recovery.go

Documentation: edge-infra.dev/pkg/sds/etcd/manager/recovery

     1  package recovery
     2  
     3  import (
     4  	"context"
     5  	"errors"
     6  	"fmt"
     7  	"net"
     8  	"time"
     9  
    10  	"edge-infra.dev/pkg/lib/fog"
    11  	"edge-infra.dev/pkg/sds/etcd/manager"
    12  	"edge-infra.dev/pkg/sds/etcd/manager/internal/socket"
    13  )
    14  
    15  // Initiate sends a message to the etcd manager to request an etcd cluster
    16  // reset.
    17  func Initiate(ctx context.Context) error {
    18  	log := fog.FromContext(ctx)
    19  	log.Info("initiating etcd cluster recovery", "eoaudit", "")
    20  
    21  	conn, err := connWithDeadline(manager.RecoverySocket)
    22  	if err != nil {
    23  		return fmt.Errorf("failed to establish socket connection: %w", err)
    24  	}
    25  	defer conn.Close()
    26  
    27  	if _, err := conn.Write([]byte(socket.ResetMessage)); err != nil {
    28  		return err
    29  	}
    30  	return handleResponse(ctx, conn)
    31  }
    32  
    33  // connWithDeadline sets up a connection to the socket with a 30 second read and
    34  // write deadline.
    35  func connWithDeadline(socketPath string) (net.Conn, error) {
    36  	conn, err := net.Dial("unix", socketPath)
    37  	if err != nil {
    38  		return conn, fmt.Errorf("failed to dial the Unix socket: %w", err)
    39  	}
    40  
    41  	err = conn.SetDeadline(time.Now().Add(30 * time.Second))
    42  	return conn, err
    43  }
    44  
    45  // handleResponse receives the response message and determines whether the
    46  // recovery was successful.
    47  func handleResponse(ctx context.Context, conn net.Conn) error {
    48  	log := fog.FromContext(ctx)
    49  	response, err := receiveMessage(conn)
    50  	if err != nil {
    51  		return err
    52  	}
    53  
    54  	switch response {
    55  	case socket.SuccessResponse:
    56  		log.Info("initiated etcd cluster recovery successfully", "eoaudit", "")
    57  	case socket.LockedResponse:
    58  		log.Info("etcd cluster recovery already initiated", "eoaudit", "")
    59  	default:
    60  		return errors.New("failed to initiate etcd cluster recovery")
    61  	}
    62  	return nil
    63  }
    64  
    65  // receiveMessage reads the connection and returns the message.
    66  func receiveMessage(conn net.Conn) (string, error) {
    67  	buf := make([]byte, 1024)
    68  	n, err := conn.Read(buf)
    69  	if err != nil {
    70  		return "", fmt.Errorf("failed to read socket message: %w", err)
    71  	}
    72  	msg := string(buf[0:n])
    73  	return msg, nil
    74  }
    75
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