logmower-shipper/cmd/mongo_struct.go

package logmower

import (
	"context"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func initializeIndexes(ctx context.Context, col *mongo.Collection) error {
	ind := col.Indexes()

	// (does not create duplicates)
	_, err := ind.CreateOne(mongoTimeoutCtx(ctx), mongo.IndexModel{
		Keys: bson.D{{Key: mLogKeyFileBasename, Value: 1}, {Key: mLogKeyOffset, Value: -1}},
	})

	return err
}

// when editing, also edit everything in this file!
type (
	mLog struct {
		RecordMetadata

		Content       any
		ContainerTime time.Time
		StdErr        bool

		// added by toBson()
		ShipTime time.Time
	}
	RecordMetadata struct {
		HostInfo HostInfo
		File     string
		Offset   int64 // byte offset where log entry ends at
	}
)

const (
	// used outside fromBson and toBson
	mLogKeyHostId = mLogKeyHostInfo + "." + mLogKeyId
)

const (
	mLogKeyHostInfo = "host_info"
	mLogKeyId       = "id"
	mLogKeyName     = "name"
	mLogKeyArch     = "arch"

	mLogKeyFileBasename  = "file"
	mLogKeyOffset        = "offset"
	mLogKeyContent       = "content"
	mLogKeyContainerTime = "container_time"
	mLogKeyStderr        = "stderr"
	mLogKeyShipTime      = "ship_time"
)

// not using marshal, since it is <0.1x performance
func (l *mLog) toBson() bson.M {
	// DO NOT USE QUOTED STRINGS! Move them to const and use variable instead
	return bson.M{
		mLogKeyHostInfo: bson.M{
			mLogKeyId:   l.HostInfo.Id,
			mLogKeyName: l.HostInfo.Name,
			mLogKeyArch: l.HostInfo.Arch,
		},
		mLogKeyFileBasename:  l.File,
		mLogKeyOffset:        l.Offset,
		mLogKeyContent:       l.Content,
		mLogKeyContainerTime: l.ContainerTime,
		mLogKeyStderr:        l.StdErr,

		mLogKeyShipTime: time.Now(),
	}
}

// really, mongo should support tagged structs
func mLogfromBson(b *bson.Raw) mLog {
	return mLog{
		RecordMetadata: RecordMetadata{
			HostInfo: HostInfo{
				Id:   bsonLookupStringValue(b, mLogKeyHostInfo, mLogKeyId),
				Name: bsonLookupStringValue(b, mLogKeyHostInfo, mLogKeyName),
				Arch: bsonLookupStringValue(b, mLogKeyHostInfo, mLogKeyArch),
			},
			File:   bsonLookupStringValue(b, mLogKeyFileBasename),
			Offset: bsonLookupInt64(b, mLogKeyOffset),
		},
		Content:       bsonLookupStringValue(b, mLogKeyContent),
		ContainerTime: bsonLookupTime(b, mLogKeyContainerTime),
		StdErr:        bsonLookupBoolean(b, mLogKeyStderr),
		ShipTime:      bsonLookupTime(b, mLogKeyShipTime),
	}
}

// default values without ok

func bsonLookupBoolean(b *bson.Raw, key ...string) bool {
	v, _ := b.Lookup(key...).BooleanOK()
	return v
}

func bsonLookupStringValue(b *bson.Raw, key ...string) string {
	v, _ := b.Lookup(key...).StringValueOK()
	return v
}

func bsonLookupInt64(b *bson.Raw, key ...string) int64 {
	v, _ := b.Lookup(key...).Int64OK()
	return v
}

func bsonLookupTime(b *bson.Raw, key ...string) time.Time {
	v, _ := b.Lookup(key...).TimeOK()
	return v
}