Razzle: How to use environment variables at runtime?

[alex2]

I've just started using Razzle but it seems like a webpack DefinePlugin is stripping out all the environment variables at runtime and replacing them with pre-baked ones. Since environment variables are the standard way to configure applications in different environments (e.g. heroku, lambda, all 12-factor compatible hosting) I assume there's something I'm missing. Do you have any advice for how to stop razzle replacing everything in process.env?

Many thanks

[iamrommel]

I second the motion for @alex2 claim, I just found out that it really really replaces the existing process.env because of that DefinePlugin,

I need it NOT be overwritten too

[whs]

What I do is by breaking static analysis:

let proc = process;
module.exports = proc.exports;

Then require('./env').RUNTIME_ENV

[ikappas]

I've personally struggled with this issue and spend several hours figuring out a solution to this issue.

This is inherent to webpack compilation and not related to razzle it self.

After looking into how create-react-app handles this, and porting some javascript and ruby code, across two projects, I've successfully deployed a razzle typescript react app in a docker container on heroku with the following solution:

env.ts

This script is used as a module to handle runtime env.

export interface EnvironmentStore {
  NODE_ENV?: string;
  [key: string]: string | undefined;
}

// Capture environment as module variable to allow testing.
let compileTimeEnv: EnvironmentStore;
try {
  compileTimeEnv = process.env as EnvironmentStore;
} catch (error) {
  compileTimeEnv = {};
  // tslint:disable-next-line no-console
  console.log(
    '`process.env` is not defined. ' +
    'Compile-time environment will be empty.'
  );
}

// This template tag should be rendered/replaced with the environment in production.
// Padded to 4KB so that the data can be inserted without offsetting character
// indexes of the bundle (avoids breaking source maps).
/* tslint:disable:max-line-length */
const runtimeEnv = '{{RAZZLE_VARS_AS_BASE64_JSON__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________}}';
/* tslint:enable:max-line-length */

// A function returning the runtime environment, so that
// JSON parsing & errors occur at runtime instead of load time.
export const loadRuntimeEnv = (): EnvironmentStore => {
  let env;
  if (typeof env === 'undefined') {
    if (compileTimeEnv.NODE_ENV === 'production') {
      try {
        env = JSON.parse((Buffer.from(runtimeEnv.trim(), 'base64').toString()));
      } catch (error) {
        env = {};
        const overflowsMessage = runtimeEnv.slice(32, 33) !== null;
        // tslint:disable-next-line no-console
        console.error(
          'Runtime env vars cannot be parsed. Content is `%s`',
          runtimeEnv.slice(0, 31) + (overflowsMessage ? '…' : '')
        );
      }

    } else {
      env = compileTimeEnv;
    }
  }
  return env;
};

export default loadRuntimeEnv;

usage:

import { loadRuntimeEnv, EnvironmentStore } from './env';
const env: EnvironmentStore = loadRuntimeEnv();

const serverHost: string =env.RAZZLE_SERVER_HOST || 'localhost';

docker-start.js

This script is used as the entrypoint point instead of server.js and is used to inject {{RAZZLE_VARS_AS_BASE64_JSON___... }} placehoder with the actual runtime environment variables.

require('newrelic');
const logger = require('heroku-logger');
const path = require('path');
const fs = require('fs');

const PLACEHOLDER = /\{\{RAZZLE_VARS_AS_BASE64_JSON_*?\}\}/;
const MATCHER = /^RAZZLE_/i;

const InjectableEnv = {

    inject: function(file, ...args) {

        const buffer = fs.readFileSync(file, { encoding: 'utf-8' });
        let injectee = buffer.toString();

        const matches = injectee.match(PLACEHOLDER);
        if (!matches) {
            return;
        }

        const placeholderSize = matches[0].length;

        let env = InjectableEnv.create(args);
        const envSize = env.length;
        const newPadding = placeholderSize - envSize;
        if (newPadding < 0) {
            console.log('You need to increase your placeholder size');
            process.exit();
        }
        const padding = Array(newPadding).join(' ');
        env = InjectableEnv.pad(padding, env);

        const injected = injectee.replace(PLACEHOLDER, env);

        fs.writeFileSync(file, injected, { encoding: 'utf-8' });
    },

    create: function() {

        const vars = Object.keys(process.env)
            .filter(key => MATCHER.test(key))
            .reduce((env, key) => {
                env[key] = process.env[key];
                return env;
            }, {});

        vars.NODE_ENV = process.env.NODE_ENV;

        if (typeof process.env.HOST !== 'undefined' && typeof vars.RAZZLE_SERVER_HOST === 'undefined') {
          vars.RAZZLE_SERVER_HOST = process.env.HOST;
        }

        if (typeof process.env.PORT !== 'undefined' && typeof vars.RAZZLE_SERVER_PORT === 'undefined') {
          vars.RAZZLE_SERVER_PORT = process.env.PORT;
        }

        if (typeof process.env.REDIS_URL !== 'undefined' && typeof vars.RAZZLE_REDIS_URL === 'undefined') {
          vars.RAZZLE_REDIS_URL = process.env.REDIS_URL;
        }

        return Buffer.from(JSON.stringify(vars)).toString('base64');
    },

    pad: function(pad, str, padLeft) {
        if (typeof str === 'undefined')
            return pad;
        if (padLeft) {
            return (pad + str).slice(-pad.length);
        } else {
            return (str + pad).substring(0, pad.length);
        }
    }
}

const root = process.cwd();
const serverBundle = path.resolve(path.join(root, '/build/server.js'));

if (fs.existsSync(serverBundle)) {
    logger.info('Injecting runtime env');
    InjectableEnv.inject(serverBundle);
    logger.info('Launching server instance');
    require(serverBundle);
}

Dockerfile

# You should always specify a full version here to ensure all of your developers
# are running the same version of Node.
FROM node:8.9.4

ENV NODE_ENV=production \
    REACT_BUNDLE_PATH=/static/js/vendor.js \
    PATH=/app/node_modules/.bin:$PATH \
    NPM_CONFIG_LOGLEVEL=warn

RUN curl -o- -L https://yarnpkg.com/install.sh | bash

# use changes to package.json to force Docker not to use the cache
# when we change our application's nodejs dependencies:
COPY package.json yarn.lock /tmp/
RUN cd /tmp \
  && yarn install --production=false --pure-lockfile \
  && mkdir -p /app \
  && cp -a /tmp/node_modules /app \
  && yarn cache clean \
  && rm -rf *.*

# From here we load our application's code in, therefore the previous docker
# "layer" thats been cached will be used if possible
WORKDIR /app
ADD . /app

RUN yarn build

EXPOSE 3000

CMD ["node", "docker-start.js"]

Please note that the overflow message processing is not finished, but I hope this helps

References:

Heroku Buildpack for create-react-app
Inner layer of Heroku Buildpack for create-react-app

[ikappas]

Not relevant to the issue but here is the Dockerfile for completeness:

# You should always specify a full version here to ensure all of your developers
# are running the same version of Node.
FROM node:8.9.4

ENV NODE_ENV=production \
    REACT_BUNDLE_PATH=/static/js/vendor.js \
    PATH=/app/node_modules/.bin:$PATH \
    NPM_CONFIG_LOGLEVEL=warn

RUN curl -o- -L https://yarnpkg.com/install.sh | bash

# use changes to package.json to force Docker not to use the cache
# when we change our application's nodejs dependencies:
COPY package.json yarn.lock /tmp/
RUN cd /tmp \
  && yarn install --production=false --pure-lockfile \
  && mkdir -p /app \
  && cp -a /tmp/node_modules /app \
  && yarn cache clean \
  && rm -rf *.*

# From here we load our application's code in, therefore the previous docker
# "layer" thats been cached will be used if possible
WORKDIR /app
ADD . /app

RUN yarn build

EXPOSE 3000

CMD ["node", "docker-start.js"]

[ikappas]

@jaredpalmer Can you have a look at this and see whether this solution can be used to solve #356, #394 and this issue in razzle or a child package?

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[HamidTanhaei]

if anyone want to use .env variables in client side in runtime, use this little package.
https://www.npmjs.com/package/razzle-plugin-runtimeenv

[albert-the-creator]

I came across this during a google search for an issue related to this. Full disclosure: im not using razzle but I think this might be helpful.

A way to circumvent webpack's replacement of process.env is to access the env vars in a different way.

You can access it via

const env = process['env']; 
console.log(env.RUNTIME_VAR); // should be var passed in at runtime

or by importing process... import * as process from 'process'; basically, any way other than process.env

DefinePlugin only replaces free variables

[HamidTanhaei]

@albert-the-creator Razzle clear env variable's during development in browser area.