kubectl-jsonlogs Plugin

kubectl plugin to parse and colorize JSON and timestamped logs, similar to jq but optimized for Kubernetes log streams.

• kubectl-jsonlogs: Works as both a kubectl plugin and k9s plugin (pods/logs scope)

Features

• JSON Log Parsing: Pretty-prints JSON logs with colorized output (similar to jq)
• Pulumi Output Formatting: Automatically detects and pretty-prints Pulumi output in msg fields with colorized resource status, outputs, and summaries
• Timestamped Logs: Automatically detects and colorizes timestamps in non-JSON logs
• Log Level Detection: Colorizes log lines based on detected log levels (ERROR, WARN, INFO, DEBUG)
• Minimal Dependencies: Uses only Python standard library (no external modules required)
• Virtual Environment Support: Optional venv loader for future extensions

Installation

Option 1: Direct Installation (Recommended)

1. Make the script executable and copy it to a directory in your PATH:

   chmod +x kubectl-jsonlogs
   cp kubectl-jsonlogs $HOME/.local/bin

2. Verify installation:

   kubectl jsonlogs --help

Option 2: Symlink to kubectl plugin directory

# Create kubectl plugin directory if it doesn't exist
mkdir -p ~/.kubectl/plugins

# Create symlink
ln -s /path/to/workspace/kubectl-jsonlogs ~/.kubectl/plugins/kubectl-jsonlogs

k9s Plugin Configuration

Option 1: Use the provided plugins.yaml (Recommended)

A ready-to-use plugins.yaml file is included in the repository. To use it:

1. Copy the plugins.yaml to your k9s config directory:

   k9s info # check the plugin path
   mkdir -p ~/.config/k9s
   cp /path/to/workspace/plugins.yaml ~/.config/k9s/plugins.yaml

2. Or merge it into your existing ~/.config/k9s/config.yml under the plugins: section.

Option 2: Manual Configuration

To manually configure kubectl-jsonlogs for k9s, add the following to your ~/.config/k9s/config.yml:

plugins:
  json-logs:
    shortCut: Ctrl-J
    confirm: false
    description: "Pretty JSON Logs (All Containers)"
    scopes:
      - container
    command: kubectl
    background: false
    args:
      - jsonlogs
      - $POD
      - $NAMESPACE
      - $CONTEXT
      - $NAME

Note:

• The container scope allows you to use the plugin from the container view in k9s
• The plugin shows logs from the selected container only
• k9s variables: $POD (pod name), $NAMESPACE, $CONTEXT, $NAME (container name)
• When container is not specified (e.g., direct command line usage), the plugin uses --all-containers flag to tail logs from all containers in the pod
• Container names are highlighted in bold cyan to distinguish logs from different containers

Make sure kubectl-jsonlogs is in your PATH for k9s to find it.

Usage

kubectl-jsonlogs (Direct Mode or k9s Plugin)

As kubectl plugin (pipe mode):

kubectl logs <pod-name> | kubectl jsonlogs

As k9s plugin (container scope):

1. Navigate to a container in k9s container view
2. Press Ctrl-J (or your configured shortcut)
3. The plugin will automatically fetch and colorize logs from the selected container with pretty JSON formatting
4. Container names are highlighted in bold cyan when viewing logs from multiple containers

Direct usage (with arguments):

# Show logs from all containers (when container is not specified)
kubectl jsonlogs <pod-name> <namespace> <context>

# Show logs from a specific container
kubectl jsonlogs <pod-name> <namespace> <context> <container-name>

Why use kubectl-jsonlogs for k9s?

• Works from container view (scope: container)
• Shows logs from the selected container only
• Container names are colorized and highlighted for easy identification
• Automatically formats and colorizes JSON logs
• Better integration with k9s workflow

Examples

JSON Logs:

kubectl logs my-app | kubectl jsonlogs

Output will be colorized JSON with:

• Blue keys
• Green strings
• Magenta numbers
• Yellow booleans
• Cyan brackets/braces

Timestamped Logs:

kubectl logs nginx-pod | kubectl jsonlogs

Output will have:

• Gray timestamps
• Red ERROR level logs
• Yellow WARN level logs
• Cyan INFO level logs
• Gray DEBUG level logs

Mixed Content: The plugin automatically detects JSON objects within log lines and colorizes them appropriately.

Pulumi Output: When JSON logs contain Pulumi output in the msg field, it is automatically detected and formatted as a multi-line, colorized block:

kubectl logs my-pulumi-app | kubectl jsonlogs

Pulumi output formatting includes:

• Resource status lines: Colorized based on status (green for creating/created, yellow for updating)
• Section headers: Bold cyan for "Outputs:", "Resources:", "Duration:"
• Status indicators: Yellow for "@ updating" lines
• Output values: Formatted with colored keys and values
• Summary lines: Formatted resource counts and durations

Example output:

{
  "level": "info",
  "msg":
    Resource Updated Updating (resource):
    
     +  pulumi:pulumi:Stack my-stack creating (0s)
     +  aws:iam:Policy my-policy created (0.91s)
    
    Outputs:
        roleArn: "arn:aws:iam::123456789012:role/my-role"
    
    Resources:
        + 5 created
    
    Duration: 5s
}

Virtual Environment Support

If you need to add optional dependencies in the future:

1. Create a virtual environment:

   cd /path/to/workspace
   python3 -m venv venv

2. Install any optional dependencies:

   source venv/bin/activate
   pip install <optional-package>

3. The script will automatically detect and use the venv if it exists in:

   • $HOME/.venv/ (default location)
   • $HOME/.kubectl-jsonlogs-venv/ (plugin-specific location)
   • ./venv/ (relative to script)
   • ./.venv/
   • ../venv/

Color Output

Colors are automatically disabled when output is not a TTY (e.g., when piping to a file). This ensures compatibility with log aggregation tools.

Requirements

• Python 3.6+
• No external dependencies (uses only Python standard library)

Troubleshooting

Plugin not found:

• Ensure the script is in your PATH
• Verify the script is executable: ls -l kubectl-jsonlogs
• For k9s: Make sure kubectl-jsonlogs is accessible via kubectl jsonlogs command
• For k9s: Ensure the plugin is configured with scope container and uses correct variables: $POD, $NAMESPACE, $CONTEXT, $NAME

No colors:

• Colors are disabled when output is not a TTY
• Ensure you're running in a terminal that supports ANSI colors

Performance:

• The script processes logs line-by-line for real-time streaming
• For very high-volume logs, consider using jq for pure JSON logs