Add download-beta page with live build progress

[elee1766]

New /download-beta page that provides live build progress when downloading custom Caddy builds.

Pages

/download-beta -- Plugin selection

• Same look and feel as the existing /download page (same CSS, header, footer, package icons, download counts, version inputs, module docs previews)
• Vanilla JS instead of jQuery (no dependencies)
• Clicking Download posts to POST /api/build, then navigates to the build page
• If the build is already cached, skips straight to the download

/download-beta/build/?key={hash} -- Build progress

• Connects to GET /api/build/{key}/events via SSE
• Shows current build step as a prominent label with a progress bar
• Scrolling build log with live output
• Auto-downloads the artifact on completion
• Fallback "click here if download did not start" link
• Error state with "Try Again" button linking back to the selection page

User flow

1. User selects platform and plugins, clicks Download
2. POST /api/build returns the build key
3. Browser navigates to /download-beta/build/?key=abc123
4. SSE streams step/log events in real time
5. On result event with success: true, the download starts automatically
6. If the user refreshes or shares the URL, they reconnect and get all buffered events replayed

Multiple users building the same configuration share progress -- the first request triggers the build and everyone else joins the same stream.

---

Local test setup

This requires three services running together: the build worker, the portal (API), and the website (frontend). You'll also need PostgreSQL.

Related PRs

• buildworker: caddyserver/buildworker#6 (streaming endpoint)
• portal: caddyserver/portal#10 (streaming build API, depends on caddyserver/portal#9)
• xcaddy: elee1766/xcaddy@observable-builds (OnStep callback)

1. Build the custom Caddy binaries

Build worker binary (includes the streaming build handler):

mkdir -p /tmp/caddybuilder/buildworker && cd /tmp/caddybuilder/buildworker

cat > main.go << 'EOF'
package main

import (
    caddycmd "github.com/caddyserver/caddy/v2/cmd"
    _ "github.com/caddyserver/caddy/v2/modules/standard"
    _ "github.com/caddyserver/buildworker"
)

func main() { caddycmd.Main() }
EOF

go mod init caddybuilder/buildworker
go mod edit -replace github.com/caddyserver/buildworker=<path-to-buildworker-checkout>
go mod edit -replace github.com/caddyserver/xcaddy=github.com/elee1766/xcaddy@v0.0.0-20260708021516-c9f96ab945a0
GOPROXY=direct go mod tidy
go build -o /tmp/caddybuilder/caddy-buildworker .

Portal binary (includes the API handler):

mkdir -p /tmp/caddybuilder/portal && cd /tmp/caddybuilder/portal

cat > main.go << 'EOF'
package main

import (
    caddycmd "github.com/caddyserver/caddy/v2/cmd"
    _ "github.com/caddyserver/caddy/v2/modules/standard"
    _ "github.com/caddyserver/portal/backend"
)

func main() { caddycmd.Main() }
EOF

go mod init caddybuilder/portal
go mod edit -replace github.com/caddyserver/portal=<path-to-portal-checkout>
go mod tidy
go build -o /tmp/caddybuilder/caddy-portal .

2. PostgreSQL setup

Create the database and load the schema:

psql -h 127.0.0.1 -p 5432 -U postgres -c "CREATE DATABASE caddy"
psql -h 127.0.0.1 -p 5432 -U postgres -d caddy -f <path-to-portal-checkout>/db.sql

Seed with the top 10 plugins for testing:

-- dummy account for foreign key
INSERT INTO accounts (id, name, email, password)
VALUES ('f89c8f71-263d-445f-9bab-f18b3d91c85b', 'Test', 'test@test.local', '\x00')
ON CONFLICT DO NOTHING;

-- top 10 plugins by download count
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('1fab5617-a93f-4617-b886-cfc8e44253ae', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/greenpau/caddy-security', true, true, 1574081) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('7cdc6c32-a6c4-40f0-93d1-4fb470915528', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/caddy-dns/route53', true, true, 1553610) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('e97af045-03cf-427c-96f5-5607516080e7', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/caddy-dns/cloudflare', true, true, 395614) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('f567fc49-b0d5-4340-99a4-e6f02703af65', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/dunglas/vulcain/caddy', true, true, 204568) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('20925127-9a0c-4b73-8fc9-ece394d54833', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/dunglas/mercure/caddy', true, true, 203633) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('093c4864-5c74-4d2d-b75e-9756ba00278d', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/caddyserver/replace-response', true, true, 117680) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('1de15c74-1a7e-4465-8279-ecfe9e5b3765', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/sjtug/caddy2-filter', true, true, 88317) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('ecead391-831c-4f52-a99a-0eb403e07c9e', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/caddyserver/transform-encoder', true, true, 65432) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('cae8ce32-6e4c-4a26-ae98-e5bc33cfd0a1', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/mastercactapus/caddy2-proxyprotocol', true, true, 45868) ON CONFLICT DO NOTHING;
INSERT INTO packages (id, account_id, path, listed, available, downloads) VALUES ('7d996720-ae83-4a79-8684-cba7f1fa682a', 'f89c8f71-263d-445f-9bab-f18b3d91c85b', 'github.com/caddy-dns/duckdns', true, true, 43306) ON CONFLICT DO NOTHING;

3. Config files

Build worker (buildworker.json) -- serves on :8888:

{
  "admin": {"disabled": true},
  "apps": {
    "http": {
      "servers": {
        "worker": {
          "listen": ["127.0.0.1:8888"],
          "routes": [
            {
              "match": [{"path": ["/streaming-build"]}],
              "handle": [{"handler": "caddy_builder_streaming", "timeout": "10m"}]
            },
            {
              "match": [{"path": ["/build"]}],
              "handle": [{"handler": "caddy_builder", "timeout": "10m"}]
            }
          ]
        }
      }
    }
  }
}

Portal (Caddyfile.portal) -- API on :4444, proxies to worker:

{
    order portal last
    admin off
}

:4444 {
    portal {
        dsn "postgresql://postgres:postgres@127.0.0.1:5432/caddy?sslmode=disable"
        build_worker_endpoint 127.0.0.1:5555
        streaming_build_worker_endpoint 127.0.0.1:5556
    }
}

# legacy build worker proxy
:5555 {
    bind 127.0.0.1
    reverse_proxy 127.0.0.1:8888 {
        rewrite /build
    }
}

# streaming build worker proxy
:5556 {
    bind 127.0.0.1
    reverse_proxy 127.0.0.1:8888 {
        rewrite /streaming-build
    }
}

Website (Caddyfile.website) -- frontend on :2015:

{
    admin off
}

:2015 {
    root * <path-to-website-checkout>/src
    file_server
    templates
    encode zstd gzip
    try_files {path}.html {path}
    reverse_proxy /api/* 127.0.0.1:4444
}

4. Run

In three terminals:

# Terminal 1: build worker
./caddy-buildworker run --config buildworker.json

# Terminal 2: portal
./caddy-portal run --config Caddyfile.portal --adapter caddyfile

# Terminal 3: website (stock caddy binary works)
caddy run --config Caddyfile.website --adapter caddyfile

Then open http://localhost:2015/download-beta

Supervisor script

#!/bin/bash
set -e
DIR="$(cd "$(dirname "$0")" && pwd)"

cleanup() { kill $PID1 $PID2 $PID3 2>/dev/null; wait 2>/dev/null; }
trap cleanup EXIT INT TERM

"$DIR/caddy-buildworker" run --config "$DIR/buildworker.json" &
PID1=$!; sleep 1

"$DIR/caddy-portal" run --config "$DIR/Caddyfile.portal" --adapter caddyfile &
PID2=$!; sleep 1

caddy run --config "$DIR/Caddyfile.website" --adapter caddyfile &
PID3=$!; sleep 1

echo "Ready: http://localhost:2015/download-beta"
wait