Add Gemfile, Gemfile.lock

A build time dependency installation is considered a security
vulnerability, because compromised dependencies can lead to remote code
execution at build time or runtime.  Added required files to address
this.

Change-Id: I69caeaf79cb3611291829bd5a51cf3c1226e91f2
Google-Bug-Id: b/280554949
diff --git a/jenkins-docker/agent-jekyll/Dockerfile b/jenkins-docker/agent-jekyll/Dockerfile
index 2ac7c9d..d89f56b 100644
--- a/jenkins-docker/agent-jekyll/Dockerfile
+++ b/jenkins-docker/agent-jekyll/Dockerfile
@@ -4,7 +4,6 @@
     apt-get install -y ruby-full && \
     apt-get clean && \
     rm -Rf /var/lib/apt/lists && \
-    gem install jekyll bundler:1.17.1
 
 RUN git clone https://gerrit.googlesource.com/homepage /tmp/homepage && \
     cd /tmp/homepage && \
diff --git a/jenkins-docker/agent-jekyll/Gemfile b/jenkins-docker/agent-jekyll/Gemfile
new file mode 100644
index 0000000..35d91e0
--- /dev/null
+++ b/jenkins-docker/agent-jekyll/Gemfile
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+gem 'jekyll'
+gem 'bundler'
+
+# gem "rails"
diff --git a/jenkins-docker/agent-jekyll/Gemfile.lock b/jenkins-docker/agent-jekyll/Gemfile.lock
new file mode 100644
index 0000000..07bde4d
--- /dev/null
+++ b/jenkins-docker/agent-jekyll/Gemfile.lock
@@ -0,0 +1,73 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    addressable (2.8.4)
+      public_suffix (>= 2.0.2, < 6.0)
+    colorator (1.1.0)
+    concurrent-ruby (1.2.2)
+    em-websocket (0.5.3)
+      eventmachine (>= 0.12.9)
+      http_parser.rb (~> 0)
+    eventmachine (1.2.7)
+    ffi (1.15.5)
+    forwardable-extended (2.6.0)
+    google-protobuf (3.22.3-x86_64-linux)
+    http_parser.rb (0.8.0)
+    i18n (1.13.0)
+      concurrent-ruby (~> 1.0)
+    jekyll (4.3.2)
+      addressable (~> 2.4)
+      colorator (~> 1.0)
+      em-websocket (~> 0.5)
+      i18n (~> 1.0)
+      jekyll-sass-converter (>= 2.0, < 4.0)
+      jekyll-watch (~> 2.0)
+      kramdown (~> 2.3, >= 2.3.1)
+      kramdown-parser-gfm (~> 1.0)
+      liquid (~> 4.0)
+      mercenary (>= 0.3.6, < 0.5)
+      pathutil (~> 0.9)
+      rouge (>= 3.0, < 5.0)
+      safe_yaml (~> 1.0)
+      terminal-table (>= 1.8, < 4.0)
+      webrick (~> 1.7)
+    jekyll-sass-converter (3.0.0)
+      sass-embedded (~> 1.54)
+    jekyll-watch (2.2.1)
+      listen (~> 3.0)
+    kramdown (2.4.0)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
+    liquid (4.0.4)
+    listen (3.8.0)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
+    mercenary (0.4.0)
+    pathutil (0.16.2)
+      forwardable-extended (~> 2.6)
+    public_suffix (5.0.1)
+    rake (13.0.6)
+    rb-fsevent (0.11.2)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
+    rexml (3.2.5)
+    rouge (4.1.0)
+    safe_yaml (1.0.5)
+    sass-embedded (1.62.1)
+      google-protobuf (~> 3.21)
+      rake (>= 10.0.0)
+    terminal-table (3.0.2)
+      unicode-display_width (>= 1.1.1, < 3)
+    unicode-display_width (2.4.2)
+    webrick (1.8.1)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  bundler
+  jekyll
+
+BUNDLED WITH
+   2.4.12