// Package exec implements a DNS provider which runs a program for adding/removing the DNS record. package exec import ( "errors" "fmt" "os" "os/exec" "time" "github.com/go-acme/lego/v3/challenge/dns01" "github.com/go-acme/lego/v3/log" "github.com/go-acme/lego/v3/platform/config/env" ) // Environment variables names. const ( envNamespace = "EXEC_" EnvPath = envNamespace + "PATH" EnvMode = envNamespace + "MODE" EnvPropagationTimeout = envNamespace + "PROPAGATION_TIMEOUT" EnvPollingInterval = envNamespace + "POLLING_INTERVAL" ) // Config Provider configuration. type Config struct { Program string Mode string PropagationTimeout time.Duration PollingInterval time.Duration } // NewDefaultConfig returns a default configuration for the DNSProvider. func NewDefaultConfig() *Config { return &Config{ PropagationTimeout: env.GetOrDefaultSecond(EnvPropagationTimeout, dns01.DefaultPropagationTimeout), PollingInterval: env.GetOrDefaultSecond(EnvPollingInterval, dns01.DefaultPollingInterval), } } // DNSProvider implements the challenge.Provider interface. type DNSProvider struct { config *Config } // NewDNSProvider returns a new DNS provider which runs the program in the // environment variable EXEC_PATH for adding and removing the DNS record. func NewDNSProvider() (*DNSProvider, error) { values, err := env.Get(EnvPath) if err != nil { return nil, fmt.Errorf("exec: %w", err) } config := NewDefaultConfig() config.Program = values[EnvPath] config.Mode = os.Getenv(EnvMode) return NewDNSProviderConfig(config) } // NewDNSProviderConfig returns a new DNS provider which runs the given configuration // for adding and removing the DNS record. func NewDNSProviderConfig(config *Config) (*DNSProvider, error) { if config == nil { return nil, errors.New("the configuration is nil") } return &DNSProvider{config: config}, nil } // Present creates a TXT record to fulfill the dns-01 challenge. func (d *DNSProvider) Present(domain, token, keyAuth string) error { var args []string if d.config.Mode == "RAW" { args = []string{"present", "--", domain, token, keyAuth} } else { fqdn, value := dns01.GetRecord(domain, keyAuth) args = []string{"present", fqdn, value} } cmd := exec.Command(d.config.Program, args...) output, err := cmd.CombinedOutput() if len(output) > 0 { log.Println(string(output)) } return err } // CleanUp removes the TXT record matching the specified parameters. func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error { var args []string if d.config.Mode == "RAW" { args = []string{"cleanup", "--", domain, token, keyAuth} } else { fqdn, value := dns01.GetRecord(domain, keyAuth) args = []string{"cleanup", fqdn, value} } cmd := exec.Command(d.config.Program, args...) output, err := cmd.CombinedOutput() if len(output) > 0 { log.Println(string(output)) } return err } // Timeout returns the timeout and interval to use when checking for DNS propagation. // Adjusting here to cope with spikes in propagation times. func (d *DNSProvider) Timeout() (timeout, interval time.Duration) { return d.config.PropagationTimeout, d.config.PollingInterval } // Sequential All DNS challenges for this provider will be resolved sequentially. // Returns the interval between each iteration. func (d *DNSProvider) Sequential() time.Duration { return d.config.PropagationTimeout }