Module logging 

Opt-in client-side tracing for the decdn CLI.

The CLI is a terminal UI: by default it installs no tracing subscriber, so its output is only the command’s own stdout result and the stderr progress bar. That keeps the common case clean, but it also means every tracing::debug!/info!/warn! in decdn-client, decdn-incentive, and iroh goes to a no-op collector — a stalled decdn fetch is silent on the side that is actually failing.

init turns logging on only when the operator asks for it, through -v/-vv/-vvv, --log-level, or the RUST_LOG environment variable. RUST_LOG wins (the same precedence the daemon uses), then --log-level, then the -v count (requested_level). With none of them set the CLI installs no subscriber and stays silent.

Progress-bar coexistence

decdn fetch draws an indicatif progress bar to stderr, and a plain stderr subscriber would shred it. When init installs a subscriber it also creates one process-global indicatif::MultiProgress: log lines are written through indicatif::MultiProgress::suspend, and the fetch bar is registered with the same MultiProgress (see attach_progress_bar), so the two share stderr without corrupting each other. When no subscriber is installed the bar draws straight to stderr as it always has.

Functions

attach_progress_bar

Register a freshly built progress bar with the shared indicatif::MultiProgress when a subscriber is installed, so log lines and the bar coexist on stderr.

init

Install the CLI tracing subscriber when the operator opts in.

progress_container

The indicatif::MultiProgress a multi-bar command (bundle pull) draws its bars into: the process-global one when a subscriber is installed — so its bars share stderr with log lines through indicatif::MultiProgress::suspend — or a fresh standalone container on the default silent path, where there are no log lines to coordinate with. Either way the bars stack coherently, and a non-terminal stderr auto-hides them.

requested_level

The level the command line asks for: an explicit --log-level wins over the -v count, and a zero count with no --log-level asks for nothing.