deploy: web Studio on isokit.buildfor.life (same pipeline as cnxvinyl.lol)

Gitea Actions workflow builds dist/web (rustup + wasm32 target, prebuilt
wasm-bindgen CLI at the Cargo.lock version, tools/build_web.py) and
publishes it to /var/www/isokit.buildfor.life on s1 with the blog's
two-directory rename swap and the same VPS_* secrets as cnx_vinyl.
deploy/Caddyfile mirrors the vhost applied on s1 (no-cache so the
unversioned wasm glue never goes stale at Cloudflare).

.gitea/workflows/deploy-web.yml

@@ -0,0 +1,155 @@
+name: Deploy web Studio
+
+# Builds the web Studio (tools/build_web.py -> dist/web) and publishes it to
+# https://isokit.buildfor.life/ on the buildfor.life web server (s1): the
+# same Caddy, deploy user and two-directory swap as the blog and cnxvinyl.lol.
+# One-time server setup (Caddy vhost, web root): deploy/Caddyfile.
+#
+# Secrets (repo or org level), the same ones the blog and cnx_vinyl use:
+#   VPS_HOST, VPS_USER, VPS_SSH_KEY   required
+#   VPS_PORT                          optional, default 22
+#   VPS_KNOWN_HOSTS                   optional pinned host key line(s);
+#                                     without it the key is scanned per run
+
+on:
+  push:
+    branches: [master]
+    paths:
+      - "crates/**"
+      - "studio/**"
+      - "viewer/**"
+      - "web/**"
+      - "examples/demo/**"
+      - "tools/build_web.py"
+      - "Cargo.toml"
+      - "Cargo.lock"
+      - ".gitea/workflows/deploy-web.yml"
+  workflow_dispatch:
+
+# A newer push supersedes a running deploy. Safe to cancel mid-run: rsync
+# writes the non-live directory and the rename swap happens last.
+concurrency:
+  group: deploy-isokit-web
+  cancel-in-progress: true
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    env:
+      VPS_HOST: ${{ secrets.VPS_HOST }}
+      VPS_USER: ${{ secrets.VPS_USER }}
+      VPS_PORT: ${{ secrets.VPS_PORT }}
+      SITE_DIR: /var/www/isokit.buildfor.life
+      SITE_URL: https://isokit.buildfor.life
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install curl, python3, rsync if missing
+        run: |
+          missing=""
+          for c in curl python3 rsync; do
+            command -v "$c" > /dev/null || missing="$missing $c"
+          done
+          if [ -n "$missing" ]; then
+            sudo=""
+            [ "$(id -u)" = 0 ] || sudo=sudo
+            # shellcheck disable=SC2086
+            $sudo apt-get update && $sudo apt-get install -y $missing
+          fi
+
+      - name: Install Rust (rustup, wasm32 target) and the wasm-bindgen CLI
+        # build_web.py wants rustup's cargo and the wasm-bindgen CLI at the
+        # version in Cargo.lock; the CLI comes prebuilt from its GitHub release.
+        run: |
+          cargo_home=${CARGO_HOME:-$HOME/.cargo}
+          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs |
+            sh -s -- -y --profile minimal --default-toolchain stable --target wasm32-unknown-unknown --no-modify-path
+          "$cargo_home/bin/rustup" target add wasm32-unknown-unknown
+          echo "$cargo_home/bin" >> "$GITHUB_PATH"
+          ver=$(grep -A1 '^name = "wasm-bindgen"$' Cargo.lock | sed -n 's/^version = "\(.*\)"$/\1/p')
+          [ -n "$ver" ] || { echo "::error::no wasm-bindgen version in Cargo.lock"; exit 1; }
+          tmp=$(mktemp -d)
+          curl -sSfL "https://github.com/wasm-bindgen/wasm-bindgen/releases/download/$ver/wasm-bindgen-$ver-x86_64-unknown-linux-musl.tar.gz" |
+            tar xz -C "$tmp"
+          install -m 755 "$tmp/wasm-bindgen-$ver-x86_64-unknown-linux-musl/wasm-bindgen" "$cargo_home/bin/"
+          "$cargo_home/bin/rustc" --version
+          "$cargo_home/bin/wasm-bindgen" --version
+
+      - name: Build dist/web
+        run: |
+          python3 tools/build_web.py
+          echo "$GITHUB_SHA" > dist/web/version.txt
+
+      - name: Set up SSH
+        env:
+          VPS_SSH_KEY: ${{ secrets.VPS_SSH_KEY }}
+          VPS_KNOWN_HOSTS: ${{ secrets.VPS_KNOWN_HOSTS }}
+        run: |
+          if [ -z "$VPS_HOST" ] || [ -z "$VPS_USER" ] || [ -z "$VPS_SSH_KEY" ]; then
+            echo "::error::VPS_HOST, VPS_USER and VPS_SSH_KEY must be set as Actions secrets (the blog's / cnx_vinyl's values)"
+            exit 1
+          fi
+          port=${VPS_PORT:-22}
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          printf '%s\n' "$VPS_SSH_KEY" | tr -d '\r' > ~/.ssh/deploy_key
+          chmod 600 ~/.ssh/deploy_key
+          # Fail here, not at the server, when the secret is not a usable key,
+          # and log its (public) fingerprint for comparison with
+          # `ssh-keygen -lf ~deploy/.ssh/authorized_keys` on the server.
+          if ! ssh-keygen -y -P "" -f ~/.ssh/deploy_key > ~/.ssh/deploy_key.pub 2> /dev/null; then
+            echo "::error::VPS_SSH_KEY does not load as an unencrypted private key; paste the whole OpenSSH-format key including the BEGIN/END lines"
+            exit 1
+          fi
+          echo "key in VPS_SSH_KEY: $(ssh-keygen -lf ~/.ssh/deploy_key.pub)"
+          if [ -n "$VPS_KNOWN_HOSTS" ]; then
+            printf '%s\n' "$VPS_KNOWN_HOSTS" >> ~/.ssh/known_hosts
+          else
+            for i in 1 2 3; do
+              ssh-keyscan -T 10 -p "$port" "$VPS_HOST" > ~/.ssh/keyscan.out && [ -s ~/.ssh/keyscan.out ] && break
+              echo "ssh-keyscan attempt $i failed; retrying in 15 s" >&2
+              sleep 15
+            done
+            if [ ! -s ~/.ssh/keyscan.out ]; then
+              echo "::error::ssh-keyscan could not reach $VPS_HOST:$port (server down or runner IP blocked?)"
+              exit 1
+            fi
+            cat ~/.ssh/keyscan.out >> ~/.ssh/known_hosts
+          fi
+          {
+            echo "Host webhost"
+            echo "  HostName $VPS_HOST"
+            echo "  User $VPS_USER"
+            echo "  Port $port"
+            echo "  IdentityFile ~/.ssh/deploy_key"
+            echo "  IdentitiesOnly yes"
+            echo "  BatchMode yes"
+          } > ~/.ssh/config
+
+      - name: Deploy (rsync to the idle copy, then rename swap)
+        # Two persistent directories alternate as live and previous: rsync
+        # only ever writes the one that is not live, and the swap is three
+        # same-filesystem renames, so Caddy never serves a half-written tree.
+        # The previous build stays on disk for rollback.
+        run: |
+          # SC2029: the paths are meant to expand on the runner side
+          # shellcheck disable=SC2029
+          ssh webhost "mkdir -p '$SITE_DIR' '$SITE_DIR-prev' && rm -rf '$SITE_DIR-tmp'"
+          rsync -az --delete dist/web/ "webhost:$SITE_DIR-prev/"
+          # shellcheck disable=SC2029
+          ssh webhost "mv '$SITE_DIR' '$SITE_DIR-tmp' && mv '$SITE_DIR-prev' '$SITE_DIR' && mv '$SITE_DIR-tmp' '$SITE_DIR-prev'"
+          # shellcheck disable=SC2029
+          live=$(ssh webhost "cat '$SITE_DIR/version.txt'")
+          echo "live on server: $live"
+          [ "$live" = "$GITHUB_SHA" ] || { echo "::error::server holds $live, expected $GITHUB_SHA"; exit 1; }
+
+      - name: Check the public URL
+        # Warning only: DNS, Cloudflare or a login can make this fail while
+        # the files on the server are already correct.
+        run: |
+          got=$(curl -sS --max-time 20 "$SITE_URL/version.txt?nocache=$GITHUB_SHA" || true)
+          if [ "$got" = "$GITHUB_SHA" ]; then
+            echo "$SITE_URL serves $GITHUB_SHA"
+          else
+            echo "::warning::$SITE_URL/version.txt returned '${got:0:80}', expected $GITHUB_SHA"
+          fi

README.md

@@ -59,6 +59,9 @@ python tools/build_web.py                          # -> dist/web/ (static files,
 ```
 
 `dist/web/` runs from any static web server (http or https, not `file://`).
+A live build is at https://isokit.buildfor.life/: every push to `master` that
+touches the engine or the front end rebuilds and deploys it
+(`.gitea/workflows/deploy-web.yml`; server setup in `deploy/Caddyfile`).
 The first visit opens a copy of the demo. Everything the desktop Studio does
 works the same, because the page runs the same engine and answers the same
 requests. In addition:
@@ -144,6 +147,7 @@ viewer/                isokit-view.js/.css: pan, zoom, levels, rotation, tooltip
 studio/                the Studio GUI (served by `isokit studio`, and by the web Studio)
 web/                   web Studio shell: WASM backend for studio.js, projects, folders, zip, code editor
 examples/demo          demo project
+deploy/Caddyfile       the web Studio's vhost on the buildfor.life web server (s1)
 ```
 
 The layers are independent. A Rust program can draw with `isokit-core` alone.

deploy/Caddyfile

@@ -0,0 +1,25 @@
+# isokit.buildfor.life: the web Studio on the buildfor.life web server (s1).
+# Static web root /var/www/isokit.buildfor.life, filled by
+# .gitea/workflows/deploy-web.yml (tools/build_web.py -> dist/web).
+#
+# Append this block to /etc/caddy/Caddyfile on s1, then
+#   runuser -u caddy -- caddy validate --config /etc/caddy/Caddyfile --adapter caddyfile
+#   systemctl reload caddy
+# This file mirrors what s1 runs; keep the two in step.
+#
+# DNS: *.buildfor.life is a proxied wildcard at Cloudflare that reaches s1,
+# so the name needs no record of its own. Caddy gets its certificate itself.
+
+isokit.buildfor.life {
+	header X-Frame-Options "SAMEORIGIN"
+	# Testing deployment: keep it out of search engines.
+	header X-Robots-Tag "noindex, nofollow"
+	# Revalidate everything: isokit_wasm.js and its .wasm load without a
+	# version query, and a stale copy at Cloudflare would not match the
+	# new glue code after a deploy. Unchanged files still come back as 304.
+	header Cache-Control "no-cache"
+
+	root * /var/www/isokit.buildfor.life
+	encode zstd gzip
+	file_server
+}