healthcheck.go

package http_handlers

import (
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/surahman/mcq-platform/pkg/cassandra"
	"github.com/surahman/mcq-platform/pkg/logger"
	"github.com/surahman/mcq-platform/pkg/model/http"
	"github.com/surahman/mcq-platform/pkg/redis"
	"go.uber.org/zap"
)

// Healthcheck checks if the service is healthy.
//	@Summary		Healthcheck for service liveness.
//	@Description	This endpoint is exposed to allow load balancers etc. to check the health of the service.
//	@Tags			health healthcheck liveness
//	@Id				healthcheck
//	@Produce		json
//	@Success		200	{object}	model_http.Success	"message: healthy"
//	@Failure		503	{object}	model_http.Error	"error message with any available details"
//	@Router			/health [get]
func Healthcheck(logger *logger.Logger, db cassandra.Cassandra, cache redis.Redis) gin.HandlerFunc {
	return func(context *gin.Context) {
		var err error

		// Database health.
		if _, err = db.Execute(cassandra.HealthcheckQuery, nil); err != nil {
			msg := "Cassandra healthcheck failed"
			logger.Warn(msg, zap.Error(err))
			context.AbortWithStatusJSON(http.StatusServiceUnavailable, &model_http.Error{Message: msg})
			return
		}

		// Cache health.
		if err = cache.Healthcheck(); err != nil {
			msg := "Redis healthcheck failed"
			logger.Warn(msg, zap.Error(err))
			context.AbortWithStatusJSON(http.StatusServiceUnavailable, &model_http.Error{Message: msg})
			return
		}

		context.JSON(http.StatusOK, &model_http.Success{Message: "healthy"})
	}
}