Nightly docker builds, plus add a DOCKER_README

.github/workflows/docker-push.yml

@@ -2,8 +2,8 @@
 name: Create and publish a Docker image
 
 on:
-  push:
-    branches: ['main']
+  schedule:
+    - cron: "0 0 * * *"
   release:
     types: [published]
   workflow_dispatch:
@@ -34,7 +34,7 @@ jobs:
             **/go.sum
             **/Makefile
             Makefile
-            e2e.Dockerfile
+            Dockerfile
 
       - name: Log in to the Container registry
         uses: docker/[email protected]
@@ -48,12 +48,13 @@ jobs:
         uses: docker/[email protected]
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          flavor: "latest=false"
 
       - name: Build and push docker image
         uses: docker/[email protected]
         with:
           context: .
-          file: e2e.Dockerfile
+          file: Dockerfile
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}

DOCKER_README.md

@@ -0,0 +1,42 @@
+# Gaia Docker image
+
+There's a `gaia` docker image built on a nightly basis, as well as for every
+release tag, and pushed to `ghcr.io/cosmos/gaia`. It's built from the
+[`Dockerfile`](./Dockerfile) in this directory.
+
+The images contain statically compiled `gaiad` binaries running on an `alpine`
+container. By default, `gaiad` runs as user `nonroot`, with UID/GUID `1025`.
+The image exposes ports `26656,26657,1317,9090`. This is how the `gaiad` is
+compiled:
+
+```Dockerfile
+RUN LEDGER_ENABLED=false LINK_STATICALLY=true BUILD_TAGS=muslc make build
+```
+
+Since the image has an entrypoint of `gaiad start`, you can use it to start a
+node by mounting in a `.gaia` config directory. So, for instance, you can start
+a `v17.3.0` node running a chain configured at `$HOME/.gaia` by running:
+
+```bash
+docker run --rm -it -v "$HOME/.gaia:/opt/gaia" ghcr.io/cosmos/gaia:v17.3.0 --home /opt/gaia
+```
+
+Of course, you can also use the images to just run generic gaia commands:
+
+```bash
+docker run --rm -it --entrypoint gaiad -v "$HOME/.gaia:/opt/gaia" ghcr.io/cosmos/gaia:v17.3.0 q tendermint-validator-set --home /opt/gaia
+```
+
+## Building
+
+The images are built by workflow
+[docker-push.yml](./.github/workflows/docker-push.yml). This workflow is
+invoked on release as well as every night, and may be invoked manually by
+people to build an arbitrary branch. It uses the `docker/metadata-action` to
+decide how to tag the image, according to the following rules:
+
+* If invoked via schedule, the image is tagged `nightly` and `main` (since it's a build of the `main` branch)
+* If invoked from a release, including an rc, it is tagged with the release tag
+* If invoked manually on a branch, it is tagged with the branch name
+
+**NOTE:** To avoid surprising users, there is no `latest` tag generated.

e2e.Dockerfile → Dockerfile

@@ -1,3 +1,4 @@
+# Info on how to use this docker image can be found in DOCKER_README.md
 ARG IMG_TAG=latest
 
 # Compile the gaiad binary

Makefile

@@ -285,7 +285,7 @@ endif
 .PHONY: run-tests $(TEST_TARGETS)
 
 docker-build-debug:
-	@docker build -t cosmos/gaiad-e2e -f e2e.Dockerfile .
+	@docker build -t cosmos/gaiad-e2e -f Dockerfile .
 
 # TODO: Push this to the Cosmos Dockerhub so we don't have to keep building it
 # in CI.