Documentation
¶
Overview ¶
Package clientv3util contains utility functions derived from clientv3.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func KeyExists ¶
KeyExists returns a comparison operation that evaluates to true iff the given key exists. It does this by checking if the key `Version` is greater than 0. It is a useful guard in transaction delete operations.
Example (Delete) ¶
package main
import (
"context"
"log"
"github.com/coreos/etcd/clientv3"
"github.com/coreos/etcd/clientv3/clientv3util"
)
func main() {
cli, err := clientv3.New(clientv3.Config{
Endpoints: []string{"127.0.0.1:2379"},
})
if err != nil {
log.Fatal(err)
}
defer cli.Close()
kvc := clientv3.NewKV(cli)
// perform a delete only if key already exists
_, err = kvc.Txn(context.Background()).
If(clientv3util.KeyExists("purpleidea")).
Then(clientv3.OpDelete("purpleidea")).
Commit()
if err != nil {
log.Fatal(err)
}
}
Example (Put) ¶
package main
import (
"context"
"log"
"github.com/coreos/etcd/clientv3"
"github.com/coreos/etcd/clientv3/clientv3util"
)
func main() {
cli, err := clientv3.New(clientv3.Config{
Endpoints: []string{"127.0.0.1:2379"},
})
if err != nil {
log.Fatal(err)
}
defer cli.Close()
kvc := clientv3.NewKV(cli)
// perform a put only if key is missing
// It is useful to do the check (transactionally) to avoid overwriting
// the existing key which would generate potentially unwanted events,
// unless of course you wanted to do an overwrite no matter what.
_, err = kvc.Txn(context.Background()).
If(clientv3util.KeyMissing("purpleidea")).
Then(clientv3.OpPut("purpleidea", "hello world")).
Commit()
if err != nil {
log.Fatal(err)
}
}
func KeyMissing ¶
KeyMissing returns a comparison operation that evaluates to true iff the given key does not exist.
Types ¶
This section is empty.
Source Files
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