Initial commit

Signed-off-by: Sebastian Wicki <[email protected]>

.github/workflows/image.yaml

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+name: Create and publish a Docker image
+
+on:
+  push:
+    branches:
+    - main
+  pull_request:
+    branches:
+    - main
+    tags:
+      - v[0-9]+.[0-9]+.[0-9]+
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    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@65b78e6e13532edd9afa3aa52ac7964289d1a9c1
+        if: ${{ (github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v') }}
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+      - name: Build and push Docker image
+        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
+        with:
+          context: .
+          push: ${{ (github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v') }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

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+FROM golang:alpine as builder
+COPY main.go .
+RUN CGO_ENABLED=0 go build -o /go/bin/peephole main.go
+
+FROM scratch
+COPY --from=builder /go/bin/peephole /peephole
+ENTRYPOINT ["/peephole"]

LICENSE

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+MIT License
+
+Copyright (c) Luxeria
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# jitsi-peephole-service
+
+A simple service which exposes the
+[mod_muc_census](https://github.com/jitsi/jitsi-meet/blob/6682b52a1947deb0cf28043d3816b1081ef84c2b/resources/prosody-plugins/mod_muc_census.lua)
+Prosody room statistics for one single room (configured via `PEEPHOLE_ROOM_NAME`).
+
+## Environment variables
+
+- `PEEPHOLE_ROOM_NAME` _(required)_: Room name for which statistics are exposed (example: `[email protected]`)
+- `PEEPHOLE_HTTP_ADDR` _(required)_: Address on which the peephole HTTP server will listen on (example: `:8080`)
+- `XMPP_SERVER` _(required)_: Hostname of the Prosody HTTP service (example: `xmpp.meet.jitsi`)
+- `PROSODY_HTTP_PORT` _(required)_: Port of the Prosody HTTP service (example `5280`)

main.go

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+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log/slog"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+)
+
+var (
+	roomName = envVar("PEEPHOLE_ROOM_NAME")
+	httpAddr = envVar("PEEPHOLE_HTTP_ADDR")
+
+	prosodyHTTPHost = envVar("XMPP_SERVER")
+	prosodyHTTPPort = envVar("PROSODY_HTTP_PORT")
+
+	roomCensusURL = (&url.URL{
+		Scheme: "http",
+		Host:   net.JoinHostPort(prosodyHTTPHost, prosodyHTTPPort),
+		Path:   "/room-census",
+	}).String()
+)
+
+func envVar(name string) string {
+	val := os.Getenv(name)
+	if val == "" {
+		slog.Error("missing environment variable", slog.String("name", name))
+		os.Exit(1)
+	}
+	return val
+}
+
+type room struct {
+	RoomName     string `json:"room_name"`
+	Participants int    `json:"participants"`
+	CreatedTime  int64  `json:"created_time,omitempty"`
+}
+
+type roomList []room
+
+func (l *roomList) UnmarshalJSON(data []byte) error {
+	// Attempt to unmarshal data as a array of rooms
+	err := json.Unmarshal(data, (*[]room)(l))
+	if err != nil {
+		// Check if the empty list is represented as `{}`
+		if emptyErr := json.Unmarshal(data, &struct{}{}); emptyErr == nil {
+			return nil
+		}
+	}
+	return err
+}
+
+func peephole(w http.ResponseWriter) error {
+	// Fetch "room census" from internal API
+	resp, err := http.Get(roomCensusURL)
+	if err != nil {
+		return fmt.Errorf("failed to fetch room census from %q: %w", roomCensusURL, err)
+	}
+	defer resp.Body.Close()
+
+	// Parse JSON response payload into roomList
+	var payload struct {
+		RoomCensus roomList `json:"room_census,omitempty"`
+	}
+	err = json.NewDecoder(resp.Body).Decode(&payload)
+	if err != nil {
+		return fmt.Errorf("failed to parse room census payload: %w", err)
+	}
+
+	// Extract configured room from room list. If no census for the configured
+	// room is found, we fall back on just displaying zero participants
+	var found = room{
+		RoomName:     roomName,
+		Participants: 0,
+	}
+	for _, r := range payload.RoomCensus {
+		if r.RoomName == roomName {
+			found = r
+			break
+		}
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	return json.NewEncoder(w).Encode(found)
+}
+
+func main() {
+	slog.Info("starting HTTP server", "addr", httpAddr)
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+		if err := peephole(w); err != nil {
+			slog.Error("failed to serve request", slog.Any("error", err))
+			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		}
+	})
+	err := http.ListenAndServe(httpAddr, handler)
+	if !errors.Is(err, http.ErrServerClosed) {
+		slog.Error("listener failed", slog.Any("error", err))
+		os.Exit(1)
+	}
+}