Here is the full logs that are relevant.
==> eks: Waiting for instance (i-02802c4ff2bc6eb91) to become ready...
2019/04/22 12:30:13 packer: 2019/04/22 12:30:13 [INFO] Not using winrm communicator, skipping get password...
==> eks: Using ssh communicator to connect: 18.232.50.43
2019/04/22 12:30:13 packer: 2019/04/22 12:30:13 [INFO] Waiting for SSH, up to timeout: 5m0s
==> eks: Waiting for SSH to become available...
2019/04/22 12:30:15 packer: 2019/04/22 12:30:15 [DEBUG] TCP connection to SSH ip/port failed: dial tcp
18.232.50.43:22: connect: connection refused
2019/04/22 12:30:20 packer: 2019/04/22 12:30:20 [INFO] Attempting SSH connection to 18.232.50.43:22...
2019/04/22 12:30:20 packer: 2019/04/22 12:30:20 [DEBUG] Config to &ssh.Config{SSHConfig:(*ssh.ClientConfig)(0xc0002be0d0), Connection:(func() (net.Conn, error))(0x1a02bc0), Pty:true, DisableAgentForwarding:false, HandshakeTimeout:0, UseSftp:false, KeepAliveInterval:5000000000, Timeout:0}...
2019/04/22 12:30:20 packer: 2019/04/22 12:30:20 [DEBUG] reconnecting to TCP connection for SSH
2019/04/22 12:30:20 packer: 2019/04/22 12:30:20 [DEBUG] handshaking with SSH
2019/04/22 12:30:20 packer: 2019/04/22 12:30:20 [DEBUG] handshake complete!
2019/04/22 12:30:20 packer: 2019/04/22 12:30:20 [DEBUG] Opening new ssh session
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] agent forwarding enabled
==> eks: Connected to SSH!
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 Running the provision hook
2019/04/22 12:30:21 [INFO] (telemetry) Starting provisioner shell
==> eks: Provisioning with shell script: /var/folders/h_/lz750kv55h7gm_fc8svh52nr1_gwwm/T/packer-shell643574894
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 Opening /var/folders/h_/lz750kv55h7gm_fc8svh52nr1_gwwm/T/packer-shell643574894 for reading
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] 72 bytes written for 'uploadData'
2019/04/22 12:30:21 [INFO] 72 bytes written for 'uploadData'
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] Opening new ssh session
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] Starting remote scp process: scp -vt /tmp
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] Started SCP session, beginning transfers...
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] Copying input data into temporary file so we can read the length
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] scp: Uploading script_6094.sh: perms=C0644 size=72
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] SCP session complete, closing stdin pipe.
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] Waiting for SSH session to complete.
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] scp stderr (length 30): Sink: C0644 72 script_6094.sh
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] Opening new ssh session
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] starting remote command: chmod 0755 /tmp/script_6094.sh
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] RPC endpoint: Communicator ended with: 0
2019/04/22 12:30:21 [INFO] RPC client: Communicator ended with: 0
2019/04/22 12:30:21 [INFO] RPC endpoint: Communicator ended with: 0
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] RPC client: Communicator ended with: 0
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] Opening new ssh session
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [DEBUG] starting remote command: chmod +x /tmp/script_6094.sh; PACKER_BUILDER_TYPE='amazon-ebs' PACKER_BUILD_NAME='eks' /tmp/script_6094.sh
2019/04/22 12:30:21 [INFO] 46 bytes written for 'stdout'
2019/04/22 12:30:21 [INFO] 0 bytes written for 'stderr'
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [ERROR] Remote command exited with '126': chmod +x /tmp/script_6094.sh; PACKER_BUILDER_TYPE='amazon-ebs' PACKER_BUILD_NAME='eks' /tmp/script_6094.sh
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] RPC endpoint: Communicator ended with: 126
2019/04/22 12:30:21 [INFO] RPC client: Communicator ended with: 126
2019/04/22 12:30:21 [INFO] RPC endpoint: Communicator ended with: 126
eks: bash: /tmp/script_6094.sh: Permission denied
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] 46 bytes written for 'stdout'
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] 0 bytes written for 'stderr'
2019/04/22 12:30:21 packer: 2019/04/22 12:30:21 [INFO] RPC client: Communicator ended with: 126
2019/04/22 12:30:21 [INFO] (telemetry) ending shell