config-store-vault.md

How to read secrets from Vault

In this how-to we will configure Pyron to read secrets from Vault with vault-ext config store and reference them in routing rules configuration.

In Scala/Java plugin development guide we implemented a sample plugin that verifies API key sent by the client against the one configured in a routing rule. We stored the API key value in configuration as plain-text. However, in production we don't want to do that.

Instead, we will read the API keys from Vault secrets store and reference them in routing rule config.

NOTE
Pyron stores the secrets in-memory, i.e. they are not printed in log messages.

vault-ext is a wrapper around Vertx vault config store. vault supports several authentication method. In this how-to we use token-based authentication.

Set content of meta-config.json:

{
  "scanPeriod": 5000,
  "stores": [
    {
      "type": "classpath",
      "format": "json",
      "config": {
        "path": "config.json"
      }
    },
    {
      "type": "file",
      "format": "json",
      "config": {
        "path": "rules.json"
      }
    },
    {
      "type": "vault-ext",
      "format": "json",
      "config": {
        "host": "$env:VAULT_HOST:string",
        "port": "$env:VAULT_PORT:int:8200",
        "ssl": "$env:VAULT_SSL:boolean:false",
        "token": "$env:VAULT_TOKEN:string",
        "path": "$env:VAULT_SECRETS_PATH:string",
        "ext": {
          "outputPath": "secrets",
          "maskSecrets": true,
          "cache": "$env:?VAULT_SECRETS_CACHE:boolean"
        }
      }
    }
  ]
}

ext.outputPath value defines the root path of reference we will use. For example secret with key example can be referenced as secrets.example.

NOTE
Routing rules are read from rules.json file in /configs folder.

Set environment variables in envs file:

Name	Description
VAULT_HOST	host
VAULT_POST	port (default 8200)
VAULT_SSL	SSL enabled (default false)
VAULT_TOKEN	token
VAULT_SECRETS_PATH	secrets path
VAULT_SECRETS_CACHE	set to true if using one-time Vault token (default false)

Run Pyron with updated environment variables and meta-config.json.

Reference secrets in routing rules config

The snippet below configures a routing rule with secret reference:

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user",
          "requestPlugins": [
            {
              "name": "sample-verify-apikey",
              "conf": {
                "apiKey": "$ref:secrets.example"
              }
            }
          ]
        }
      ]
    }
  ]
}

Example:

If the secret API key was set with vault kv put secret/api-keys example=abc command then:

• VAULT_SECRETS_PATH environment variable should be set to secret/data/api-keys
• apiKey value in sample-verify-apikey plugin config is resolved to abc