/**
* Get the value of a tag for a specified DB instance.
*
* @param string $instanceIdentifier Identifier of the DB instance to get
* the tag of.
* @param string $tagKey Key of tag to get.
* @return string|null Value of tag or null if the db instance or tag does
* not exist.
*/
public function getRdsDbInstanceTag($instanceIdentifier, $tagKey)
{
// Compose the ARN of the DB instance.
$accountId = explode(':', $this->iam->GetUser()['User']['Arn'])[4];
$arn = sprintf('arn:aws:rds:%s:%s:db:%s', $this->region, $accountId, $instanceIdentifier);
try {
$tags = $this->rds->ListTagsForResource(['ResourceName' => $arn])['TagList'];
} catch (Rds\Exception\DBInstanceNotFoundException $e) {
return null;
}
foreach ($tags as $tag) {
if ($tag['Key'] === $tagKey) {
return $tag['Value'];
}
}
return null;
}
