From 76d9ea14519f36d8eabc06a7150d0bc6d7fdb65c Mon Sep 17 00:00:00 2001
From: Michael Smith <michael.smith@puppet.com>
Date: Mon, 2 Sep 2019 01:47:55 -0700
Subject: [PATCH] Fetch remote before testing whether the publish branch exists
 (#7)

This re-uses the existing branch rather than always overwriting it with
a new branch with a single commit.

Signed-off-by: Michael Smith <michael.smith@puppet.com>
---
 Dockerfile    | 10 ++++++----
 entrypoint.sh | 49 +++++++++++++++++++++++++++++++++++--------------
 2 files changed, 41 insertions(+), 18 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 6f8b6bb..c4e85dd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.9
+FROM ubuntu:18.04
 
 LABEL "com.github.actions.name"="Deploy to GitHub Pages for Static Site Generator"
 LABEL "com.github.actions.description"="A GitHub Action to deploy your static site to GitHub Pages with Static Site Generator"
@@ -9,9 +9,11 @@ LABEL "repository"="https://github.com/peaceiris/actions-gh-pages"
 LABEL "homepage"="https://github.com/peaceiris/actions-gh-pages"
 LABEL "maintainer"="peaceiris"
 
-RUN apk add --no-cache \
+RUN apt-get update && apt-get install -y --no-install-recommends \
     git \
-    openssh-client
+    openssh-client \
+    ca-certificates && \
+    rm -rf /var/lib/apt/lists/*
 
-ADD entrypoint.sh /entrypoint.sh
+COPY entrypoint.sh /entrypoint.sh
 ENTRYPOINT [ "/entrypoint.sh" ]
diff --git a/entrypoint.sh b/entrypoint.sh
index 2314d36..643c144 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -1,33 +1,54 @@
-#!/bin/sh
+#!/bin/bash
+
+set -e
+# set -ex
+
+function print_error() {
+    echo -e "\e[31mERROR: ${1}\e[m"
+}
+
+function print_info() {
+    echo -e "\e[36mINFO: ${1}\e[m"
+}
 
 # check values
 if [ -z "${GITHUB_TOKEN}" ]; then
-    echo "error: not found GITHUB_TOKEN"
+    print_error "not found GITHUB_TOKEN"
     exit 1
 fi
 
 if [ -z "${PUBLISH_BRANCH}" ]; then
-    echo "error: not found PUBLISH_BRANCH"
+    print_error "not found PUBLISH_BRANCH"
     exit 1
 fi
 
 if [ -z "${PUBLISH_DIR}" ]; then
-    echo "error: not found PUBLISH_DIR"
+    print_error "not found PUBLISH_DIR"
     exit 1
 fi
-cd "${PUBLISH_DIR}" || exit 1
 
-# initialize git
 remote_repo="https://${GITHUB_ACTOR}:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git"
 remote_branch="${PUBLISH_BRANCH}"
-git init
-git config user.name "${GITHUB_ACTOR}"
-git config user.email "${GITHUB_ACTOR}@users.noreply.github.com"
-git remote add origin "${remote_repo}"
+
+local_dir="${HOME}/$(tr -cd 'a-f0-9' < /dev/urandom | head -c 32)"
+if git clone --depth=1 --single-branch --branch "${remote_branch}" "${remote_repo}" "${local_dir}"; then
+    cd "${local_dir}"
+    git rm -r '*'
+    find "${GITHUB_WORKSPACE}/${PUBLISH_DIR}" -maxdepth 1 | \
+        tail -n +2 | \
+        xargs -I % cp -rf % "${local_dir}/"
+else
+    cd "${PUBLISH_DIR}"
+    git init
+    git checkout --orphan "${remote_branch}"
+fi
 
 # push to publishing branch
-git checkout "${remote_branch}" || git checkout --orphan "${remote_branch}"
+git config user.name "${GITHUB_ACTOR}"
+git config user.email "${GITHUB_ACTOR}@users.noreply.github.com"
+git remote rm origin || true
+git remote add origin "${remote_repo}"
 git add --all
-timestamp=$(date -u)
-git commit -m "Automated deployment: ${timestamp} ${GITHUB_SHA}"
-git push origin "${remote_branch}" --force
+git commit --allow-empty -m "Automated deployment: $(date -u) ${GITHUB_SHA}"
+git push origin "${remote_branch}"
+print_info "${GITHUB_SHA} was successfully deployed"