Configuration

AnyCable Ruby uses anyway_config gem for configuration. Thus, it is possible to set configuration parameters through environment vars, config/anycable.yml file, etc.

When running a gRPC server via our CLI, you can also pass configuration variables as follows:

$ bundle exec anycable --rpc-host 0.0.0.0:50120 \
                       --redis-channel my_redis_channel \
                       --log-level debug

NOTE: CLI options take precedence over parameters from other sources (files, env).

Primary settings

secret (ANYCABLE_SECRET) (@since v1.5.0)

The application secret used to secure AnyCable features: signed streams, JWT authentication, etc. We recommend setting this value as a single AnyCable-related application secret and rely on libraries to glue pieces together.

streams_secret (ANYCABLE_STREAMS_SECRET) (@since v1.5.0)

A dedicated secret key used to sign streams. If none specified, the application secret is used.

broadcast_adapter (ANYCABLE_BROADCAST_ADAPTER)

Broadcasting adapter to use. Available options out-of-the-box: redis (default), http (will be default in v2), nats, redisx. For adapter specific options, see broadcast adapters documentation.

broadcast_key (ANYCABLE_BROADCAST_KEY) (@since v1.5.0)

A secret key used to authorize broadcast requests. Currently, only used by the HTTP adapter. If not set, the value is inferred from the application secret. See the broadcast adapters documentation.

JWT settings

AnyCable supports JWT authentication out-of-the-box.

AnyCable Ruby provides an API for generating tokens relying on the following configuration parameters:

jwt_secret (ANYCABLE_JWT_SECRET) (@since v1.5.0)
The secret key used to sign JWT tokens. Optional (the application secret is used if no JWT secret specified)
jwt_ttl (ANYCABLE_JWT_TTL) (@since v1.5.0)
The time-to-live (TTL) for tokens in seconds. Default: 3600 (1 hour).

Presets

AnyCable Ruby comes with a few built-in configuration presets for particular deployments environments, such as Fly. The presets are detected and activated automatically

To disable automatic presets activation, provide ANYCABLE_PRESETS=none environment variable (or pass the corresponding option to the CLI: bundle exec anycable --presets=none).

NOTE: Presets do not override explicitly provided configuration values.

Preset: fly

Automatically activated if all of the following environment variables are defined: FLY_APP_NAME, FLY_REGION, FLY_ALLOC_ID.

The preset provide the following defaults:

rpc_host: "0.0.0.0:50051"

If the ANYCABLE_FLY_WS_APP_NAME env variable is provided, the following defaults are configured as well:

nats_servers: "nats://<FLY_REGION>.<ANYCABLE_FLY_WS_APP_NAME>.internal:4222"
http_broadcast_url: "http://<FLY_REGION>.<ANYCABLE_FLY_WS_APP_NAME>.internal:8090/_broadcast"

gRPC settings

rpc_host (ANYCABLE_RPC_HOST, --rpc-host)

Local address to run gRPC server on (default: "127.0.0.1:50051"). Set it to 0.0.0.0:50051 to make gRPC server accessible to the outside world (for example, when using containerized environment).

rpc_tls_cert (ANYCABLE_RPC_TLS_CERT, --rpc-tls-cert) and rpc_tls_key (ANYCABLE_RPC_TLS_KEY, --rpc-tls-key)

Specify file paths or contents for TLS certificate and private key for gRPC server.

Concurrency settings

AnyCable gRPC server maintains a pool of worker threads to execute commands. We rely on the grpc gem default pool size, which is equal to 30.

You can configure the pool size via rpc_pool_size parameter (or ANYCABLE_RPC_POOL_SIZE env var).

Increasing pool size makes sense if you have a lot of IO operations in your channels (DB, HTTP, etc.).

NOTE: Make sure the gRPC pool size is aligned with concurrency limits you have in your application, such as database pool size.

IMPORTANT: AnyCable server concurrency limit must correlate to the RPC server pool size (read more here).

Alternative gRPC implementations

AnyCable Ruby uses the grpc gem to run its gRPC server by default. The gem heavily relies on native extensions, which may lead to complications during installation (e.g., on Alpine Linux) and compatibility issues with modern Ruby versions.

To be closer to Ruby and depend less on extensions, AnyCable Ruby also supports an alternative gRPC implementation—grpc_kit.

You can opt-in to use grpc_kit by setting ANYCABLE_GRPC_IMPL=grpc_kit environment variable for your bundle exec anycable process. You also need to update your Gemfile to include the grpc_kit gem and gRPC-less versions of AnyCable gems:

# For Rails applications
gem "anycable-rails-core", require: ["anycable-rails"]
gem "grpc_kit"

# For non-Rails applications
gem "anycable-core", require: ["anycable"]
gem "grpc_kit"

CLI

HTTP RPC