このエラーメッセージに関する原因と対処に関して説明します。
エラーメッセージ(英語)：
efs access denied
対処
関連リンク
AWS Developer Forums: Access denied in EFS mount folder from ...
https://forums.aws.amazon.com/thread.jspa?messageID=838374&tstart=0
Amazon EFS access denied while mounting in docker container ...
https://stackoverflow.com/questions/43590413/amazon-efs-access-denied-while-mounting-in-docker-conta・・・
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