test: Makefile target to run against local Prometheus

Adds several Makefile targets, but mainly:

- `make test-daemon`
- `make clean-pod`

Which can be used by developers to build&run host-metering locally
within couple seconds againts a Prometheus server that is spawned in
a podman container/pod.

The run can be cleaned-up via.

```
make clean
make clean-pod
```

`README.md` is updated to reflect this + several basic stuff that were
missing.

Signed-off-by: Petr Vobornik <[email protected]>

.gitignore

@@ -5,8 +5,14 @@ contrib/rpm/host-metering.spec
 contrib/selinux/tmp/
 contrib/selinux/host-metering.pp
 
+# testing
+hack/test-cert.crt
+hack/test-cert.key
+hack/cpumetrics/
+
 # Coverage
 coverage.*
 
 # Binary
 host-metering
+dist/host-metering

Makefile

@@ -12,6 +12,10 @@ RPMTOPDIR := $(DISTDIR)/rpmbuild
 GO := go
 TESTDIR := $(CURDIR)/test
 
+CONTAINER_POD := host-metering-pod
+DASHBOARD_URL = http://localhost:9090/graph?g0.expr=system_cpu_logical_count&g0.tab=0&g0.range_input=1m
+
+# Test
 .PHONY: test
 test:
 	@echo "Running the unit tests..."
@@ -31,12 +35,69 @@ test:
 	@cat coverage.txt
 
 # Build
+.PHONY: build
+build:
+	@echo "Building the project..."
+	$(GO) build -o $(DISTDIR)/$(PROJECT)
+
 .PHONY: build-selinux
 build-selinux:
 	@echo "Building SELinux policy..."
 	cd contrib/selinux && \
 		make -f /usr/share/selinux/devel/Makefile $(PROJECT).pp || exit
 
+# Functional testing (manual or automatic)
+
+.PHONY: test-daemon
+test-daemon: cert build prometheus
+	@echo "Running the $(PROJECT) in deamon mode..."
+
+	PATH=$(TESTDIR)/bin:$(PATH) \
+	$(DISTDIR)/$(PROJECT) --config hack/host-metering.conf daemon
+
+cert: hack/test-cert.crt hack/test-cert.key
+
+hack/test-cert.crt hack/test-cert.key:
+	@echo "Generating test certificates..."
+	cd hack && ./create-cert.sh
+
+# Containers
+
+.PHONY: container-pod
+container-pod:
+	if podman pod exists $(CONTAINER_POD); then \
+        echo "Pod $(CONTAINER_POD) exists."; \
+        exit 0; \
+	else \
+		echo "Creating the $(CONTAINER_POD)..."; \
+		podman pod create --replace -p 9090:9090 ${CONTAINER_POD}; \
+	fi
+
+.PHONY: prometheus
+prometheus: container-pod
+	@echo "See the dashboard at: ${DASHBOARD_URL}"
+
+	if podman ps --filter "name=hm-prometheus" --format '{{.Names}}' | grep -q "hm-prometheus"; then \
+		echo "Prometheus is already running."; \
+		exit 0; \
+	else \
+		echo "Starting Prometheus..."; \
+		podman run --pod ${CONTAINER_POD} \
+			   --name hm-prometheus \
+			   -d \
+			   -v ./hack/prometheus.yml:/etc/prometheus/prometheus.yml:Z \
+			   prometheus/prometheus \
+			   --config.file=/etc/prometheus/prometheus.yml \
+			   --storage.tsdb.path=/prometheus \
+			   --web.console.libraries=/usr/share/prometheus/console_libraries \
+			   --web.console.templates=/usr/share/prometheus/consoles \
+			   --web.enable-remote-write-receiver; \
+	fi
+
+.PHONY: clean-pod
+clean-pod:
+	podman pod rm -f ${CONTAINER_POD}
+
 # Release
 .PHONY: version
 version:
@@ -120,3 +181,6 @@ clean:
 	rm -rf $(CURDIR)/$(PROJECT)
 	rm -rf $(CURDIR)/contrib/selinux/tmp
 	rm -rf $(CURDIR)/contrib/selinux/*.pp
+	rm -rf $(CURDIR)/hack/cpumetrics
+	rm -f $(CURDIR)/hack/test-cert.crt
+	rm -f $(CURDIR)/hack/test-cert.key

README.md

@@ -1,3 +1,84 @@
 # Host Metering
 
 Host metering client.
+
+## Usage
+
+```
+$ host-metering daemon
+```
+
+Or if run from RPMs as a service:
+
+```
+# yum install host-metering
+# systemctl enable host-metering
+# systemctl start host-metering
+```
+
+See output/log:
+
+```
+# journalctl -feu host-metering
+```
+
+## RPM repository
+
+RPM builds of `main` branch are available at COPR:  https://copr.fedorainfracloud.org/coprs/pvoborni/host-metering/
+
+## Build
+
+```
+$ go build
+```
+
+rpms via mock:
+
+```
+$ make mock   # EPEL 7
+$ make mock-8 # CentOS Stream 8
+$ make mock-9 # CentOS Stream 9
+```
+
+rpms directly via `rpmbuild`
+
+```
+$ make rpm
+```
+
+## Testing
+
+### Unit tests
+
+To run go unit test:
+```
+$ make test
+```
+
+### Local run / development
+
+```
+$ make test-daemon
+```
+
+It will run `host-metering` with:
+* mocked `subscriptin-manager`
+* test configuration file that is lowering intervals and using the following:
+* test certificate
+* custom path for metrics WAL
+* Prometheus server started in a podman container
+
+Query Prometheus, e.g., via command:
+
+```
+$ curl 'http://localhost:9090/api/v1/query?query=system_cpu_logical_count' | jq
+```
+
+Or visit the Prometheus Web UI at http://localhost:9090/graph?g0.expr=system_cpu_logical_count&g0.tab=0&g0.range_input=1m
+
+### Clean-up
+
+```
+$ make clean      # clean build&test files
+$ make clean-pod  # destroy podman pod
+```

hack/create-cert.sh

@@ -0,0 +1,14 @@
+
+# Execute this script in the directory with test-cert.cnf
+# Purpose: Create a self-signed certificate for testing
+
+openssl genrsa -out test-cert.key
+
+# To create a CSR for submitting to CA
+# openssl req -new -key test-cert.key -out test-cert.csr -config test-cert.cnf
+
+# Create a self-signed certificate
+openssl req -x509 -new -key test-cert.key -out test-cert.crt -config test-cert.cnf
+
+# Show the certificate
+openssl x509 -in test-cert.crt -text -noout

hack/host-metering.conf

@@ -0,0 +1,17 @@
+# Test host-metering configuration file which writes to a local prometheus
+# and uses a test certificate and key.
+
+# E.g. could be used as:
+# ./host-metering -config hack/host-metering.conf daemon
+
+[host-metering]
+write_url=http://localhost:9090/api/v1/write
+write_interval_sec=5
+host_cert_path=./hack/test-cert.crt
+host_cert_key_path=./hack/test-cert.key
+collect_interval_sec=0
+label_refresh_interval_sec=10
+write_retry_attempts=4
+write_retry_interval_sec=2
+metrics_wal_path=./hack/cpumetrics
+log_level=DEBUG

hack/prometheus.yml

@@ -0,0 +1 @@
+---

hack/test-cert.cnf

@@ -0,0 +1,16 @@
+[req]
+prompt = no
+req_extensions = req_ext
+distinguished_name = dn
+
+[ dn ]
+C=US
+ST=North Carolina
+L=Raleigh
+O=Milton
+OU=Information Technology
+emailAddress[email protected]
+CN = test-host.host-metering.test
+
+[ req_ext ]
+subjectAltName = DNS:test-host.host-metering.test