This project, my Grinnell College Digital Library Application Developer's blog, is no longer a Docker "Multi-Stage" build.

I successfully moved this blog to GitHub Pages in October 2021, after creating instances of it on DigitalOcean and Azure. GH Pages, specifically https://static.grinnell.edu/dlad-blog/ seems like the right home for it, finally.

I've create a OneTab of resources that I used here: https://www.one-tab.com/page/Pm1eXBmxS8KOe7PjCt_DLg. Enjoy!

Step 2/17 : COPY . /data ---> a473877e4ad9 Step 3/17 : WORKDIR /data ---> Running in 6e1b6e2796a4 Removing intermediate container 6e1b6e2796a4 ---> 1fcaafec077f Step 4/17 : RUN rm -rf themes/* ---> Running in 020d0c4f303f Removing intermediate container 020d0c4f303f ---> 00a81909f7a0 Step 5/17 : RUN git clone https://github.com/nanxiaobei/hugo-paper.git themes/hugo-paper ---> Running in 4d7c71cd51ac Cloning into 'themes/hugo-paper'... Removing intermediate container 4d7c71cd51ac ---> 5e67ef78f4b8 Step 6/17 : FROM skyscrapers/hugo:0.46 ---> 434ff241d9e8 Step 7/17 : COPY --from=0 /data /data ---> 3d27347872c5 Step 8/17 : WORKDIR /data ---> Running in f0875071a444 Removing intermediate container f0875071a444 ---> ca8120476886 Step 9/17 : RUN hugo ---> Running in e2b6817fe000

               | EN

+------------------+----+ Pages | 12 Paginator pages | 0 Non-page files | 0 Static files | 2 Processed images | 0 Aliases | 0 Sitemaps | 1 Cleaned | 0

Total in 15 ms Removing intermediate container e2b6817fe000 ---> cc2be3328f07 Step 10/17 : FROM mysocialobservations/docker-tdewolff-minify ---> 43c3688d88ad Step 11/17 : COPY --from=1 /data/public /data/public ---> 144634f56841 Step 12/17 : WORKDIR /data ---> Running in 404cb0f24509 Removing intermediate container 404cb0f24509 ---> d0a02742aa3c Step 13/17 : RUN minify --recursive --verbose --match=..js$ --type=js --output public/ public/ ---> Running in 38f21d784856 INFO: use mimetype text/javascript INFO: expanding directory public/ recursively INFO: minify input file public/js/custom.js INFO: minify to output directory public/ INFO: ( 68.167µs, 32 B, 49.2%, 954 kB/s) - public/js/custom.js INFO: 3.055423ms total Removing intermediate container 38f21d784856 ---> d0d80a7d1ab1 Step 14/17 : RUN minify --recursive --verbose --match=..css$ --type=css --output public/ public/ ---> Running in 81e9840eb053 INFO: use mimetype text/css INFO: expanding directory public/ recursively INFO: minify input file public/css/style.css INFO: minify to output directory public/ INFO: (389.209µs, 6.0 kB, 100.0%, 15 MB/s) - public/css/style.css INFO: 3.797968ms total Removing intermediate container 81e9840eb053 ---> 80108c675341 Step 15/17 : RUN minify --recursive --verbose --match=.*.html$ --type=html --output public/ public/ ---> Running in d0c1c70b3e80 INFO: use mimetype text/html INFO: expanding directory public/ recursively INFO: minify 30 input files INFO: minify to output directory public/ INFO: (283.292µs, 2.2 kB, 99.7%, 7.6 MB/s) - public/404.html INFO: (192.584µs, 3.4 kB, 99.8%, 18 MB/s) - public/about/index.html INFO: (286.917µs, 3.7 kB, 99.8%, 13 MB/s) - public/categories/development/index.html INFO: ( 68µs, 275 B, 100.0%, 4.0 MB/s) - public/categories/development/page/1/index.html INFO: (219.375µs, 3.7 kB, 99.8%, 17 MB/s) - public/categories/golang/index.html INFO: ( 56.709µs, 260 B, 100.0%, 4.6 MB/s) - public/categories/golang/page/1/index.html INFO: (253.918µs, 2.7 kB, 99.8%, 11 MB/s) - public/categories/index.html INFO: ( 56.625µs, 239 B, 100.0%, 4.2 MB/s) - public/categories/page/1/index.html INFO: (272.709µs, 5.8 kB, 99.9%, 21 MB/s) - public/index.html INFO: ( 68.126µs, 206 B, 100.0%, 3.0 MB/s) - public/page/1/index.html INFO: (1.140128ms, 56 kB, 100.0%, 49 MB/s) - public/post/creating-a-new-theme/index.html INFO: (487.084µs, 15 kB, 100.0%, 30 MB/s) - public/post/goisforlovers/index.html INFO: (317.792µs, 5.8 kB, 99.9%, 18 MB/s) - public/post/hugoisforlovers/index.html INFO: (252.542µs, 5.2 kB, 99.9%, 21 MB/s) - public/post/index.html INFO: (349.251µs, 11 kB, 99.9%, 31 MB/s) - public/post/migrate-from-jekyll/index.html INFO: ( 77µs, 221 B, 100.0%, 2.9 MB/s) - public/post/page/1/index.html INFO: (317.834µs, 3.8 kB, 99.8%, 12 MB/s) - public/tags/development/index.html INFO: ( 80.792µs, 257 B, 100.0%, 3.2 MB/s) - public/tags/development/page/1/index.html INFO: (351.584µs, 3.8 kB, 99.8%, 11 MB/s) - public/tags/go/index.html INFO: ( 68.083µs, 230 B, 100.0%, 3.4 MB/s) - public/tags/go/page/1/index.html INFO: (280.542µs, 3.8 kB, 99.8%, 14 MB/s) - public/tags/golang/index.html INFO: ( 69.042µs, 242 B, 100.0%, 3.5 MB/s) - public/tags/golang/page/1/index.html INFO: (255.334µs, 3.0 kB, 99.8%, 12 MB/s) - public/tags/hugo/index.html INFO: ( 68.417µs, 236 B, 100.0%, 3.4 MB/s) - public/tags/hugo/page/1/index.html INFO: (221.125µs, 3.7 kB, 99.8%, 17 MB/s) - public/tags/index.html INFO: ( 81.125µs, 221 B, 100.0%, 2.7 MB/s) - public/tags/page/1/index.html INFO: (198.083µs, 2.9 kB, 99.8%, 15 MB/s) - public/tags/templates/index.html INFO: (118.167µs, 251 B, 100.0%, 2.1 MB/s) - public/tags/templates/page/1/index.html INFO: ( 242µs, 2.9 kB, 99.8%, 12 MB/s) - public/tags/themes/index.html INFO: ( 67.75µs, 242 B, 100.0%, 3.6 MB/s) - public/tags/themes/page/1/index.html INFO: 112.866806ms total Removing intermediate container d0c1c70b3e80 ---> f31a796feec7 Step 16/17 : FROM nginx:alpine ---> 36f3464a2197 Step 17/17 : COPY --from=2 /data/public /usr/share/nginx/html ---> 5c0ffab7f6be Successfully built 5c0ffab7f6be Successfully tagged hugo-test:latest

Inside this single `Dockerfile` are 4 `FROM` sections. What Docker actually
ends up doing is creating 3 intermediary images, and one final image. The final
image contains nothing but what you explicitly `COPY` into it, and the end
result is a tiny image:

```bash
$ docker image ls
REPOSITORY  <... snip ...>  SIZE
<none>      <... snip ...>  262MB
hugo-test   <... snip ...>  18.8MB
<none>      <... snip ...>  106MB
<none>      <... snip ...>  25.1MB

This tiny image is what we end up deploying to production. It contains Nginx and all the static, minified files.

You can test it yourself by running:

docker container run --rm -it -p 8080:80 hugo-test

and going to http://localhost:8080

After you have played around a bit with Hugo, commit any changes you have made and push to a public repo on Github.

In our next steps we will get the Docker Hub to do the exact same process as above whenever we push a new change to Github.

If you do not yet have an account, create one at hub.docker.com.

We are now going to grant the Docker Hub to access our Github repos and add hooks.

This simply means whenever a commit is pushed to the repo, Github will notify the Docker Hub and it will automatically create a new image for us.

Go to Linked Accounts & Services and follow the directions.

Next, go to the Automated Builds page and click Create Auto-build Github.

From there you can find the repo you created earlier.

{{% notice yellow %}} There are currently two bugs with the Docker Hub GUI when creating an automated build.

1. The repository you create for the automated build must not exist on Docker Hub. For example, my Hub username is jtreminio and my repo's name is jtreminio.com (found here). Using the GUI found here the Hub will auto-populate the fields for you, even if you already have a repo by that name! Either change the name on this page or delete your existing repo. This is on the Docker Hub, not on Github!
2. The URL you end up in, after the GUI found here, may be incorrect! For me it generated a URL that ended with /github/form/jtreminio/jtreminio.com/?namespace=github. This silently fails when you submit the form. The ?namespace= part should actually contain your Docker Hub username! I had to change my URL to /github/form/jtreminio/jtreminio.com/?namespace=jtreminio {{% /notice %}}

After you follow the instructions you will find the Docker Hub repo page now includes several more options than before, including Dockerfile, Build Details, and Build Settings.

If you go to Build Settings you can manually start your first build by clicking Trigger on the right side of the page. This may take a few minutes.

Once the first build is finished on the Docker Hub we can create the initial container for our blog on our server.

SSH into your server and run the following:

NAME=jtreminio_com
HOST=jtreminio.com
IMAGE="jtreminio/jtreminio.com"
docker container run -d --name ${NAME} \
    --label traefik.backend=${NAME} \
    --label traefik.docker.network=traefik_webgateway \
    --label traefik.frontend.rule=Host:${HOST} \
    --label traefik.port=80 \
    --label com.centurylinklabs.watchtower.enable=true \
    --network traefik_webgateway \
    --restart always \
    ${IMAGE}

Make sure to change NAME, HOST and IMAGE to your own information!

A few things will now happen:

1. The container with your website inside will start,
2. Traefik detects this new container and automatically generates a new, free SSL certificate from Let's Encrypt. It will continue monitoring this certificate and renew it long before it expires, all without you needing to worry about it.
3. Watchtower takes note of this new container, but does nothing right now.

If you go to your website URL you will see your blog up and running with a brand new SSL certificate!

So what exactly does Watchtower do? If you run

docker container logs watchtower

you may not see anything very interesting at first. The magic happens when you make changes to your website, commit and push to Github, and after the Docker Hub automatically creates a new image of your website.

Watchtower polls the Docker Hub every few minutes to detect if any of the containers you are currently running have new image versions. Once Docker Hub finishes creating the new image with the latest changes of your website, Watchtower will automatically download the image, gracefully shut down your blog container and immediately restart it with the new image, and your new changes.

Here is what the logs show when this happens:

root@docker:/opt# docker container logs -f watchtower
time="2018-08-09T00:28:50Z" level=info msg="First run: 2018-08-09 00:33:50 +0000 UTC"

// ...

time="2018-08-09T00:33:53Z" level=info msg="Found new jtreminio/jtreminio.com:latest image (sha256:5a8c9299091b6892753128792a6d6c90f26dd27ed10c5286b3fc8f0b8799c503)"
time="2018-08-09T00:33:57Z" level=info msg="Stopping /jtreminio_com (ebae9539acfcedf2279115f2c19ebddaf3c34271aa5d048142c6b90d091bf987) with SIGTERM"
time="2018-08-09T00:33:58Z" level=info msg="Creating /jtreminio_com"

Watchtower can monitor any number of containers and is the final piece in our automated puzzle.

Today you learned how to utilize free, open source tools to automate your blog deployment process.

While Docker Hub automated builds may not be suitable for more complex requirements, it can easily meet what we created today.

No more FTP, nor more pulling from repo directly from your server. Automating this boring and error-prone process helps lift a small weight off of your shoulders and lets you focus on what you enjoy doing best: writing about things you love.

Until next time, this is Señor PHP Developer Juan Treminio wishing you adios!

fin init

Will initialize new site, append a test content and compile the site.

Your new site will be instantly available at http://static.$VIRTUAL_HOST

To develop a Hugo project you need Hugo running in a server mode (Hugo Quickstart guide for more details).

fin develop

Starts a Hugo server. The server will be available at http://$VIRTUAL_HOST. Updates as you edit, reload the page to see your changes.

NOTE: once started, the Hugo server will run, blocking the console. Kill it with Ctrl-C, when you are done.

fin compile

Will re-compile static site into public folder. It is available at http://static.$VIRTUAL_HOST