Instance is showing errors in nginx error.log and `journalctl -f`

We should not be seeing errors such as this in the nginx error log:

1
2019-07-30T11:58:54.452-04:00
2019/07/30 15:58:48 [error] 1223#1223: *3 open() "/usr/share/nginx/html/api/spin" failed (2: No such file or directory), client: 10.0.1.127, server: localhost, request: "GET /api/spin HTTP/1.1", host: "10.0.1.81"
@ingestionTime
1564502339490
@log
976851222302:nginx-error
@logStream
i-03a0b66f27af4afca
@message
2019/07/30 15:58:48 [error] 1223#1223: *3 open() "/usr/share/nginx/html/api/spin" failed (2: No such file or directory), client: 10.0.1.127, server: localhost, request: "GET /api/spin HTTP/1.1", host: "10.0.1.81"
@timestamp
1564502334452

Nor should we be seeing errors like this from Emperor when we do journalctl -f:

Jul 30 16:17:48 ip-10-0-1-81.ec2.internal uwsgi[3620]: ImportError: Import by filename is not supported.
Jul 30 16:17:48 ip-10-0-1-81.ec2.internal uwsgi[3620]: unable to load app 1 (mountpoint='/api') (callable not found or import error)
Jul 30 16:17:48 ip-10-0-1-81.ec2.internal uwsgi[3620]: ImportError: Import by filename is not supported.
Jul 30 16:17:48 ip-10-0-1-81.ec2.internal uwsgi[3620]: unable to load app 1 (mountpoint='/api') (callable not found or import error)
Jul 30 16:17:48 ip-10-0-1-81.ec2.internal uwsgi[3620]: [pid: 3641|app: 0|req: 31/127] 10.0.1.127 () {38 vars in 444 bytes} [Tue Jul 30 16:17:48 2019] GET /api/spin => generated 150 bytes in 70 msecs (HTTP/1.1 200) 2 headers in 66 bytes (1 switches on core 0)
Jul 30 16:17:49 ip-10-0-1-81.ec2.internal uwsgi[3620]: [pid: 3685|app: 0|req: 86/128] 10.0.2.111 () {38 vars in 444 bytes} [Tue Jul 30 16:17:48 2019] GET /api/spin => generated 149 bytes in 808 msecs (HTTP/1.1 200) 2 headers in 66 bytes (1 switches on core 0)
Jul 30 16:18:00 ip-10-0-1-81.ec2.internal sudo[6351]:   centos : TTY=pts/0 ; PWD=/home/centos ; USER=root ; COMMAND=/bin/journalctl -f
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: ImportError: Import by filename is not supported.
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: unable to load app 1 (mountpoint='/api') (callable not found or import error)
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: [pid: 3685|app: 0|req: 87/129] 10.0.3.114 () {38 vars in 444 bytes} [Tue Jul 30 16:18:18 2019] GET /api/spin => generated 149 bytes in 74 msecs (HTTP/1.1 200) 2 headers in 66 bytes (1 switches on core 0)
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: ImportError: Import by filename is not supported.
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: unable to load app 1 (mountpoint='/api') (callable not found or import error)
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: ImportError: Import by filename is not supported.
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: unable to load app 1 (mountpoint='/api') (callable not found or import error)
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: [pid: 3669|app: 0|req: 1/130] 10.0.1.127 () {38 vars in 444 bytes} [Tue Jul 30 16:18:18 2019] GET /api/spin => generated 151 bytes in 99 msecs (HTTP/1.1 200) 2 headers in 66 bytes (1 switches on core 0)
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: announcing my loyalty to the Emperor...
Jul 30 16:18:18 ip-10-0-1-81.ec2.internal uwsgi[3620]: Tue Jul 30 16:18:18 2019 - [emperor] vassal infra-demo.ini is now loyal
Jul 30 16:18:19 ip-10-0-1-81.ec2.internal uwsgi[3620]: [pid: 3685|app: 0|req: 88/131] 10.0.2.111 () {38 vars in 444 bytes} [Tue Jul 30 16:18:18 2019] GET /api/spin => generated 149 bytes in 618 msecs (HTTP/1.1 200) 2 headers in 66 bytes (1 switches on core 0)

Investigate the root cause and fix it.

Start by tracing the /api/spin request through the nginx error log and the Emperor/uWSGI messages shown in the issue, using journalctl -f to reproduce the behavior. Identify the cause of the missing-file and import errors, then verify that /api/spin returns successfully without those recurring errors.