move back to ruby 3.1 (#83)

* move back to ruby 3.1
* gem system update and fixing local builds
* fixing 2nd build, adding ignore
* adding dockerignore

.dockerignore

@@ -0,0 +1,5 @@
+.jekyll-cache
+_site
+.github
+.git
+README.md

.github/workflows/call-docker-build.yaml

@@ -58,7 +58,7 @@ jobs:
 
     needs: build-jekyll-image
 
-    if: github.event_name == 'push'
+    # if: github.event_name == 'push'
 
     permissions:
       contents: read

.gitignore

@@ -1,3 +1,3 @@
+.jekyll-cache
 # this repo only builds a docker image for jekyll, and doesn't store a jekyll site.
 _site
-

Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:3-slim-bullseye as jekyll
+FROM ruby:3.1-slim-bullseye as jekyll
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
     build-essential \
@@ -8,7 +8,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 # used in the jekyll-server image, which is FROM this image
 COPY docker-entrypoint.sh /usr/local/bin/
 
-RUN gem install bundler jekyll
+RUN gem update --system && gem install jekyll && gem cleanup
 
 EXPOSE 4000
 
@@ -19,7 +19,7 @@ ENTRYPOINT [ "jekyll" ]
 CMD [ "--help" ]
 
 # build from the image we just built with different metadata
-FROM ghcr.io/bretfisher/jekyll:latest as jekyll-serve
+FROM jekyll as jekyll-serve
 
 # on every container start, check if Gemfile exists and warn if it's missing
 ENTRYPOINT [ "docker-entrypoint.sh" ]