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Heroku Deployment

Lesson Objectives​

  1. Make a new github repository
  2. Create a basic express app
  3. set up environmental variables
  4. Remove node_modules
  5. Get started with Heroku
  6. Create app on heroku
  7. Attach mongolab addon
  8. Update code for heroku & mongolab
  9. Push git to heroku

New Github Repository​

This is going to be a portfolio piece so you'll want it hosted on regular github.

Make a new repo! Click the + on the upper right navigation bar

new repo

Choose​

  • a repository name
  • public (let your instructors help you if you get stuck, you can always change this later)
  • initialize with a README
  • Add .gitignore scroll down and choose Node
  • license - optional

Press the Create Repository button when you're ready!

Clone Your New Repository to Your Computer​

In Terminal​

  • navigate OUTSIDE the class repository

  • check you are not already in a git repository

    • GOOD -

    not a repo

  • BAD -

    find a new location for your project!

    already a repo

On Github​

  • click the Clone or Download button
  • check if you are grabbing the right url for https or ssh
  • click the clipboard button

clone or download

In Terminal type git clone and then paste the URL that you copied from github

Should look something like this

clone command in terminal

  • Important! Don't forget to cd into your new directory/repo!
  • ls -a - you should see your README.md and .gitignore that you created on github

Basic Express App​

Let's build a basic express app

  • touch server.js
  • npm init
  • npm install express mongoose method-override

Check out package.json make sure everything looks as expected

package.json

Set the Node Engine​

You should always specify a Node.js version that matches the runtime you're developing and testing with. Without setting this, Heroku will 'guess' a version Node.js for you. One big gotcha is that some newer/updated npm packages just won't run on an older version of Node.js and vice versa.

So let's set the correct version:

In Terminal II​

node --version

The line returned is the version, currently, I have v10.11.0, but you should set it to whatever your version is.

In package.json, you can add engines anywhere, just make sure you don't break the JSON format. In this example we are putting it between the auto-generated version and description fields. Don't forget double quotes and a ,

package.json
  "version": "1.0.0",
  "engines": {
    "node": "10.11.0"
  },
  "description": "",

in server.js​


Test your app​

  • If your express app doesn't run locally it definitely won't run on Heroku!
  • test it out and fix any bugs

git add/git commit​

  • git add .
  • git commit -m 'first commit'
  • git push origin master

Check this step carefully! Make sure node_modules are NOT on github!! If they made it to github, that means they are not being ignored by .gitignore. If you don't properly ignore them now you'll have massive headaches with heroku later!

If You Need to Remove node_modules​

In order for heroku to work, you can't have node_modules in your repo. Instead, heroku will add this dir itself!

  1. go to local repo dir
  2. rm -r node_modules
  3. git: add, commit, push
  4. touch .gitignore
  5. atom .gitignore
  6. add a line that says just node_modules to .gitignore
  7. save .gitignore
  8. git: add, commit, push
  9. to get it working locally again: npm install

Get started with Heroku​

  • Sign up for Heroku
    • You may need a CC at some point although you will not be charged
  • Install Heroku CLI Tools
    • Verify by typing heroku login anywhere in your terminal
    • Follow prompts to sync up your heroku credentials, DO NOT HEROKU CREATE yet.

Create an app on heroku​

  • Once you have Heroku CLI, you can access terminal commands to heroku.
  • Let's start by creating an app on heroku. If you don't yet have a name for your app it's ok, you can change it later (just make sure you update your git remotes too)
    • heroku create [unique name] from your project's root directory where you first initialized git. This will check heroku to see if the app name exists, if so you'll get an error message and have to try again.
    • If you don't specify a name, heroku will generate a unique name for you. There names are pretty cool and somewhat thematic so feel free to do either.
    • You can also do this step off their website if you want but since you'll be working in terminal anyway, might as well just do it through terminal.
    • Notice that if you successfully created a heroku app, you can see that the heroku remote was automatically added to your project's repo. Confirm this by typing git remote -v, you should see origin as well as heroku.

Attach mongolab addon​

Now that you've partitioned an app on heroku's side, you need to attach a free addon called mongolab (mLab). Mongolab provides you with heroku's version of mongodb. Up until now, we've just been using express on local connecting to our local mongodb. Now we need to connect our heroku app onto heroku's version of mongodb.

  • Go to heroku and login, then hit personal apps (https://dashboard.heroku.com/apps), click on your new app, then click on the resources tab.
    • Search for mLab and add the free version Sandbox.

Push Git​

  • First update your remote repo so you're code is up to date.
    • git add -A
    • git commit -m "updating code for heroku"
    • git push origin master
  • Now also push to heroku
    • git push heroku master

Wait 1 minute then type heroku open. You should have your deployed app open up in your browser.

  • If thing's don't work out, relax and try to find out the error.
  • heroku logs

Troubleshooting​

Having weird errors?​

Heroku Can't Figure Out Your Language​

  • the hidden folder .git and package.json MUST be on the same level in your directory (the root)
  • if it is a Rails app, .git and GemFile MUST be on the same level in your directory (the root)
  • move your files up to .git accordingly

Check that your have ignored node modules​

Your node modules should NOT appear on github

no node modules

If you have not ignored your node modules, follow the steps listed above to remove and ignore them

Heroku recommends setting the proper node version​

scroll down for an example

Check that your config variables match​

In heroku, under your app and its settings, Reveal Config Vars

reveal config vars

In the above example -

In your own app, make sure you have your mongo uri equal to process.env and then .MONGODB_URI

const mongoURI = process.env.MONGODB_URI

It won't work if you make it a different variable name (lowercase, no underscore) - do not change it in heroku! If you change it in heroku you'll have to hunt how to update more things. Just set it in your own app.

Note: your the variable for the port is not listed, but it must be PORT all caps. It is accessed by process.env.PORT

You Need to Add More Config Variables​

Using the NPM package dotenv? If you've added new variables, like SECRET, be sure to add those custom config variables

  • In heroku, under your app and its settings, Reveal Config Vars

Otherwise you might be looking at a Internal server error

reveal config vars

You must make the variable names match.

You changed your heroku URL​

If you changed your app name, you'll have to update the git remote url. Get the right url from heroku (see towards the bottom

right url

In terminal, in your repo

  • git remote -v (should have origin and heroku)
  • git remote remove heroku
  • git remote add heroku whateverURLherokuListed

You changed your github project name​

changed github project name

Go back to the main code view and grab the url from the clone or download button

git clone

  • git remote -v (should have origin and heroku)
  • git remote remove origin
  • git remote add origin whateverURLgithubListed

Cannot read filetype MIME re: CSS file​

  • your CSS file is not linked properly/cannot be found/named incorrectly (working locally? see next issue)
  • you have a mismatch in opening/closing HTML tags

Cannot find a file but it is there??? You think you might have changed it?​

There is weirdness. If you had named your file Index.html and then changed it to index.html git, by default, will ignore this change.

Locally, you'll see index.html (your updated name). But if you go to github, you'll see it's still Index.html. This will 'confuse' heroku as well.

First try to use git to change the name:

git mv -f Index.html index.html

Success?

changed file name

go ahead and git add . git commit -m 'file name changed'

If that fails,

  • touch tempfile,
  • copy paste your code from the offending file in there
  • rm the offending file
  • git add . git commit -m 'removed Index.html
  • touch index.html
  • git add . git commit -m 'added index.html

The data from your database is not in sync with your heroku version​

git/github/heroku does NOT track and sync things in your database. Your local version and heroku are two separate instances and you cannot sync them with git.

You must add/change things manually.

mLab has a nice GUI, where you can make changes

mLab

On the other hand, Postgres does not. You must connect to it via heroku ie heroku pg:psql