56 lines
1.4 KiB
Go
56 lines
1.4 KiB
Go
package app
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import (
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"math/rand"
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"time"
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"github.com/miekg/dns"
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"github.com/mr-karan/doggo/pkg/models"
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"github.com/mr-karan/doggo/pkg/resolvers"
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"github.com/mr-karan/logf"
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)
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// App represents the structure for all app wide configuration.
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type App struct {
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Logger *logf.Logger
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Version string
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QueryFlags models.QueryFlags
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Questions []dns.Question
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Resolvers []resolvers.Resolver
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ResolverOpts resolvers.Options
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Nameservers []models.Nameserver
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}
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// NewApp initializes an instance of App which holds app wide configuration.
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func New(logger *logf.Logger, buildVersion string) App {
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app := App{
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Logger: logger,
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Version: buildVersion,
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QueryFlags: models.QueryFlags{
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QNames: []string{},
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QTypes: []string{},
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QClasses: []string{},
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Nameservers: []string{},
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},
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Nameservers: []models.Nameserver{},
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}
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return app
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}
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// Attempts a DNS Lookup with retries for a given Question.
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func (app *App) LookupWithRetry(attempts int, resolver resolvers.Resolver, ques dns.Question) (resolvers.Response, error) {
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resp, err := resolver.Lookup(ques)
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if err != nil {
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// Retry lookup.
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attempts--
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if attempts > 0 {
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// Add some random delay.
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time.Sleep(time.Millisecond*300 + (time.Duration(rand.Int63n(int64(time.Millisecond*100))))/2)
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app.Logger.Debug("retrying lookup")
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return app.LookupWithRetry(attempts, resolver, ques)
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}
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return resolvers.Response{}, err
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}
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return resp, nil
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}
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