index.js

const core = require("@actions/core");
const ssm = require("./ssm-helper");
const fs = require("fs");

async function run_action() {
  try {
    const ssmPath = core.getInput("ssm-path", { required: true });
    const getChildren = core.getInput("get-children") === "true";
    const prefix = core.getInput("prefix");
    const region = process.env.AWS_DEFAULT_REGION;
    const decryption = core.getInput("decryption") === "true";
    const maskValues = core.getInput("mask-values") === "true";

    const out = core.getInput("out", { required: false }) || ".env";
    const params = await ssm.getParameters(
      ssmPath,
      getChildren,
      decryption,
      region
    );
    const envs = [];
    for (let param of params) {
      console.log("param: ", param);
      const parsedValue = parseValue(param.Value);
      if (typeof parsedValue === "object") {
        console.log(`parsedValue: ${JSON.stringify(parsedValue)}`);
        // Assume basic JSON structure
        for (var key in parsedValue) {
          setEnvironmentVar(prefix + key, parsedValue[key], maskValues);
          envs.push(`${prefix + key}=${parsedValue[key]}`);
        }
      } else {
        console.log(`parsedValue: ${parsedValue}`);
        // Set environment variable with ssmPath name as the env variable
        var split = param.Name.split("/");
        var envVarName = prefix + split[split.length - 1];
        console.log(
          `Using prefix + end of ssmPath for env var name: ${envVarName}`
        );
        setEnvironmentVar(envVarName, parsedValue, maskValues);
        envs.push(`${envVarName}=${parsedValue}`);
      }
    }
    writeEnvFile(out, envs);
  } catch (e) {
    core.setFailed(e.message);
  }
}

function writeEnvFile(output, envs) {
  if (fs.existsSync(output)) {
    console.log(`append to ${output} file`);
    fs.appendFileSync(output, "\n" + envs.join("\n"));
  } else {
    console.log(`create ${output} file`);
    fs.writeFileSync(output, envs.join("\n"));
  }
}

function parseValue(val) {
  try {
    return JSON.parse(val);
  } catch {
    console.log(
      "JSON parse failed - assuming parameter is to be taken as a string literal"
    );
    return val;
  }
}

function setEnvironmentVar(key, value, maskValue) {
  if (maskValue) {
    core.setSecret(value);
  }
  core.exportVariable(key, value);
}

run_action();