feat: add health check command

Dockerfile

@@ -45,8 +45,6 @@ FROM alpine:3.22 AS runner
 
 WORKDIR /tinyauth
 
-RUN apk add --no-cache curl
-
 COPY --from=builder /tinyauth/tinyauth ./
 
 EXPOSE 3000

cmd/health.go

@@ -0,0 +1,109 @@
+package cmd
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"tinyauth/internal/config"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+type healthzResponse struct {
+	Status  string `json:"status"`
+	Message string `json:"message"`
+}
+
+type healthCmd struct {
+	root *cobra.Command
+	cmd  *cobra.Command
+
+	viper  *viper.Viper
+	appUrl string
+}
+
+func newHealthCmd(root *cobra.Command) *healthCmd {
+	return &healthCmd{
+		root:  root,
+		viper: viper.New(),
+	}
+}
+
+func (c *healthCmd) Register() {
+	c.cmd = &cobra.Command{
+		Use:   "health",
+		Short: "Health check",
+		Long:  `Use the health check endpoint to verify that Tinyauth is running and it's healthy.`,
+		Run:   c.run,
+	}
+
+	c.viper.AutomaticEnv()
+	c.cmd.Flags().StringVar(&c.appUrl, "app-url", "http://localhost:3000", "The URL where the Tinyauth server is running on.")
+	c.viper.BindEnv("app-url", "APP_URL")
+	c.viper.BindPFlags(c.cmd.Flags())
+
+	if c.root != nil {
+		c.root.AddCommand(c.cmd)
+	}
+}
+
+func (c *healthCmd) GetCmd() *cobra.Command {
+	return c.cmd
+}
+
+func (c *healthCmd) run(cmd *cobra.Command, args []string) {
+	log.Logger = log.Level(zerolog.InfoLevel)
+
+	appUrl := c.viper.GetString("app-url")
+
+	if appUrl == "" {
+		log.Fatal().Err(errors.New("app-url is required")).Msg("App URL is required")
+	}
+
+	if config.Version == "development" {
+		log.Warn().Msg("Running in development mode. Overriding the app-url to http://localhost:3000")
+		appUrl = "http://localhost:3000"
+	}
+
+	log.Info().Msgf("Health check endpoint is available at %s/api/healthz", appUrl)
+
+	client := http.Client{}
+
+	req, err := http.NewRequest("GET", appUrl+"/api/healthz", nil)
+
+	if err != nil {
+		log.Fatal().Err(err).Msg("Failed to create request")
+	}
+
+	resp, err := client.Do(req)
+
+	if err != nil {
+		log.Fatal().Err(err).Msg("Failed to perform request")
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		log.Fatal().Err(errors.New("service is not healthy")).Msgf("Service is not healthy. Status code: %d", resp.StatusCode)
+	}
+
+	defer resp.Body.Close()
+
+	var healthResp healthzResponse
+
+	body, err := io.ReadAll(resp.Body)
+
+	if err != nil {
+		log.Fatal().Err(err).Msg("Failed to read response")
+	}
+
+	err = json.Unmarshal(body, &healthResp)
+
+	if err != nil {
+		log.Fatal().Err(err).Msg("Failed to decode response")
+	}
+
+	log.Info().Interface("response", healthResp).Msg("Service is healthy")
+}

cmd/root.go

@@ -140,6 +140,7 @@ func Run() {
 	newVerifyUserCmd(userCmd).Register()
 	newGenerateTotpCmd(totpCmd).Register()
 	newVersionCmd(root).Register()
+	newHealthCmd(root).Register()
 
 	root.AddCommand(userCmd)
 	root.AddCommand(totpCmd)

internal/controller/health_controller.go

@@ -13,8 +13,8 @@ func NewHealthController(router *gin.RouterGroup) *HealthController {
 }
 
 func (controller *HealthController) SetupRoutes() {
-	controller.router.GET("/health", controller.healthHandler)
+	controller.router.GET("/healthz", controller.healthHandler)
-	controller.router.HEAD("/health", controller.healthHandler)
+	controller.router.HEAD("/healthz", controller.healthHandler)
 }
 
 func (controller *HealthController) healthHandler(c *gin.Context) {