systemd logs filled with mount unit entries if healtcheck is enabled

[jpalus]

I've got a simple container running with healthcheck script executed every 5s. It's's working fine but each healtcheck script execution results in 4 log entries:

May 27 22:48:48 kalarepa systemd[2300]: run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.
May 27 22:48:48 kalarepa systemd[2300]: var-run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.
May 27 22:48:48 kalarepa systemd[1]: run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.
May 27 22:48:48 kalarepa systemd[1]: var-run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.

With debug enabled that's:

May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.815505736+02:00" level=debug msg="Running health check for container 77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f ..."
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.815561970+02:00" level=debug msg="starting exec command a06d7465f747162bc42fca702cd6c55bb90a5c3008982758b2ebe57add88f9d6 in container 77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f"
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.816125174+02:00" level=debug msg="attach: stdout: begin"
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.816128671+02:00" level=debug msg="attach: stderr: begin"
May 27 22:48:48 kalarepa systemd[2300]: run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.
May 27 22:48:48 kalarepa systemd[2300]: var-run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.
May 27 22:48:48 kalarepa systemd[1]: run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.
May 27 22:48:48 kalarepa systemd[1]: var-run-docker-runtime\x2drunc-moby-77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f-runc.9eXMMp.mount: Succeeded.
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.843852552+02:00" level=debug msg="event published" ns=moby topic="/tasks/exec-started" type=containerd.events.TaskExecStarted
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.843961419+02:00" level=debug msg=event module=libcontainerd namespace=moby topic=/tasks/exec-started
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.886514278+02:00" level=debug msg="event published" ns=moby topic="/tasks/exit" type=containerd.events.TaskExit
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.886633850+02:00" level=debug msg=event module=libcontainerd namespace=moby topic=/tasks/exit
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.886693524+02:00" level=debug msg="attach: stdout: end"
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.886702591+02:00" level=debug msg="attach: stderr: end"
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.886710935+02:00" level=debug msg="attach done"
May 27 22:48:48 kalarepa dockerd[15377]: time="2019-05-27T22:48:48.886721924+02:00" level=debug msg="Health check for container 77cf7d360fd7d22b228b85135481c57f95111ba9f70ced68d4665abe55e9167f done (exitCode=0)"

Therefore system logs are literally filled with mount unit entries. Is this something to be expected by default? What would be the best way to get rid of it?

[philippelt]

👍

[thaJeztah]

WIth "With debug enabled" you mean both dockerd having debug enabled and systemd debugging enabled?

The logs you're describing (...mount: Succeeded) are generated by systemd, and given that a health check starts a new process in a container (using the equivalent of docker exec under the hood), that looks expected.

Therefore system logs are literally filled with mount unit entries. Is this something to be expected by default? What would be the best way to get rid of it?

The obvious answer would be; don't enable debug. It's assumed to be verbose and intended for debugging purposes (not usually enabled when running in production, unless you're debugging a problem). Perhaps systemd has more granular controls to enable/disable certain type of debugging messages (https://freedesktop.org/wiki/Software/systemd/Debugging/), but I haven't dug deep on finding if that's possible

I'll close this issue, because this doesn't seem to be a bug, but feel free to continue the conversation

[jpalus]

I meant debug of dockerd only to figure out what is triggering this message. systemd debugging was not enabled.

[thaJeztah]

What version of docker are you running and on what distro? (could you post the full output of docker version and docker info?)

[jpalus]

$ docker version
Client:
 Version:           18.09.6-ce
 API version:       1.39
 Go version:        go1.10.8
 Git commit:        PLD-Linux/18.09.6
 Built:             Tue May  7 22:50:53 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server:
 Engine:
  Version:          18.09.6-ce
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.8
  Git commit:       PLD-Linux/18.09.6
  Built:            Tue May  7 22:51:07 2019
  OS/Arch:          linux/amd64
  Experimental:     false

$ docker info
Containers: 7
 Running: 1
 Paused: 0
 Stopped: 6
Images: 65
Server Version: 18.09.6-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: false
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: .m
runc version: N/A
init version: v0.18.0 (expected: fec3683b971d9c3ef73f284f176672c44b448662)
Kernel Version: 5.1.5-1
Operating System: PLD Linux 3.0 (Th)
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 31.42GiB
Name: kalarepa
ID: FG27:EOG3:SL3K:LU4N:T4OL:KM42:IOHE:OXQJ:NITK:GOYM:G2Z5:SWVQ
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): true
 File Descriptors: 30
 Goroutines: 51
 System Time: 2019-06-14T17:03:45.242364627+02:00
 EventsListeners: 0
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

[thaJeztah]

That looks like a non-official package; did you build that yourself, or where did you get it from?

[jpalus]

It's a build provided by my distribution of choice "PLD Linux" but I guess that's kind of a blocker so let's forget about it and focus on officially provided docker build inside Ubuntu 19.04 (note that docker is taken from 18.10 as 19.04 does not have docker-ce yet, hopefully it's not a big issue):

$ docker version
Client:
 Version:           18.09.6
 API version:       1.39
 Go version:        go1.10.8
 Git commit:        481bc77156
 Built:             Sat May  4 02:35:29 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.6
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.8
  Git commit:       481bc77
  Built:            Sat May  4 01:59:36 2019
  OS/Arch:          linux/amd64
  Experimental:     false

$ docker info
Containers: 1
 Running: 1
 Paused: 0
 Stopped: 0
Images: 2
Server Version: 18.09.6
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: bb71b10fd8f58240ca47fbb579b9d1028eea7c84
runc version: 2b18fe1d885ee5083ef9f0838fee39b62d653e30
init version: fec3683
Security Options:
 apparmor
 seccomp
  Profile: default
Kernel Version: 5.0.0-17-generic
Operating System: Ubuntu 19.04
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 3.85GiB
Name: ubuntu
ID: Y6MQ:3QLC:AJPH:JFWJ:ZAAZ:FKCH:RXMZ:CI6M:HBRZ:FZIN:A6DX:OH3Y
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false
Product License: Community Engine

WARNING: No swap limit support

Minimal docker-compose.yml with reproducer that I came up with:

version: '2.1'
services:
        test:
                image: ubuntu:18.04
                healthcheck:
                        test: ["CMD", "/bin/true"]
                        interval: 5s
                command: ["/bin/sh", "-c", "cat < /dev/zero > /dev/null"]

Outcome in journalctl:

Jun 18 17:51:19 ubuntu systemd[1669]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.yKidSk.mount: Succeeded.
Jun 18 17:51:19 ubuntu systemd[1]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.yKidSk.mount: Succeeded.
Jun 18 17:51:25 ubuntu systemd[1669]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.BrrYWJ.mount: Succeeded.
Jun 18 17:51:25 ubuntu systemd[1]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.BrrYWJ.mount: Succeeded.
Jun 18 17:51:30 ubuntu systemd[1669]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.trsjYk.mount: Succeeded.
Jun 18 17:51:30 ubuntu systemd[1]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.trsjYk.mount: Succeeded.
Jun 18 17:51:35 ubuntu systemd[1669]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.wmhsHV.mount: Succeeded.
Jun 18 17:51:35 ubuntu systemd[1]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.wmhsHV.mount: Succeeded.
Jun 18 17:51:40 ubuntu systemd[1669]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.KbUfAz.mount: Succeeded.
Jun 18 17:51:40 ubuntu systemd[1]: run-docker-runtime\x2drunc-moby-24bbba796718663d3a3f38f11d6ec03f47aa308dc6e8f86731595a74f1e95993-runc.KbUfAz.mount: Succeeded.

[gertjanklein]

I see the same log entries (in /var/log/daemon.log), but two every minute, and I have no healthcheck script (that I know of):

Jun 19 08:45:19 www systemd[24262]: run-docker-runtime\x2drunc-moby-63cc81f9426f05a7417acc0a776c428f21c797b83e9b3f12b9cd14fb0bf513a2-runc.jgSO4w.mount: Succeeded.
Jun 19 08:45:19 www systemd[1]: run-docker-runtime\x2drunc-moby-63cc81f9426f05a7417acc0a776c428f21c797b83e9b3f12b9cd14fb0bf513a2-runc.jgSO4w.mount: Succeeded.

This is on Debian Buster, docker from the docker repository.

$ docker version
Client:
 Version:           18.09.6
 API version:       1.39
 Go version:        go1.10.8
 Git commit:        481bc77
 Built:             Sat May  4 02:36:00 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.6
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.8
  Git commit:       481bc77
  Built:            Sat May  4 01:59:36 2019
  OS/Arch:          linux/amd64
  Experimental:     false

$ docker info
Containers: 1
 Running: 1
 Paused: 0
 Stopped: 0
Images: 21
Server Version: 18.09.6
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: bb71b10fd8f58240ca47fbb579b9d1028eea7c84
runc version: 2b18fe1d885ee5083ef9f0838fee39b62d653e30
init version: fec3683
Security Options:
 apparmor
 seccomp
  Profile: default
Kernel Version: 4.19.0-5-amd64
Operating System: Debian GNU/Linux 10 (buster)
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 961.6MiB
Name: www.gklein.org
ID: AEFF:NNWE:D3K5:2I6T:OETQ:K6NX:FET7:RSMU:UVNX:J2W5:LUG7:PCIK
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false
Product License: Community Engine

WARNING: No swap limit support

I would also like to know if there is a way to mute these messages! Please let me know if I should open a new issue.

[philippelt]

Same problem for me, if this can help (as some parts are different) :

$ docker version
Client:
 Version:           18.09.5
 API version:       1.39
 Go version:        go1.10.4
 Git commit:        e8ff056
 Built:             Fri Apr 12 00:34:27 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server:
 Engine:
  Version:          18.09.5
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.4
  Git commit:       e8ff056
  Built:            Fri Apr 12 00:27:37 2019
  OS/Arch:          linux/amd64
  Experimental:     false

$ docker info
Containers: 6
 Running: 6
 Paused: 0
 Stopped: 0
Images: 35
Server Version: 18.09.5
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 
runc version: N/A
init version: v0.18.0 (expected: fec3683b971d9c3ef73f284f176672c44b448662)
Security Options:
 apparmor
 seccomp
  Profile: default
Kernel Version: 5.0.0-18-generic
Operating System: Ubuntu 19.04
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 15.56GiB
Name: testbox3
ID: JFOI:XIYK:GGTV:JC2I:Y23Q:JIRY:DHA4:FRHM:42W5:ZWOU:KVLN:IAET
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Username: philippelt
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

WARNING: No swap limit support
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled

6 containers are running and all have health check enabled, using run <...> --health-cmd '<...>'

[kolyshkin]

This is some systemd stuff. From my limited knowledge, systemd watches for all mounts in the system and treats every one as a "unit". Why it prints success, I have no idea :(

[jpalus]

Looks like healthcheck execution results in a temporary mount (always different directory, mounted for short enough period that I could never spot it in "mount" output). Any idea where this mount is coming from? I've tried to look at containerd code but gave up.

On a daily basis I'm running about 4 containers in my dev env, all having different forms of healthcheck and this log thing is quite a pain.

[infabo]

This is a real pain. I have ~10 entries per minute just about this annoying systemd mount: Succeed crap.

[infabo]

Jul 08 11:41:06 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-f3bb63065fd3ed4f1db4c9dc27045a08bbfb71e12f945fe5bd09ee8b64fa5460-runc.6f0IeU.mount: Succeeded.
Jul 08 11:41:06 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-f3bb63065fd3ed4f1db4c9dc27045a08bbfb71e12f945fe5bd09ee8b64fa5460-runc.6f0IeU.mount: Succeeded.
Jul 08 11:41:06 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-4d03b7262c6b5c700c4338c8b8a1986367ca2223cf57cf2b4e93bb16b95c2884-runc.Kcvkh0.mount: Succeeded.
Jul 08 11:41:06 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-4d03b7262c6b5c700c4338c8b8a1986367ca2223cf57cf2b4e93bb16b95c2884-runc.Kcvkh0.mount: Succeeded.
Jul 08 11:41:06 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.ZnJX5Z.mount: Succeeded.
Jul 08 11:41:06 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.ZnJX5Z.mount: Succeeded.
Jul 08 11:41:06 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-824f11608bf956118c58729987a7ea8c4385e7566fc3936ee0d7d4f3ddcda82e-runc.0TkKV2.mount: Succeeded.
Jul 08 11:41:06 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-824f11608bf956118c58729987a7ea8c4385e7566fc3936ee0d7d4f3ddcda82e-runc.0TkKV2.mount: Succeeded.
Jul 08 11:41:15 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.hRqJW2.mount: Succeeded.
Jul 08 11:41:15 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.hRqJW2.mount: Succeeded.
Jul 08 11:41:26 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-284fa22a3e46d4680b89d7d9fd6d9cdd2b01803137aababf29020ec80febb304-runc.0myuOo.mount: Succeeded.
Jul 08 11:41:32 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.OPrvYt.mount: Succeeded.
Jul 08 11:41:32 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.OPrvYt.mount: Succeeded.
Jul 08 11:41:41 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-6682a2879beb126cf6a235d21c8a79cd5611d5aa448b958c0574ea089051cdf0-runc.HdnGBe.mount: Succeeded.
Jul 08 11:41:41 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-6682a2879beb126cf6a235d21c8a79cd5611d5aa448b958c0574ea089051cdf0-runc.HdnGBe.mount: Succeeded.
Jul 08 11:41:42 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-d750ad138604ac840a1eaba7d924685cac2e9c8c30919dfbe43d44c31ea330e1-runc.qaPgi8.mount: Succeeded.
Jul 08 11:41:42 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-d750ad138604ac840a1eaba7d924685cac2e9c8c30919dfbe43d44c31ea330e1-runc.qaPgi8.mount: Succeeded.
Jul 08 11:41:45 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.37ZUuT.mount: Succeeded.
Jul 08 11:41:45 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.37ZUuT.mount: Succeeded.
Jul 08 11:41:45 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.40ZXcc.mount: Succeeded.
Jul 08 11:41:45 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.40ZXcc.mount: Succeeded.
Jul 08 11:41:48 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-acfb04fe15443274224b5729b2b5dd4f52005a24e9cbb86187c775d5a5d7701f-runc.hfPzHR.mount: Succeeded.
Jul 08 11:41:48 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-acfb04fe15443274224b5729b2b5dd4f52005a24e9cbb86187c775d5a5d7701f-runc.hfPzHR.mount: Succeeded.
Jul 08 11:41:49 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-824f11608bf956118c58729987a7ea8c4385e7566fc3936ee0d7d4f3ddcda82e-runc.KmxKjw.mount: Succeeded.
Jul 08 11:41:49 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-824f11608bf956118c58729987a7ea8c4385e7566fc3936ee0d7d4f3ddcda82e-runc.KmxKjw.mount: Succeeded.
Jul 08 11:41:50 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.qjW3jN.mount: Succeeded.
Jul 08 11:41:50 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.qjW3jN.mount: Succeeded.
Jul 08 11:41:50 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.VYyyZ5.mount: Succeeded.
Jul 08 11:41:50 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.VYyyZ5.mount: Succeeded.
Jul 08 11:41:51 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-acfb04fe15443274224b5729b2b5dd4f52005a24e9cbb86187c775d5a5d7701f-runc.aS7T9L.mount: Succeeded.
Jul 08 11:41:54 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-acfb04fe15443274224b5729b2b5dd4f52005a24e9cbb86187c775d5a5d7701f-runc.jUzyPo.mount: Succeeded.
Jul 08 11:41:54 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-acfb04fe15443274224b5729b2b5dd4f52005a24e9cbb86187c775d5a5d7701f-runc.jUzyPo.mount: Succeeded.
Jul 08 11:41:54 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-d750ad138604ac840a1eaba7d924685cac2e9c8c30919dfbe43d44c31ea330e1-runc.eB2rG1.mount: Succeeded.
Jul 08 11:41:55 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.dX002P.mount: Succeeded.
Jul 08 11:41:55 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.dX002P.mount: Succeeded.
Jul 08 11:41:55 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.04LKie.mount: Succeeded.
Jul 08 11:41:55 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.04LKie.mount: Succeeded.
Jul 08 11:42:00 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.Cz4ug8.mount: Succeeded.
Jul 08 11:42:00 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-4413d423a12cb493ab75cf453aceb8312395453653b3801730216f8436463a8b-runc.Cz4ug8.mount: Succeeded.
Jul 08 11:42:00 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-e27873fdf2281609fa1e91e673a241946b486d05cf5f5259d4e37e7da15cb8f0-runc.IrHIDg.mount: Succeeded.
Jul 08 11:42:00 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-284fa22a3e46d4680b89d7d9fd6d9cdd2b01803137aababf29020ec80febb304-runc.7nlIrh.mount: Succeeded.
Jul 08 11:42:00 NOTEBOOK023 systemd[1]: run-docker-runtime\x2drunc-moby-824f11608bf956118c58729987a7ea8c4385e7566fc3936ee0d7d4f3ddcda82e-runc.ogwQiB.mount: Succeeded.
Jul 08 11:42:00 NOTEBOOK023 systemd[1157]: run-docker-runtime\x2drunc-moby-824f11608bf956118c58729987a7ea8c4385e7566fc3936ee0d7d4f3ddcda82e-runc.ogwQiB.mount: Succeeded.

[gertjanklein]

Hopefully docker will be updated to address this issue at some point. In the mean time I have added a filter for syslogd that mutes these mesages. This is on Debian Buster, but probably can be adapted to other environments.

I created a new file /etc/rsyslog.d/01-blocklist.conf, containing:

if $msg contains "run-docker-runtime" and $msg contains ".mount: Succeeded." then {
    stop
}

With this, after a sudo service rsyslog restart, the messages stopped appearing. Hopefully this helps someone.