WARNING

Implementing this is highly dangerous unless you fully control the repository and its contents. Proceed with caution.

Purpose

1. Feasibility Test: Assess the practicality of implementing a post-clone action in Git repositories.
2. Tool Automation: Facilitate the automatic addition of tools (like git hooks) to repositories, enhancing our existing setup-hooks script.

Implementation

Overload Git Command

Modify your shell profile to replace the native git command with a custom wrapper. This can be achieved by adding the following to your .bash_profile, .bashrc or .bash_aliases.

function git()
{
    command git-wrapper "$@"
}

Git Wrapper Script

Create a git-wrapper script that manages the cloning process and triggers a post-clone action. This scripts needs to be able to run from anywhere, we recommend placing it in your ~/bin directory or any other directory that is part of your $PATH.

#!/usr/bin/env bash

function get_git_root()
{
    local repo

    IFS=' ' read -r -a array <<< "$@"

    repo=${array[-1]}
    repo=${repo##*/}
    repo=${repo%%.*}
    realpath "${repo}"
}

function main()
{
    if [[ $1 == "clone" ]]; then
        shift

        if command git clone "$@"; then
            root=$(get_git_root "$@")
            if [[ -d "${root}" ]]; then
                command post-clone "$root"
            fi
        fi
     else
        command git "$@";
     fi
}

main "$@"

Post-clone Script

Create a post-clone script which is executed by the git wrapper. This script also needs to be able to run from anywhere, we recommend placing it in your ~/bin directory or any other directory that is part of your $PATH.

#!/usr/bin/env bash

cd $1
echo $PWD

In this example we simply have the script echoing the current directory to show that it is indeed executing inside the newly cloned repository.

Real World Example

Expand the post-clone script to execute additional scripts.

#!/usr/bin/env bash

cd $1
bash repo-post-clone.sh

This is a very overly-simplified example!

Security Measures

To prevent unauthorized modifications:

1. Repository Whitelist: Ensure the repository is in a list of approved repositories.
2. Ownership Verification: Extend checks to verify the repository's owning organization.

Example with Security Checks

#!/usr/bin/env bash

safe_repos=("GitToolbox/post-clone")

# Function to check if a value is in an array
function not_in()
{
  local array="$1[@]"
  local seeking="$2"
  local in=0

  for element in "${!array}"; do
      if [[ "$element" == "$seeking" ]]; then
        in=1
        break
      fi
    done
  return $in
}

cd $1

# Get the remote URL of the repository
remote_url=$(git config --get remote.origin.url)

# Check if remote_url is empty
if [ -z "$remote_url" ]; then
    echo "This directory is not a Git repository or has no remote origin set. Aborting!"
    exit 1
fi

# Extract the org and repo name from the URL
# Support different URL formats (HTTPS and SSH)

if [[ $remote_url =~ ^https:// ]]; then
    # HTTPS URL format: https://github.com/org/repo.git
    org_name=$(echo "$remote_url" | awk -F'/' '{print $(NF-1)}')
    repo_name=$(echo "$remote_url" | awk -F'/' '{print $NF}' | sed 's/.git$//')
elif [[ $remote_url =~ ^git@ ]]; then
    # SSH URL format: git@github.com:org/repo.git
    org_name=$(echo "$remote_url" | awk -F'[/:]' '{print $(NF-1)}')
    repo_name=$(echo "$remote_url" | awk -F'[/:]' '{print $NF}' | sed 's/.git$//')
else
    echo "Unsupported URL format. Aborting!"
    exit 1
fi

if not_in safe_repos "$org_name/$repo_name"; then
    echo "This is not from an a safe source - Aborting!"
    exit 1
fi

echo "Executing post-clone.sh in ${org_name}/${repo_name}"
bash repo-post-clone.sh

Conclusion

Use these scripts with caution and implement security checks to avoid potential misuse. Ensure thorough testing in a controlled environment.