AWSがよくわからないメッセージを繰り返し出力しエラーですべてのサービスが停止する

再びインスタンスのUbuntu20.04TSLがエラーで停止してしまった。

syslogを見ると

autorefresh.go:398: Cannot prepare auto-refresh change due to a permanent network error: persistent network error: Get https://api.snapcraft.io/api/v1/snaps/assertions/snap-declaration/16/CSO04Jhav2yK0uz97cr0ipQRyqg0qQL6?max-format=4: dial tcp: lookup api.snapcraft.io: Temporary failure in name resolution
stateengine.go:150: state ensure error: persistent network error: Get https://api.snapcraft.io/api/v1/snaps/assertions/snap-declaration/16/CSO04Jhav2yK0uz97cr0ipQRyqg0qQL6?max-format=4: dial tcp: lookup api.snapcraft.io: Temporary failure in name resolution

とメッセージが続いたあと全てのサービスがstopしている。

調べてみたが他でも多発している様子がどれも20.04のようだ。AWSのフォーラムにこの問題の提起がされているが解決していないみたい。何だろこれ？

何かネットワークエラーで更新の準備ができないってのと名前解決できないって言ってる。でもこれの後に全てのサービスがStoppingしているなぜ？

Removed slice system-modprobe.slice.
Stopped target Cloud-init target.
Stopped target Graphical Interface.
Stopped target Timers.
apt-daily-upgrade.timer: Succeeded.
Stopped Daily apt upgrade and clean activities.
apt-daily.timer: Succeeded.
Stopped Daily apt download activities.
e2scrub_all.timer: Succeeded.
Stopped Periodic ext4 Online Metadata Check for All Filesystems.
fstrim.timer: Succeeded.
Stopped Discard unused blocks once a week.
fwupd-refresh.timer: Succeeded.
Stopped Refresh fwupd metadata regularly.
logrotate.timer: Succeeded.
Stopped Daily rotation of log files.
man-db.timer: Succeeded.
Stopped Daily man-db regeneration.
motd-news.timer: Succeeded.
Stopped Message of the Day.
phpsessionclean.timer: Succeeded.
Stopped Clean PHP session files every 30 mins.
snap.certbot.renew.timer: Succeeded.
Stopped Timer renew for snap application certbot.renew.
systemd-tmpfiles-clean.timer: Succeeded.
Stopped Daily Cleanup of Temporary Directories.
Stopped target System Time Synchronized.
Stopped target System Time Set.
lvm2-lvmpolld.socket: Succeeded.
Closed LVM2 poll daemon socket.
systemd-rfkill.socket: Succeeded.
Closed Load/Save RF Kill Switch Status /dev/rfkill Watch.
Stopping Accounts Service...
Stopping ACPI event daemon...
Stopping Availability of block devices...
cloud-final.service: Succeeded.
Stopped Execute cloud user/final scripts.
Stopped target Multi-User System.
Stopped target Login Prompts.
Nov 8 01:23:29 ip-172-31-0-104 blkdeactivate[237819]: Deactivating block devices:
Stopping The Apache HTTP Server...
Stopping LSB: automatic crash report generation...
Stopping Deferred execution scheduler...
cloud-config.service: Succeeded.
Stopped Apply the settings specified in cloud-config.
Stopped target Cloud-config availability.
Stopping Regular background program processing daemon...
Stopping Dovecot IMAP/POP3 email server...
Stopping Create final runtime dir for shutdown pivot root...
Stopping Firmware update daemon...
Nov 8 01:23:29 ip-172-31-0-104 dovecot: master: Warning: Killed with signal 15 (by pid=237845 uid=0 code=kill)
Stopping Getty on tty1...
Stopping LSB: Record successful boot for GRUB...
Stopping MySQL Community Server...
Stopping Dispatcher daemon for systemd-networkd...
Stopping The PHP 7.4 FastCGI Process Manager...
Stopping Authorization Manager...
postfix.service: Succeeded.
Stopped Postfix Mail Transport Agent.
Stopping Postfix Mail Transport Agent (instance -)...