Take a configuration stored in SSM as a series of hierarchical path / value pairs and return it as an object

configFromSsm.ts

// Take a configuration stored in SSM as a series of hierarchical path / value pairs and return it as an object
import {
  GetParametersByPathCommand,
  GetParametersByPathCommandOutput,
  SSMClient,
} from '@aws-sdk/client-ssm

async function getBackupConfig = async (parameterRoot: string) => {
  const ssm = new SSMClient({})
  let NextToken: string
  const config = {}
  while (true) {
    let res: GetParametersByPathCommandOutput
    try {
      res = await ssm.send(
        new GetParametersByPathCommand({
          Path: parameterRoot,
          Recursive: true,
          NextToken,
        })
      )
    } catch (e) {
      e.message = `Failed to get config: ${e}`
      throw e
    }

    for (let param of res.Parameters) {
      let { Name, Value } = param
      Name = Name.replace(new RegExp(`^${parameterRoot}`), '')
      let bits = Name.split('/')
      let ptr: unknown = config
      for (let i = 0; i < bits.length; i++) {
        let bit = bits[i].toLowerCase()
        if (i === bits.length - 1) {
          ptr[bit] = Value
        } else {
          if (!ptr[bit]) {
            ptr[bit] = {}
          }
          ptr = ptr[bit]
        }
      }
    }
    NextToken = res.NextToken
    if (!NextToken) {
      break
    }
  }
  return config
}