OpenSlides3 Autoupdate Service

The OpenSlides3 autoupdate service is a messaging system for openslides 3.x.

To work, the service needs running OpenSlides 3 instance. It reads the data from redis, gets autoupdates via redis and authenticates request via the openslides service.

IMPORTANT: The data are sent via an open http-connection. All browsers limit the amount of open http1.1 connections to a domain. For this service to work, the browser has to connect to the service with http2 and therefore needs https.

Install and Start

To start the service, the file /run/secrets/django has to exist and has to contain the same django secret that is used be the server. It can be created with:

mkdir -p /run/secrets
echo "DJANGO_SECRET_KEY='MY_SECRET'" > /run/secrets/django

With Go

When Go is installed, the service can be installed with:

go install github.com/OpenSlides/openslides3-autoupdate-service/cmd/autoupdate@latest

This command is case sensitive!

After this command, the binary is installed inside the gopath. When the gopath is integrated correctly, the autoupdate service can be started with:

autoupdate

With Checked out repository and Go

When the repository is checked out, the service can be build and started with

go build ./cmd/autoupdate && ./autoupdate

With Docker

docker build . --tag openslides3-autoupdate
docker run --network host openslides3-autoupdate

This example uses the host network to connect to redis.

Example requests with curl

Curl needs the flag -N / --no-buffer or it can happen, that the output is not printed immediately. With a self signed certificat (the default of the autoupdate-service) is also needs the flag -k / --insecure.

Autoupdate

To get all data:

curl -N localhost:8002/system/autoupdate

To get all data after a change id:

curl -N localhost:8002/system/autoupdate?change_id=133188953000

To test an authenticated request, login to OpenSlides and find the given session id. Afterwards the session cookie can be used with curl:

curl -N --cookie "OpenSlidesSessionID=3e38tw8kpx64p4gxq80qf2hg4k60ix6w" localhost:8002/system/autoupdate

Projector

To get the projector data for a list of projectors:

curl -N localhost:8002/system/projector?projector_ids=1,2,3

Notify

To listen for messages:

curl -N localhost:8002/system/notify

It returns a message like this one to tell the channel id:

{"channelID": "lVbO2irQ:1:0"}

The value of channelID is just a string. The format may change in the future. Currently the first part is a random string that is constant for a server instance. The second part is the user id. The last part is a counter.

If a message is received, it has the format:

{
  "sender_user_id": int -> User id of the sender.
  "sender_channel_id": string -> Channel id of the sender.
  "name": string -> Name of the message.
  "message": json -> Message send by the sender.
}

To send a messages:

To send a notify message, you need to be logged-in. A seesion cookies has to be created and used. See the --cookie flag above.

curl localhost:8002/system/notify/send -d '{"channel_id":"foo:1:0", "name":"title", "to_all":true, "message": "some json"}'

The body has to be a valid json object with at least the fields channel_id, name, and message.

{
  "channel_id": string -> channel_id of the sender.
  "name": string -> Name of the message.
  "message": json -> valid json containing the message.
  "to_all": bool -> If true, message is send to every connection.
  "to_users": list[int] -> List of user ids that should receive the message.
  "to_channels": list[string] -> List of channel ids that should receive the message.
}

Applause:

The notify system also handels applause. To send an applause, send the following request:

curl localhost:8002/system/applause

For this to work, a sessionID is required (see above)

Run Test

To run the tests, call:

go test ./...

To replace the export.json copy it to internal/test/export.json and run:

go generate ./...

Environment variables

The service can be configured with the following environment variables:

• AUTOUPDATE_PORT:Port to listen on. The default is 8002.
• AUTOUPDATE_HOST: The device where the service starts. The default is an empty string which starts the service on every device.
• MESSAGE_BUS_HOST: Host of the redis server for reading. The default is localhost.
• MESSAGE_BUS_PORT: Port of the redis server for reading. The default is 6379.
• REDIS_WRITE_HOST: Host of the redis server for writing. The default is the same as MESSAGE_BUS_HOST.
• REDIS_WRITE_PORT: Port of the redis server for writing. The default is the same as MESSAGE_BUS_PORT.
• APPLAUSE_INTERVAL_MS: Time to calc the applause in milliseconds (Default: 1000)
• COOKIE_NAME: Name of the auth-session-cookie (Default: OpenSlidesSessionID).
• SESSION_PREFIX: Prefix of the redis session keys (Default: session:).
• FAKE_AUTH: If set, the auth system is skipped and the given user id is used for all requests (Default: -1).