Add error fallback webserver with custom error pages and deployment configuration

.github/workflows/cla-assistant.yml

@@ -17,4 +17,4 @@ jobs:
     uses: ctfpilot/ci/.github/workflows/cla-assistant.yml@v1.3.0
     secrets: inherit
     with:
-      repository: <repository-name>
+      repository: error-fallback

.github/workflows/release.yml

@@ -8,27 +8,30 @@ on:
 
 jobs:
   release:
-    name: Release
-    uses: ctfpilot/ci/.github/workflows/release.yml@v1.3.0
     permissions:
       contents: write
       packages: write
       id-token: write
+    name: Release
+    uses: ctfpilot/ci/.github/workflows/release.yml@v1.3.0
     secrets:
       RELEASE_GH_TOKEN: ${{ secrets.RELEASE_GH_TOKEN }}
     with:
-      repository: ctfpilot/<repository-name>
+      repository: ctfpilot/error
       ENVIRONMENT: Release
 
-  update-develop:
-    if: github.ref == 'refs/heads/main'
-    name: "Update Develop Branch"
+  docker:
+    name: Docker build and push
     needs:
       - release
-    uses: ctfpilot/ci/.github/workflows/develop-update.yml@v1.3.0
+    uses: ctfpilot/ci/.github/workflows/docker.yml@v1.3.0
+    if: needs.release.outputs.version != '' && needs.release.outputs.version != null
     permissions:
       contents: read
-      pull-requests: write
-      issues: write
+      packages: write
+      id-token: write
     with:
-      repository: ctfpilot/<repository-name>
+      repository: ctfpilot/error
+      semver: ${{ needs.release.outputs.version }}
+      arguments: |
+        VERSION=${{ needs.release.outputs.version }}

.gitignore

@@ -0,0 +1 @@
+public/

.releaserc.json

@@ -0,0 +1,47 @@
+{
+    "branches": [
+        "main",
+        {
+            "name": "develop",
+            "prerelease": "r"
+        }
+    ],
+    "plugins": [
+        [
+            "@semantic-release/commit-analyzer",
+            {
+                "preset": "conventionalcommits"
+            }
+        ],
+        [
+            "@semantic-release/release-notes-generator",
+            {
+                "preset": "conventionalcommits"
+            }
+        ],
+        [
+            "@semantic-release/github",
+            {
+                "successComment": false,
+                "assets": [
+                ]
+            }
+        ],
+        [
+            "@semantic-release/exec",
+            {
+                "prepareCmd": "echo ${nextRelease.version} > version.txt && cp template/k8s.yml k8s/k8s.yml && sed -i 's/{ .Version }/${nextRelease.version}/g' k8s/k8s.yml",
+                "publishCmd": "echo 'Published version ${nextRelease.version}'"
+            }
+        ],
+        [
+            "@semantic-release/git",
+            {
+                "assets": [
+                    "k8s/k8s.yml"
+                ],
+                "message": "chore(release): ${nextRelease.version} [skip ci]\n\n${nextRelease.notes}"
+            }
+        ]
+    ]
+}

Dockerfile

@@ -0,0 +1,13 @@
+FROM python:3.14-slim AS builder
+
+WORKDIR /app
+
+COPY src/ /app/src
+
+RUN python3 src/generator.py
+
+FROM joseluisq/static-web-server
+
+COPY --from=builder /app/public/ /public
+
+ENV SERVER_CACHE_CONTROL_HEADERS=false

README.md

@@ -1,13 +1,34 @@
-# CTF Pilot's Template Repository
+# CTF Pilot's Error Fallback
 
-## Template information
+**Error fallback webserver**
 
-This repository, is a template repository for open-source projects within CTF Pilot.
+This repository contains a webserver, which is used as the fallback webserver for errors.  
+It allows for custom error pages to be shown when errors occur in the CTF Pilot ecosystem.
 
-It provices a EUPL-1.2 License, release system and other standard files.
+## How to run
 
-Please remove this section, and replace with relevant information.  
-Replace `<repository-name>` with the repository name in `.github/workflows/cla-assistant.yml`and `.github/workflows/release.yml`.
+For Kubernetes environments, deploy the deployment file provided in `k8s`.  
+This can be done with `kubectl`:
+
+```sh
+kubectl apply -f k8s/k8s.yml
+```
+
+The service can also be run locally, using the provided Docker compose file:
+
+```sh
+docker compose up -d
+```
+
+### Development
+
+In order to generate the pages, run the [`generator.py`](./src/generator.py) script in `src`:
+
+```sh
+python3 src/generator.py
+```
+
+*This is done automatically in the Docker container build process.*
 
 ## Contributing
 

docker-compose.yml

@@ -0,0 +1,6 @@
+services:
+  error-fallback:
+    build: .
+    ports:
+      - "8080:80"
+    restart: always

k8s/k8s.yml

@@ -0,0 +1,63 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: error-fallback
+  labels:
+    app.kubernetes.io/part-of: ctfpilot
+    app.kubernetes.io/name: error-fallback
+    app.kubernetes.io/version: 1.0.0-r.1
+    app.kubernetes.io/component: challenges
+    ctfpilot.com/component: error-fallback
+
+spec:
+  # HA setup
+  replicas: 3
+  selector:
+    matchLabels:
+      ctfpilot.com/component: error-fallback
+
+  template:
+    metadata:
+      labels:
+        ctfpilot.com/component: error-fallback
+    spec:
+      enableServiceLinks: false
+      automountServiceAccountToken: false
+      containers:
+        - name: instancing-fallback
+          image: ctfpilot/error-fallback:1.0.0-r.1
+          imagePullPolicy: Always
+          ports:
+          - name:  http
+            containerPort: 80
+          resources:
+            requests:
+              memory: "128Mi"
+              cpu: "10m"
+            limits:
+              memory: "256Mi"
+              cpu: "100m"
+          livenessProbe:
+            httpGet:
+              path: /
+              port: 80
+            initialDelaySeconds: 5
+            periodSeconds: 10
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: error-fallback
+  labels:
+    app.kubernetes.io/part-of: ctfpilot
+    app.kubernetes.io/name: error-fallback
+    app.kubernetes.io/version: 1.0.0-r.1
+    app.kubernetes.io/component: challenges
+    ctfpilot.com/component: error-fallback
+spec:
+  selector:
+    ctfpilot.com/component: error-fallback
+  ports:
+  - name: http
+    port: 80
+    targetPort: http

src/README.md

@@ -0,0 +1,29 @@
+# Error page generation
+
+In order to generate the error pages, run the `generator.py` script in `src`:
+
+```sh
+python3 src/generator.py
+```
+
+This will generate the error pages based on the layouts and content defined in the `layouts` and `content` folders respectively.
+
+## Templating
+
+A custom templating system is used to insert content into the layouts.  
+Placeholders in the layout files are defined using the format `/**PLACEHOLDER_NAME**/`.  
+The generator script replaces these placeholders with the corresponding content.
+
+The placeholders used are:
+
+- `/**ERROR_HTML**/`: The main HTML content for the error page. Inserted from `content`.
+- `/**ERROR_JS**/`: Any JavaScript code to be included in the error page. Inserted from `js`.
+- `/**ERROR_CSS**/`: Any CSS styles to be included in the error page . Inserted from `css`.
+
+For `error` layout pages, an additional placeholder is used:
+
+- `/**ERROR_CODE**/`: The error code for the error page (e.g., 404, 500). Replaced with the filename part of the content file.
+
+The templating use multiple layouts, which are defined in the `layouts` folder.  
+Each content file in the `content` folder should be prefixed with the layout name, followed by an underscore.  
+For example, a content file named `error_404.html` will use the `error` layout, and produce a page named `404.html`.

src/content/error_404.html

@@ -0,0 +1,4 @@
+<h1>Not found</h1>
+<p>
+    The page you are looking for could not be found.
+</p>

src/content/error_500.html

@@ -0,0 +1,7 @@
+<h1>Error</h1>
+<p>
+  An unexpected error has occurred.
+</p>
+<p>
+  Go back to the <a href="/">home page</a>.<br />
+</p>

src/content/error_502.html

@@ -0,0 +1,4 @@
+<h1>Bad gateway</h1>
+<p>
+  The service did not answer correctly.
+</p>

src/content/error_503.html

@@ -0,0 +1,5 @@
+<h1>No service available</h1>
+<p>
+  The service is currently unavailable. Please try again later. <br />
+  The service may be restarting or undergoing maintenance.
+</p>

src/content/error_504.html

@@ -0,0 +1,5 @@
+<h1>Gateway timeout</h1>
+<p>
+  The service was unable to respond in a timely manner. <br />
+  The service may be restarting or undergoing maintenance.
+</p>

src/content/error_index.html

@@ -0,0 +1,4 @@
+<h1>Error</h1>
+<p>
+    An unexpected error has occurred.
+</p>

src/css/main.css

@@ -0,0 +1,64 @@
+:root {
+  --header-font: "Hack", monospace, sans-serif;
+  --body-font: "Hack", monospace, sans-serif;
+
+  --light-theme-color: #eebc1d;
+  --dark-theme-color: #eebc1d;
+  --text-light: #232323;
+  --text-dark: #f9f9f9;
+  --bg-light: #f9f9f9;
+  --bg-dark: #232323;
+
+  --theme-color: var(--light-theme-color);
+  --bg-color: var(--bg-light);
+  --text-color: var(--text-light);
+}
+
+@media (prefers-color-scheme: dark) {
+  :root {
+    --theme-color: var(--dark-theme-color);
+    --bg-color: var(--bg-dark);
+    --text-color: var(--text-dark);
+  }
+}
+
+html,
+body {
+  background-color: var(--bg-color);
+  color: var(--text-color) !important;
+  font-family: var(--body-font) !important;
+  margin: 0;
+  padding: 0;
+}
+
+main {
+  padding: 2rem;
+}
+
+h1,
+h2,
+h3,
+h4,
+h5 {
+  font-family: var(--header-font) !important;
+}
+
+a {
+  color: var(--theme-color);
+  filter: brightness(100%);
+  transition: filter 0.2s;
+}
+
+a:hover {
+  filter: brightness(95%);
+  transition: filter 0.2s;
+}
+
+.container {
+  display: flex;
+  justify-content: center;
+  text-align: center;
+  height: 100vh;
+  overflow-y: hidden;
+  align-items: center;
+}