github.com/inspektor-gadget/inspektor-gadget@v0.28.1/pkg/metadata/v1/metadata.go

// Copyright 2024 The Inspektor Gadget 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 metadatav1

import "github.com/inspektor-gadget/inspektor-gadget/pkg/params"

// Tracer describes the behavior of a gadget that collects and sends events to user space
// TODO: We need to rename this concept not to collide with the opentelemetry concept
type Tracer struct {
	// Name of the perf event array or ring buffer that the gadget uses to send events
	MapName string `yaml:"mapName"`
	// Name of the structure generated by this tracer
	StructName string `yaml:"structName"`
}

// Topper describes the behavior of a gadget that shows the current activity
// sorted by the highest to the lowest in the resource being observed.
type Topper struct {
	// Name of the hash map that the gadget uses to send statistics
	MapName string `yaml:"mapName"`
	// Name of the structure generated by this topper
	StructName string `yaml:"structName"`
}

// Snapshotter describes the behavior of a gadget that collects the state of a subsystem
type Snapshotter struct {
	StructName string `yaml:"structName"`
}

const (
	DefaultColumnWidth = 16
)

type Alignment string

const (
	AlignmenNone   Alignment = ""
	AlignmentLeft  Alignment = "left"
	AlignmentRight Alignment = "right"
)

type EllipsisType string

const (
	EllipsisNone   EllipsisType = ""
	EllipsisStart  EllipsisType = "start"
	EllipsisMiddle EllipsisType = "middle"
	EllipsisEnd    EllipsisType = "end"
)

// FieldAttributes describes how to format a field. It's almost 1:1 mapping with columns.Attributes,
// however we are keeping this separated because we don't want to create a strong coupling with the
// columns library now. Later on we can consider merging both of them.
type FieldAttributes struct {
	// Width to reserve for this field
	Width uint `yaml:"width,omitempty"`
	// MinWidth is the minimum width for this field
	MinWidth uint `yaml:"minWidth,omitempty"`
	// MaxWidth is the maximum width for this field
	MaxWidth uint `yaml:"maxWidth,omitempty"`
	// Alignment of this column (left or right)
	Alignment Alignment `yaml:"alignment,omitempty"`
	// Hidden defines whether a column is to be hid by default
	Hidden bool `yaml:"hidden,omitempty"`
	// EllipsisType defines how to abbreviate this column if the value needs more space than is
	// available. (start, middle or end)
	Ellipsis EllipsisType `yaml:"ellipsis,omitempty"`
	// Template defines the template that will be used.
	// TODO: add a link to existing templates
	Template string `yaml:"template,omitempty"`
}

type Field struct {
	// Field name
	Name string `yaml:"name"`
	// Field description
	Description string `yaml:"description,omitempty"`
	// Attributes defines how the field should be formatted
	Attributes FieldAttributes `yaml:"attributes"`
	// Annotations represents extra information that is not relevant to Inspektor Gadget, but
	// for other applications, like color font for instance.
	Annotations map[string]interface{} `yaml:"annotations,omitempty"`
}

// Struct describes a type generated by the gadget
type Struct struct {
	Fields []Field `yaml:"fields"`
}

type EBPFParam struct {
	params.ParamDesc `yaml:",inline"`
}

type GadgetMetadata struct {
	// Gadget name
	Name string `yaml:"name"`
	// Gadget description
	Description string `yaml:"description,omitempty"`
	// HomepageURL is the URL to the gadget's homepage
	HomepageURL string `yaml:"homepageURL,omitempty"`
	// DocumentationURL is the URL to the gadget's documentation
	DocumentationURL string `yaml:"documentationURL,omitempty"`
	// SourceURL is the URL to the gadget's source code repository
	SourceURL string `yaml:"sourceURL,omitempty"`
	// Annotations is a map of key-value pairs that provide additional information about the gadget
	Annotations map[string]string `yaml:"annotations,omitempty"`

	// Tracers implemented by the gadget
	// TODO: Rename this field to something that doesn't collide with the opentelemetry concept
	Tracers map[string]Tracer `yaml:"tracers,omitempty"`
	// Toppers implemented by the gadget
	Toppers map[string]Topper `yaml:"toppers,omitempty"`
	// Snapshotters implemented by the gadget
	Snapshotters map[string]Snapshotter `yaml:"snapshotters,omitempty"`
	// Types generated by the gadget
	Structs map[string]Struct `yaml:"structs,omitempty"`
	// Params exposed by the gadget through eBPF constants
	EBPFParams map[string]EBPFParam `yaml:"ebpfParams,omitempty"`
	// Other params exposed by the gadget
	GadgetParams map[string]params.ParamDesc `yaml:"gadgetParams,omitempty"`
}