Read multiple yamls in a file - go

Question

How does one parse multiple yamls in a file similar to how kubectl does it?
example.yaml
---
a: Easy!
b:
c: 0
d: [1, 2]
---
a: Peasy!
b:
c: 1000
d: [3, 4]

Answer 1

There's a difference in behavior between gopkg.in/yaml.v2 and gopkg.in/yaml.v3:
V2: https://play.golang.org/p/XScWhdPHukO
V3: https://play.golang.org/p/OfFY4qH5wW2
Both implementations produce an incorrect result IMHO but V3 is apparently slightly worse.
There's a workaround. If you slightly change code in the accepted answer, it works correctly and in the same fashion with both versions of yaml package: https://play.golang.org/p/r4ogBVcRLCb

Answer 2

Current gopkg.in/yaml.v3 Deocder produces quite correct result, you just need to pay attention on creating new structure for each document and check it was parsed correctly (with nil check), and handle EOF error correctly:
package main
import "fmt"
import "gopkg.in/yaml.v3"
import "os"
import "errors"
import "io"
type Spec struct {
Name string `yaml:"name"`
}
func main() {
f, err := os.Open("spec.yaml")
if err != nil {
panic(err)
}
d := yaml.NewDecoder(f)
for {
// create new spec here
spec := new(Spec)
// pass a reference to spec reference
err := d.Decode(&spec)
// check it was parsed
if spec == nil {
continue
}
// break the loop in case of EOF
if errors.Is(err, io.EOF) {
break
}
if err != nil {
panic(err)
}
fmt.Printf("name is '%s'\n", spec.Name)
}
}
Test file spec.yaml:
---
name: "doc first"
---
name: "second"
---
---
name: "skip 3, now 4"
---

Answer 3

Solution I found using gopkg.in/yaml.v2:
package main
import (
"bytes"
"fmt"
"io/ioutil"
"log"
"path/filepath"
"gopkg.in/yaml.v2"
)
type T struct {
A string
B struct {
RenamedC int `yaml:"c"`
D []int `yaml:",flow"`
}
}
func main() {
filename, _ := filepath.Abs("./example.yaml")
yamlFile, err := ioutil.ReadFile(filename)
if err != nil {
panic(err)
}
r := bytes.NewReader(yamlFile)
dec := yaml.NewDecoder(r)
var t T
for dec.Decode(&t) == nil {
fmt.Printf("a :%v\nb :%v\n", t.A, t.B)
}
}