common_options.go

// Copyright 2022 The Falco Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package options

import (
	"io"

	"github.com/spf13/pflag"

	"github.com/falcosecurity/falcoctl/pkg/output"
)

// CommonOptions provides the common flags, options, and printers for all the
// commands. All the fields provided by the CommonOptions will be initialized before
// the commands are executed through the Initialize func.
type CommonOptions struct {
	// Printer used by all commands to output messages.
	Printer *output.Printer
	// printerScope contains the data of the optional scope of a prefix.
	// It used to add a prefix to the output of a printer.
	printerScope string
	// writer is used to write the output of the printer.
	writer io.Writer
	// Used to store the verbose flag, and then passed to the printer.
	verbose bool
}

// NewOptions returns a new CommonOptions struct.
func NewOptions() *CommonOptions {
	return &CommonOptions{}
}

// Configs type of the configs accepted by the Initialize function.
type Configs func(options *CommonOptions)

// WithPrinterScope sets the scope for the printer.
func WithPrinterScope(scope string) Configs {
	return func(options *CommonOptions) {
		options.printerScope = scope
	}
}

// WithWriter sets the writer for the printer.
func WithWriter(writer io.Writer) Configs {
	return func(options *CommonOptions) {
		options.writer = writer
	}
}

// Initialize initializes the options based on the configs. Subsequent calls will overwrite the
// previous configurations based on the new configs passed to the functions.
func (o *CommonOptions) Initialize(cfgs ...Configs) {
	for _, cfg := range cfgs {
		cfg(o)
	}

	// create the printer. The value of verbose is a flag value.
	o.Printer = output.NewPrinter(o.printerScope, o.verbose, o.writer)
}

// AddFlags registers the common flags.
func (o *CommonOptions) AddFlags(flags *pflag.FlagSet) {
	flags.BoolVarP(&o.verbose, "verbose", "v", false, "Enable verbose logs (default false)")
}