purple-ssh 3.10.1

Open-source terminal SSH manager that keeps ~/.ssh/config in sync with your cloud infra. Spin up a VM on AWS, GCP, Azure, Hetzner or 12 other cloud providers and it appears in your host list. Destroy it and the entry dims. Search hundreds of hosts, transfer files, manage Docker and Podman over SSH, sign Vault SSH certs. Rust TUI, MIT licensed.
Documentation
//! State for the global Containers tab (top_page = Containers).

use std::collections::{HashMap, HashSet, VecDeque};

use super::host_state::ViewMode;
use crate::containers::{ContainerInspect, ContainerRuntime};

/// One queued host in a `R` batch refresh: everything the listing
/// thread needs to spawn an SSH `docker ps` for that alias.
#[derive(Debug, Clone)]
pub struct RefreshQueueItem {
    pub alias: String,
    pub askpass: Option<String>,
    pub cached_runtime: Option<ContainerRuntime>,
    pub has_tunnel: bool,
}

/// State of a `R` batch refresh. None when no batch is active.
/// Drives a windowed concurrency: at most `MAX_PARALLEL` listings are
/// in flight at any time. Each `ContainerListing` event decrements
/// `in_flight` and pops the next queued item; the batch ends when
/// `queue` is empty and `in_flight` drops to zero.
#[derive(Debug, Default)]
pub struct RefreshBatch {
    pub queue: VecDeque<RefreshQueueItem>,
    pub in_flight: usize,
    /// Total host count when the batch started. used for the
    /// `Refreshing N/M` progress readout in the status footer.
    pub total: usize,
    /// Hosts whose listing has already returned (success or error).
    pub completed: usize,
    /// Aliases that the batch has spawned but not yet seen complete.
    /// Listings whose alias is NOT in this set are non-batch traffic
    /// (host-list `C`, action-complete refresh, `a`-add) and must not
    /// touch the counters. Without this guard the in-flight counter
    /// gets corrupted whenever a parallel non-batch fetch completes
    /// during a `R` run.
    pub in_flight_aliases: HashSet<String>,
}

/// Cap on parallel SSH connections during a `R` batch refresh. Picked
/// to keep load on the local SSH agent and remote sshd reasonable
/// while still amortising connection setup.
pub const REFRESH_MAX_PARALLEL: usize = 4;

/// Pending request to drop the user into a remote container shell. Set
/// by the handler when Enter is pressed on a running container; drained
/// by `handle_pending_container_exec` in the main loop, which suspends
/// the TUI, runs `ssh -t <alias> <runtime> exec -it <id> sh -c
/// 'bash || sh'`, then restores the TUI on exit.
///
/// `command` is the full remote command. `None` runs the default
/// shell (`sh -c 'bash || sh'`); `Some` runs the user-typed exec
/// prompt verbatim (validated upstream. must not contain newlines).
#[derive(Debug, Clone)]
pub struct ContainerExecRequest {
    pub alias: String,
    pub askpass: Option<String>,
    pub runtime: ContainerRuntime,
    pub container_id: String,
    /// Human-readable container name (for the log line and the toast
    /// the user sees when the session ends). Not used to build the
    /// command. the validated `container_id` is what addresses the
    /// container.
    pub container_name: String,
    /// User-supplied command. `None` falls back to the interactive
    /// shell (`sh -c 'bash || sh'`) used by the default Enter binding.
    /// `Some` is the verbatim payload from the `e` exec prompt.
    pub command: Option<String>,
}

/// Pending request to fetch container logs from a remote host. Drained
/// by the main loop into a background SSH thread; the result returns
/// via `AppEvent::ContainerLogsComplete` and lands on the
/// `Screen::ContainerLogs` overlay the user opened with `l`.
#[derive(Debug, Clone)]
pub struct ContainerLogsRequest {
    pub alias: String,
    pub askpass: Option<String>,
    pub runtime: ContainerRuntime,
    pub container_id: String,
    pub container_name: String,
}

/// Pending non-interactive container action (restart, stop). Same shape
/// as `ContainerExecRequest` but plus an action tag and minus the askpass
/// handling for an interactive shell. these run in a worker thread, not
/// the foreground TUI. Reuses `containers::ContainerAction` so the
/// command formatter (`container_action_command`) is shared.
#[derive(Debug, Clone)]
pub struct ContainerActionRequest {
    pub alias: String,
    pub askpass: Option<String>,
    pub runtime: ContainerRuntime,
    pub container_id: String,
    pub container_name: String,
    pub action: crate::containers::ContainerAction,
}

/// Sort order for the containers overview screen. Cycled with `s`.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum ContainersSortMode {
    /// Alphabetical by host alias, then container name.
    #[default]
    AlphaHost,
    /// Alphabetical by container name, then host alias.
    AlphaContainer,
}

impl ContainersSortMode {
    pub fn next(self) -> Self {
        match self {
            ContainersSortMode::AlphaHost => ContainersSortMode::AlphaContainer,
            ContainersSortMode::AlphaContainer => ContainersSortMode::AlphaHost,
        }
    }

    pub fn label(self) -> &'static str {
        match self {
            ContainersSortMode::AlphaHost => "A-Z host",
            ContainersSortMode::AlphaContainer => "A-Z container",
        }
    }

    pub fn to_key(self) -> &'static str {
        match self {
            ContainersSortMode::AlphaHost => "alpha_host",
            ContainersSortMode::AlphaContainer => "alpha_container",
        }
    }

    pub fn from_key(s: &str) -> Self {
        match s {
            "alpha_container" => ContainersSortMode::AlphaContainer,
            _ => ContainersSortMode::AlphaHost,
        }
    }
}

/// One cached `docker inspect` result, paired with the wall-clock seconds
/// at which it was fetched. The detail panel treats entries older than
/// `INSPECT_CACHE_TTL_SECS` as stale and re-fires the SSH call.
#[derive(Debug, Clone)]
pub struct InspectCacheEntry {
    pub timestamp: u64,
    pub result: Result<ContainerInspect, String>,
}

/// Detail-panel inspect cache and in-flight tracking. Keyed on the full
/// container ID rather than `(alias, container_id)` because `docker`
/// container IDs are globally unique 64-char hex strings. collisions
/// across hosts are practically impossible. Keeps the key shape simple.
#[derive(Debug, Default)]
pub struct InspectCache {
    pub entries: HashMap<String, InspectCacheEntry>,
    /// Container IDs with a pending background `inspect` thread. Prevents
    /// re-firing while a previous fetch is still in flight.
    pub in_flight: HashSet<String>,
}

/// One cached `docker logs --tail N` result. Same TTL semantics as
/// `InspectCacheEntry`: the LOGS card on the detail panel re-fires the
/// SSH call once the entry is older than `LOGS_CACHE_TTL_SECS`.
#[derive(Debug, Clone)]
pub struct LogsCacheEntry {
    pub timestamp: u64,
    pub result: Result<Vec<String>, String>,
}

/// Detail-panel logs cache and in-flight tracking. Mirrors `InspectCache`
/// so the LOGS card and the inspect cards refresh on the same rhythm.
#[derive(Debug, Default)]
pub struct LogsCache {
    pub entries: HashMap<String, LogsCacheEntry>,
    pub in_flight: HashSet<String>,
}

/// Cache TTL in seconds. Kept short so resource-y fields like
/// `RestartCount` and `Health.Status` do not lag too far behind reality
/// while still avoiding an SSH storm when the user scrolls a long list.
pub const INSPECT_CACHE_TTL_SECS: u64 = 30;

/// TTL for the per-container `docker logs --tail` cache feeding the
/// LOGS card. Same value as the inspect cache so a single user-driven
/// refresh re-fires both streams in lockstep.
pub const LOGS_CACHE_TTL_SECS: u64 = 30;

/// How many log lines the LOGS card requests via `--tail`. Sized for
/// the worst-case panel height we expect (a tall terminal can fit
/// dozens of lines inside the card); the renderer slices the trailing
/// `inner_capacity` rows so a short panel only paints what fits.
pub const LOGS_TAIL: usize = 50;

/// TTL for the per-host `docker ps` cache used by the auto-list-refresh
/// helper. When the user scrolls to a row whose host has a stale (or
/// missing) entry in `container_cache`, we re-fire the listing so the
/// running/exited counts and uptime in the visible row reflect reality.
/// Same value as the inspect TTL so the two refresh streams stay
/// loosely in lockstep.
pub const LIST_CACHE_TTL_SECS: u64 = 30;

#[derive(Debug)]
pub struct ContainersOverviewState {
    pub sort_mode: ContainersSortMode,
    pub inspect_cache: InspectCache,
    pub logs_cache: LogsCache,
    /// Currently-running `R` batch, if any. `None` when idle.
    pub refresh_batch: Option<RefreshBatch>,
    /// Aliases whose `docker ps` listing was kicked off by the
    /// scroll-driven auto-refresh helper and has not yet returned.
    /// Lets the helper skip a re-spawn while one is already pending.
    /// Cleared by `handle_container_listing` on arrival.
    pub auto_list_in_flight: HashSet<String>,
    /// Toggle for the per-row detail panel on the right. Mirrors the
    /// host-list `v` toggle. Default `Detailed` so the panel is visible
    /// whenever the terminal is wide enough.
    pub view_mode: ViewMode,
    /// Aliases whose container group is currently collapsed in the
    /// AlphaHost rendering. Persisted across sessions via preferences
    /// so a folded group stays folded after restart.
    pub collapsed_hosts: HashSet<String>,
    /// Memoized render list. The render and handler paths call
    /// `visible_items` repeatedly (24 call sites, several per key
    /// event) and each call cloned 6 String fields per container. The
    /// cache stores the built `Vec<ContainerListItem>` keyed on a
    /// content fingerprint over the inputs (sort_mode, search query,
    /// collapsed_hosts, per-host (timestamp, container_count)). On a
    /// hit we skip the collect/sort/intersperse step entirely and
    /// return a clone of the cached vec. The fingerprint walks all
    /// hosts but only reads a few fields each, so it is dramatically
    /// cheaper than rebuilding the row set.
    pub view_cache:
        std::cell::RefCell<Option<(u64, Vec<crate::ui::containers_overview::ContainerListItem>)>>,
}

impl Default for ContainersOverviewState {
    fn default() -> Self {
        Self {
            sort_mode: ContainersSortMode::default(),
            inspect_cache: InspectCache::default(),
            logs_cache: LogsCache::default(),
            refresh_batch: None,
            auto_list_in_flight: HashSet::new(),
            view_mode: ViewMode::Detailed,
            collapsed_hosts: HashSet::new(),
            view_cache: std::cell::RefCell::new(None),
        }
    }
}

impl InspectCache {
    /// Returns `Some(entry)` only when the cache holds a *fresh* entry
    /// for `container_id` (`now - timestamp < TTL`). Stale entries
    /// behave like absent ones so the trigger code re-fetches.
    pub fn fresh(&self, container_id: &str, now: u64) -> Option<&InspectCacheEntry> {
        self.entries
            .get(container_id)
            .filter(|e| now.saturating_sub(e.timestamp) < INSPECT_CACHE_TTL_SECS)
    }
}

impl LogsCache {
    /// Same fresh-window contract as `InspectCache::fresh`, against
    /// `LOGS_CACHE_TTL_SECS`.
    pub fn fresh(&self, container_id: &str, now: u64) -> Option<&LogsCacheEntry> {
        self.entries
            .get(container_id)
            .filter(|e| now.saturating_sub(e.timestamp) < LOGS_CACHE_TTL_SECS)
    }
}