NPM private git module on Heroku

I am trying to deploy my app to Heroku however I rely on using some private git repos as modules. I do this for code reuse between projects, e.g. I have a custom logger I use in multiple apps.

"logger":"git+ssh://[email protected]..............#master"

The problem is Heroku obviously does not have ssh access to this code. I can't find anything on this problem. Ideally Heroku have a public key I can can just add to the modules.

Basic auth

GitHub has support for basic auth:

"dependencies" : {
    "my-module" : "git+https://my_username:[email protected]/my_github_account/my_repo.git"
}

As does BitBucket:

"dependencies" : {
    "my-module": "git+https://my_username:[email protected]/my_bitbucket_account/my_repo.git"
}

But having plain passwords in your package.json is probably not desired.

Personal access tokens (GitHub)

To make this answer more up-to-date, I would now suggest using a personal access token on GitHub instead of username/password combo.

You should now use:

"dependencies" : {
    "my-module" : "git+https://<username>:<token>@github.com/my_github_account/my_repo.git"
}

For Github you can generate a new token here:

https://github.com/settings/tokens

App passwords (Bitbucket)

App passwords are primarily intended as a way to provide compatibility with apps that don't support two-factor authentication, and you can use them for this purpose as well. First, create an app password, then specify your dependency like this:

"dependencies" : {
    "my-module": "git+https://<username>:<app-password>@bitbucket.org/my_bitbucket_account/my_repo.git"
}

[Deprecated] API key for teams (Bitbucket)

For BitBucket you can generate an API Key on the Manage Team page and then use this URL:

"dependencies" : {
    "my-module" : "git+https://<teamname>:<api-key>@bitbucket.org/team_name/repo_name.git"
}

Update 2016-03-26

The method described no longer works if you are using npm3, since npm3 fetches all modules described in package.json before running the preinstall script. This has been confirmed as a bug.

The official node.js Heroku buildpack now includes heroku-prebuild and heroku-postbuild, which will be run before and after npm install respectively. You should use these scripts instead of preinstall and postinstall in all cases, to support both npm2 and npm3.

In other words, your package.json should resemble:

 "scripts": {
      "heroku-prebuild": "bash preinstall.sh",
      "heroku-postbuild": "bash postinstall.sh"
    }

---

I've come up with an alternative to Michael's answer, retaining the (IMO) favourable requirement of keeping your credentials out of source control, whilst not requiring a custom buildpack. This was borne out of frustration that the buildpack linked by Michael is rather out of date.

The solution is to setup and tear down the SSH environment in npm's preinstall and postinstall scripts, instead of in the buildpack.

Follow these instructions:

• Create two scripts in your repo, let's call them preinstall.sh and postinstall.sh.
• Make them executable (chmod +x *.sh).
• Add the following to preinstall.sh:

    #!/bin/bash
    # Generates an SSH config file for connections if a config var exists.

    if [ "$GIT_SSH_KEY" != "" ]; then
      echo "Detected SSH key for git. Adding SSH config" >&1
      echo "" >&1

      # Ensure we have an ssh folder
      if [ ! -d ~/.ssh ]; then
        mkdir -p ~/.ssh
        chmod 700 ~/.ssh
      fi

      # Load the private key into a file.
      echo $GIT_SSH_KEY | base64 --decode > ~/.ssh/deploy_key

      # Change the permissions on the file to
      # be read-only for this user.
      chmod 400 ~/.ssh/deploy_key

      # Setup the ssh config file.
      echo -e "Host github.com\n"\
              " IdentityFile ~/.ssh/deploy_key\n"\
              " IdentitiesOnly yes\n"\
              " UserKnownHostsFile=/dev/null\n"\
              " StrictHostKeyChecking no"\
              > ~/.ssh/config
    fi

• Add the following to postinstall.sh:

    #!/bin/bash

    if [ "$GIT_SSH_KEY" != "" ]; then
      echo "Cleaning up SSH config" >&1
      echo "" >&1

      # Now that npm has finished running, we shouldn't need the ssh key/config anymore.
      # Remove the files that we created.
      rm -f ~/.ssh/config
      rm -f ~/.ssh/deploy_key

      # Clear that sensitive key data from the environment
      export GIT_SSH_KEY=0
    fi

• Add the following to your package.json:

    "scripts": {
      "preinstall": "bash preinstall.sh",
      "postinstall": "bash postinstall.sh"
    }
  

• Generate a private/public key pair using ssh-agent.

• Add the public key as a deploy key on Github.

• Create a base64 encoded version of your private key, and set it as the Heroku config var GIT_SSH_KEY.

• Commit and push your app to Github.

When Heroku builds your app, before npm installs your dependencies, the preinstall.sh script is run. This creates a private key file from the decoded contents of the GIT_SSH_KEY environment variable, and creates an SSH config file to tell SSH to use this file when connecting to github.com. (If you are connecting to Bitbucket instead, then update the Host entry in preinstall.sh to bitbucket.org). npm then installs the modules using this SSH config. After installation, the private key is removed and the config is wiped.

This allows Heroku to pull down your private modules via SSH, while keeping the private key out of the codebase. If your private key becomes compromised, since it is just one half of a deploy key, you can revoke the public key in GitHub and regenerate the keypair.

As an aside, since GitHub deploy keys have read/write permissions, if you are hosting the module in a GitHub organization, you can instead create a read-only team and assign a 'deploy' user to it. The deploy user can then be configured with the public half of the keypair. This adds an extra layer of security to your module.

It's a REALLY bad idea to have plain text passwords in your git repo, using an access token is better, but you will still want to be super careful.

"my_module": "git+https://ACCESS_TOKEN:[email protected]/me/my_module.git"

I created a custom nodeJS buildpack that will allow you to specify an SSH key that is registered with ssh-agent and used by npm when dynos are first setup. It seamlessly allows you to specify your module as an ssh url in your package.json like shown:

"private_module": "git+ssh://[email protected]:me/my_module.git"

To setup your app to use your private key:

• Generate a key: ssh-keygen -t rsa -C "[email protected]" (Enter no passphrase. The buildpack does not support keys with passphrases)
• Add the public key to github: pbcopy < ~/.ssh/id_rsa.pub (in OS X) and paste the results into the github admin
• Add the private key to your heroku app's config: cat id_rsa | base64 | pbcopy, then heroku config:set GIT_SSH_KEY=<paste_here> --app your-app-name
• Setup your app to use the buildpack as described in the heroku nodeJS buildpack README included in the project. In summary the simplest way is to set a special config value with heroku config:set to the github url of the repository containing the desired buildpack. I'd recommend forking my version and linking to your own github fork, as I'm not promising to not change my buildpack.

My custom buildpack can be found here: https://github.com/thirdiron/heroku-buildpack-nodejs and it works for my system. Comments and pull requests are more than welcome.

Based on the answer from @fiznool I created a buildpack to solve this problem using a custom ssh key stored as an environment variable. As the buildpack is technology agnostic, it can be used to download dependencies using any tool like composer for php, bundler for ruby, npm for javascript, etc: https://github.com/simon0191/custom-ssh-key-buildpack

1. Add the buildpack to your app:

   $ heroku buildpacks:add --index 1 https://github.com/simon0191/custom-ssh-key-buildpack
   

2. Generate a new SSH key without passphrase (lets say you named it deploy_key)

3. Add the public key to your private repository account. For example:

   • Github: https://help.github.com/articles/adding-a-new-ssh-key-to-your-github-account/

   • Bitbucket: https://confluence.atlassian.com/bitbucket/add-an-ssh-key-to-an-account-302811853.html

4. Encode the private key as a base64 string and add it as the CUSTOM_SSH_KEY environment variable of the heroku app.

5. Make a comma separated list of the hosts for which the ssh key should be used and add it as the CUSTOM_SSH_KEY_HOSTS environment variable of the heroku app.

   # MacOS
   $ heroku config:set CUSTOM_SSH_KEY=$(base64 --input ~/.ssh/deploy_key) CUSTOM_SSH_KEY_HOSTS=bitbucket.org,github.com
   # Ubuntu
   $ heroku config:set CUSTOM_SSH_KEY=$(base64 ~/.ssh/deploy_key) CUSTOM_SSH_KEY_HOSTS=bitbucket.org,github.com
   

6. Deploy your app and enjoy :)

I was able to setup resolving of Github private repositories in Heroku build via Personal access tokens.

• Generate Github access token here: https://github.com/settings/tokens

• Set access token as Heroku config var: heroku config:set GITHUB_TOKEN=<paste_here> --app your-app-name or via Heroku Dashboard

• Add heroku-prebuild.sh script:

    #!/bin/bash
    if [ "$GITHUB_TOKEN" != "" ]; then
        echo "Detected GITHUB_TOKEN. Setting git config to use the security token" >&1
        git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf [email protected]:
    fi
  

• add the prebuild script to package.json:

    "scripts": {
        "heroku-prebuild": "bash heroku-prebuild.sh"
    }
  

For local environment we can also use git config ... or we can add the access token to ~/.netrc file:

machine github.com
  login PASTE_GITHUB_USERNAME_HERE
  password PASTE_GITHUB_TOKEN_HERE

and installing private github repos should work.

npm install OWNER/REPO --save will appear in package.json as: "REPO": "github:OWNER/REPO"

and resolving private repos in Heroku build should also work. optionally you can setup a postbuild script to unset the GITHUB_TOKEN.

This answer is good https://stackoverflow.com/a/29677091/6135922, but I changed a little bit preinstall script. Hope this will help someone.

#!/bin/bash
# Generates an SSH config file for connections if a config var exists.

echo "Preinstall"

if [ "$GIT_SSH_KEY" != "" ]; then
  echo "Detected SSH key for git. Adding SSH config" >&1
  echo "" >&1

  # Ensure we have an ssh folder
  if [ ! -d ~/.ssh ]; then
    mkdir -p ~/.ssh
    chmod 700 ~/.ssh
  fi

  # Load the private key into a file.
  echo $GIT_SSH_KEY | base64 --decode > ~/.ssh/deploy_key

  # Change the permissions on the file to
  # be read-only for this user.
  chmod o-w ~/
  chmod 700 ~/.ssh
  chmod 600 ~/.ssh/deploy_key

  # Setup the ssh config file.
  echo -e "Host bitbucket.org\n"\
          " IdentityFile ~/.ssh/deploy_key\n"\
          " HostName bitbucket.org\n" \
          " IdentitiesOnly yes\n"\
          " UserKnownHostsFile=/dev/null\n"\
          " StrictHostKeyChecking no"\
          > ~/.ssh/config

  echo "eval `ssh-agent -s`"
  eval `ssh-agent -s`

  echo "ssh-add -l"
  ssh-add -l

  echo "ssh-add ~/.ssh/deploy_key"
  ssh-add ~/.ssh/deploy_key

  # uncomment to check that everything works just fine
  # ssh -v [email protected]
fi

You can use in package.json private repository with authentication example below:

https://usernamegit:[email protected]/reponame/web/tarball/branchname

In short it is not possible. The best solution to this problem I came up with is to use the new git subtree's. At the time of writing they are not in the official git source and so needs to be installed manual but they will be included in v1.7.11. At the moment it is available on homebrew and apt-get. it is then a case of doing

git subtree add -P /node_modules/someprivatemodue git@github.......someprivatemodule {master|tag|commit}

this bulks out the repo size but an update is easy by doing the command above with gitsubtree pull.

I have done this before with modules from github. Npm currently accepts the name of the package or a link to a tar.gz file which contains the package.

For example if you want to use express.js directly from Github (grab the link via the download section) you could do:

"dependencies" : {
  "express"   :  "https://github.com/visionmedia/express/tarball/2.5.9"
}

So you need to find a way to access you repository as a tar.gz file via http(s).