Quick'n'Dirty aws price parser

main.go

package main

import (
        "encoding/gob"
        "encoding/json"
        "flag"
        "log"
        "net/http"
        "os"
        "time"
)

type product struct {
        Sku           string `json:"sku"`
        ProductFamily string `json:"productFamily"`
        Attributes    struct {
                Servicecode                 string `json:"servicecode"`
                Location                    string `json:"location"`
                LocationType                string `json:"locationType"`
                InstanceType                string `json:"instanceType"`
                CurrentGeneration           string `json:"currentGeneration"`
                InstanceFamily              string `json:"instanceFamily"`
                Vcpu                        string `json:"vcpu"`
                PhysicalProcessor           string `json:"physicalProcessor"`
                ClockSpeed                  string `json:"clockSpeed"`
                Memory                      string `json:"memory"`
                Storage                     string `json:"storage"`
                NetworkPerformance          string `json:"networkPerformance"`
                ProcessorArchitecture       string `json:"processorArchitecture"`
                Tenancy                     string `json:"tenancy"`
                OperatingSystem             string `json:"operatingSystem"`
                LicenseModel                string `json:"licenseModel"`
                Usagetype                   string `json:"usagetype"`
                Operation                   string `json:"operation"`
                EnhancedNetworkingSupported string `json:"enhancedNetworkingSupported"`
                PreInstalledSw              string `json:"preInstalledSw"`
                ProcessorFeatures           string `json:"processorFeatures"`
        } `json:"attributes"`
}
type priceDimension struct {
        RateCode     string `json:"rateCode"`
        Description  string `json:"description"`
        BeginRange   string `json:"beginRange"`
        EndRange     string `json:"endRange"`
        Unit         string `json:"unit"`
        PricePerUnit struct {
                USD string `json:"USD"`
        } `json:"pricePerUnit"`
        AppliesTo []interface{} `json:"appliesTo"`
}

type onDemand map[string]struct {
        OfferTermCode   string                    `json:"offerTermCode"`
        Sku             string                    `json:"sku"`
        EffectiveDate   time.Time                 `json:"effectiveDate"`
        PriceDimensions map[string]priceDimension `json:"priceDimensions"`
        TermAttributes  struct {
                LeaseContractLength string `json:"LeaseContractLength"`
                                OfferingClass       string `json:"OfferingClass"`
                PurchaseOption      string `json:"PurchaseOption"`
        } `json:"termAttributes"`
}

type reserved map[string]struct {
        OfferTermCode   string                    `json:"offerTermCode"`
        Sku             string                    `json:"sku"`
        EffectiveDate   time.Time                 `json:"effectiveDate"`
        PriceDimensions map[string]priceDimension `json:"priceDimensions"`
        TermAttributes  struct {
                LeaseContractLength string `json:"LeaseContractLength"`
                OfferingClass       string `json:"OfferingClass"`
                PurchaseOption      string `json:"PurchaseOption"`
        } `json:"termAttributes"`
}

type aws struct {
        FormatVersion   string              `json:"formatVersion"`
        Disclaimer      string              `json:"disclaimer"`
        OfferCode       string              `json:"offerCode"`
        Version         string              `json:"version"`
        PublicationDate time.Time           `json:"publicationDate"`
        Products        map[string]*product `json:"products"`
        Terms           struct {
                OnDemand map[string]*onDemand `json:"OnDemand"`
                Reserved map[string]*reserved `json:"Reserved"`
        }
}

var query string
var dbFile string

func init() {
        flag.StringVar(&query, "query", "{}", "query to ask server for data")
        flag.StringVar(&dbFile, "db", "", "DB Path")
}

func main() {
        flag.Parse()
        var objects aws
        if dbFile == "" {
                log.Println("Please provide a dbFile")
                return
        }
        file, err := os.Open(dbFile) // For read access.
        if err != nil {
                // Cannot open file... Let's create it
                resp, err := http.Get("https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/AmazonEC2/20170224022054/index.json")
                if err != nil {
                        log.Fatal(err)
                }
                defer resp.Body.Close()
                dec := json.NewDecoder(resp.Body)
                err = dec.Decode(&objects)
                if err != nil {
                                                log.Fatal(err)
                }
                file, err := os.Create(dbFile)
                defer file.Close()
                if err != nil {
                        log.Fatal(err)
                }
                enc := gob.NewEncoder(file)
                err = enc.Encode(objects)
                if err != nil {
                        log.Fatal("encode error:", err)
                }
        } else {
                defer file.Close()
                dec := gob.NewDecoder(file)
                err = dec.Decode(&objects)
                if err != nil {
                        log.Fatal("decode error:", err)
                }
        }
        log.Println(objects.Products["HZC9FAP4F9Y8JW67"])
        log.Println(objects.Terms.OnDemand["HZC9FAP4F9Y8JW67"])
        log.Println(objects.Terms.Reserved["HZC9FAP4F9Y8JW67"])

}