if statement returns "invalid memory address or nil pointer dereference" error

[xescab]

if statement returns "invalid memory address or nil pointer dereference" error

[aelsabbahy]

Fixed in pr, will be in the next release.

[xescab]

Issue was due to a comment in vars.yaml

[aelsabbahy]

If you don't mind, can you provide the exact vars.yaml and goss.yaml to reproduce this?

Goss should not panic, this is definitely a bug.

[xescab]

Yes, sure! :)

Our vars.yaml starts with:

domain_name: #DOMAIN#
k8s_version: 1.25

and then on a pipeline we replace #DOMAIN# by a proper string, but when I was testing locally I forgot to change the value and that is why I got the segfault. Maybe it could be detected and show a proper error message when the variables are not well declared.

Thanks for looking into this, @aelsabbahy !

[aelsabbahy]

Just following up on this, I think I'm doing something wrong while trying to reproduce, can you also provide the matching goss.yaml that causes it to panic.

$ cat vars.yaml 
domain_name: #DOMAIN#
k8s_version: 1.25

$ cat goss.yaml
command:
  echo "hi":
    exit-status: 0
    stdout:
    - {{.Vars.domain_name}}
    stderr: []
    timeout: 10000

$ goss.3.18 --vars vars.yaml render
command:
  echo "hi":
    exit-status: 0
    stdout:
    - <no value>
    stderr: []
    timeout: 10000

$ goss.3.18 --vars vars.yaml v
.F

Failures/Skipped:

Command: echo "hi": stdout: patterns not found: [<no value>]

Total Duration: 0.002s
Count: 2, Failed: 1, Skipped: 0

[xescab]

Sorry, I am also unable to reproduce with the previous goss.yaml that caused the segfault. I think we can close it.

[aelsabbahy]

It's okay, I have some theories on how it may have happened, but can't reproduce it.

I'll roll out those "fixes" in a future PR. We can leave the ticket open for that, I won't know for sure I fixed the problem, but should help.

Thank you for following back up.

[xescab]

Got it again! It's related with the http module:

$ ./goss --version
goss version v0.4.1
		
$ cat goss.yaml
http:
  # Ensure argocd is available and redirected to HTTPS
  http://argocd.mgmt.{{ .Vars.domain_name }}/:
    status: 302
    no-follow-redirects: true
    headers:
    - "Location: https://argocd"
	
$ cat vars.yaml
domain_name: #DOMAIN#
k8s_version: 1.25

$ ./goss -g goss.yaml --vars vars.yaml render
http:
  http://argocd.mgmt.<no value>/:
    status: 302
    allow-insecure: false
    no-follow-redirects: true
    headers:
    - 'Location: https://argocd'
	
$ ./goss -g goss.yaml --vars vars.yaml  validate
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0x7ac440]

goroutine 69 [running]:
github.com/goss-org/goss/system.(*DefHTTP).Status(0xc00012b380)
        /home/travis/gopath/src/github.com/goss-org/goss/system/http.go:186 +0x40
github.com/goss-org/goss/resource.ValidateGomegaValue({_, _}, {_, _}, {_, _}, {_, _}, _)
        /home/travis/gopath/src/github.com/goss-org/goss/resource/validate.go:160 +0x3f6
github.com/goss-org/goss/resource.ValidateValue({_, _}, {_, _}, {_, _}, {_, _}, _)
        /home/travis/gopath/src/github.com/goss-org/goss/resource/validate.go:130 +0x195
github.com/goss-org/goss/resource.(*HTTP).Validate(0xc000460a20, 0xc000330370?)
        /home/travis/gopath/src/github.com/goss-org/goss/resource/http.go:81 +0x305
github.com/goss-org/goss.validate.func2()
        /home/travis/gopath/src/github.com/goss-org/goss/validate.go:184 +0x91
created by github.com/goss-org/goss.validate
        /home/travis/gopath/src/github.com/goss-org/goss/validate.go:181 +0x190

Hope that with this new info you can fix it :)

[aelsabbahy]

Awesome, I was able to reproduce it! Will fix it in the next goss release.. surprised not too many people ran into this.