Flyctl meets JSON

Summary

Flyctl adds a --json, or -j, flag that presents command output as JSON to support automation around Fly applications. For GraphQL-backed commands it emits the API data, while logs become structured JSON and deployment progress arrives as a stream of Source/Status/Message objects. The post demonstrates piping flyctl list apps --json through jq to filter fields, convert hostnames and statuses to CSV, and select undeployed apps whose names feed xargs flyctl info --json -a; jq -s then gathers the resulting objects into an array. Because deployment output currently mixes JSON with non-JSON messages, the post recommends using --detach and polling flyctl status or running flyctl monitor instead of relying on the JSON stream for deployment monitoring.

Takeaways

1. 1

   flyctl list apps --json returns an array containing application ID, name, status, deployment state, hostname, and organization.

2. 2

   jq can transform Flyctl JSON into CSV, filter applications with .Deployed==false, and use xargs to run flyctl info --json for each matching app.

3. 3

   Deployment JSON is currently mixed with non-JSON messages, so the post advises against using that stream for monitoring and recommends --detach, flyctl status, or flyctl monitor.