Closed
Description
Description
runsc seems to grab stdout/stderr itself, not inherit them, but it does not do it determistically.
Steps to reproduce
Running the command repeatedly:
runsc exec my-container-id 'date' > a
Usually it outputs
Fri Jan 10 02:36:40 UTC 2025
with a file empty.
In about 1 in 20 cases, it outputs nothing, and the file a contains the date.
Container is started with sudo runsc run my-container-id. Nothing special in config.json.
Update: The issue does not reproduce if stdin is redirected:
runsc exec my-container-id 'date' > a < /dev/null
So I guess somewhere gvisors opens stdin for stdout.
runsc version
runsc version 0.0~20230807.0
spec: 1.1.0docker version (if using docker)
No docker.uname
Linux xxx.internal 6.8.0-1020-gcp #22-Ubuntu SMP Mon Dec 9 17:09:22 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
kubectl (if using Kubernetes)
repo state (if built from source)
No response
runsc debug logs (if available)
Logs when date is printed to stderr:
I0110 02:43:38.613887 30658 main.go:180] ***************************
I0110 02:43:38.613936 30658 main.go:181] Args: [runsc --debug --strace --debug-log=/tmp/runsc/ exec my-container-id date]
I0110 02:43:38.613957 30658 main.go:182] Version 0.0~20230807.0
I0110 02:43:38.613964 30658 main.go:183] GOOS: linux
I0110 02:43:38.613972 30658 main.go:184] GOARCH: amd64
I0110 02:43:38.613981 30658 main.go:185] PID: 30658
I0110 02:43:38.613991 30658 main.go:186] UID: 0, GID: 0
I0110 02:43:38.613999 30658 main.go:187] Configuration:
I0110 02:43:38.614007 30658 main.go:188] RootDir: /var/run/runsc
I0110 02:43:38.614014 30658 main.go:189] Platform: systrap
I0110 02:43:38.614022 30658 main.go:190] FileAccess: exclusive
I0110 02:43:38.614032 30658 main.go:191] Directfs: true
I0110 02:43:38.614050 30658 main.go:192] Overlay: root:self
I0110 02:43:38.614059 30658 main.go:193] Network: sandbox, logging: false
I0110 02:43:38.614069 30658 main.go:194] Strace: true, max size: 1024, syscalls:
I0110 02:43:38.614077 30658 main.go:195] IOURING: false
I0110 02:43:38.614084 30658 main.go:196] Debug: true
I0110 02:43:38.614112 30658 main.go:197] Systemd: false
I0110 02:43:38.614120 30658 main.go:198] ***************************
D0110 02:43:38.614185 30658 state_file.go:78] Load container, rootDir: "/var/run/runsc", id: {SandboxID: ContainerID:my-container-id}, opts: {Exact:false SkipCheck:false TryLock:false RootContainer:false}
D0110 02:43:38.615759 30658 container.go:648] Signal container, cid: my-container-id, signal: signal 0 (0)
D0110 02:43:38.615797 30658 sandbox.go:1177] Signal sandbox "my-container-id"
D0110 02:43:38.615805 30658 sandbox.go:603] Connecting to sandbox "my-container-id"
D0110 02:43:38.615893 30658 urpc.go:568] urpc: successfully marshalled 95 bytes.
D0110 02:43:38.616270 30658 urpc.go:611] urpc: unmarshal success.
D0110 02:43:38.616336 30658 exec.go:129] Exec arguments: date
D0110 02:43:38.616351 30658 exec.go:130] Exec capabilities: <nil>
I0110 02:43:38.616400 30658 exec.go:148] Using exec capabilities from container: &{PermittedCaps:536871968 InheritableCaps:536871968 EffectiveCaps:536871968 BoundingCaps:536871968 AmbientCaps:0}
D0110 02:43:38.616421 30658 container.go:567] Execute in container, cid: my-container-id, args: date
D0110 02:43:38.616430 30658 sandbox.go:552] Executing new process in container "my-container-id" in sandbox "my-container-id"
D0110 02:43:38.616439 30658 sandbox.go:1454] Changing "/dev/stdin" ownership to 0/0
D0110 02:43:38.616462 30658 sandbox.go:1454] Changing "/dev/stdout" ownership to 0/0
D0110 02:43:38.616475 30658 sandbox.go:1454] Changing "/dev/stderr" ownership to 0/0
D0110 02:43:38.616483 30658 sandbox.go:603] Connecting to sandbox "my-container-id"
D0110 02:43:38.616737 30658 urpc.go:568] urpc: successfully marshalled 476 bytes.
D0110 02:43:38.617883 30658 urpc.go:611] urpc: unmarshal success.
D0110 02:43:38.617934 30658 container.go:679] Forwarding all signals to container, cid: my-container-id, PIDPID: 320, fgProcess: true
D0110 02:43:38.619040 30658 container.go:636] Wait on process 320 in container, cid: my-container-id
D0110 02:43:38.619121 30658 sandbox.go:1131] Waiting for PID 320 in sandbox "my-container-id"
D0110 02:43:38.619146 30658 sandbox.go:603] Connecting to sandbox "my-container-id"
D0110 02:43:38.619281 30658 urpc.go:568] urpc: successfully marshalled 79 bytes.
D0110 02:43:38.630816 30658 urpc.go:611] urpc: unmarshal success.
D0110 02:43:38.630892 30658 container.go:687] Done forwarding signals to container, cid: my-container-id, PID: 320, fgProcess: true
I0110 02:43:38.630953 30658 main.go:215] Exiting with status: 0
Logs when printed to file:
I0110 02:44:23.665860 30745 main.go:180] ***************************
I0110 02:44:23.665918 30745 main.go:181] Args: [runsc --debug --strace --debug-log=/tmp/runsc/ exec my-container-id date]
I0110 02:44:23.665938 30745 main.go:182] Version 0.0~20230807.0
I0110 02:44:23.665946 30745 main.go:183] GOOS: linux
I0110 02:44:23.665954 30745 main.go:184] GOARCH: amd64
I0110 02:44:23.665963 30745 main.go:185] PID: 30745
I0110 02:44:23.665973 30745 main.go:186] UID: 0, GID: 0
I0110 02:44:23.665981 30745 main.go:187] Configuration:
I0110 02:44:23.665989 30745 main.go:188] RootDir: /var/run/runsc
I0110 02:44:23.665997 30745 main.go:189] Platform: systrap
I0110 02:44:23.666004 30745 main.go:190] FileAccess: exclusive
I0110 02:44:23.666014 30745 main.go:191] Directfs: true
I0110 02:44:23.666022 30745 main.go:192] Overlay: root:self
I0110 02:44:23.666031 30745 main.go:193] Network: sandbox, logging: false
I0110 02:44:23.666041 30745 main.go:194] Strace: true, max size: 1024, syscalls:
I0110 02:44:23.666049 30745 main.go:195] IOURING: false
I0110 02:44:23.666065 30745 main.go:196] Debug: true
I0110 02:44:23.666073 30745 main.go:197] Systemd: false
I0110 02:44:23.666081 30745 main.go:198] ***************************
D0110 02:44:23.666147 30745 state_file.go:78] Load container, rootDir: "/var/run/runsc", id: {SandboxID: ContainerID:my-container-id}, opts: {Exact:false SkipCheck:false TryLock:false RootContainer:false}
D0110 02:44:23.667831 30745 container.go:648] Signal container, cid: my-container-id, signal: signal 0 (0)
D0110 02:44:23.667874 30745 sandbox.go:1177] Signal sandbox "my-container-id"
D0110 02:44:23.667882 30745 sandbox.go:603] Connecting to sandbox "my-container-id"
D0110 02:44:23.667996 30745 urpc.go:568] urpc: successfully marshalled 95 bytes.
D0110 02:44:23.668339 30745 urpc.go:611] urpc: unmarshal success.
D0110 02:44:23.668379 30745 exec.go:129] Exec arguments: date
D0110 02:44:23.668397 30745 exec.go:130] Exec capabilities: <nil>
I0110 02:44:23.668411 30745 exec.go:148] Using exec capabilities from container: &{PermittedCaps:536871968 InheritableCaps:536871968 EffectiveCaps:536871968 BoundingCaps:536871968 AmbientCaps:0}
D0110 02:44:23.668426 30745 container.go:567] Execute in container, cid: my-container-id, args: date
D0110 02:44:23.668435 30745 sandbox.go:552] Executing new process in container "my-container-id" in sandbox "my-container-id"
D0110 02:44:23.668443 30745 sandbox.go:1454] Changing "/dev/stdin" ownership to 0/0
D0110 02:44:23.668457 30745 sandbox.go:1454] Changing "/dev/stdout" ownership to 0/0
D0110 02:44:23.668470 30745 sandbox.go:1454] Changing "/dev/stderr" ownership to 0/0
D0110 02:44:23.668477 30745 sandbox.go:603] Connecting to sandbox "my-container-id"
D0110 02:44:23.668728 30745 urpc.go:568] urpc: successfully marshalled 476 bytes.
D0110 02:44:23.669893 30745 urpc.go:611] urpc: unmarshal success.
D0110 02:44:23.669978 30745 container.go:679] Forwarding all signals to container, cid: my-container-id, PIDPID: 330, fgProcess: true
D0110 02:44:23.671332 30745 container.go:636] Wait on process 330 in container, cid: my-container-id
D0110 02:44:23.671399 30745 sandbox.go:1131] Waiting for PID 330 in sandbox "my-container-id"
D0110 02:44:23.671416 30745 sandbox.go:603] Connecting to sandbox "my-container-id"
D0110 02:44:23.671633 30745 urpc.go:568] urpc: successfully marshalled 79 bytes.
D0110 02:44:23.683670 30745 urpc.go:611] urpc: unmarshal success.
D0110 02:44:23.683742 30745 container.go:687] Done forwarding signals to container, cid: my-container-id, PID: 330, fgProcess: true
I0110 02:44:23.683864 30745 main.go:215] Exiting with status: 0