Deployer\Server\Configuration::setPublicKey PHP Method

    public function setPublicKey($path)
    {
        $this->publicKey = $this->parseHome($path);
        return $this;
    }

 /**
  * Authenticate with public key
  *
  * @param string $publicKeyFile
  * @param string $privateKeyFile
  * @param string $passPhrase
  *
  * @return Builder
  */
 public function identityFile($publicKeyFile = '~/.ssh/id_rsa.pub', $privateKeyFile = '~/.ssh/id_rsa', $passPhrase = '')
 {
     $passPhrase = $this->checkPassword($passPhrase);
     if (is_null($publicKeyFile)) {
         // Use default value
         $publicKeyFile = '~/.ssh/id_rsa.pub';
     }
     if (is_null($privateKeyFile)) {
         // Use default value
         $privateKeyFile = '~/.ssh/id_rsa';
     }
     if (is_null($passPhrase)) {
         // Ask pass phrase before connection
         $passPhrase = AskPasswordGetter::createLazyGetter();
     }
     $this->config->setAuthenticationMethod(Configuration::AUTH_BY_IDENTITY_FILE);
     $this->config->setPublicKey($publicKeyFile);
     $this->config->setPrivateKey($privateKeyFile);
     $this->config->setPassPhrase($passPhrase);
     return $this;
 }