Merge pull request #1602 from dagger/europa-docs-go-on-docker-swarm

Europa docs: Go on Docker Swarm

.markdownlint.yaml

@@ -1,6 +1,11 @@
 # Default state for all rules
 default: true
 
+# MD001/heading-increment - Do not require h1 -> h2 transitions,
+# allow headings with better proportions.
+# h2 is too large, h3 is just right so we use h1 -> h3 in places.
+MD001: false
+
 # MD013/line-length - Allow long lines
 MD013: false
 

docs/use-cases/1211-go-docker-swarm.md

@@ -5,4 +5,123 @@ displayed_sidebar: europaSidebar
 
 # Go on Docker Swarm
 
-[particubes.com](https://particubes.com)
+![particubes.com](/img/use-cases/particubes.com.png)
+
+[Particubes](https://particubes.com) is a platform dedicated to voxel games, which are games made out of little cubes, like Minecraft.
+The team consists of 10 developers that like to keep things simple.
+They write primarily Go & Lua, push to GitHub and use GitHub Actions for automation.
+The production setup is a multi-node Docker Swarm cluster running on AWS.
+
+The Particubes team chose Dagger for continuous deployment because it was the easiest way of integrating GitHub with Docker Swarm.
+Every commit to the main branch goes straight to [docs.particubes.com](https://docs.particubes.com) via a Dagger pipeline that runs in GitHub Actions.
+`universe.dagger.io/docker` made building this pipeline trivial:
+
+:::danger
+TODO: this config is meta Europa, meaning that it was not tested. Next steps:
+
+- implement it in GitHub Actions and ensure that it all works as expected
+- update this meta config to the final version that we know works
+:::
+
+```cue
+package particubes
+
+import (
+  "dagger.io/dagger"
+  "universe.dagger.io/docker"
+)
+
+dagger.#Plan & {
+  inputs: {
+    directories: src: path: "./lua-docs"
+    secrets: docs: command: {
+      name: "sops"
+      args: ["-d", "../../lua-docs/sops_secrets.yaml"]
+    }
+    params: {
+      image: ref: docker.#Ref | *"registry.particubes.com/lua-docs:latest"
+    }
+  }
+
+  actions: {
+    docs: {
+      // TODO: write GITHUB_SHA into a static /github_sha.txt
+      build: docker.#Dockerfile & {
+        source: inputs.directories.src.contents
+      }
+
+      test: {
+        // TODO:
+        // - run container
+        // - check http response code
+        // - verify /github_sha.txt value matches GITHUB_SHA
+        // - stop container
+      }
+
+      push: docker.#Push {
+        dest: inputs.params.image.ref
+        image: build.output
+      }
+
+      docsSecrets: dagger.#DecodeSecret & {
+        input: inputs.secrets.docs.contents
+        format: "yaml"
+      }
+      deploy: {
+        // TODO:
+        // - run this command in the remote Docker Swarm
+        // - secrests are ready in docsSecrets, e.g. docsSecrets.output.swarmKey.contents
+      }
+
+      verifyDeploy: {
+        // TODO:
+        // - check http response code
+        // - verify /github_sha.txt value matches GITHUB_SHA
+      }
+    }
+  }
+}
+```
+
+This is the GitHub Actions workflow config that invokes `dagger`, which in turn runs the above pipeline:
+
+```yaml
+name: Dagger/docs.particubes.com
+
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+        with:
+          lfs: true
+      // TODO: install sops
+      - name: Dagger
+        uses: dagger/dagger-action@v1
+        with:
+          age-key: ${{ secrets.DAGGER_AGE_KEY }}
+          args: up
+```
+
+Since this is a Dagger pipeline, anyone on the team can run it locally with a single command:
+
+```console
+dagger up
+```
+
+This is the first step that enabled the Particubes team to have the same CI/CD experience everywhere.
+
+We don't know what comes next for particubes.com, but we would like find out. Some ideas:
+
+- deploy particubes.com with Dagger
+- manage the Docker Swarm cluster with Dagger
+- contribute `universe.dagger.io/particubes` package
+
+:::tip
+The latest version of this pipeline can be found at [github.com/voxowl/particubes/lua-docs/docs.cue](https://github.com/voxowl/particubes/blob/b698777465c02462296de37087dd3c341c29df92/lua-docs/docs.cue)
+:::