[UX] Improve dstack fleet output layout (#3529)

* [UX] Make `dstack fleet` show more useful information

* Do not show "(no instances" row placeholder for empty fleets; removed unecessary docstrings and comments.

* Linter and pyright

* PR review feedback

Author: peterschmidt85

src/dstack/_internal/cli/utils/fleet.py

@@ -1,11 +1,12 @@
-from typing import List
+from typing import Any, Dict, List, Optional, Union
 
 from rich.table import Table
 
 from dstack._internal.cli.utils.common import add_row_from_dict, console
 from dstack._internal.core.models.backends.base import BackendType
-from dstack._internal.core.models.fleets import Fleet, FleetStatus
-from dstack._internal.core.models.instances import InstanceStatus
+from dstack._internal.core.models.fleets import Fleet, FleetNodesSpec, FleetStatus
+from dstack._internal.core.models.instances import Instance, InstanceStatus
+from dstack._internal.core.models.resources import GPUSpec, ResourcesSpec
 from dstack._internal.utils.common import DateFormatter, pretty_date
 
 
@@ -18,89 +19,270 @@ def get_fleets_table(
     fleets: List[Fleet], verbose: bool = False, format_date: DateFormatter = pretty_date
 ) -> Table:
     table = Table(box=None)
-    table.add_column("FLEET", no_wrap=True)
+
+    # Columns
+    table.add_column("NAME", style="bold", no_wrap=True)
+    table.add_column("NODES")
     if verbose:
-        table.add_column("RESERVATION")
-    table.add_column("INSTANCE")
+        table.add_column("RESOURCES")
+    else:
+        table.add_column("GPU")
+    table.add_column("SPOT")
     table.add_column("BACKEND")
-    if verbose:
-        table.add_column("REGION")
-    table.add_column("RESOURCES")
     table.add_column("PRICE")
-    table.add_column("STATUS")
-    table.add_column("CREATED")
-
+    table.add_column("STATUS", no_wrap=True)
+    table.add_column("CREATED", no_wrap=True)
     if verbose:
         table.add_column("ERROR")
 
     for fleet in fleets:
-        for i, instance in enumerate(fleet.instances):
-            resources = ""
-            if instance.instance_type is not None and (
-                instance.backend != BackendType.REMOTE
-                or instance.status not in [InstanceStatus.PENDING, InstanceStatus.PROVISIONING]
-            ):
-                resources = instance.instance_type.resources.pretty_format(include_spot=True)
-
-            status = instance.status.value
-            total_blocks = instance.total_blocks
-            busy_blocks = instance.busy_blocks
-            if (
-                instance.status in [InstanceStatus.IDLE, InstanceStatus.BUSY]
-                and total_blocks is not None
-                and total_blocks > 1
-            ):
-                status = f"{busy_blocks}/{total_blocks} {InstanceStatus.BUSY.value}"
-            if instance.status in [InstanceStatus.IDLE, InstanceStatus.BUSY]:
-                if instance.unreachable:
-                    status += "\n(unreachable)"
-                elif not instance.health_status.is_healthy():
-                    status += f"\n({instance.health_status.value})"
-
-            backend = instance.backend or ""
-            if backend == "remote":
-                backend = "ssh"
-
-            region = ""
-            if instance.region:
-                region = f"{instance.region}"
-                if verbose:
-                    if instance.availability_zone:
-                        region += f" ({instance.availability_zone})"
-                else:
-                    backend += f" ({instance.region})"
-            error = ""
-            if instance.status == InstanceStatus.TERMINATED and instance.termination_reason:
-                error = f"{instance.termination_reason}"
-            row = {
-                "FLEET": fleet.name if i == 0 else "",
-                "RESERVATION": fleet.spec.configuration.reservation or "" if i == 0 else "",
-                "INSTANCE": str(instance.instance_num),
-                "BACKEND": backend,
-                "REGION": region,
-                "RESOURCES": resources,
-                "PRICE": f"${instance.price:.4f}".rstrip("0").rstrip(".")
-                if instance.price is not None
-                else "",
-                "STATUS": status,
+        # Fleet row
+        config = fleet.spec.configuration
+        merged_profile = fleet.spec.merged_profile
+
+        # Detect SSH fleet vs backend fleet
+        if config.ssh_config is not None:
+            # SSH fleet: fixed number of hosts, no cloud billing
+            nodes = str(len(config.ssh_config.hosts))
+            backend = "ssh"
+            spot_policy = "-"
+            max_price = "-"
+        else:
+            # Backend fleet: dynamic nodes, cloud billing
+            nodes = _format_nodes(config.nodes)
+            backend = _format_backends(config.backends)
+            spot_policy = "-"
+            if merged_profile and merged_profile.spot_policy:
+                spot_policy = merged_profile.spot_policy.value
+            # Format as "$0..$X.XX" range, or "-" if not set
+            if merged_profile and merged_profile.max_price is not None:
+                max_price = f"$0..{_format_price(merged_profile.max_price)}"
+            else:
+                max_price = "-"
+
+        # In verbose mode, append placement to nodes if cluster
+        if verbose and config.placement and config.placement.value == "cluster":
+            nodes = f"{nodes} (cluster)"
+
+        fleet_row: Dict[Union[str, int], Any] = {
+            "NAME": fleet.name,
+            "NODES": nodes,
+            "BACKEND": backend,
+            "PRICE": max_price,
+            "SPOT": spot_policy,
+            "STATUS": _format_fleet_status(fleet),
+            "CREATED": format_date(fleet.created_at),
+        }
+
+        if verbose:
+            fleet_row["RESOURCES"] = config.resources.pretty_format() if config.resources else "-"
+            fleet_row["ERROR"] = ""
+        else:
+            fleet_row["GPU"] = _format_fleet_gpu(config.resources)
+
+        add_row_from_dict(table, fleet_row)
+
+        # Instance rows (indented)
+        for instance in fleet.instances:
+            # Check if this is an SSH instance
+            is_ssh_instance = instance.backend == BackendType.REMOTE
+
+            # Format backend with region (and AZ in verbose mode)
+            if verbose and instance.availability_zone:
+                # In verbose mode, show AZ instead of region (AZ is more specific)
+                backend_with_region = _format_backend(instance.backend, instance.availability_zone)
+            else:
+                backend_with_region = _format_backend(instance.backend, instance.region)
+
+            # Get spot info from instance resources (not applicable to SSH)
+            if is_ssh_instance:
+                instance_spot = "-"
+                instance_price = "-"
+            else:
+                instance_spot = "-"
+                if (
+                    instance.instance_type is not None
+                    and instance.instance_type.resources is not None
+                ):
+                    instance_spot = (
+                        "spot" if instance.instance_type.resources.spot else "on-demand"
+                    )
+                instance_price = _format_price(instance.price)
+
+            instance_row: Dict[Union[str, int], Any] = {
+                "NAME": f"   instance={instance.instance_num}",
+                "NODES": "",
+                "BACKEND": backend_with_region,
+                "PRICE": instance_price,
+                "SPOT": instance_spot,
+                "STATUS": _format_instance_status(instance),
                 "CREATED": format_date(instance.created),
-                "ERROR": error,
             }
-            add_row_from_dict(table, row)
-
-        if len(fleet.instances) == 0 and fleet.status != FleetStatus.TERMINATING:
-            row = {
-                "FLEET": fleet.name,
-                "RESERVATION": "-",
-                "INSTANCE": "-",
-                "BACKEND": "-",
-                "REGION": "-",
-                "RESOURCES": "-",
-                "PRICE": "-",
-                "STATUS": "-",
-                "CREATED": format_date(fleet.created_at),
-                "ERROR": "-",
-            }
-            add_row_from_dict(table, row)
+
+            if verbose:
+                instance_row["RESOURCES"] = _format_instance_resources(instance)
+                error = ""
+                if instance.status == InstanceStatus.TERMINATED and instance.termination_reason:
+                    error = instance.termination_reason
+                instance_row["ERROR"] = error
+            else:
+                instance_row["GPU"] = _format_instance_gpu(instance)
+
+            add_row_from_dict(table, instance_row, style="secondary")
 
     return table
+
+
+def _format_nodes(nodes: Optional[FleetNodesSpec]) -> str:
+    """Format nodes spec as '0..1', '3', '2..10', etc."""
+    if nodes is None:
+        return "-"
+    if nodes.min == nodes.max:
+        return str(nodes.min)
+    if nodes.max is None:
+        return f"{nodes.min}.."
+    return f"{nodes.min}..{nodes.max}"
+
+
+def _format_backends(backends: Optional[List[BackendType]]) -> str:
+    if backends is None or len(backends) == 0:
+        return "*"
+    return ", ".join(b.value.replace("remote", "ssh") for b in backends)
+
+
+def _format_range(min_val: Optional[Any], max_val: Optional[Any]) -> str:
+    if min_val is None and max_val is None:
+        return ""
+    if min_val == max_val:
+        return str(min_val)
+    if max_val is None:
+        return f"{min_val}.."
+    if min_val is None:
+        return f"..{max_val}"
+    return f"{min_val}..{max_val}"
+
+
+def _format_fleet_gpu(resources: Optional[ResourcesSpec]) -> str:
+    """Extract GPU-only info from fleet requirements, handling ranges."""
+    if resources is None or resources.gpu is None:
+        return "-"
+
+    gpu: GPUSpec = resources.gpu
+
+    # Check if there's actually a GPU requirement
+    count = gpu.count
+    if count is None or (count.min == 0 and (count.max is None or count.max == 0)):
+        return "-"
+
+    parts = []
+
+    # GPU name(s)
+    if gpu.name:
+        parts.append(",".join(gpu.name))
+    else:
+        parts.append("gpu")
+
+    # GPU memory (range)
+    if gpu.memory is not None:
+        mem_str = _format_range(gpu.memory.min, gpu.memory.max)
+        if mem_str:
+            parts.append(mem_str)
+
+    # GPU count (range)
+    count_str = _format_range(count.min, count.max)
+    if count_str:
+        parts.append(count_str)
+
+    return ":".join(parts)
+
+
+def _format_fleet_status(fleet: Fleet) -> str:
+    status = fleet.status
+    status_text = status.value
+
+    color_map = {
+        FleetStatus.SUBMITTED: "grey",
+        FleetStatus.ACTIVE: "white",
+        FleetStatus.TERMINATING: "deep_sky_blue1",
+        FleetStatus.TERMINATED: "grey",
+        FleetStatus.FAILED: "indian_red1",
+    }
+    color = color_map.get(status, "white")
+    is_finished = status in [FleetStatus.TERMINATED, FleetStatus.FAILED]
+    status_style = f"bold {color}" if not is_finished else color
+    return f"[{status_style}]{status_text}[/]"
+
+
+def _format_instance_status(instance: Instance) -> str:
+    """Format instance status with colors and health info."""
+    status = instance.status
+    status_text = status.value
+
+    total_blocks = instance.total_blocks
+    busy_blocks = instance.busy_blocks
+    if (
+        status in [InstanceStatus.IDLE, InstanceStatus.BUSY]
+        and total_blocks is not None
+        and total_blocks > 1
+    ):
+        status_text = f"{busy_blocks}/{total_blocks} {InstanceStatus.BUSY.value}"
+
+    # Add health status
+    health_suffix = ""
+    if status in [InstanceStatus.IDLE, InstanceStatus.BUSY]:
+        if instance.unreachable:
+            health_suffix = " (unreachable)"
+        elif not instance.health_status.is_healthy():
+            health_suffix = f" ({instance.health_status.value})"
+
+    color_map = {
+        InstanceStatus.PENDING: "deep_sky_blue1",
+        InstanceStatus.PROVISIONING: "deep_sky_blue1",
+        InstanceStatus.IDLE: "sea_green3",
+        InstanceStatus.BUSY: "white",
+        InstanceStatus.TERMINATING: "deep_sky_blue1",
+        InstanceStatus.TERMINATED: "grey",
+    }
+    color = color_map.get(status, "white")
+    is_finished = status == InstanceStatus.TERMINATED
+    status_style = f"bold {color}" if not is_finished else color
+    return f"[{status_style}]{status_text}{health_suffix}[/]"
+
+
+def _format_backend(backend: Optional[BackendType], region: Optional[str]) -> str:
+    if backend is None:
+        return "-"
+    backend_str = backend.value
+    if backend == BackendType.REMOTE:
+        backend_str = "ssh"
+    if region:
+        backend_str += f" ({region})"
+    return backend_str
+
+
+def _format_price(price: Optional[float]) -> str:
+    if price is None:
+        return "-"
+    return f"${price:.4f}".rstrip("0").rstrip(".")
+
+
+def _format_instance_gpu(instance: Instance) -> str:
+    if instance.instance_type is None:
+        return "-"
+    if instance.backend == BackendType.REMOTE and instance.status in [
+        InstanceStatus.PENDING,
+        InstanceStatus.PROVISIONING,
+    ]:
+        return "-"
+    return instance.instance_type.resources.pretty_format(gpu_only=True, include_spot=False) or "-"
+
+
+def _format_instance_resources(instance: Instance) -> str:
+    if instance.instance_type is None:
+        return "-"
+    if instance.backend == BackendType.REMOTE and instance.status in [
+        InstanceStatus.PENDING,
+        InstanceStatus.PROVISIONING,
+    ]:
+        return "-"
+    return instance.instance_type.resources.pretty_format(include_spot=False)