Possible to initialise Consul Key Value store at startup?

Question

I can initialise the Consul services at startup using the /consul/config directory. I would like to be able to initialise my application settings into the Consul kv store when I start the Consul container. Is this possible?

Answer 1

I wanted a simple approach to set application settings in Consul for a microservice project. I'm sure there are a number of existing tools but I wanted something that was lightweight and suits my development process. So rather than try to work with some of @mgyongyosi's suggestions I wrote a quick dotnet console application to do the (not so) heavy lifting. Under the project root directory I've created a directory structure Consul/kv. The child directories under that path represent keys in the Consul KV store and a json file at a leaf represents the application settings. Note there is only expected to be a single json file per leaf directory. The application uses the Consul.NET nuget package for communicating with Consul.

using System;
using System.IO;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Consul;

namespace ConfigureConsulKv
{
    class Program
    {
        private static readonly string _basePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments),
                                                                "Projects", "MyProject", "Consul", "kv");

        static void Main(string[] args)
        {
            RecurseDirectory(_basePath);
        }

        static void RecurseDirectory(string path)
        {
            foreach (var dir in Directory.EnumerateDirectories(path)) RecurseDirectory(dir);

            var file = Directory.EnumerateFiles(path, "*.json").FirstOrDefault();
            if (!string.IsNullOrWhiteSpace(file))
            {
                var key = path.Substring(_basePath.Length + 1);
                var json = File.ReadAllBytes(file);
                Console.WriteLine($"key {key} file {file}");
                using (var client = new ConsulClient())
                {
                    var attempt = client.KV.Put(new KVPair(key) { Value = json }).Result;
                    Console.WriteLine($"status {attempt.StatusCode}");
                }
            }
        }
    }
}

Answer 2

There are several projects which might be interesting for this scenario:

• https://github.com/zerotens/consul-kv-bootstrap
• https://github.com/cimpress-mcp/git2consul
• https://github.com/cimpress-mcp/fsconsul