influx --full restore causes panic (segfault) at v2.0.6

[kyontan]

Steps to reproduce:
List the minimal actions needed to reproduce the behavior.

1. influx restore --full ./

(No exported data is required to reproduce error, it seems panic occured before accessing exported data.)

Expected behavior:

Start restore process.

Describe what you expected to happen.

Actual behavior:

Panic occurs

Environment info:

• System info: Run uname -srm and copy the output here
• Linux 5.4.0-72-generic x86_64
• InfluxDB version: Run influxd version and copy the output here
• InfluxDB 2.0.6 (git: 4db98b4c9a) build_date: 2021-04-29T16:48:12Z
• Other relevant environment details: Container runtime, disk info, etc
• Used docker image influx:2.0.6 (the latest release as of 2021-05-09)

Config:
Copy any non-default config values here or attach the full config as a gist or file.

Logs:
Include snippet of errors in log.

# influx restore --full ./
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1047cbb]

goroutine 1 [running]:
github.com/influxdata/influxdb/v2/restore.(*restoreRunner).restoreKV(0xc0007bf9a0, 0x1b1ea00, 0xc000042050, 0x7ffe74e3dedd, 0x2, 0x0, 0x0)
        /home/circleci/go/src/github.com/influxdata/influxdb/restore/restore.go:169 +0x5b
github.com/influxdata/influxdb/v2/restore.(*restoreRunner).fullRestore(0xc0007bf9a0, 0x1b1ea00, 0xc000042050, 0x7ffe74e3dedd, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/circleci/go/src/github.com/influxdata/influxdb/restore/restore.go:131 +0x79
github.com/influxdata/influxdb/v2/restore.RunRestore(0x1b1ea00, 0xc000042050, 0x7ffe74e3dedd, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/circleci/go/src/github.com/influxdata/influxdb/restore/restore.go:76 +0x138
main.(*cmdRestoreBuilder).restoreRunE(0xc0005be270, 0xc0005b7080, 0xc0005ec8e0, 0x1, 0x2, 0x0, 0x0)
        /home/circleci/go/src/github.com/influxdata/influxdb/cmd/influx/restore.go:126 +0x4b8
main.checkSetupRunEMiddleware.func1.1(0xc0005b7080, 0xc0005ec8e0, 0x1, 0x2, 0x0, 0x0)
        /home/circleci/go/src/github.com/influxdata/influxdb/cmd/influx/main.go:466 +0x76
github.com/spf13/cobra.(*Command).execute(0xc0005b7080, 0xc0005ec8c0, 0x2, 0x2, 0xc0005b7080, 0xc0005ec8c0)
        /home/circleci/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:842 +0x47c
github.com/spf13/cobra.(*Command).ExecuteC(0xc000556840, 0x0, 0x0, 0xc000556840)
        /home/circleci/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:950 +0x375
github.com/spf13/cobra.(*Command).Execute(...)
        /home/circleci/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:887
main.main()
        /home/circleci/go/src/github.com/influxdata/influxdb/cmd/influx/main.go:43 +0x58

Performance:
Generate profiles with the following commands for bugs related to performance, locking, out of memory (OOM), etc.

# Commands should be run when the bug is actively happening.
# Note: This command will run for ~30 seconds.
curl -o profiles.tar.gz "http://localhost:8086/debug/pprof/all?cpu=30s"
iostat -xd 1 30 > iostat.txt
# Attach the `profiles.tar.gz` and `iostat.txt` output files.

[danxmoran]

I believe this was fixed by #21477. As of 2.0.7 influx restore will return an error instead of panicking when it doesn't find any backup manifests at the given path.