How to get a configuration array of objects using viper in golang?

Question

I have a config file that looks like:

{
    "auth": {
        "client_id": "foo",
        "client_secret": "bar",
        "account": "[email protected]",
        "secrets_type": "auto"
    },
    "jobs": [
    {
        "source_folder": "folder1",
        "create_albums": "off",
        "delete_after_upload": false,
        "include": [
            "*.jpg"
        ],
        "exclude": []
    },
    {
        "source_folder": "folder2",
        "create_albums": "folderName",
        "delete_after_upload": true,
        "include": [
            "*.jpg", "*.webp"
        ],
        "exclude": [
            "abc*"
        ]
    }   
    ]
}

And I'm reading it using the viper package in golang.

I'm having problems to get the jobs settings:

    type FolderUpload struct {
        sourceFolder      string   `mapstructure:"source_folder"`
        createAlbums      string   `mapstructure:"create_albums"`
        deleteAfterUpload bool     `mapstructure:"delete_after_upload"`
        include           []string `mapstructure:"include"`
        exclude           []string `mapstructure:"exclude"`
    }

    // Read the "jobsSettings" section as a slice of maps
    jobsSettings := viper.Get("jobs").([]interface{})

    // Iterate over each job item
    for _, job := range jobsSettings {
        jobMap := job.(map[string]interface{})

        j := FolderUploadJob{
            sourceFolder:      jobMap["source_folder"].(string),
            createAlbums:      jobMap["create_albums"].(string),
            deleteAfterUpload: jobMap["delete_after_upload"].(bool),
            include:           jobMap["include"].([]string),
            exclude:           jobMap["exclude"].([]string),
        }
    }

I've tried with viper.UnmarshalKey() too, but I always receive a panic when trying to read the include and exclude.

Can anyone point me to the right way?

Answer 1

viper.UnmarshalKey works and please note that the fields of FolderUpload should be exported. See the demo below:

package main

import (
    "fmt"
    "strings"

    "github.com/spf13/viper"
)

func main() {
    viper.SetConfigType("json")

    jsonConfig := `
{
    "jobs": [
    {
        "source_folder": "folder1",
        "create_albums": "off",
        "delete_after_upload": false,
        "include": [
            "*.jpg"
        ],
        "exclude": []
    },
    {
        "source_folder": "folder2",
        "create_albums": "folderName",
        "delete_after_upload": true,
        "include": [
            "*.jpg", "*.webp"
        ],
        "exclude": [
            "abc*"
        ]
    }
    ]
}`

    type FolderUpload struct {
        SourceFolder      string   `mapstructure:"source_folder"`
        CreateAlbums      string   `mapstructure:"create_albums"`
        DeleteAfterUpload bool     `mapstructure:"delete_after_upload"`
        Include           []string `mapstructure:"include"`
        Exclude           []string `mapstructure:"exclude"`
    }

    if err := viper.ReadConfig(strings.NewReader(jsonConfig)); err != nil {
        panic(err)
    }
    var jobs []FolderUpload

    if err := viper.UnmarshalKey("jobs", &jobs); err != nil {
        panic(err)
    }

    fmt.Printf("%+v\n", jobs)
}