How to view MinIO request logs for debugging

Use the minio client mc like this:

mc admin trace myminio

where myminio is an alias (URL + access key + secret key) which you can setup using mc alias ....

This will show output like

2022-03-27T18:22:22:000 [403 Forbidden] s3.GetObject minio.haar.techoverflow.net/api/v1/login 95.114.116.235    5.488ms      ↑ 273 B ↓ 634 B
2022-03-27T18:22:23:000 [403 Forbidden] s3.ListObjectsV1 minio.haar.techoverflow.net/login 95.114.116.235    3.677ms      ↑ 320 B ↓ 584 B
2022-03-27T18:24:19:000 [200 OK] s3.GetBucketLocation minio.haar.techoverflow.net/mybucket/?location=  192.168.192.2     6.089ms      ↑ 211 B ↓ 444 B
2022-03-27T18:24:19:000 [200 OK] s3.GetBucketLocation minio.haar.techoverflow.net/mybucket/?location=  192.168.192.2     256µs       ↑ 211 B ↓ 444 B
2022-03-27T18:24:19:000 [200 OK] s3.GetBucketLocation minio.haar.techoverflow.net/mybucket/?location=  192.168.192.2     251µs       ↑ 211 B ↓ 444 B
2022-03-27T18:24:19:000 [200 OK] s3.GetBucketVersioning minio.haar.techoverflow.net/mybucket/?versioning=  192.168.192.2     407µs       ↑ 211 B ↓ 414 B
2022-03-27T18:24:19:000 [404 Not Found] s3.GetBucketObjectLockConfig minio.haar.techoverflow.net/mybucket/?object-lock=  192.168.192.2     519µs       ↑ 211 B ↓ 663 B
2022-03-27T18:24:19:000 [200 OK] s3.GetBucketLocation minio.haar.techoverflow.net/mybucket/?location=  192.168.192.2     269µs       ↑ 211 B ↓ 444 B
2022-03-27T18:24:19:000 [404 Not Found] s3.GetBucketPolicy minio.haar.techoverflow.net/mybucket/?policy=  192.168.192.2     223µs       ↑ 211 B ↓ 621 B
2022-03-27T18:24:19:000 [404 Not Found] s3.GetBucketTagging minio.haar.techoverflow.net/mybucket/?tagging=  192.168.192.2     284µs       ↑ 211 B ↓ 608 B
2022-03-27T18:24:19:000 [200 OK] s3.ListObjectsV2 minio.haar.techoverflow.net/mybucket/?delimiter=%2F&encoding-type=url&fetch-owner=true&list-type=2&prefix=  192.168.192.2     516.96ms     ↑ 211 B ↓ 1.7 KiB
2022-03-27T18:24:20:000 [200 OK] s3.GetBucketLocation minio.haar.techoverflow.net/mybucket/?location=  192.168.192.2     270µs       ↑ 211 B ↓ 444 B
2022-03-27T18:24:20:000 [200 OK] s3.ListObjectsV2 minio.haar.techoverflow.net/mybucket/?delimiter=%2F&encoding-type=url&fetch-owner=true&list-type=2&prefix=  192.168.192.2     45.061ms

If you want even more verbose output, use

mc admin trace -v myminio

This will log the entire HTTP request:

minio.mydomain.com [REQUEST s3.GetBucketLocation] [2022-03-27T18:25:20:000] [Client IP: 192.168.192.2]
minio.mydomain.com GET /mybucket/?location=
minio.mydomain.com Proto: HTTP/1.1
minio.mydomain.com Host: minio.mydomain.com
minio.mydomain.com X-Forwarded-Host: minio.mydomain.com
minio.mydomain.com X-Amz-Content-Sha256: UNSIGNED-PAYLOAD
minio.mydomain.com X-Amz-Date: 20220327T162520Z
minio.mydomain.com X-Forwarded-Port: 443
minio.mydomain.com X-Forwarded-Proto: https
minio.mydomain.com X-Forwarded-Server: MyVM
minio.mydomain.com Authorization: AWS4-HMAC-SHA256 Credential=GFAHJAODMI71TXAFCXZW/20220327/us-east-1/s3/aws4_request, SignedHeaders=host;x-amz-content-sha256;x-amz-date;x-amz-security-token, Signature=e1edcc3fb0d2130573f7f6633f9f9130810ee0cebcff3359312084c168f2d428
minio.mydomain.com User-Agent: MinIO (linux; amd64) minio-go/v7.0.23
minio.mydomain.com Content-Length: 0
minio.mydomain.com X-Amz-Security-Token: eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJhY2Nlc3NLZXkiOiJHRkFISkFPRE1JNzFUWEFGQ1haVyIsImV4cCI6MTY0ODQwMTQ0OSwicGFyZW50IjoibWluaW9hZG1pbiJ9.ZiuFcseCRRHOmxFs6j6H6nePV6kt9qBnOJESMCIZ-XiPaQrPm5kMlYHGR2zHOfAxf5EUAX3cN8CFbw9BBAQ-2g
minio.mydomain.com Accept-Encoding: gzip
minio.mydomain.com X-Forwarded-For: 192.168.192.2
minio.mydomain.com X-Real-Ip: 192.168.192.2
minio.mydomain.com 
minio.mydomain.com [RESPONSE] [2022-03-27T18:25:20:000] [ Duration 2.771ms  ↑ 211 B  ↓ 444 B ]
minio.mydomain.com 200 OK
minio.mydomain.com X-Amz-Request-Id: 16E04989FD22A42E
minio.mydomain.com X-Xss-Protection: 1; mode=block
minio.mydomain.com Accept-Ranges: bytes
minio.mydomain.com Content-Length: 128
minio.mydomain.com Content-Security-Policy: block-all-mixed-content
minio.mydomain.com Content-Type: application/xml
minio.mydomain.com Vary: Origin,Accept-Encoding
minio.mydomain.com Server: MinIO
minio.mydomain.com Strict-Transport-Security: max-age=31536000; includeSubDomains
minio.mydomain.com X-Content-Type-Options: nosniff
minio.mydomain.com <?xml version="1.0" encoding="UTF-8"?>
<LocationConstraint xmlns="http://s3.amazonaws.com/doc/2006-03-01/"></LocationConstraint>