Tag Archives: Git

Heroku deploy sub-directory

Going through a couple of Udemy courses, and figured it was nice to keep all the code I wrote while doing them in a single github repository.

Was working nicely until I started the Node with React where part of the course is to deploy the app to Heroku which wants a full repository pushed to a certain git repo it creates for deployment. But in my case the app I want to deploy is of course a sub-directory…

Turns out there’s a git command called subtree one can use here:

# Setup
heroku login
heroku create

git remote add heroku/some-name https://git.heroku.com/{created-heroku-app-id}.git

# Deploy
git subtree push --force --prefix path/to/app heroku/some-name master

The subtree command needs to be run from the top-level directory of the git repository, but one can add a script command to the apps package.json, for example like this:

{
  "scripts": {
    "deploy": "cd ../../.. && git subtree push --prefix path/to/app heroku/some-name master"
  }
}

Unfortunately, subtree push doesn’t support --force, but a workaround for that is running it nested like this:

git push heroku/some-name `git subtree split --prefix path/to/app master`:master --force

Which unfortunately doesn’t work on Windows… but you can do it in two steps instead:

git subtree split --prefix path/to/app master
git push heroku/some-name {id-from-previous-command}:master --force

Stop Git from messing with my newlines

I’m sorry, but I just hate when Git is messing with my files…

warning: CRLF will be replaced by LF in some/file.ext.
The file will have its original line endings in your working directory.

That’s just not its job! If I want to enforce a certain new line regime, there’s linting tools, pre-commit hooks, etc.

The following should stop it, but frankly, sometimes it feels like git just keeps inventing new ways of reverting to its hyper annoying default…

# First run this to see where it's configured now
> git config --list --show-origin

# Then run whichever works...
> git config --global core.autocrlf false
> git config --system core.autocrlf false
> git config --local core.autocrlf false

Using SSH keys with GitHub / BitBucket / Azure DevOps on Windows

Couldn’t get this to work, but now it does, so… time for another “note to self”. 🙂

Prerequisites

  • Git, obviously…
  • PuTTY, with puttygen, plink and pageant, to be exact…

Setup

  1. Open puttygen.

  2. Either Load an existing private key, or Generate a new one.

  3. Copy the public key (“Public key for pasting …”) and add it to the git provider settings:

    • https://github.com/settings/keys
    • https://bitbucket.org/account/user/[username]/ssh-keys/
    • https://dev.azure.com/[organization]/_usersSettings/keys
  4. Open pageant.

  5. Load your private key.

  6. Check that the key authentication works with plink:

    plink -v git@github.com
    plink -v git@bitbucket.org
    plink -v git@ssh.dev.azure.com
  7. Set the GIT_SSH environment variable to C:\Program Files\PuTTY\plink.exe.

    ^^ This is the detail that so many StackOverflow answers and blog/forum posts didn’t mention. Without this, plink worked fine, but git commands still failed with authentication errors.

  8. (optional) Add a shortcut to the private key file to your startup folder. This way pageant will be automatically started, with your key, ready to go, whenever Windows boots up.

    start shell:startup

Usage

Now, as long as pageant is running with your private key loaded, it should work to clone, pull, push, etc., both to and from, both private and public git repositories. E.g. like this:

git clone git@github.com:example/some-private-repo.git

Note: If you’re asked to accept/store/cache a key, but pressing y doesn’t work, connect using putty first, which should give you a dialog with the same question which does work. Putty will complain/crash because there’s not actually an ssh shell to connect to, but that’s fine. After the key has been saved by putty, git should work fine. E.g. like this:

putty -ssh git@github.com

Sources: makandracards.com, vladmihalcea.com

Setting up GPG signing for Git/GitHub on Windows

What I did to get from working GPG to green and verified signatures for Git commits and tags on GitHub.

  1. Find the long id of the Signing key we want to use:
    🔶 > gpg --edit-key alice
    gpg (GnuPG) 2.0.30; Copyright (C) 2015 Free Software Foundation, Inc.
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.

    Secret key is available.

    pub  4096R/AA79CCAE  created: 2017-08-23  expires: never       usage: SC
                         trust: ultimate      validity: ultimate
    sub  4096R/62275E24  created: 2017-08-23  expires: never       usage: S 👈
    sub  4096R/4AEA9524  created: 2017-08-23  expires: never       usage: E
    [ultimate] (1). Alice Person (alice) <alice.person@example.com>
    [ultimate] (2)  Alice Person (alice) <alice@example.org>

    🔶 gpg> quit

    🔶 > gpg --list-secret-keys --keyid-format LONG alice
    sec   4096R/8C0BBECBAA79CCAE 2017-08-23
    uid                          Alice Person (alice) <alice.person@example.com>
    uid                          Alice Person (alice) <alice@example.org>
    ssb   4096R/6ADB9D4262275E24 2017-08-23 👈
    ssb   4096R/33F2E1644AEA9524 2017-08-23

    Note: So in this case we want 6ADB9D4262275E24

  2. Configure git and (optionally) make it sign commits and tags by default:
    🔷 > git config --global user.name "Alice Person"
    🔷 > git config --global user.email "alice.person@example.com"
    🔶 > git config --global user.signingkey "6ADB9D4262275E24"
    🔷 > git config --global commit.gpgsign true
    🔷 > git config --global tag.forceSignAnnotated true
    🔷 > git config --global push.gpgsign if-asked
    🔶 > where gpg
    C:\Program Files (x86)\GNU\GnuPG\pub\gpg.exe
    🔶 > git config --global gpg.program "C:/Program Files (x86)/GNU/GnuPG/pub/gpg.exe"
    🔶 > echo no-tty >> %APPDATA%\gnupg\gpg.conf

    Note: If repo specific, just skip --global and run the command in the repo instead.

Test it…

  1. Do a commit:
    🔷 > git init gpg-test
    🔷 > cd gpg-test
    🔷 > touch file.txt
    🔶 > git commit -a -m "Signed commit"
    [master (root-commit) 2814856] Signed commit
     1 file changed, 0 insertions(+), 0 deletions(-)
     create mode 100644 file.txt

    Note: If not using commit.gpgsign true, one can also use -S to explicitly sign a commit.

  2. Verify commit was signed:
    🔷 > git log --show-signature
    commit 2814856365a07b3deb374f1337258102c06b77ef
    gpg: Signature made 08/23/17 06:18:50 W. Europe Daylight Time^M
    gpg:                using RSA key 6ADB9D4262275E24^M
    gpg: Good signature from "Alice Person (alice) <alice.person@example.com>" [ultimate]^M
    gpg:                 aka "Alice Person (alice) <alice@example.org>" [ultimate]^M
    Author: Alice Person <alice.person@example.com>
    Date:   Wed Aug 23 06:18:48 2017 +0200

        Signed commit
  3. Add a signed tag, using -s:
    🔶 > git tag v1 -m "Signed tag"

    Note: If not using tag.forceSignAnnotated true, one can also use -s to explicitly sign a tag.

  4. Verify tag was signed:
    🔷 > git tag -v v1
    gpg: Signature made 08/23/17 06:34:18 W. Europe Daylight Time
    gpg:                using RSA key 6ADB9D4262275E24
    gpg: Good signature from "Alice Person (alice) <alice.person@example.com>" [ultimate]
    gpg:                 aka "Alice Person (alice) <alice@example.org>" [ultimate]
    object 53e7f2e637eaf3c47b5dcad30b57be7b6829be02
    type commit
    tag v1
    tagger Alice Person <alice.person@example.com> 1503462856 +0200

    Signed tag

Add GPG key to GitHub

  1. Export the public key:
    🔶 gpg -a --export alice > public.txt
  2. Copy it.
  3. Go to GPG keys on GitHub.
  4. New GPG Key.
  5. Paste it.
  6. Add GPG Key.
  7. Pushed commits and tags should now look verified, as in this post: GPG signature verification

Sources: help.github.com, StackOverflow, git-scm.com