add dockerize to test targets

Check for whether Redis is running with Make, so the dev and CI
environments run similarly and show the same warnings.

Now the tests can be only "make test"!

.circleci/config.yml

@@ -31,17 +31,7 @@ jobs:
       - image: redis:6
     steps:
       - checkout
-      - run:
-          name: install dockerize
-          command: wget https://github.com/jwilder/dockerize/releases/download/$DOCKERIZE_VERSION/dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz && sudo tar -C /usr/local/bin -xzvf dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz && rm dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz
-          environment:
-            DOCKERIZE_VERSION: v0.3.0
-      - run:
-          name: Wait for redis
-          command: dockerize -wait tcp://localhost:6379 -timeout 1m
-      - run:
-          name: Tests
-          command: make test
+      - run: make test
 
   build_binaries:
     docker:

Makefile

@@ -1,19 +1,55 @@
+MAKEFLAGS += --warn-undefined-variables
+MAKEFLAGS += --no-builtin-rules
+MAKEFLAGS += --no-builtin-variables
+
 .PHONY: test
 #: run all tests
 test: test_with_race test_all
 
 .PHONY: test_with_race
 #: run only tests tagged with potential race conditions
-test_with_race:
+test_with_race: wait_for_redis
 	@echo
 	@echo "+++ testing - race conditions?"
 	@echo
 	go test -tags race --race --timeout 60s -v ./...
 
 .PHONY: test_all
 #: run all tests, but with no race condition detection
-test_all:
+test_all: wait_for_redis
 	@echo
 	@echo "+++ testing - all the tests"
 	@echo
 	go test -tags all --timeout 60s -v ./...
+
+.PHONY: wait_for_redis
+# wait for Redis to become available for test suite
+wait_for_redis: dockerize
+	@echo
+	@echo "+++ We need a Redis running to run the tests."
+	@echo
+	@echo "Checking with dockerize $(shell ./dockerize --version)"
+	@./dockerize -wait tcp://localhost:6379 -timeout 30s
+
+# ensure the dockerize command is available
+dockerize: dockerize.tar.gz
+	tar xzvmf dockerize.tar.gz
+
+HOST_OS := $(shell uname -s | tr A-Z a-z)
+# You can override this version from an environment variable.
+DOCKERIZE_VERSION ?= v0.6.1
+DOCKERIZE_RELEASE_ASSET := dockerize-${HOST_OS}-amd64-${DOCKERIZE_VERSION}.tar.gz
+
+dockerize.tar.gz:
+	@echo
+	@echo "+++ Retrieving dockerize tool for Redis readiness check."
+	@echo
+	curl --location --silent --show-error \
+		--output dockerize.tar.gz \
+		https://github.com/jwilder/dockerize/releases/download/${DOCKERIZE_VERSION}/${DOCKERIZE_RELEASE_ASSET} \
+	&& file dockerize.tar.gz | grep --silent gzip
+
+.PHONY: clean
+clean:
+	rm -f dockerize.tar.gz
+	rm -f dockerize