Using a non-root user who is NOT member of the docker group I get a panic using docker info --format '{{.Swarm.LocalNodeState}}'

[friesje306]

Description

Installation of docker version 19.03.04 on flatcar. Using a non-root user who is NOT member of the docker group I get a panic using docker info --format '{{.Swarm.LocalNodeState}}'. Running docker info gives the normal error.

Steps to reproduce the issue:

1. Create a new user without docker group permissions
2. Run docker info --format '{{.Swarm.LocalNodeState}}'

Describe the results you received:

$ docker info --format '{{.Swarm.LocalNodeState}}'
panic: reflect: indirection through nil pointer to embedded struct [recovered]
        panic: reflect: indirection through nil pointer to embedded struct
 
goroutine 1 [running]:
text/template.errRecover(0xc0003b9340)
        /usr/lib/go1.15/src/text/template/exec.go:169 +0x19e
panic(0x55f8c909a8e0, 0x55f8c93a94f0)
        /usr/lib/go1.15/src/runtime/panic.go:969 +0x1b9
reflect.Value.FieldByIndex(0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0xc00036c480, 0x2, 0x2, 0x0, 0x55f8c9449a80, 0x55f8c9311e60)
        /usr/lib/go1.15/src/reflect/value.go:889 +0x350
text/template.(*state).evalField(0xc0003b92b0, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0xc000521741, 0x5, 0x55f8c9431400, 0xc0002475c0, 0x0, 0x0, ...)
        /usr/lib/go1.15/src/text/template/exec.go:612 +0x48d
text/template.(*state).evalFieldChain(0xc0003b92b0, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0x55f8c9431400, 0xc0002475c0, 0xc00000e5e0, ...)
        /usr/lib/go1.15/src/text/template/exec.go:562 +0x110
text/template.(*state).evalFieldNode(0xc0003b92b0, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0xc0002475c0, 0xc00039f1d0, 0x1, 0x1, 0x55f8c9136280, 0x55f8ca0fb338, ...)
        /usr/lib/go1.15/src/text/template/exec.go:529 +0x115
text/template.(*state).evalCommand(0xc0003b92b0, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0xc000247560, 0x55f8c9136280, 0x55f8ca0fb338, 0x99, 0x7f4d64769e98, 0xc000255110, ...)
        /usr/lib/go1.15/src/text/template/exec.go:457 +0x8f0
text/template.(*state).evalPipeline(0xc0003b92b0, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0xc0000a1140, 0x0, 0xc0003b9200, 0x55f8c779aff0)
        /usr/lib/go1.15/src/text/template/exec.go:431 +0x125
text/template.(*state).walk(0xc0003b92b0, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0x55f8c94311c0, 0xc0002475f0)
        /usr/lib/go1.15/src/text/template/exec.go:255 +0x335
text/template.(*state).walk(0xc0003b92b0, 0x55f8c9248dc0, 0xc00011c9c0, 0x99, 0x55f8c9431520, 0xc000247530)
        /usr/lib/go1.15/src/text/template/exec.go:263 +0x11e
text/template.(*Template).execute(0xc00011c900, 0x55f8c93cbe20, 0xc0003becc0, 0x55f8c9248dc0, 0xc00011c9c0, 0x0, 0x0)
        /usr/lib/go1.15/src/text/template/exec.go:220 +0x1c6
text/template.(*Template).Execute(...)
        /usr/lib/go1.15/src/text/template/exec.go:203
github.com/docker/cli/cli/command/system.formatInfo(0x55f8c9445f00, 0xc00049c1c0, 0x0, 0xc00039f170, 0x1, 0x1, 0xc00011c8c0, 0x0, 0x0, 0x0, ...)
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/cli/command/system/info.go:478 +0x1fd
github.com/docker/cli/cli/command/system.runInfo(0xc000168c80, 0x55f8c9445f00, 0xc00049c1c0, 0xc00039eb20, 0x0, 0x0)
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/cli/command/system/info.go:85 +0x35d
github.com/docker/cli/cli/command/system.NewInfoCommand.func1(0xc000168c80, 0xc00000e240, 0x0, 0x2, 0x0, 0x0)
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/cli/command/system/info.go:52 +0x48
github.com/docker/cli/vendor/github.com/spf13/cobra.(*Command).execute(0xc000168c80, 0xc000246880, 0x2, 0x2, 0xc000168c80, 0xc000246880)
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/vendor/github.com/spf13/cobra/command.go:762 +0x47c
github.com/docker/cli/vendor/github.com/spf13/cobra.(*Command).ExecuteC(0xc00042c500, 0xc000246870, 0x3, 0x3)
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/vendor/github.com/spf13/cobra/command.go:852 +0x308
github.com/docker/cli/vendor/github.com/spf13/cobra.(*Command).Execute(...)
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/vendor/github.com/spf13/cobra/command.go:800
main.runDocker(0xc00049c1c0, 0x55f8c93ce340, 0xc000010020)
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/cmd/docker/docker.go:281 +0x1de
main.main()
        /build/amd64-usr/var/tmp/portage/app-emulation/docker-19.03.14/work/docker-19.03.14/src/github.com/docker/cli/cmd/docker/docker.go:292 +0xf3

Describe the results you expected:

Client:
Debug Mode: false
 
Server:
ERROR: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.40/info": dial unix /var/run/docker.sock: connect: permission denied
errors pretty printing info

Additional information you deem important (e.g. issue happens only occasionally):

Output of docker version:

Client:
 Version:           19.03.14
 API version:       1.40
 Go version:        go1.15.5
 Git commit:        f8db474
 Built:             Tue Dec  1 19:10:28 2020
 OS/Arch:           linux/amd64
 Experimental:      false

Server:
 Engine:
  Version:          19.03.14
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.15.5
  Git commit:       f8db474
  Built:            Tue Dec  1 19:10:28 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.4.3
  GitCommit:        6806845b4f638417933f68721e289c9aeda456b1
 runc:
  Version:          1.0.0-rc92+dev.docker-19.03
  GitCommit:        3d68c79de7184b0eba97946d4f478736f46bf207
 docker-init:
  Version:          0.18.0fec3683b971d9c3ef73f284f176672c44b448662
  GitCommit:

Output of docker info:

Client:
 Debug Mode: false

Server:
 Containers: 8
  Running: 6
  Paused: 0
  Stopped: 2
 Images: 22
 Server Version: 19.03.14
 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 ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: active
  NodeID: wo1595lddpc50p4oxu9yi06nu
  Is Manager: true
  ClusterID: kvhk1s5tyzq5gqtogqojimq5x
  Managers: 3
  Nodes: 3
  Default Address Pool: 10.0.0.0/8
  SubnetSize: 24
  Data Path Port: 4789
  Orchestration:
   Task History Retention Limit: 5
  Raft:
   Snapshot Interval: 10000
   Number of Old Snapshots to Retain: 0
   Heartbeat Tick: 1
   Election Tick: 10
  Dispatcher:
   Heartbeat Period: 5 seconds
  CA Configuration:
   Expiry Duration: 3 months
   Force Rotate: 0
  Autolock Managers: false
  Root Rotation In Progress: false
  Node Address: 10.23.125.42
  Manager Addresses:
   10.23.125.42:2377
   10.23.125.43:2377
   10.23.125.44:2377
 Runtimes: runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 6806845b4f638417933f68721e289c9aeda456b1
 runc version: 3d68c79de7184b0eba97946d4f478736f46bf207
 init version:
 Security Options:
  seccomp
   Profile: default
  selinux
 Kernel Version: 5.4.83-flatcar
 Operating System: Flatcar Container Linux by Kinvolk 2605.10.0 (Oklo)
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 15.61GiB
 Name: sldclr1182
 ID: PZHZ:GRXH:U7U6:FLMC:HZQ5:WHW2:ZE5G:PXBR:VWCU:TX7P:UP5J:UEYN
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http://dcproxy.kpn.org:80
 No Proxy: 10.23.125.43,10.23.125.44,specials-registry.kpn.org,m2612.mgt.gen.local,m1612.mgt.gen.local,slnc6r1003.mgt.gen.local,slnc6r1004.mgt.gen.local
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

Additional environment details (AWS, VirtualBox, physical, etc.):
Vmware, Linux XXXXXXXXX 5.4.83-flatcar #1 SMP Tue Dec 15 18:31:34 -00 2020 x86_64 Intel(R) Xeon(R) Platinum 8160 CPU @ 2.10GHz GenuineIntel GNU/Linux

[thaJeztah]

This looks to be a duplicate of;

• docker info --format panic #3593

The panic happens when trying to format the output, but an error occurred when connecting to the daemon / API. To reproduce, I used a -H pointing to a non-existing socket;

docker info --format '{{.Swarm.LocalNodeState}}'
inactive

docker -H unix:///no/such/socket info --format '{{.Swarm.LocalNodeState}}'
panic: reflect: indirection through nil pointer to embedded struct [recovered]
	panic: reflect: indirection through nil pointer to embedded struct

goroutine 1 [running]:
text/template.errRecover(0xc0003cf320)
	/usr/local/go/src/text/template/exec.go:170 +0x1b3
panic(0x1a91bc0, 0x2076db0)
	/usr/local/go/src/runtime/panic.go:679 +0x1b2
reflect.Value.FieldByIndex(0x1c71900, 0xc000287cc0, 0x99, 0xc0000e4840, 0x2, 0x2, 0x0, 0x21514c0, 0x1d47940)
	/usr/local/go/src/reflect/value.go:883 +0x39c
text/template.(*state).evalField(0xc0003cf2a0, 0x1c71900, 0xc000287cc0, 0x99, 0xc0000505e1, 0x5, 0x210fa40, 0xc000317950, 0x0, 0x0, ...)
	/usr/local/go/src/text/template/exec.go:605 +0x473
text/template.(*state).evalFieldChain(0xc0003cf2a0, 0x1c71900, 0xc000287cc0, 0x99, 0x1c71900, 0xc000287cc0, 0x99, 0x210fa40, 0xc000317950, 0xc00036c9e0, ...)
	/usr/local/go/src/text/template/exec.go:555 +0x10e
text/template.(*state).evalFieldNode(0xc0003cf2a0, 0x1c71900, 0xc000287cc0, 0x99, 0xc000317950, 0xc000254d30, 0x1, 0x1, 0x1b41ee0, 0x304c918, ...)
	/usr/local/go/src/text/template/exec.go:522 +0x113
text/template.(*state).evalCommand(0xc0003cf2a0, 0x1c71900, 0xc000287cc0, 0x99, 0xc0003178f0, 0x1b41ee0, 0x304c918, 0x99, 0xd0, 0x1c497c0, ...)
	/usr/local/go/src/text/template/exec.go:460 +0x79a
text/template.(*state).evalPipeline(0xc0003cf2a0, 0x1c71900, 0xc000287cc0, 0x99, 0xc0003426c0, 0x7cb4a6aa30c1, 0x2, 0x89)
	/usr/local/go/src/text/template/exec.go:434 +0x11a
text/template.(*state).walk(0xc0003cf2a0, 0x1c71900, 0xc000287cc0, 0x99, 0x210f8c0, 0xc000317980)
	/usr/local/go/src/text/template/exec.go:258 +0x49b
text/template.(*state).walk(0xc0003cf2a0, 0x1c71900, 0xc000287cc0, 0x99, 0x210fb00, 0xc0003178c0)
	/usr/local/go/src/text/template/exec.go:266 +0x142
text/template.(*Template).execute(0xc000287b40, 0x209a740, 0xc0001ad020, 0x1c71900, 0xc000287cc0, 0x0, 0x0)
	/usr/local/go/src/text/template/exec.go:221 +0x20a
text/template.(*Template).Execute(...)
	/usr/local/go/src/text/template/exec.go:204
github.com/docker/cli/cli/command/system.formatInfo(0x2147080, 0xc00031c000, 0x0, 0xc000254cd0, 0x1, 0x1, 0xc000287a80, 0x0, 0x0, 0x0, ...)
	/go/src/github.com/docker/cli/cli/command/system/info.go:478 +0x1f3
github.com/docker/cli/cli/command/system.runInfo(0xc00029c500, 0x2147080, 0xc00031c000, 0xc000254720, 0x0, 0x0)
	/go/src/github.com/docker/cli/cli/command/system/info.go:85 +0x341
github.com/docker/cli/cli/command/system.NewInfoCommand.func1(0xc00029c500, 0xc00036c880, 0x0, 0x2, 0x0, 0x0)
	/go/src/github.com/docker/cli/cli/command/system/info.go:52 +0x46
github.com/docker/cli/vendor/github.com/spf13/cobra.(*Command).execute(0xc00029c500, 0xc0001b4650, 0x2, 0x4, 0xc00029c500, 0xc0001b4650)
	/go/src/github.com/docker/cli/vendor/github.com/spf13/cobra/command.go:762 +0x460
github.com/docker/cli/vendor/github.com/spf13/cobra.(*Command).ExecuteC(0xc0000b3b80, 0xc0001b4640, 0x3, 0x5)
	/go/src/github.com/docker/cli/vendor/github.com/spf13/cobra/command.go:852 +0x2ea
github.com/docker/cli/vendor/github.com/spf13/cobra.(*Command).Execute(...)
	/go/src/github.com/docker/cli/vendor/github.com/spf13/cobra/command.go:800
main.runDocker(0xc00031c000, 0x209cc60, 0xc00000e028)
	/go/src/github.com/docker/cli/cmd/docker/docker.go:281 +0x1d1
main.main()
	/go/src/github.com/docker/cli/cmd/docker/docker.go:292 +0xf1

On Docker 20.10;

docker -H unix:///no/such/socket info --format '{{.Swarm.LocalNodeState}}'

template: :1:8: executing "" at <.Swarm.LocalNodeState>: reflect: indirection through nil pointer to embedded struct field Info

On Docker 23.0 and up;

docker info --format '{{.Swarm.LocalNodeState}}'
inactive

docker -H unix:///no/such/socket info --format '{{.Swarm.LocalNodeState}}'

Cannot connect to the Docker daemon at unix:///no/such/socket. Is the docker daemon running?