMAGE_TAG=${IMAGE_TAG} envsubst ${SUBSTITUTE_VARS}
+	@kubectl kustomize ./overlays/minikube/ | sed $(SED_EXPRESSIONS)
 
 k8s-config-gke: ensure-spanner-database-uri-env ensure-blob-storage-env ensure-workflow-artifacts-bucket
-	@kubectl kustomize ./overlays/gke/ | IMAGE_PREFIX=${IMAGE_PREFIX} IMAGE_TAG=${IMAGE_TAG} envsubst ${SUBSTITUTE_VARS}
+	@kubectl kustomize ./overlays/gke/ | sed $(SED_EXPRESSIONS)
 
 migrate-job.yaml: ensure-spanner-database-uri-env
-	@cat db-mgmt/migrate-job.yaml | IMAGE_PREFIX=${IMAGE_PREFIX} IMAGE_TAG=${IMAGE_TAG} envsubst
+	@cat db-mgmt/migrate-job.yaml | sed $(SED_EXPRESSIONS)
 
 fetch-kernels-once.yaml:
 	@cat kernel-disk/fetch-kernels-once.yaml