From 85d0a458c25e8fcc976f94f40178489497fd64d8 Mon Sep 17 00:00:00 2001
From: teor <teor@torproject.org>
Date: Thu, 17 Oct 2019 13:52:05 +1000
Subject: [PATCH] scripts: Add git-setup-dirs.sh, which sets up maintainer git
 repos

git-setup-dirs.sh sets up an upstream git repository and worktrees,
so that tor maintainers can do merges.

Closes ticket 29603.
---
 scripts/git/git-setup-dirs.sh | 510 ++++++++++++++++++++++++++++++++++
 1 file changed, 510 insertions(+)
 create mode 100755 scripts/git/git-setup-dirs.sh

diff --git a/scripts/git/git-setup-dirs.sh b/scripts/git/git-setup-dirs.sh
new file mode 100755
index 0000000000..87779c7304
--- /dev/null
+++ b/scripts/git/git-setup-dirs.sh
@@ -0,0 +1,510 @@
+#!/usr/bin/env bash
+
+SCRIPT_NAME=`basename $0`
+
+function usage()
+{
+  echo "$SCRIPT_NAME [-h] [-n] [-u]"
+  echo
+  echo "  arguments:"
+  echo "   -h: show this help text"
+  echo "   -n: dry run mode"
+  echo "       (default: run commands)"
+  echo "   -u: if a directory or worktree already exists, use it"
+  echo "       (default: fail and exit on existing directories)"
+  echo
+  echo " env vars:"
+  echo "   required:"
+  echo "   TOR_FULL_GIT_PATH: where the git repository directories reside."
+  echo "       You must set this env var, we recommend \$HOME/git/"
+  echo "       (default: fail if this env var is not set;"
+  echo "       current: $GIT_PATH)"
+  echo
+  echo "   optional:"
+  echo "   TOR_MASTER: the name of the directory containing the tor.git clone"
+  echo "       The tor master git directory is \$GIT_PATH/\$TOR_MASTER"
+  echo "       (default: tor; current: $TOR_MASTER_NAME)"
+  echo "   TOR_WKT_NAME: the name of the directory containing the tor"
+  echo "       worktrees. The tor worktrees are:"
+  echo "       \$GIT_PATH/\$TOR_WKT_NAME/{maint-*,release-*}"
+  echo "       (default: tor-wkt; current: $TOR_WKT_NAME)"
+  echo "   TOR_GIT_ORIGIN_PULL: the origin remote pull URL."
+  echo "       (current: $GIT_ORIGIN_PULL)"
+  echo "   TOR_GIT_ORIGIN_PUSH: the origin remote push URL"
+  echo "       (current: $GIT_ORIGIN_PUSH)"
+  echo "   TOR_UPSTREAM_REMOTE_NAME: the default upstream remote."
+  echo "       If \$TOR_UPSTREAM_REMOTE_NAME is not 'origin', we have a"
+  echo "       separate upstream remote, and we don't push to origin."
+  echo "       (default: $DEFAULT_UPSTREAM_REMOTE)"
+  echo "   TOR_GITHUB_PULL: the tor-github remote pull URL"
+  echo "       (current: $GITHUB_PULL)"
+  echo "   TOR_GITHUB_PUSH: the tor-github remote push URL"
+  echo "       (current: $GITHUB_PUSH)"
+  echo "   we recommend that you set these env vars in your ~/.profile"
+}
+
+#################
+# Configuration #
+#################
+
+# Don't change this configuration - set the env vars in your .profile
+
+# Where are all those git repositories?
+GIT_PATH=${TOR_FULL_GIT_PATH:-"FULL_PATH_TO_GIT_REPOSITORY_DIRECTORY"}
+# The tor master git repository directory from which all the worktree have
+# been created.
+TOR_MASTER_NAME=${TOR_MASTER_NAME:-"tor"}
+# The worktrees location (directory).
+TOR_WKT_NAME=${TOR_WKT_NAME:-"tor-wkt"}
+
+# Origin repositories
+GIT_ORIGIN_PULL=${TOR_GIT_ORIGIN_PULL:-"https://git.torproject.org/tor.git"}
+GIT_ORIGIN_PUSH=${TOR_GIT_ORIGIN_PUSH:-"git@git-rw.torproject.org:tor.git"}
+# The upstream remote which git.torproject.org/tor.git points to.
+DEFAULT_UPSTREAM_REMOTE=${TOR_UPSTREAM_REMOTE_NAME:-"upstream"}
+# Copy the URLs from origin
+GIT_UPSTREAM_PULL="$GIT_ORIGIN_PULL"
+GIT_UPSTREAM_PUSH="$GIT_ORIGIN_PUSH"
+# And avoid pushing to origin if we have an upstream
+if [ "$DEFAULT_UPSTREAM_REMOTE" != "origin" ]; then
+  GIT_ORIGIN_PUSH="No pushes to origin, if there is an upstream"
+fi
+# GitHub repositories
+GITHUB_PULL=${TOR_GITHUB_PULL:-"https://github.com/torproject/tor.git"}
+GITHUB_PUSH=${TOR_GITHUB_PUSH:-"No pushes to GitHub"}
+
+##########################
+# Git branches to manage #
+##########################
+
+# The branches and worktrees need to be modified when there is a new branch,
+# and when an old branch is no longer supported.
+
+# Configuration of the branches that needs merging. The values are in order:
+#   (0) current maint/release branch name
+#   (1) Full path of the git worktree
+#
+# First set of arrays are the maint-* branch and then the release-* branch.
+# New arrays need to be in the WORKTREE= array else they aren't considered.
+MAINT_029=( "maint-0.2.9" "$GIT_PATH/$TOR_WKT_NAME/maint-0.2.9" )
+MAINT_035=( "maint-0.3.5" "$GIT_PATH/$TOR_WKT_NAME/maint-0.3.5" )
+MAINT_040=( "maint-0.4.0" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.0" )
+MAINT_041=( "maint-0.4.1" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.1" )
+MAINT_042=( "maint-0.4.2" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.2" )
+MAINT_MASTER=( "master" "$GIT_PATH/$TOR_MASTER_NAME" )
+
+RELEASE_029=( "release-0.2.9" "$GIT_PATH/$TOR_WKT_NAME/release-0.2.9" )
+RELEASE_035=( "release-0.3.5" "$GIT_PATH/$TOR_WKT_NAME/release-0.3.5" )
+RELEASE_040=( "release-0.4.0" "$GIT_PATH/$TOR_WKT_NAME/release-0.4.0" )
+RELEASE_041=( "release-0.4.1" "$GIT_PATH/$TOR_WKT_NAME/release-0.4.1" )
+RELEASE_042=( "release-0.4.2" "$GIT_PATH/$TOR_WKT_NAME/release-0.4.2" )
+
+# The master branch path has to be the main repository thus contains the
+# origin that will be used to fetch the updates. All the worktrees are created
+# from that repository.
+ORIGIN_PATH="$GIT_PATH/$TOR_MASTER_NAME"
+
+# SC2034 -- shellcheck thinks that these are unused.  We know better.
+ACTUALLY_THESE_ARE_USED=<<EOF
+${MAINT_029[0]}
+${MAINT_035[0]}
+${MAINT_040[0]}
+${MAINT_041[0]}
+${MAINT_042[0]}
+${MAINT_MASTER[0]}
+${RELEASE_029[0]}
+${RELEASE_035[0]}
+${RELEASE_040[0]}
+${RELEASE_041[0]}
+${RELEASE_042[0]}
+EOF
+
+#######################
+# Argument processing #
+#######################
+
+# Controlled by the -n option. The dry run option will just output the command
+# that would have been executed for each worktree.
+DRY_RUN=0
+
+# Controlled by the -s option. The use existing option checks for existing
+# directories, and re-uses them, rather than creating a new directory.
+USE_EXISTING=0
+USE_EXISTING_HINT="Use existing: '$SCRIPT_NAME -u'."
+
+while getopts "hnu" opt; do
+  case "$opt" in
+    h) usage
+       exit 0
+       ;;
+    n) DRY_RUN=1
+       echo "    *** DRY RUN MODE ***"
+       ;;
+    u) USE_EXISTING=1
+       echo "    *** USE EXISTING DIRECTORIES MODE ***"
+       ;;
+    *)
+       echo
+       usage
+       exit 1
+       ;;
+  esac
+done
+
+###########################
+# Git worktrees to manage #
+###########################
+
+WORKTREE=(
+  MAINT_029[@]
+  RELEASE_029[@]
+
+  MAINT_035[@]
+  RELEASE_035[@]
+
+  MAINT_040[@]
+  RELEASE_040[@]
+
+  MAINT_041[@]
+  RELEASE_041[@]
+
+  MAINT_042[@]
+  RELEASE_042[@]
+
+  MAINT_MASTER[@]
+)
+
+COUNT=${#WORKTREE[@]}
+
+#############
+# Constants #
+#############
+
+# Control characters
+CNRM=$'\x1b[0;0m'   # Clear color
+
+# Bright color
+BGRN=$'\x1b[1;32m'
+BBLU=$'\x1b[1;34m'
+BRED=$'\x1b[1;31m'
+BYEL=$'\x1b[1;33m'
+IWTH=$'\x1b[3;37m'
+
+# Strings for the pretty print.
+MARKER="${BBLU}[${BGRN}+${BBLU}]${CNRM}"
+SUCCESS="${BGRN}success${CNRM}"
+SKIPPED="${BYEL}skipped${CNRM}"
+FAILED="${BRED}failed${CNRM}"
+
+####################
+# Helper functions #
+####################
+
+# Validate the given returned value (error code), print success or failed. The
+# second argument is the error output in case of failure, it is printed out.
+# On failure, this function exits.
+function validate_ret
+{
+  if [ "$1" -eq 0 ]; then
+    printf "%s\\n" "$SUCCESS"
+  else
+    printf "%s\\n" "$FAILED"
+    printf "      %s\\n" "$2"
+    exit 1
+  fi
+}
+
+# Validate the given returned value (error code), print success, skipped, or
+# failed. If $USE_EXISTING is 0, fail on error, otherwise, skip on error.
+# The second argument is the error output in case of failure, it is printed
+# out. On failure, this function exits.
+function validate_ret_skip
+{
+  if [ "$1" -ne 0 ]; then
+    if [ "$USE_EXISTING" -eq "0" ]; then
+      # Fail and exit with error
+      validate_ret "$1" "$2 $USE_EXISTING_HINT"
+    else
+      printf "%s\\n" "$SKIPPED"
+      printf "      %s\\n" "${IWTH}$2${CNRM}"
+      # Tell the caller to skip the rest of the function
+      return 0
+    fi
+  fi
+  # Tell the caller to continue
+  return 1
+}
+
+# Create a directory, and any missing enclosing directories.
+# If the directory already exists: fail if $USE_EXISTING is 0, otherwise skip.
+function make_directory
+{
+  local cmd="mkdir -p '$1'"
+  printf "  %s Creating directory %s..." "$MARKER" "$1"
+  local check_cmd="[ ! -d '$1' ]"
+  msg=$( eval "$check_cmd" 2>&1 )
+  if validate_ret_skip $? "Directory already exists."; then
+    return
+  fi
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Go into the directory or repository, even if $DRY_RUN is non-zero.
+# If the directory does not exist, fail and log an error.
+# Otherwise, silently succeed.
+function goto_dir
+{
+  if ! cd "$1" 1>/dev/null 2>/dev/null ; then
+    printf "  %s Changing to directory %s..." "$MARKER" "$1"
+    validate_ret 1 "$1: Not found. Stopping."
+  fi
+}
+
+# Clone a repository into a directory.
+# If the directory already exists: fail if $USE_EXISTING is 0, otherwise skip.
+function clone_repo
+{
+  local cmd="git clone '$1' '$2'"
+  printf "  %s Cloning %s into %s..." "$MARKER" "$1" "$2"
+  local check_cmd="[ ! -d '$2' ]"
+  msg=$( eval "$check_cmd" 2>&1 )
+  if validate_ret_skip $? "Directory already exists."; then
+    # If we skip the clone, we need to do a fetch
+    goto_dir "$ORIGIN_PATH"
+    fetch_remote "origin"
+    return
+  fi
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Add a remote by name and URL.
+# If the remote already exists: fail if $USE_EXISTING is 0, otherwise skip.
+function add_remote
+{
+  local cmd="git remote add '$1' '$2'"
+  printf "  %s Adding remote %s at %s..." "$MARKER" "$1" "$2"
+  local check_cmd="git remote get-url '$1'"
+  msg=$( eval "$check_cmd" 2>&1 )
+  # We don't want a remote, so we invert the exit status
+  if validate_ret_skip $[ ! $? ] "Remote already exists for $1 at $msg."; then
+    return
+  fi
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Set a remote's push URL by name and URL.
+function set_remote_push
+{
+  local cmd="git remote set-url --push '$1' '$2'"
+  printf "  %s Setting remote %s push URL to '%s'..." "$MARKER" "$1" "$2"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Fetch a remote by name.
+function fetch_remote
+{
+  local cmd="git fetch '$1'"
+  printf "  %s Fetching %s..." "$MARKER" "$1"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Replace the fetch configs for a remote with config if they match a pattern.
+function replace_fetch_config
+{
+  local cmd="git config --replace-all remote.'$1'.fetch '$2' '$3'"
+  printf "  %s Replacing %s fetch configs for '%s'..." \
+    "$MARKER" "$1" "$3"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Set up the tor-github PR config, so tor-github/pr/NNNN/head points to GitHub
+# PR NNNN. In some repositories, "/head" is optional.
+function set_tor_github_pr_fetch_config
+{
+  # Standard branches
+  replace_fetch_config tor-github \
+    "+refs/heads/*:refs/remotes/tor-github/*" \
+    "refs/heads"
+  # PRs
+  replace_fetch_config "tor-github" \
+    "+refs/pull/*:refs/remotes/tor-github/pr/*" \
+    "refs/pull.*pr"
+}
+
+# Add a new worktree for branch at path.
+# If the directory already exists: fail if $USE_EXISTING is 0, otherwise skip.
+function add_worktree
+{
+  local cmd="git worktree add '$2' '$1'"
+  printf "  %s Adding worktree for %s at %s..." "$MARKER" "$1" "$2"
+  local check_cmd="[ ! -d '$2' ]"
+  msg=$( eval "$check_cmd" 2>&1 )
+  if validate_ret_skip $? "Directory already exists."; then
+    return
+  fi
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Switch to the given branch name.
+# If the branch does not exist: fail.
+function switch_branch
+{
+  local cmd="git checkout '$1'"
+  printf "  %s Switching branch to %s..." "$MARKER" "$1"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Checkout a new branch with the given branch name.
+# If the branch already exists: fail if $USE_EXISTING is 0, otherwise skip.
+function new_branch
+{
+  local cmd="git checkout -b '$1'"
+  printf "  %s Creating new branch %s..." "$MARKER" "$1"
+  local check_cmd="git branch --list '$1'"
+  msg=$( eval "$check_cmd" 2>&1 )
+  if validate_ret_skip $? "Branch already exists."; then
+    return
+  fi
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Switch to an existing branch, or checkout a new branch with the given
+# branch name.
+function switch_or_new_branch
+{
+  local cmd="git rev-parse --verify '$1'"
+  if [ $DRY_RUN -eq 0 ]; then
+    # Call switch_branch if there is a branch, or new_branch if there is not
+    msg=$( eval "$cmd" 2>&1 )
+    RET=$?
+    if [ $RET -eq 0 ]; then
+      # Branch: (commit id)
+      switch_branch "$1"
+    elif [ $RET -eq 128 ]; then
+      # Not a branch: "fatal: Needed a single revision"
+      new_branch "$1"
+    else
+      # Unexpected return value
+      validate_ret $RET "$msg"
+    fi
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}, then depending on the result:"
+    switch_branch "$1"
+    new_branch "$1"
+  fi
+}
+
+# Set the upstream for branch to upstream.
+function set_upstream
+{
+  # Note the argument order is swapped
+  local cmd="git branch --set-upstream-to='$2' '$1'"
+  printf "  %s Setting upstream for %s to %s..." "$MARKER" "$1" "$2"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+###############
+# Entry point #
+###############
+
+printf "%s Setting up the repository and remote %s\\n" "$MARKER" \
+  "${BYEL}origin${CNRM}"
+# First, fetch the origin.
+ORIGIN_PARENT=$(dirname "$ORIGIN_PATH")
+make_directory "$ORIGIN_PARENT"
+# This is just cd with an error check
+goto_dir "$ORIGIN_PARENT"
+
+# clone repository / origin remote
+clone_repo "$GIT_ORIGIN_PULL" "$TOR_MASTER_NAME"
+goto_dir "$ORIGIN_PATH"
+set_remote_push "origin" "$GIT_ORIGIN_PUSH"
+
+# upstream remote, if different to origin
+if [ "$DEFAULT_UPSTREAM_REMOTE" != "origin" ]; then
+  printf "%s Setting up remote %s\\n" "$MARKER" \
+    "${BYEL}$DEFAULT_UPSTREAM_REMOTE${CNRM}"
+  add_remote "$DEFAULT_UPSTREAM_REMOTE" "$GIT_UPSTREAM_PULL"
+  set_remote_push "$DEFAULT_UPSTREAM_REMOTE" "$GIT_UPSTREAM_PUSH"
+  fetch_remote "$DEFAULT_UPSTREAM_REMOTE"
+fi
+
+# GitHub remote
+printf "%s Setting up remote %s\\n" "$MARKER" "${BYEL}tor-github${CNRM}"
+# Add remote
+add_remote "tor-github" "$GITHUB_PULL"
+set_remote_push "tor-github" "$GITHUB_PUSH"
+# Add custom fetch for PRs
+set_tor_github_pr_fetch_config
+# Now fetch them all
+fetch_remote "tor-github"
+
+# Go over all configured worktree.
+for ((i=0; i<COUNT; i++)); do
+  branch=${!WORKTREE[$i]:0:1}
+  repo_path=${!WORKTREE[$i]:1:1}
+
+  printf "%s Handling branch %s\\n" "$MARKER" "${BYEL}$branch${CNRM}"
+  # We cloned the repository, and master is the default branch
+  if [ "$branch" != "master" ]; then
+    # git makes worktree directories if they don't exist
+    add_worktree "origin/$branch" "$repo_path"
+  fi
+  goto_dir "$repo_path"
+  switch_or_new_branch "$branch"
+  set_upstream "$branch" "origin/$branch"
+done
+
+echo
+echo "Remember to copy the git hooks from tor/git/hooks/*.git-hook to"
+echo "$ORIGIN_PATH/.git/hooks/*"