docker logs -t needs to strip carriage return character to show timestamp

[bluepuma77]

Description

docker logs -t should prefix every log line with a timestamp like 2024-12-12T10:47:47.310209758Z.

When the container is using \n\r at the end of a log line (or \r at beginning), then the timestamp is overwritten and not shown.

2024-12-12T11:25:38.363477610Z There are only two hard things in computer science:
cache invalidation and naming things.
2024-12-12T11:25:38.363527859Z

docker logs should probably strip the /r, at least when used with -t option, maybe just on Linux.

The issue happens for example with containers based on mcr.microsoft.com/mssql/server:2022-latest image on Linux.

See discussion on Docker Community Forum.

Reproduce

docker run -d --name t1 bash echo -e "There are only two hard things in computer science: \ncache invalidation and naming things.\n"
docker logs -t t1
docker rm t1

docker run -d --name t2 bash echo -e "There are only two hard things in computer science: \r\ncache invalidation and naming things.\r\n"
docker logs -t t2
docker rm t2

docker run -d --name t3 bash echo -e "There are only two hard things in computer science: \n\rcache invalidation and naming things.\n\r"
docker logs -t t3
docker rm t3

outputs

2024-12-12T11:25:37.492133962Z There are only two hard things in computer science:
2024-12-12T11:25:37.492317272Z cache invalidation and naming things.
2024-12-12T11:25:37.492330714Z

2024-12-12T11:25:37.932053082Z There are only two hard things in computer science:
2024-12-12T11:25:37.932101138Z cache invalidation and naming things.
2024-12-12T11:25:37.932106578Z

2024-12-12T11:25:38.363477610Z There are only two hard things in computer science:
cache invalidation and naming things.
2024-12-12T11:25:38.363527859Z

The last example has an overwritten timestamp

Expected behavior

The timestamp should always be shown, irrespectively of the log line content.

docker version

# docker version
Client: Docker Engine - Community
 Version:           27.4.0
 API version:       1.47
 Go version:        go1.22.10
 Git commit:        bde2b89
 Built:             Sat Dec  7 10:38:55 2024
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          27.4.0
  API version:      1.47 (minimum version 1.24)
  Go version:       go1.22.10
  Git commit:       92a8393
  Built:            Sat Dec  7 10:38:55 2024
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.7.24
  GitCommit:        88bf19b2105c8b17560993bee28a01ddc2f97182
 runc:
  Version:          1.2.2
  GitCommit:        v1.2.2-0-g7cb3632
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

# docker info
Client: Docker Engine - Community
 Version:    27.4.0
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.19.2
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.31.0
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 19
  Running: 16
  Paused: 0
  Stopped: 3
 Images: 52
 Server Version: 27.4.0
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 88bf19b2105c8b17560993bee28a01ddc2f97182
 runc version: v1.2.2-0-g7cb3632
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.8.0-50-generic
 Operating System: Ubuntu 24.04.1 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 15.25GiB
 Name: myhost
 ID: d0b46f47-c57e-4b70-bdfe-39a9f8e01234
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled

Additional Info

No response