67 lines
1.5 KiB
Go
67 lines
1.5 KiB
Go
package dns
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import (
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"context"
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"fmt"
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"net"
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"os"
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"time"
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"github.com/AlecAivazis/survey/v2"
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"github.com/sirupsen/logrus"
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)
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// NewToken constructs a new DNS provider token.
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func NewToken(provider, providerTokenEnvVar string) (string, error) {
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if token, present := os.LookupEnv(providerTokenEnvVar); present {
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return token, nil
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}
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logrus.Debugf("no %s in environment, asking via stdin", providerTokenEnvVar)
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var token string
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prompt := &survey.Input{
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Message: fmt.Sprintf("%s API token?", provider),
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}
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if err := survey.AskOne(prompt, &token); err != nil {
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return "", err
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}
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return token, nil
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}
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// EnsureIPv4 ensures that an ipv4 address is set for a domain name
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func EnsureIPv4(domainName string) (string, error) {
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var ipv4 string
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// comrade librehosters DNS resolver -> https://www.privacy-handbuch.de/handbuch_93d.htm
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freifunkDNS := "5.1.66.255:53"
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resolver := &net.Resolver{
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PreferGo: false,
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Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
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d := net.Dialer{
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Timeout: time.Millisecond * time.Duration(10000),
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}
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return d.DialContext(ctx, "udp", freifunkDNS)
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},
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}
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logrus.Debugf("created DNS resolver via '%s'", freifunkDNS)
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ctx := context.Background()
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ips, err := resolver.LookupIPAddr(ctx, domainName)
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if err != nil {
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return ipv4, err
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}
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if len(ips) == 0 {
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return ipv4, fmt.Errorf("unable to retrieve ipv4 address for %s", domainName)
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}
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ipv4 = ips[0].IP.To4().String()
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logrus.Debugf("discovered the following ipv4 addr: %s", ipv4)
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return ipv4, nil
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}
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