Cannot ssh into an AWS ECS instance Permission denied (publickey)-CodePudding

I have been able to ssh into my AWS ECS instances for well over a year without issue.

However, in recent days I have begun getting Permission denied (publickey) errors when trying to ssh into any of my instances.

I have the public keys stored in my .ssh folder and they get added to the ssh agent successfully before any attempt to ssh. My AWS setup has also not changed.

I have included the verbose output from my ssh command below. Any help or insights are much appreciated!

OpenSSH_7.4p1, OpenSSL 1.0.2k-fips  26 Jan 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 58: Applying options for *
debug1: Connecting to 10.10.0.168 [10.10.0.168] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ec2-user/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 10.10.0.168:22 as 'ec2-user'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: curve25519-sha256 need=64 dh_need=64
debug1: kex: curve25519-sha256 need=64 dh_need=64
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:qi60acx6tKhNsV3z756IaixRe0bXlIyuCc3782hn8rY
debug1: Host '10.10.0.168' is known and matches the ECDSA host key.
debug1: Found key in /home/ec2-user/.ssh/known_hosts:33
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/ec2-user/.ssh/id_rsa
debug1: Trying private key: /home/ec2-user/.ssh/id_dsa
debug1: Trying private key: /home/ec2-user/.ssh/id_ecdsa
debug1: Trying private key: /home/ec2-user/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey).

CodePudding user response：

Have you tried restarting the instances in the AWS Console?

I've seen this previously when the instances have run our of memory due to temp files. Rebooting cleared the temp files and allowed me to connect again.

It's not exactly the most helpful error message!