Config Server

What is Config Server?

Config Server is a Cross-Platform key/value store which dynamically converts yaml files into rest services.

How it works?

1. Config server fetchs yaml files from git repo (or any remote)
2. Hierarchically saves all keys in all yaml files to the state file. In case of restart or crash, first task of config server is reloading this file to cache.
3. Hierarchically caches each key and it's value. You should take care of cached objects because currently there is no capacity limitation or caching policy like LRU,MRU,etc.
4. Creates routes for each cached keys and each routes return cached values.
5. If a new yaml file or key is added it will be remarked by config server and .
6. If a yaml file or key is deleted, related routes will be deleted from cache and state file. Deleted routes will start to get http 404.

How to store Config Files?

Actually it is up to you. schedules/get-repo.ps1 file is responsible from getting yamls from remote and by default, config server assumes that yaml files are kept in a git repository.

But it is possible to add custom logic to get/sync yaml files or completely disabling and working on existing local yaml files by changing schedules/get-repo.ps1.

Yaml file Format

Assume that you have 2 yaml files test1.yaml and test2.yaml;

• test1.yaml

nested:
  array:
  - this
  - is
  - an
myKey: world1

• test2.yaml

myKey2: myValue2

Config server will convert all keys in all yaml files to the following endpoints:

• /test1/nested/array
• /test1/myKey
• /test2/myKey2

How to run?

Prerequisites

There is no prerequisites for cnsn/config-server base image, all requirements are already installed inside docker image.

If you want to run config-server out of container, first thing you need is Powershell Core (PS > 6.0). Also git should be installed and finally config-server should be able to reach repos defined in Powershell Gallery. When you start config-server.ps1 for the first time, following modules will be installed from Powershell Gallery if they are not installed already:

• Powershell-Yaml (Powershell Module)
• Pode (Powershell Module)
• PSCache (Powershell Module)

If you want to install them manually, you can use following commands:

Install-Module -Name "powershell-yaml" -RequiredVersion 0.4.1 -Force -Scope CurrentUser
Install-Module -Name "pode" -RequiredVersion 1.6.1 -Force -Scope CurrentUser
Install-Module -Name "pscache" -RequiredVersion 0.1.0 -Force -Scope CurrentUser

Environment Variables

Config server will use environment variables during server startup to configure itself. They are:

• repo: Remote git repo address that config server will clone and pull periodically. Default: https://github.com/haidouks/configs
• PodePort: Port that will config server will be listening. Default: 8085
• ThreadCount: Dedicated thread count for all routes. Default: 5
• VerbosePreference: Enable verbose logging. Default: SilentlyContinue
• enableAuthentation: Enable authentication. Default: False
• authenticatedRoutes: List of routes that will be authenticated. Default: Null
• defaultAuthToken: Bearer token for default authencation type. Default:QweAsdZxc123

Examples

Example 1: Quick start

docker run -d -p 8085:8085 cnsn/config-server:latest

Now browse http://localhost:8085/test/myKey:

• test is the name of yaml file in default source repository: https://github.com/haidouks/configs
• myKey is a key in test.yaml

Response should see something like {"value":"world1"} which is the value of key myKey

Example 2: Configure variables

docker run -d -p 8085:8085 \
    -e VerbosePreference=Continue \
    -e ThreadCount=10 \
    -e repo=https://github.com/haidouks/configs \
    cnsn/config-server

Example 3: Authenticate some routes

docker run -d -p 8085:8085 \
    -e repo=https://github.com/haidouks/configs \
    -e enableAuthentation=true \
    -e authenticatedRoutes=test/*:DefaultAuth \
    -e defaultAuthToken=Qweasd123 \
    cnsn/config-server

Roadmap

• Just in time synchronizer -> DONE
• Configure cache capacity and policy