package main import ( "fmt" "io" "log" "net/http" "os" "path" "time" ) const ( digitalOceanMetaDataURL = "http://169.254.169.254/metadata/v1/" ) // ProviderDigitalOcean is the type implementing the Provider interface for DigitalOcean type ProviderDigitalOcean struct { } // NewDigitalOcean returns a new ProviderDigitalOcean func NewDigitalOcean() *ProviderDigitalOcean { return &ProviderDigitalOcean{} } func (p *ProviderDigitalOcean) String() string { return "DigitalOcean" } // Probe checks if we are running on DigitalOcean func (p *ProviderDigitalOcean) Probe() bool { // Getting the index should always work... _, err := digitalOceanGet(digitalOceanMetaDataURL) return err == nil } // Extract gets both the DigitalOcean specific and generic userdata func (p *ProviderDigitalOcean) Extract() ([]byte, error) { // Get host name. This must not fail hostname, err := digitalOceanGet(digitalOceanMetaDataURL + "hostname") if err != nil { return nil, err } err = os.WriteFile(path.Join(ConfigPath, Hostname), hostname, 0644) if err != nil { return nil, fmt.Errorf("DigitalOcean: Failed to write hostname: %s", err) } // public ipv4 digitalOceanMetaGet("interfaces/public/0/ipv4/address", "public_ipv4", 0644) // private ipv4 digitalOceanMetaGet("interfaces/private/0/ipv4/address", "private_ipv4", 0644) // region digitalOceanMetaGet("region", "region", 0644) // droplet id digitalOceanMetaGet("id", "id", 0644) // ssh if err := p.handleSSH(); err != nil { log.Printf("DigitalOcean: Failed to get ssh data: %s", err) } // Generic userdata userData, err := digitalOceanGet(digitalOceanMetaDataURL + "user-data") if err != nil { log.Printf("DigitalOcean: Failed to get user-data: %s", err) // This is not an error return nil, nil } return userData, nil } // lookup a value (lookupName) in DigitalOcean metaservice and store in given fileName func digitalOceanMetaGet(lookupName string, fileName string, fileMode os.FileMode) { if lookupValue, err := digitalOceanGet(digitalOceanMetaDataURL + lookupName); err == nil { // we got a value from the metadata server, now save to filesystem err = os.WriteFile(path.Join(ConfigPath, fileName), lookupValue, fileMode) if err != nil { // we couldn't save the file for some reason log.Printf("DigitalOcean: Failed to write %s:%s %s", fileName, lookupValue, err) } } else { // we did not get a value back from the metadata server log.Printf("DigitalOcean: Failed to get %s: %s", lookupName, err) } } // digitalOceanGet requests and extracts the requested URL func digitalOceanGet(url string) ([]byte, error) { var client = &http.Client{ Timeout: time.Second * 2, } req, err := http.NewRequest("", url, nil) if err != nil { return nil, fmt.Errorf("DigitalOcean: http.NewRequest failed: %s", err) } resp, err := client.Do(req) if err != nil { return nil, fmt.Errorf("DigitalOcean: Could not contact metadata service: %s", err) } if resp.StatusCode != 200 { return nil, fmt.Errorf("DigitalOcean: Status not ok: %d", resp.StatusCode) } body, err := io.ReadAll(resp.Body) if err != nil { return nil, fmt.Errorf("DigitalOcean: Failed to read http response: %s", err) } return body, nil } // SSH keys: func (p *ProviderDigitalOcean) handleSSH() error { sshKeys, err := digitalOceanGet(digitalOceanMetaDataURL + "public-keys") if err != nil { return fmt.Errorf("Failed to get sshKeys: %s", err) } if err := os.Mkdir(path.Join(ConfigPath, SSH), 0755); err != nil { return fmt.Errorf("Failed to create %s: %s", SSH, err) } err = os.WriteFile(path.Join(ConfigPath, SSH, "authorized_keys"), sshKeys, 0600) if err != nil { return fmt.Errorf("Failed to write ssh keys: %s", err) } return nil }