Plugin crashes on notification

[AR1ES]

I have Mattermost v7.5.2 bundled with gitlab.
I'm using the AlertManager Plugin v0.4.0.
I configured everything according to Readme.

When I open /plugins/alertmanager/api/webhook I get the text "Mattermost AlertManager Plugin".

But when I send notification like this

POST https://xxxxxx/plugins/alertmanager/api/webhook?token=yyyyyy
Content-type: application/json
{
    "text": "Hello, world."
}

I got an error "500 internal server error'

Server logs:

{"timestamp":"2023-03-05 21:10:34.109 Z","level":"info","msg":"Received alertmanager notification","caller":"app/plugin_api.go:973","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:10:34.114 Z","level":"error","msg":"Plugin failed to ServeHTTP, RPC call failed","caller":"plugin/client_rpc.go:423","plugin_id":"alertmanager","error":"unexpected EOF"}
{"timestamp":"2023-03-05 21:10:34.114 Z","level":"error","msg":"plugin process exited","caller":"plugin/hclog_adapter.go:79","plugin_id":"alertmanager","wrapped_extras":"path/var/opt/gitlab/mattermost/plugins/alertmanager/server/dist/plugin-linux-amd64pid29375errorexit status 2"}

Debug logs:

{"timestamp":"2023-03-05 21:19:55.161 Z","level":"info","msg":"Received alertmanager notification","caller":"app/plugin_api.go:973","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"panic: runtime error: invalid memory address or nil pointer dereference","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0xee6fd5]","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"goroutine 27 [running]:","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"main.(*Plugin).handleWebhook(0xc000400900, {0x156b2e0, 0xc000420c60}, 0xc00050e200, {{0x1c8ce20, 0x1}, {0xc0007c84a0, 0x20}, {0xc00011ac78, 0x6}, ...})","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"\tgithub.com/cpanato/mattermost-plugin-alertmanager/server/webhook.go:33 +0x115","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"main.(*Plugin).ServeHTTP(0x7f2da5187f68?, 0x10d68c0?, {0x156b2e0, 0xc000420c60}, 0xc00050e200)","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"\tgithub.com/cpanato/mattermost-plugin-alertmanager/server/plugin.go:131 +0x3d5","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"github.com/mattermost/mattermost-server/v6/plugin.(*hooksRPCServer).ServeHTTP(0xc0004224a0, 0xc0003378a0, 0x1?)","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"\tgithub.com/mattermost/mattermost-server/v6@v6.0.0-20221109191448-21aec2741bfe/plugin/client_rpc.go:453 +0x417","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"reflect.Value.call({0xc0000c1560?, 0xc0000bc868?, 0x13?}, {0x111d53e, 0x4}, {0xc000781ef8, 0x3, 0x3?})","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"\treflect/value.go:584 +0x8c5","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"reflect.Value.Call({0xc0000c1560?, 0xc0000bc868?, 0x0?}, {0xc0000db6f8?, 0x0?, 0x0?})","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"\treflect/value.go:368 +0xbc","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"net/rpc.(*service).call(0xc0000cc340, 0x0?, 0x0?, 0xc0000ce120, 0xc000334b80, 0x0?, {0xf51dc0?, 0xc0003378a0?, 0x0?}, {0xf5eb40, ...}, ...)","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"\tnet/rpc/server.go:382 +0x226","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"created by net/rpc.(*Server).ServeCodec","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.164 Z","level":"debug","msg":"\tnet/rpc/server.go:479 +0x3fe","caller":"plugin/hclog_adapter.go:54","plugin_id":"alertmanager"}
{"timestamp":"2023-03-05 21:19:55.166 Z","level":"error","msg":"Plugin failed to ServeHTTP, RPC call failed","caller":"plugin/client_rpc.go:423","plugin_id":"alertmanager","error":"unexpected EOF"}
{"timestamp":"2023-03-05 21:19:55.166 Z","level":"error","msg":"plugin process exited","caller":"plugin/hclog_adapter.go:79","plugin_id":"alertmanager","wrapped_extras":"path/var/opt/gitlab/mattermost/plugins/alertmanager/server/dist/plugin-linux-amd64pid30003errorexit status 2"}

[cpanato]

Hello, if you curl the endpoint it will return that text. This is expected.
also if you make a post and do not pass the expected payload it will fail but should not panic

[AR1ES]

@cpanato
Thanks for the answer. The request was given as an example. In fact, the problem is observed when receiving messages from AlertManager. Then the plugin crashes.

It turns out that the AlertManager should have some additional settings if its messages are not suitable? In this case, can you tell me what the correct payload should look like so that you can test and make sure that the plugin works correctly?

[cpanato]

@AR1ES the plugin expect the payload that Alertmanager sends to the plugin

you can check a sample config for the alertmanager here https://github.com/cpanato/mattermost-plugin-alertmanager/blob/main/hack/config.yml