feat: Support configuration via flags, env vars and config file

Author: irvinlim

Makefile

@@ -8,6 +8,9 @@ else
 GOBIN=$(shell go env GOBIN)
 endif
 
+# Set license header files.
+LICENSE_HEADER_GO ?= hack/boilerplate.go.txt
+
 # Setting SHELL to bash allows bash commands to be executed by recipes.
 # This is a requirement for 'setup-envtest.sh' in the test target.
 # Options are set to exit when a recipe line exits non-zero or a piped command fails.
@@ -56,6 +59,12 @@ tidy: ## Run go mod tidy.
 test: ## Run tests with coverage. Outputs to combined.cov.
 	go test -v -coverprofile=coverage.txt -covermode=count ./...
 
+.PHONY: generate
+generate: generate-deepcopy fmt ## Generate Go code.
+
+generate-deepcopy: controller-gen ## Generate code containing DeepCopy, DeepCopyInto, and DeepCopyObject method implementations.
+	$(CONTROLLER_GEN) object:headerFile="$(LICENSE_HEADER_GO)" paths="./..."
+
 ##@ Building
 
 .PHONY: build
@@ -72,9 +81,11 @@ $(LOCALBIN): ## Ensure that the directory exists
 ## Tool Binaries
 GOIMPORTS ?= $(LOCALBIN)/goimports
 GOLANGCI_LINT ?= $(LOCALBIN)/golangci-lint@$(GOLANGCILINT_VERSION)
+CONTROLLER_GEN ?= $(LOCALBIN)/controller-gen@$(CONTROLLER_TOOLS_VERSION)
 
 ## Tool Versions
 GOLANGCILINT_VERSION ?= v1.61.0
+CONTROLLER_TOOLS_VERSION ?= v0.16.1
 
 .PHONY: goimports
 goimports: $(GOIMPORTS) ## Download goimports locally if necessary.
@@ -87,3 +98,9 @@ golangci-lint: $(GOLANGCI_LINT) ## Download golangci-lint locally if necessary.
 $(GOLANGCI_LINT):
 	@[ -f $(GOLANGCI_LINT) ] || curl -sSfL $(GOLANGCILINT_INSTALL_SCRIPT) | sh -s $(GOLANGCILINT_VERSION)
 	mv $(LOCALBIN)/golangci-lint $(LOCALBIN)/golangci-lint@$(GOLANGCILINT_VERSION)
+
+.PHONY: controller-gen
+controller-gen: $(CONTROLLER_GEN) ## Download controller-gen locally if necessary.
+$(CONTROLLER_GEN):
+	GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-tools/cmd/controller-gen@$(CONTROLLER_TOOLS_VERSION)
+	mv $(LOCALBIN)/controller-gen $(LOCALBIN)/controller-gen@$(CONTROLLER_TOOLS_VERSION)

README.md

@@ -65,7 +65,17 @@ $ docker run --rm irvinlim/apple-health-ingester --help
 
 ## Configuration
 
-### Command-line Flags
+### Specifying Configuration 
+
+We use [spf13/viper](https://github.com/spf13/viper) for configuration, and therefore configuration can be specified in the following places, in order of precedence from highest to lowest:
+
+- Command-line flags
+- Environment variables
+- Config file
+
+See the following sections for available configuration keys for each of the available configuration methods.
+
+#### Command-line Flags
 
 ```sh
 $ ./build/ingester --help
@@ -88,6 +98,12 @@ Usage of ./build/ingester:
       --log string                           Log level to use. (default "info")
 ```
 
+#### Environment Variables
+
+Any environment variables 
+
+#### Config Files
+
 ### Global Configuration
 
 #### `http.listenAddr`

apis/config/v1/appconfig_types.go

@@ -0,0 +1,12 @@
+package v1
+
+// Config contains the application configuration.
+//
+// Configuration be loaded from configuration file, or possibly overridden from
+// environment variables if the `env` struct tag is specified.
+type Config struct {
+	// Configuration for the ingester's HTTP server.
+	HttpServer HttpServerConfig `json:"httpServer"`
+	// Configuration for individual ingester backends.
+	Backends BackendsConfig `json:"backends"`
+}

apis/config/v1/backendconfig_types.go

@@ -0,0 +1,44 @@
+package v1
+
+type BackendsConfig struct {
+	// If specified, enables the LocalFile backend.
+	LocalFile LocalFileBackendConfig `json:"localFile,omitempty"`
+	// If specified, enables the InfluxDB backend.
+	InfluxDB InfluxdbBackendConfig `json:"influxdb,omitempty"`
+}
+
+type LocalFileBackendConfig struct {
+	// Whether the LocalFile backend is enabled.
+	// Defaults to false.
+	Enabled bool `json:"enabled"`
+	// Output path to write metrics, with one metric per file. Required.
+	// All data will be aggregated by timestamp.
+	// Any existing data will be merged together.
+	MetricsPath string `json:"metricsPath"`
+}
+
+type InfluxdbBackendConfig struct {
+	// Whether the InfluxDB backend is enabled.
+	// Defaults to false.
+	Enabled bool `json:"enabled"`
+	// The URL to the InfluxDB server.
+	ServerURL string `json:"serverURL" env:"INFLUXDB_SERVER_URL"`
+	// If true, skips TLS verification of the certificate chain and host name for
+	// the InfluxDB server.
+	InsecureSkipVerify bool `json:"insecureSkipVerify,omitempty" env:"INFLUXDB_INSECURE_SKIP_VERIFY"`
+	// Auth token to connect to InfluxDB.
+	AuthToken string `json:"authToken,omitempty" env:"INFLUXDB_AUTH_TOKEN"`
+	// InfluxDB organization name.
+	OrgName string `json:"orgName" env:"INFLUXDB_ORG_NAME"`
+	// Configuration for InfluxDB bucket names for various data points.
+	BucketNames InfluxdbBucketNamesConfig `json:"bucketNames"`
+	// Additional tags to add to InfluxDB for every single request, in key=value format.
+	StaticTags map[string]string `json:"staticTags,omitempty"`
+}
+
+type InfluxdbBucketNamesConfig struct {
+	// InfluxDB bucket name for metrics.
+	Metrics string `json:"metrics" env:"INFLUXDB_METRICS_BUCKET"`
+	// InfluxDB bucket name for workouts.
+	Workouts string `json:"workouts" env:"INFLUXDB_WORKOUTS_BUCKET"`
+}

apis/config/v1/doc.go

@@ -0,0 +1,3 @@
+// Package v1 contains API Schema definitions for the config v1 API group
+// +kubebuilder:object:generate=true
+package v1

apis/config/v1/httpconfig_types.go

@@ -0,0 +1,37 @@
+package v1
+
+type HttpServerConfig struct {
+	// The address to listen on. Required.
+	// Must be specified as one of the following:
+	//  - "<ip>:<port>": Binds to the IP address on the given interface only
+	//  - ":<port>": Binds to all interfaces
+	ListenAddr string `json:"listenAddr" env:"LISTEN_ADDR"`
+	// Specify TLS configuration for the HTTP server.
+	// Defaults to running without TLS.
+	TLS HttpTLSConfig `json:"tls"`
+	// Specify authentication for the HTTP server.
+	// Defaults to no authentication.
+	Auth HttpAuthConfig `json:"auth,omitempty"`
+}
+
+type HttpTLSConfig struct {
+	// Whether TLS is enabled for the HTTP server.
+	// If enabled, certificate and key files must also be specified.
+	Enabled bool `json:"enabled" env:"TLS_ENABLED"`
+	// The path to the TLS certificate to serve.
+	// At most one of CertFile or CertData can be specified.
+	CertFile string `json:"certFile,omitempty" env:"TLS_CERT_FILE"`
+	// The TLS certificate data to serve.
+	// At most one of CertFile or CertData can be specified.
+	CertData []byte `json:"certificateData,omitempty"`
+	// The path to the TLS private key.
+	KeyFile string `json:"keyFile,omitempty" env:"TLS_KEY_FILE"`
+	// The TLS private key.
+	// At most one of KeyFile or KeyData can be specified.
+	KeyData []byte `json:"keyData,omitempty"`
+}
+
+type HttpAuthConfig struct {
+	// Optionally specify a fixed Bearer token that can be used to authenticate incoming requests.
+	AuthorizationToken string `json:"authorizationToken,omitempty" env:"AUTH_TOKEN"`
+}

apis/config/v1/zz_generated.deepcopy.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pkg/errors"
 
+	configv1 "github.com/irvinlim/apple-health-ingester/apis/config/v1"
 	"github.com/irvinlim/apple-health-ingester/pkg/backends/influxdb"
 	"github.com/irvinlim/apple-health-ingester/pkg/backends/localfile"
 	"github.com/irvinlim/apple-health-ingester/pkg/ingester"
@@ -15,27 +16,35 @@ const (
 )
 
 // RegisterDebugBackend registers the Debug backend.
-func RegisterDebugBackend(ingester *ingester.Ingester, mux *http.ServeMux) error {
-	if !enableLocalFile {
+func RegisterDebugBackend(cfg *configv1.Config, ingester *ingester.Ingester, mux *http.ServeMux) error {
+	if cfg == nil {
+		cfg = &configv1.Config{}
+	}
+	backendCfg := cfg.Backends.LocalFile.DeepCopy()
+	if !backendCfg.Enabled {
 		return nil
 	}
-	backend, err := localfile.NewBackend()
+	backend, err := localfile.NewBackend(backendCfg)
 	if err != nil {
 		return err
 	}
 	return RegisterBackend(backend, ingester, mux, pathPrefix+"/localfile/ingest")
 }
 
 // RegisterInfluxDBBackend registers the InfluxDB backend.
-func RegisterInfluxDBBackend(ingester *ingester.Ingester, mux *http.ServeMux) error {
-	if !enableInfluxDB {
+func RegisterInfluxDBBackend(cfg *configv1.Config, ingester *ingester.Ingester, mux *http.ServeMux) error {
+	if cfg == nil {
+		cfg = &configv1.Config{}
+	}
+	backendCfg := cfg.Backends.InfluxDB.DeepCopy()
+	if !backendCfg.Enabled {
 		return nil
 	}
-	client, err := influxdb.NewClient()
+	client, err := influxdb.NewClient(backendCfg)
 	if err != nil {
 		return errors.Wrapf(err, "cannot initialize client")
 	}
-	backend, err := influxdb.NewBackend(client)
+	backend, err := influxdb.NewBackend(backendCfg, client)
 	if err != nil {
 		return err
 	}