rockstorm101 / jekyll-docker Goto Github PK

With the default config that Jekyll provides from jekyll build, webrick binds to 127.0.0.1:4000, and hence says Server address: http://127.0.0.1:4000/ in the log when it is run with jekyll serve. This is fine when running Jekyll natively on the host and connecting to it from a browser on the same host.

With Jekyll inside a container and 127.0.0.1 being the loopback interface, it is only accessible from within the container. A browser running on the Docker host makes no connection. If you try to connect from curl you get curl: (56) Recv failure: Connection reset by peer. After much messing around with the EXPOSE 4000 statement in the Docker file I ran a shell in the Jekyll container, installed the iproute2 package and ran ss -ptl which shows:

/srv/jekyll # ss -ptl
State           Recv-Q          Send-Q                    Local Address:Port                     Peer Address:Port          Process
LISTEN          0               128                           127.0.0.1:4000                          0.0.0.0:*              users:(("bundler",pid=1,fd=11))

proving that the Jekyll process is only listening for connections coming via 127.0.0.1, i.e. from within the same container. You can also prove this by running curl localhost:4000 within the container which receives a load of HTML, whereas it does not even connect from the host.

As I see it there are at least two possible fixes. Either add a note in the README.md instructing the user to add an entry host: 0.0.0.0 to their _config.yml after the initial jekyll build, or change the ENTRYPOINT statement in the Dockerfile provided by this repo to ENTRYPOINT ["bundler", "exec", "jekyll", "--host", "0.0.0.0"].