Refactor linux-pop-extension into Cosmic Containers applet for managing Docker containers. Update AGENTS.md and README.md for improved clarity on functionality and usage. Enhance Cargo.toml with new dependencies and features, and modify CHANGELOG.md to reflect added features and changes. Revise desktop entry and metainfo for branding consistency.

Author: vaulttec-dev

AGENTS.md

@@ -10,7 +10,7 @@
 
 ## Overview
 
-Rust crate (`linux-pop-extension`): **COSMIC panel applet** for Pop!_OS via `libcosmic` (`cosmic::applet::run`). Binary requires feature `applet` and system Wayland/GTK-related dev packages. See `README.md` for install and “Add widget” steps.
+Rust crate (`linux-pop-extension`): **Cosmic Containers** — COSMIC panel applet for Pop!_OS that lists and starts/stops Docker containers via CLI (`libcosmic`, `cosmic::applet::run`). Binary requires feature `applet`, Docker in PATH, and system Wayland/GTK-related dev packages. See `README.md` for install and “Add widget” steps.
 
 **Chat language**: Reply to the user in **Ukrainian** unless they ask for another language. Keep code, identifiers, commits, and this file in **English**.
 
@@ -63,16 +63,17 @@ Prefer `cargo check` for fast feedback during edits; run `cargo build` or `cargo
 linux-pop-extension/
   AGENTS.md              # This file
   Cargo.toml             # `applet` feature → libcosmic
-  src/lib.rs             # APP_ID, PANEL_EMOJI (unit tests)
+  src/lib.rs             # APP_ID, ContainerSummary, parse_ps_output
   src/main.rs            # cosmic::applet::run
-  src/app.rs             # Application impl (panel view)
+  src/app.rs             # Application impl (panel + popup)
+  src/services/docker.rs # async docker CLI
   resources/             # .desktop, metainfo, icon
   scripts/install-local.sh
   .githooks/
   .cursor/skills/
 ```
 
-Panel UI lives in `src/app.rs`; shared constants in `src/lib.rs`. Register applets with `X-CosmicApplet=true` in `resources/*.desktop`.
+Panel UI lives in `src/app.rs`; parsing and types in `src/lib.rs`; Docker in `src/services/docker.rs`. Register applets with `X-CosmicApplet=true` in `resources/*.desktop`.
 
 ## Testing
 

CHANGELOG.md

@@ -9,8 +9,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- Click popup on panel smiley (toggle open/close with greeting text)
-- COSMIC panel applet using `libcosmic` (smiley `😀` on the panel)
+- **Cosmic Containers**: panel badge with running Docker container count
+- Popup list from `docker ps -a` (async CLI, non-blocking UI)
+- **Play** / **Stop** per container with automatic list refresh
+- Docker error hints (missing CLI, daemon, permission denied)
+- `src/services/docker.rs` and `ContainerSummary` parser with unit tests
+
+### Changed
+
+- Replaced smiley demo with Docker manager UI
+- Desktop/metainfo branding: **Cosmic Containers**
+
+### Added (initial scaffold)
+
+- COSMIC panel applet using `libcosmic` with popup support
 - Desktop entry and AppStream metainfo for **Add widget** in COSMIC settings
 - `scripts/install-local.sh` for `~/.local` installation
 - Optional `applet` feature so library tests build without GUI system libraries

Cargo.lock

@@ -3,7 +3,7 @@ name = "linux-pop-extension"
 version = "0.1.0"
 edition = "2024"
 license = "MIT"
-description = "COSMIC panel applet for Pop!_OS (smiley starter widget)"
+description = "COSMIC panel applet for Pop!_OS — Docker container manager on the panel"
 readme = "README.md"
 
 [features]
@@ -19,6 +19,7 @@ path = "src/main.rs"
 required-features = ["applet"]
 
 [dependencies]
+tokio = { version = "1", features = ["process", "rt"] }
 libcosmic = { git = "https://github.com/pop-os/libcosmic.git", optional = true, features = [
     "applet",
     "tokio",

Cargo.toml

@@ -1,10 +1,11 @@
-# linux-pop-extension
+# Cosmic Containers (linux-pop-extension)
 
-COSMIC panel applet for **Pop!_OS** (COSMIC desktop). Starter widget that shows a smiley on the panel and can be added from system settings.
+COSMIC panel applet for **Pop!_OS**: manage Docker containers from the panel — running count at a glance, list in a popup, **Play** / **Stop** without keeping a terminal open on `docker ps`.
 
 ## Requirements
 
 - **Pop!_OS 24.04+** (or another distro with COSMIC panel)
+- **Docker** CLI (`docker` in `PATH`, daemon running, user in `docker` group or rootless Docker)
 - Rust 1.85 or newer (edition 2024)
 - System libraries for building `libcosmic`:
 
@@ -35,8 +36,17 @@ This installs to `~/.local` (binary, `.desktop`, AppStream metainfo, icon).
 
 1. Restart the panel or log out and back in (if the widget list does not update).
 2. Open **Settings → Desktop → Panel → Widgets → Add widget**.
-3. Select **Linux Pop Extension** → **Add**.
-4. The panel shows **😀**.
+3. Select **Cosmic Containers** (desktop id: `dev.linuxpop.Extension`) → **Add**.
+4. The panel shows the number of **running** containers (`0`, `1`, …). Click to open the list.
+
+## Usage
+
+| Panel | Meaning |
+|-------|---------|
+| `N` | `N` containers in `running` state |
+| `!` | Docker error (not installed, daemon down, or permission denied) |
+
+In the popup: **Refresh**, **Play** (start stopped container), **Stop** (stop running container).
 
 ## Development
 
@@ -67,7 +77,9 @@ cargo test --lib --no-default-features && cargo test --all-features
 | Item | Description |
 |------|-------------|
 | `APP_ID` | Desktop entry ID: `dev.linuxpop.Extension` |
-| `PANEL_EMOJI` | Panel label text (`😀`) |
+| `ContainerSummary` | Parsed `name` + `state` from `docker ps` |
+| `parse_ps_output` | Parse CLI stdout (`name\|state` per line) |
+| `running_count` | Count containers with `running` state |
 
 ## Contributing
 

README.md

@@ -1,14 +1,14 @@
 [Desktop Entry]
-Name=Linux Pop Extension
-Name[uk]=Linux Pop Extension
-Comment=Panel widget with smiley and click popup
-Comment[uk]=Віджет панелі зі смайликом і popup по кліку
+Name=Cosmic Containers
+Name[uk]=Cosmic Containers
+Comment=Docker container manager on the COSMIC panel
+Comment[uk]=Менеджер Docker-контейнерів на панелі COSMIC
 Type=Application
 Icon=dev.linuxpop.Extension
 Exec=linux-pop-extension
 Terminal=false
 StartupNotify=true
 Categories=COSMIC
-Keywords=COSMIC
+Keywords=COSMIC;Docker;containers;
 NoDisplay=true
 X-CosmicApplet=true

resources/dev.linuxpop.Extension.desktop

@@ -3,21 +3,24 @@
   <id>dev.linuxpop.Extension</id>
   <metadata_license>CC0-1.0</metadata_license>
   <project_license>MIT</project_license>
-  <name>Linux Pop Extension</name>
-  <summary>Simple COSMIC panel widget (smiley starter)</summary>
+  <name>Cosmic Containers</name>
+  <summary>Docker container manager for the COSMIC panel</summary>
   <description>
-    <p>A starter panel applet for Pop!_OS COSMIC that shows a smiley on the panel.</p>
+    <p>Panel applet for Pop!_OS COSMIC: shows how many Docker containers are running, lists all containers in a popup, and lets you start or stop them without a terminal.</p>
+    <p>Requires the Docker CLI and a running Docker daemon.</p>
   </description>
   <launchable type="desktop-id">dev.linuxpop.Extension.desktop</launchable>
   <provides>
     <binary>linux-pop-extension</binary>
   </provides>
   <categories>
     <category>COSMIC</category>
+    <category>Development</category>
   </categories>
   <keywords>
     <keyword>COSMIC</keyword>
     <keyword>applet</keyword>
-    <keyword>widget</keyword>
+    <keyword>Docker</keyword>
+    <keyword>containers</keyword>
   </keywords>
 </component>

resources/dev.linuxpop.Extension.metainfo.xml

@@ -1,24 +1,62 @@
 use cosmic::app::{Core, Task};
+use cosmic::iced::Length;
+use cosmic::iced::alignment::Alignment;
 use cosmic::iced::theme::Style;
 use cosmic::iced::window;
 use cosmic::iced::window::Id;
 use cosmic::prelude::*;
 use cosmic::surface::action::{app_popup, destroy_popup};
 use cosmic::widget;
-use linux_pop_extension::{PANEL_EMOJI, POPUP_GREETING};
+use linux_pop_extension::services::docker;
+use linux_pop_extension::{ContainerSummary, running_count};
 
 /// COSMIC panel applet state.
 #[derive(Default)]
 pub struct App {
     core: Core,
     popup: Option<Id>,
+    containers: Vec<ContainerSummary>,
+    loading: bool,
+    error: Option<String>,
 }
 
-/// Messages from the panel button and popup lifecycle.
+/// Messages from the panel button, popup, and Docker CLI results.
 #[derive(Clone, Debug)]
 pub enum Message {
     PopupClosed(Id),
     TogglePopup,
+    Refresh,
+    ContainersLoaded(Result<Vec<ContainerSummary>, String>),
+    Start(String),
+    Stop(String),
+}
+
+impl App {
+    fn panel_label(&self) -> String {
+        if self.error.is_some() && self.containers.is_empty() {
+            return "!".to_string();
+        }
+        format!("{}", running_count(&self.containers))
+    }
+
+    fn fetch_containers_task() -> Task<Message> {
+        Task::perform(docker::list_containers(), |result| {
+            cosmic::Action::App(Message::ContainersLoaded(result))
+        })
+    }
+
+    fn apply_loaded(&mut self, result: Result<Vec<ContainerSummary>, String>) {
+        self.loading = false;
+        match result {
+            Ok(containers) => {
+                self.containers = containers;
+                self.error = None;
+            }
+            Err(err) => {
+                self.error = Some(err);
+            }
+        }
+    }
 }
 
 impl cosmic::Application for App {
@@ -37,7 +75,13 @@ impl cosmic::Application for App {
     }
 
     fn init(core: Core, _flags: Self::Flags) -> (Self, Task<Self::Message>) {
-        (Self { core, popup: None }, Task::none())
+        (
+            Self {
+                core,
+                ..Default::default()
+            },
+            Self::fetch_containers_task(),
+        )
     }
 
     fn on_close_requested(&self, id: window::Id) -> Option<Self::Message> {
@@ -57,29 +101,51 @@ impl cosmic::Application for App {
                         cosmic::app::Action::Surface(destroy_popup(id)),
                     ));
                 }
-                return cosmic::task::message(cosmic::Action::Cosmic(
+                self.loading = true;
+                let fetch = Self::fetch_containers_task();
+                let open = cosmic::task::message(cosmic::Action::Cosmic(
                     cosmic::app::Action::Surface(app_popup::<App>(
                         |state: &mut App| {
                             let new_id = Id::unique();
                             state.popup = Some(new_id);
                             state.core.applet.get_popup_settings(
                                 state.core.main_window_id().unwrap(),
                                 new_id,
-                                None,
+                                Some((360, 420)),
                                 None,
                                 None,
                             )
                         },
                         Some(Box::new(popup_view)),
                     )),
                 ));
+                return Task::batch([open, fetch]);
+            }
+            Message::Refresh => {
+                self.loading = true;
+                return Self::fetch_containers_task();
+            }
+            Message::ContainersLoaded(result) => {
+                self.apply_loaded(result);
+            }
+            Message::Start(name) => {
+                self.loading = true;
+                return Task::perform(docker::start_then_list(name), |result| {
+                    cosmic::Action::App(Message::ContainersLoaded(result))
+                });
+            }
+            Message::Stop(name) => {
+                self.loading = true;
+                return Task::perform(docker::stop_then_list(name), |result| {
+                    cosmic::Action::App(Message::ContainersLoaded(result))
+                });
             }
         }
         Task::none()
     }
 
     fn view(&self) -> Element<'_, Self::Message> {
-        widget::button::text(PANEL_EMOJI)
+        widget::button::text(self.panel_label())
             .padding(4)
             .on_press(Message::TogglePopup)
             .into()
@@ -95,12 +161,53 @@ impl cosmic::Application for App {
 }
 
 fn popup_view(state: &App) -> Element<'_, cosmic::Action<Message>> {
-    let content = widget::column![
-        widget::text(PANEL_EMOJI).size(28),
-        widget::text(POPUP_GREETING),
-    ]
-    .spacing(8)
-    .padding(12);
-
-    Element::from(state.core.applet.popup_container(content)).map(cosmic::Action::App)
+    let mut content = widget::column![].spacing(6).padding(12);
+
+    content = content.push(
+        widget::row![
+            widget::text("Containers").size(18),
+            widget::button::text("Refresh").on_press(Message::Refresh),
+        ]
+        .align_y(Alignment::Center)
+        .spacing(12),
+    );
+
+    if state.loading {
+        content = content.push(widget::text("Loading..."));
+    }
+
+    if let Some(err) = &state.error {
+        content = content.push(widget::text(err).size(12));
+    }
+
+    if state.containers.is_empty() && !state.loading && state.error.is_none() {
+        content = content.push(widget::text("No containers."));
+    }
+
+    for container in &state.containers {
+        let name = container.name.clone();
+        let line = format!("{} — {}", container.name, container.state);
+        let row = if container.is_running() {
+            widget::row![
+                widget::text(line).width(Length::FillPortion(3)),
+                widget::button::text("Stop").on_press(Message::Stop(name)),
+            ]
+        } else {
+            widget::row![
+                widget::text(line).width(Length::FillPortion(3)),
+                widget::button::text("Play").on_press(Message::Start(name)),
+            ]
+        };
+        content = content.push(row.align_y(Alignment::Center).spacing(8));
+    }
+
+    Element::from(
+        state
+            .core
+            .applet
+            .popup_container(content)
+            .max_width(360.0)
+            .max_height(420.0),
+    )
+    .map(cosmic::Action::App)
 }