Add bns logs command for streaming container logs

[alexo-bunnyshell]

Summary

This PR adds a new top-level bns logs command that streams container application logs (stdout/stderr) from Kubernetes pods with support for multi-component streaming and multiple output formats.

Key Features:

• Stream logs from single or multiple components with merged output
• Environment-wide log streaming (--environment flag streams all components)
• Component filtering by ID or name (--name flag, repeatable)
• Context fallback support (uses component from context if not specified)
• kubectl-compatible flags: --follow, --tail, --since, --since-time, --timestamps, --previous
• Thread-safe concurrent streaming from multiple pods/containers
• Color-coded prefixes for easy identification: [component/pod/container]
• Multiple output formats: stylish (default), JSON, YAML
• Graceful error handling and signal interruption (Ctrl+C)

Architecture:

• Follows the pattern from bns exec command (top-level utility command)
• Reuses existing component/environment APIs and K8s infrastructure
• Goroutine-based concurrent streaming with proper synchronization
• Wraps Kubernetes client-go Pods().GetLogs() API

New Files:

• cmd/logs/root.go (524 lines) - Main command with component resolution and orchestration
• pkg/k8s/kubectl/logs/logs.go (142 lines) - K8s log streaming wrapper
• pkg/k8s/kubectl/logs/multiplexer.go (377 lines) - Concurrent streaming coordinator with JSON/YAML writers

Modified Files:

• cmd/utils/root.go - Register logs command alongside exec, git, etc.

Usage Examples

# Stream logs from component in context with follow mode
bns configure set-context --component comp-123
bns logs --follow --tail 100

# Stream logs from multiple specific components
bns logs --component comp-1,comp-2,comp-3 --follow

# Stream logs from all components in environment
bns logs --environment env-123 --tail 50

# Filter by component name
bns logs --environment env-123 --name api --name worker --follow

# JSON output for programmatic processing
bns logs --environment env-123 --since 5m -o json | jq 'select(.component == "api")'

# YAML output
bns logs --component comp-123 --tail 10 -o yaml

# Time-based filtering
bns logs --component comp-123 --since 5m --timestamps

Output Formats

Stylish (default):

[vote/vote-7c6d4d6b8-85k5h/vote] 127.0.0.1 - - [17/Jan/2026 23:47:08] "GET / HTTP/1.1" 200 -
[db/db-c4dd4bcd8-jjchg/db] 2026-01-17 23:46:57 UTC [27] LOG:  checkpoint starting

JSON:

{"timestamp":"2026-01-17T23:54:32Z","component":"vote","componentId":"5qzDbeXOmg","pod":"vote-7c6d4d6b8-85k5h","container":"vote","namespace":"env-homi2s","message":"127.0.0.1 - - [17/Jan/2026 23:54:08] \"GET / HTTP/1.1\" 200 -"}

YAML:

---
timestamp: "2026-01-17T23:54:54Z"
component: db
componentId: rDzYNObxG8
pod: db-c4dd4bcd8-jjchg
container: db
namespace: env-homi2s
message: '2026-01-17 23:46:57 UTC [27] LOG:  checkpoint starting'

Test Plan

• Basic single component log streaming (--component)
• Environment-wide streaming (--environment)
• Component name filtering (--name, multiple names)
• Context fallback (no flags, uses context)
• Follow mode (--follow)
• Tail limit (--tail)
• Time-based filtering (--since)
• Timestamp inclusion (--timestamps)
• Multiple pods per component
• Multiple containers per pod
• Color-coded prefixes (stylish format)
• JSON output format (-o json)
• YAML output format (-o yaml)
• Signal handling (Ctrl+C graceful shutdown)
• Error handling (component not found, no pods, etc.)
• Concurrent streaming (no interleaved output)
• Integration with jq for JSON processing

Tested with:

• Real Bunnyshell environment (5 components, 6 containers)
• All output formats verified
• JSON output piped to jq for filtering

Notes

• No new dependencies added (uses existing k8s.io/client-go, gopkg.in/yaml.v3)
• Follows existing CLI patterns (command structure, flag naming, help text)
• Thread-safe output handling prevents log line corruption
• Warning messages go to stderr, logs to stdout (proper separation)

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