A powerful and intuitive command-line tool for interacting with AWS CloudWatch Logs. Stream logs in real-time, query historical data, and manage log groups with ease.

• Real-time log streaming - Tail logs from CloudWatch in real-time
• Historical queries - Search through past logs with time ranges
• Time range support - Use flexible time formats (--since 1h, --start, --end)
• String filtering - Filter logs with simple patterns or CloudWatch filter syntax
• List log groups - Browse available log groups with pattern matching
• Colored output - Enhanced readability with syntax highlighting
• Progress indicators - Visual feedback during operations
• AWS profile support - Switch between multiple AWS accounts
• Formatted table output - Dynamic column detection with intelligent sorting

# Clone the repository
git clone https://github.com/yourusername/cwl.git
cd cwl

# Build the project
cargo build --release

# Install to your PATH
cargo install --path .

# List all log groups
cwl groups

# Filter log groups
cwl groups --filter "production"

# Tail logs (last 5 minutes)
cwl tail /aws/lambda/my-function

# Follow logs continuously
cwl tail /aws/lambda/my-function --follow

# Filter while tailing
cwl tail /aws/lambda/my-function --filter "ERROR" --highlight

# Query logs from the last hour
cwl query /aws/lambda/my-function --since 1h

# Query with specific time range
cwl query /aws/lambda/my-function --start "2024-01-01 10:00:00" --end "2024-01-01 12:00:00"

# Query with filter and limit
cwl query /aws/lambda/my-function --filter "user_id=12345" --limit 500

# Query with formatted table output (auto-detects JSON structure)
cwl query /aws/lambda/my-function --since 1h --formatted

The --formatted flag automatically parses JSON log entries and displays them in a dynamic table:

# View logs as a formatted table with all JSON fields as columns
cwl query /aws/lambda/my-function --formatted --since 1h

# Combine with filters for focused analysis
cwl query /aws/ecs/my-app --formatted --filter "ERROR" --limit 100

Features of formatted output:

• Automatically detects all JSON fields across log entries
• Uses dot notation for nested fields (e.g., payload.message, user.id)
• Sorts columns by frequency (most common fields appear leftmost)
• Calculates optimal column widths
• Truncates long values with ellipsis
• Colored headers and separators for clarity

Example output:

timestamp               │ log_group     │ level │ message      │ payload.error
────────────────────────┼───────────────┼───────┼──────────────┼───────────────
2024-01-01 10:15:23.456 │ my-app        │ ERROR │ Failed auth  │ Invalid token
2024-01-01 10:15:24.789 │ my-app        │ WARN  │ Retry attempt│ Connection timeout

The tool supports multiple time formats:

• Relative time: --since 1h, --since 30m, --since 2d
• ISO 8601: --start 2024-01-01T10:00:00Z
• Human-readable: --start "2024-01-01 10:00:00"
• Unix timestamps: --start 1704103200

# Use a specific AWS profile
cwl tail /aws/lambda/my-function --profile production

# Use a specific region
cwl tail /aws/lambda/my-function --region us-west-2

The tool respects standard AWS environment variables:

• AWS_PROFILE
• AWS_REGION
• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY

# Stream errors from multiple Lambda functions
cwl tail /aws/lambda/prod-api --filter "ERROR" --follow --highlight

# Find all logs for a specific user in the last 24 hours
cwl query /aws/ecs/my-app --since 24h --filter "user_id=abc123"

# Check recent logs (last 5 minutes by default)
cwl tail /aws/lambda/my-function

Create a configuration file at ~/.config/cwl/config.toml:

[defaults]
region = "us-east-1"
output = "colored"
max_events = 1000

[profiles.production]
assume_role = "arn:aws:iam::123456789:role/ProdReader"
region = "us-west-2"

[aliases]
lambda-errors = "query /aws/lambda/* --filter ERROR --since 1h"

Contributions are welcome! Please feel free to submit a Pull Request.

MIT License - see LICENSE file for details

Built with:

• aws-sdk-rust - AWS SDK for Rust
• clap - Command-line argument parser
• tokio - Async runtime
• colored - Terminal colors
• indicatif - Progress indicators