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Edge Proxy

Configuration​

The Edge Proxy can be configured using a json configuration file (named config.json here).

You can set the following configuration in config.json to control the behaviour of the Edge Proxy:

environment_key_pairs​

An array of environment key pair objects:

"environment_key_pairs": [{
  "server_side_key": "your_server_side_key",
  "client_side_key": "your_client_side_environment_key"
}]

api_poll_frequency​

note

This setting is optional.

Control how often the Edge Proxy is going to ping the server for changes, in seconds:

"api_poll_frequency": 30

Defaults to 10.

api_poll_timeout​

note

This setting is optional.

Specify the request timeout when trying to retrieve new changes, in seconds:

"api_poll_timeout": 1

Defaults to 5.

api_url​

note

This setting is optional.

Set if you are running a self hosted version of Flagsmith:

"api_url": "https://my-flagsmith.domain.com/api/v1"

If not set, defaults to Flagsmith's Edge API.

allow_origins​

note

This setting is optional.

Set a value for the Access-Control-Allow-Origin header.

"allow_origins": "https://my-flagsmith.domain.com"

If not set, defaults to *.

endpoint_caches​

note

This setting is optional.

Enable a LRU cache per endpoint.

Optionally, specify the LRU cache size with cache_max_size (defaults to 128):

"endpoint_caches": {
  "flags": {
    "use_cache": false
  },
  "identities": {
    "use_cache": true,
    "cache_max_size": 1000,
  }
}

logging.log_level​

note

This setting is optional.

Choose a logging level from "CRITICAL", "ERROR", "WARNING", "INFO", "DEBUG". Defaults to "INFO".

"logging": {"log_level": "DEBUG"}

logging.log_format​

note

This setting is optional.

Choose a logging forman between "generic" and "json". Defaults to "generic".

"logging": {"log_format": "json"}

logging.log_event_field_name​

note

This setting is optional.

Set a name used for human-readable log entry field when logging events in JSON. Defaults to "message".

"logging": {"log_event_field_name": "event"}

config.json example​

Here's an example of a minimal working Edge Proxy configuration:

{
 "environment_key_pairs": [
  {
   "server_side_key": "your_server_side_environment_key",
   "client_side_key": "your_client_side_environment_key"
  }
 ],
 "api_poll_frequency": 10,
 "api_url": "https://api.flagsmith.com/api/v1"
}

Environment Variables​

You can configure the Edge Proxy with the following Environment Variables:

  • WEB_CONCURRENCY The number of Uvicorn workers. Defaults to 1. Set to the number of available CPU cores.

Running the Edge Proxy​

The Edge Proxy runs as a docker container. It is currently available at the Docker Hub.

With docker run​

# Download the Docker Image
docker pull flagsmith/edge-proxy

# Run it
docker run \
    -v /<path-to-local>/config.json:/app/config.json \
    -p 8000:8000 \
    flagsmith/edge-proxy:latest

With docker compose​

version: '3.9'
services:
 edge_proxy:
  image: flagsmith/edge-proxy:latest
  volumes:
   - type: bind
     source: ./config.json
     target: /app/config.json
  ports:
   - target: 8000
   - published: 8000

The Proxy is now running and available on port 8000.

Consuming the Edge Proxy​

The Edge Proxy provides an identical set of API methods as our Core API. You need to point your SDK to the Edge Proxy domain name and you're good to go. For example, lets say you had your proxy running locally as per the instructions above:

curl "http://localhost:8000/api/v1/flags" -H "x-environment-key: 95DybY5oJoRNhxPZYLrxk4" | jq

[
    {
        "enabled": true,
        "feature_state_value": 5454,
        "feature": {
            "name": "feature_1",
            "id": 2,
            "type": "MULTIVARIATE"
        }
    },
    {
        "enabled": true,
        "feature_state_value": "some_value",
        "feature": {
            "name": "feature_2",
            "id": 9,
            "type": "STANDARD"
        }
    },
]

Monitoring​

There are 2 health check endpoints for the Edge Proxy.

SDK Proxy Health Check​

When making a request to /proxy/health the proxy will respond with a HTTP 200 and {"status": "ok"}. You can point your orchestration health checks to this endpoint. This endpoint checks that the Environment document is not stale, and that the proxy is serving SDK requests.

Realtime Flags/Server Sent Events Health Check​

If you are using the Proxy to power Server Sent Events for realtime flag updates. When making a request to /sse/health the proxy will respond with a HTTP 200 and {"status": "ok"}.

Architecture​

The standard Flagsmith architecture:

Image

With the proxy added to the mix:

Image