fix(docker): set up workflow and update dockerfile

Signed-off-by: SphericalKat <amolele@gmail.com>

Author: SphericalKat

.github/workflows/fly.yml

@@ -1,12 +1,41 @@
-name: Fly Deploy
-on: [push]
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches: [ develop ]
+
 env:
-  FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
 jobs:
-  deploy:
-      name: Deploy to fly.io
-      runs-on: ubuntu-latest
-      steps:
-        - uses: actions/checkout@v3
-        - uses: superfly/flyctl-actions/setup-flyctl@master
-        - run: flyctl deploy --remote-only
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/SphericalKat/katbin
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -1,4 +1,4 @@
-FROM elixir:alpine AS build
+FROM elixir:1.16-otp-24-alpine AS build
 
 # install build dependencies
 RUN apk add --no-cache build-base npm git curl py-pip rust cargo