Invalid memory address or nil pointer dereference runtime error

[MonicaisHer]

🐞 Bug Report

Affected Services [REQUIRED]

The issue is located in:

• support-scheduler
• support-notifications
• core-data
• core-command
• core-metadata

Is this a regression?

Yes, the previous version in which this bug was not present was:

edgexfoundry_3.0.0-dev.108

Description and Minimal Reproduction [REQUIRED]

There is a runtime error caused by a nil pointer dereference or invalid memory address access while setting certain environment variables:

$ snap install edgexfoundry --edge
edgexfoundry (edge) 3.0.0-dev.114 from Canonical✓ installed
$ sudo snap set edgexfoundry apps.core-data.config.edgex-config-provider='none'
$ sudo snap set edgexfoundry apps.core-data.config.edgex-common-config=./config/core-common-config-bootstrapper/res/configuration.yaml
$ sudo snap set edgexfoundry apps.core-data.config.service-startupmsg='manual-snap-testing'
$ snap restart edgexfoundry.core-data

🔥 Exception or Error

$ journalctl -f | grep core-data
Mär 27 14:51:55 ubuntu systemd[1]: Started Service for snap application edgexfoundry.core-data.
Mär 27 14:51:55 ubuntu edgex-core-data.service-config-overrides.sh[34122]: sourcing /var/snap/edgexfoundry/4359/config/core-data/res/core-data.env
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.473473087Z app=core-data source=secret.go:65 msg="Creating SecretClient"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.473585204Z app=core-data source=variables.go:457 msg="Variables override of 'SecretStore/TokenFile' by environment variable: SECRETSTORE_TOKENFILE=/var/snap/edgexfoundry/4359/secrets/core-data/secrets-token.json"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.473645868Z app=core-data source=secret.go:159 msg="SecretStore information created with 1 overrides applied"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.473653455Z app=core-data source=secret.go:75 msg="Reading secret store configuration and authentication token"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.473660562Z app=core-data source=secret.go:200 msg="load token from file"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.473732885Z app=core-data source=secret.go:93 msg="Attempting to create secret client"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.474765087Z app=core-data source=secret.go:104 msg="Created SecretClient"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.474775605Z app=core-data source=secret.go:109 msg="SecretsFile not set, skipping seeding of service secrets."
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.474787185Z app=core-data source=variables.go:457 msg="Variables override of 'Configuration Provider Information' by environment variable: EDGEX_CONFIG_PROVIDER=none"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.474795573Z app=core-data source=variables.go:457 msg="Variables override of '-cc/--commonConfig' by environment variable: EDGEX_COMMON_CONFIG=./config/core-common-config-bootstrapper/res/configuration.yaml"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.474801088Z app=core-data source=config.go:565 msg="Loading configuration file from ./config/core-common-config-bootstrapper/res/configuration.yaml"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: level=INFO ts=2023-03-27T12:51:55.475239929Z app=core-data source=secrets.go:277 msg="kick off token renewal with interval: 30m0s"
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: panic: runtime error: invalid memory address or nil pointer dereference
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: [signal SIGSEGV: segmentation violation code=0x1 addr=0x98 pc=0x7553df]
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: goroutine 1 [running]:
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/environment.(*Variables).buildPaths(0xc0004b0f38?, 0x5?)
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/environment/variables.go:236 +0x11f
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/environment.(*Variables).buildPaths(0xc0004b10a8?, 0x5?)
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/environment/variables.go:243 +0x1d4
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/environment.(*Variables).buildPaths(0x852dc0?, 0xc0004423e0?)
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/environment/variables.go:243 +0x1d4
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/environment.(*Variables).OverrideConfigMapValues(0xc000012378, 0x61c?)
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/environment/variables.go:149 +0x3e
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/environment.(*Variables).OverrideConfiguration(0xc0000b69a0?, {0x8ccd00, 0xc0003c5e00})
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/environment/variables.go:130 +0x14f
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/config.(*Processor).Process(0xc0000b69a0, {0x9132b7, 0x9}, {0x90f6dc, 0x5}, {0x912c27, 0x8}, {0x9ce3b8, 0xc0003c5e00}, {0x9ceea0, ...})
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/config/config.go:188 +0x765
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap.RunAndReturnWaitGroup({0x9cb2d0, 0xc0003eeaa0}, 0xc0003fb7b0, {0x9ce418?, 0xc00042a770}, {0x9132b7, 0x9}, {0x912c27, 0x8}, {0x9ce3b8, ...}, ...)
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/bootstrap.go:126 +0x4ac
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap.Run({0x9cb2d0?, 0xc0003eeaa0?}, 0xc0003fb7b0, {0x9ce418?, 0xc00042a770?}, {0x9132b7?, 0x0?}, {0x912c27?, 0x0?}, {0x9ce3b8, ...}, ...)
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/go-mod-bootstrap/[email protected]/bootstrap/bootstrap.go:215 +0x11d
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: github.com/edgexfoundry/edgex-go/internal/core/data.Main({0x9cb2d0, 0xc0003eeaa0}, 0x405391?, 0xc000001d40)
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/edgex-go/internal/core/data/main.go:62 +0x705
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]: main.main()
Mär 27 14:51:55 ubuntu edgexfoundry.core-data[34092]:         github.com/edgexfoundry/edgex-go/cmd/core-data/main.go:27 +0x89
Mär 27 14:51:55 ubuntu systemd[1]: snap.edgexfoundry.core-data.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Mär 27 14:51:55 ubuntu systemd[1]: snap.edgexfoundry.core-data.service: Failed with result 'exit-code'.

🌍 Your Environment

Deployment Environment:
Ubuntu 22.04 LTS
EdgeX Version [REQUIRED]:

3.0.0-dev.114
Anything else relevant?
it's possible that the error is being caused by the item variable in the for loop. if item is a nil pointer, then attempting to access its Kind() method would result in a runtime error. To fix this issue, we can add a check to see if item is not nil before calling Kind() on it.