Go parse yaml file

Question

I'm trying to parse a yaml file with Go. Unfortunately I can't figure out how. The yaml file I have is this:

--- firewall_network_rules:   rule1:     src:       blablabla-host     dst:       blabla-hostname ... 

I have this Go code, but it does not work:

package main  import (     "fmt"     "io/ioutil"     "path/filepath"      "gopkg.in/yaml.v2" )  type Config struct {     Firewall_network_rules map[string][]string }  func main() {     filename, _ := filepath.Abs("./fruits.yml")     yamlFile, err := ioutil.ReadFile(filename)      if err != nil {         panic(err)     }      var config Config      err = yaml.Unmarshal(yamlFile, &config)     if err != nil {         panic(err)     }      fmt.Printf("Value: %#v\n", config.Firewall_network_rules) } 

When I run this, I get an error. I think it's because I haven't created a struct for the src and dst key/values. FYI: when I change that to a list, it works.

So above code parses this:

--- firewall_network_rules:   rule1:     - value1     - value2 ... 

Answer 1

If you're working with google cloud or kubernetes more specifically and want to parse a service.yaml like this:

apiVersion: v1 kind: Service metadata:   name: myName   namespace: default   labels:     router.deis.io/routable: "true"   annotations:     router.deis.io/domains: "" spec:   type: NodePort   selector:     app: myName   ports:     - name: http       port: 80       targetPort: 80     - name: https       port: 443       targetPort: 443 

Supplying a real world example so you get the hang of how nesting can be written.

type Service struct {     APIVersion string `yaml:"apiVersion"`     Kind       string `yaml:"kind"`     Metadata   struct {         Name      string `yaml:"name"`         Namespace string `yaml:"namespace"`         Labels    struct {             RouterDeisIoRoutable string `yaml:"router.deis.io/routable"`         } `yaml:"labels"`         Annotations struct {             RouterDeisIoDomains string `yaml:"router.deis.io/domains"`         } `yaml:"annotations"`     } `yaml:"metadata"`     Spec struct {         Type     string `yaml:"type"`         Selector struct {             App string `yaml:"app"`         } `yaml:"selector"`         Ports []struct {             Name       string `yaml:"name"`             Port       int    `yaml:"port"`             TargetPort int    `yaml:"targetPort"`             NodePort   int    `yaml:"nodePort,omitempty"`         } `yaml:"ports"`     } `yaml:"spec"` } 

There's a convenient service called yaml-to-go https://yaml.to-go.online/ which converts YAML to go structs, just input your YAML into that service and you get an autogenerated struct.

And last unmarshal as a previous poster wrote:

var service Service  err = yaml.Unmarshal(yourFile, &service) if err != nil {     panic(err) }  fmt.Print(service.Metadata.Name)