cannot unmarshal !!seq into string in Go - go

Question

I am getting the following error while using sequence of array in yaml file. I am not sure what fix required to be applied as I am new to 'Go' and learning the program.
2021/07/28 14:16:07 yaml: unmarshal errors:
line 3: cannot unmarshal !!seq into string
Yaml:
ENV:
attributes:
- foo
- boo
- coo
code:
package test
import (
"fmt"
"gopkg.in/yaml.v3"
"io/ioutil"
"log"
"testing"
)
type ENV struct {
Attributes string `yaml:"attributes"`
}
func TestTerraformAzureCosmosDBExample(t *testing.T) {
yFile, err := ioutil.ReadFile("config.yaml")
if err != nil {
log.Fatal(err)
}
data := make(map[string]ENV)
err = yaml.Unmarshal(yFile, &data)
if err != nil {
log.Fatal(err)
}
for k, v := range data {
fmt.Printf(`key: %v, value: %v`, k,v)
}
}
Expected:
foo
boo
coo
Actual:
C:\Pfoo\boo>go test -v
=== RUN TestTerraformAzureCosmosDBExample
2021/07/28 14:16:07 yaml: unmarshal errors:
line 3: cannot unmarshal !!seq into string
exit status 1
FAIL foo_test 0.199s

Answer 1

As mkopriva, said in the comments, you should change to []string, so the struct would be
type ENV struct {
Attributes []string `yaml:"attributes"`
}
And why is that ? the yaml, reconizes the
ENV: attributes: - foo - boo - coo as a array.
What you can do to turn into one string, is use:
strings.Join(String Slice,{ something to separate, you can let this as "")`
the imports are : "strings", and strings.Join returns a string.

Answer 2

As per suggestion of mkopriva changing Attributes field to string[] instead of string:
package test
import (
"fmt"
"gopkg.in/yaml.v3"
"io/ioutil"
"log"
"testing"
)
type ENV struct {
Attributes []string `yaml:"attributes"`
}
func TestTerraformAzureCosmosDBExample(t *testing.T) {
yFile, err := ioutil.ReadFile("config.yaml")
if err != nil {
log.Fatal(err)
}
data := make(map[string]ENV)
err = yaml.Unmarshal(yFile, &data)
if err != nil {
log.Fatal(err)
}
for k, v := range data {
fmt.Printf(`key: %v, value: %v`, k, v)
}
}

Answer 3

Here is an example I did. Hope it helps
package main
import (
"fmt"
"gopkg.in/yaml.v2"
"io/ioutil"
"log"
)
type Image struct {
Name string `yaml:"name"`
Image string `yaml:"image"`
}
type Specification struct {
Spec struct {
Container []Image `yaml:"containers,flow"`
}
}
func main() {
container := Specification{}
content, err := ioutil.ReadFile("final-result.yml")
if err != nil {
log.Fatal(err.Error())
return
}
err = yaml.Unmarshal(content, &container)
if err != nil {
log.Fatalf("error: %v", err)
}
log.Println(container)
for _, ct := range container.Spec.Container {
fmt.Println(ct.Name)
}
}
spec:
containers:
- name: nginx
image: nginx:1.14.2
- name: php
image: php:1.4.8
- name: golang
image: golang:1.4.3
Output
nginx
php
golang