💡 Add flag to enable WARP routing

[0x2b3bfa0]

Feature description

When using cloudflared tunnel to connect a network, users have to enable WARP routing by writing a config.yml file or using RemoteConfig as showcased below to let Cloudflare manage the tunnel configuration.

For people using the cloudflare/cloudflared container images, it would be more convenient to expose a --warp-routing flag instead of requiring the presence of a configuration file.

Alternative solutions

terraform {
  required_providers {
    cloudflare = {
      source  = "cloudflare/cloudflare"
      version = ">= 3.29"
    }
  }
}

data "cloudflare_accounts" "main" {
  name = "..."
}

resource "cloudflare_tunnel" "example" {
  account_id = data.cloudflare_accounts.main.accounts[0].id
  ...
  config_src = "cloudflare"
}

resource "cloudflare_tunnel_config" "iterative" {
  account_id = cloudflare_tunnel.example.account_id
  tunnel_id  = cloudflare_tunnel.example.id

  config {
    warp_routing {
      enabled = true
    }

    ingress_rule {
      service = "http_status:404"
    }
  }
}

Additional context

• Add WARP routing flag #1011

Problem description

While some container orchestrators can easily inject configuration files into containers using e.g. Kubernetes (ConfigMap), others like AWS ECS don't provide any straightforward way of achieving this.

Given that the official cloudflared container images don't even include a shell binary, this use case would require building and hosting a new container image to include the configuration file. Other solutions, like mounting volumes from an ad-hoc sidecar container would be still more cumbersome.

[joliveirinha]

We discussed this and for now we decided to not support this via command line argument.
The reasoning is because we are actually considering removing this config flag from the configuration in the future.

The reason why it was initially added was as an extra feature flag when TCP traffic was supported.

Furthermore, if you use remotely managed tunnels, this flag is actually managed automatically depending if the tunnel has routes associated to it or not.