Panic if "every" field is omitted in NotificationRulesAPI.createNotificationRule

Steps to reproduce:
We are using the InfluxDB JavaScript Client.

For instance:

    create_result = await notificationRulesAPI.createNotificationRule({
        body: {
            type: 'http',
            endpointID: user.notificationEndpointId,
            name: "E-mail Notification Rule",
            description: "Notification rule for sending e-mail to SendGrid.",
            orgID: user.orgId,
            status: user.sendDeviceEmails === 'email' ? 'active' : 'inactive',
            statusRules: statusRules
        }});

causes a panic. "every" is listed as an optional field, but including it fixes the issue:

    create_result = await notificationRulesAPI.createNotificationRule({
        body: {
            type: 'http',
            endpointID: user.notificationEndpointId,
            name: "E-mail Notification Rule",
            description: "Notification rule for sending e-mail to SendGrid.",
            every: '1h',
            orgID: user.orgId,
            status: user.sendDeviceEmails === 'email' ? 'active' : 'inactive',
            statusRules: statusRules
        }});

fixes the issue.

Expected behavior:
"every" is listed as an optional field, but omitting it causes a kernel panic. If it is intended to be necessary, an enlightening error like "missing required field: every" should be returned. If it is not intended to be necessary, then the issue should be fixed.

Actual behavior:
The server shows msg="a panic has occurred" log_id=0ZP2H~~l000 handler=panic error="/api/v2/notificationRules: runtime error: invalid memory address or nil pointer dereference".

Environment info:

• System info: Linux 5.15.15-76051515-generic x86_64
• InfluxDB version: influxdb:latest (2.1.1)
• Other relevant environment details: Docker version 20.10.7, build f0df350

Config:

docker run -p 8086:8086 \
           -e DOCKER_INFLUXDB_INIT_USERNAME=influx_dev_user \
           -e DOCKER_INFLUXDB_INIT_PASSWORD=influx_not_secure \
           -e DOCKER_INFLUXDB_INIT_ORG=required_but_unused_org \
           -e DOCKER_INFLUXDB_INIT_BUCKET=required_but_unused_bucket \
           -e DOCKER_INFLUXDB_INIT_MODE=setup \
           -e DOCKER_INFLUXDB_INIT_ADMIN_TOKEN=not_secure_admin_token \
           influxdb:latest

Logs:

ts=2022-02-01T07:35:09.397252Z lvl=error msg="a panic has occurred" log_id=0ZP2H~~l000 handler=panic error="/api/v2/notificationRules: runtime error: invalid memory address or nil pointer dereference" stacktrace="goroutine 4595 [running]:\nruntime/debug.Stack()\n\t/home/circleci/.tools/go/src/runtime/debug/stack.go:24 +0x65\ngithub.com/influxdata/influxdb/v2/http.baseHandler.panic({{0x4058600, 0xc0026caae0}}, {0x4077400, 0xc00141d460}, 0x0, {0x3c52600, 0x53e34d0})\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/router.go:96 +0x1b3\ngithub.com/influxdata/httprouter.(*Router).recv(0xc00279b170, {0x4077400, 0xc00141d460}, 0xaa45ab)\n\t/home/circleci/go/pkg/mod/github.com/influxdata/httprouter@v1.3.1-0.20191122104820-ee83e2772f69/router.go:361 +0x5e\npanic({0x3c52600, 0x53e34d0})\n\t/home/circleci/.tools/go/src/runtime/panic.go:1038 +0x215\ngithub.com/influxdata/influxdb/v2/notification/rule.increaseDur(0x0)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/notification/rule/rule.go:258 +0x34\ngithub.com/influxdata/influxdb/v2/notification/rule.(*Base).generateFluxASTStatuses(0xc000669260)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/notification/rule/rule.go:296 +0x3d\ngithub.com/influxdata/influxdb/v2/notification/rule.(*HTTP).generateFluxASTBody(0xc000669260, 0xc001177dc0)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/notification/rule/http.go:54 +0x287\ngithub.com/influxdata/influxdb/v2/notification/rule.(*HTTP).GenerateFluxAST(0xc000669260, 0xc000754648)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/notification/rule/http.go:30 +0x45\ngithub.com/influxdata/influxdb/v2/notification/rule.(*HTTP).GenerateFlux(0xc000669260, {0x40f6120, 0xc0005fe500})\n\t/home/circleci/go/src/github.com/influxdata/influxdb/notification/rule/http.go:25 +0x36\ngithub.com/influxdata/influxdb/v2/notification/rule/service.(*RuleService).createNotificationTask(0xc000676d20, {0x40a6bc0, 0xc000964810}, {{0x40fd088, 0xc000669260}, {0xc0008b38f8, 0x23abcb8}})\n\t/home/circleci/go/src/github.com/influxdata/influxdb/notification/rule/service/service.go:163 +0xc5\ngithub.com/influxdata/influxdb/v2/notification/rule/service.(*RuleService).CreateNotificationRule(0xc000676d20, {0x40a6bc0, 0xc000964810}, {{0x40fd088, 0xc000669260}, {0xc0008b38f8, 0x23abcb8}}, 0x8d905ced0228000)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/notification/rule/service/service.go:122 +0x1a5\ngithub.com/influxdata/influxdb/v2/task/backend/middleware.(*CoordinatingNotificationRuleStore).CreateNotificationRule(0xc0012f8b40, {0x40a6bc0, 0xc000964810}, {{0x40fd088, 0xc000669260}, {0xc0008b38f8, 0xc000754a68}}, 0xa5b86b)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/task/backend/middleware/notification_middleware.go:39 +0x70\ngithub.com/influxdata/influxdb/v2/authorizer.(*NotificationRuleStore).CreateNotificationRule(0xc0027916e0, {0x40a6bc0, 0xc000964810}, {{0x40fd088, 0xc000669260}, {0xc0008b38f8, 0x10}}, 0x10)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/authorizer/notification_rule.go:57 +0xe2\ngithub.com/influxdata/influxdb/v2/http.(*NotificationRuleHandler).handlePostNotificationRule(0xc00279b200, {0x4077400, 0xc00141d460}, 0xc0005fe400)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/notification_rule.go:594 +0x37d\nnet/http.HandlerFunc.ServeHTTP(0x7f22dcb48e60, {0x4077400, 0xc00141d460}, 0x7f23071f3a68)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/http.(*proxyHandler).ServeHTTP(0xc0013fe340, {0x4077400, 0xc00141d460}, 0x90)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/proxy_handler.go:33 +0x68\ngithub.com/influxdata/httprouter.(*Router).Handler.func1({0x4077400, 0xc00141d460}, 0x3c4d440, {0x0, 0x3b69c00, 0xc0013e1240})\n\t/home/circleci/go/pkg/mod/github.com/influxdata/httprouter@v1.3.1-0.20191122104820-ee83e2772f69/router.go:325 +0x2c4\ngithub.com/influxdata/httprouter.(*Router).ServeHTTP(0xc00279b170, {0x4077400, 0xc00141d460}, 0xc0005fe300)\n\t/home/circleci/go/pkg/mod/github.com/influxdata/httprouter@v1.3.1-0.20191122104820-ee83e2772f69/router.go:453 +0x4c3\ngithub.com/go-chi/chi.(*Mux).Mount.func1({0x4077400, 0xc00141d460}, 0xc0005fe300)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/mux.go:298 +0x13b\nnet/http.HandlerFunc.ServeHTTP(0x3c2d5a0, {0x4077400, 0xc00141d460}, 0xc0011a0920)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/go-chi/chi.(*Mux).routeHTTP(0xc0026f9800, {0x4077400, 0xc00141d460}, 0xc0005fe300)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/mux.go:431 +0x1f9\nnet/http.HandlerFunc.ServeHTTP(0xc000964240, {0x4077400, 0xc00141d460}, 0xc0007550b8)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/kit/transport/http.SetCORS.func1({0x4077400, 0xc00141d460}, 0xc0005fe300)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/kit/transport/http/middleware.go:36 +0x308\nnet/http.HandlerFunc.ServeHTTP(0xe, {0x4077400, 0xc00141d460}, 0x203000)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/go-chi/chi/middleware.StripSlashes.func1({0x4077400, 0xc00141d460}, 0xc0005fe300)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/middleware/strip.go:25 +0x102\nnet/http.HandlerFunc.ServeHTTP(0xc000964240, {0x4077400, 0xc00141d460}, 0x30)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/kit/transport/http.SkipOptions.func1({0x4077400, 0xc00141d460}, 0xc0005fe300)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/kit/transport/http/middleware.go:81 +0xb9\nnet/http.HandlerFunc.ServeHTTP(0xc000964330, {0x4077400, 0xc00141d460}, 0xc000755238)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/http.panicMW.func1.1({0x4077400, 0xc00141d460}, 0xc0007552f0)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/router.go:126 +0x9b\nnet/http.HandlerFunc.ServeHTTP(0x90, {0x4077400, 0xc00141d460}, 0x1000000023ca01f)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/go-chi/chi.(*Mux).ServeHTTP(0xc0026f9800, {0x4077400, 0xc00141d460}, 0xc0005fe300)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/mux.go:70 +0x40e\ngithub.com/influxdata/influxdb/v2/kit/feature.(*Handler).ServeHTTP(0xc0027da240, {0x4077400, 0xc00141d460}, 0xc0005fe200)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/kit/feature/middleware.go:43 +0x3c2\ngithub.com/influxdata/influxdb/v2/http.(*AuthenticationHandler).ServeHTTP(0xc0026b9110, {0x4077400, 0xc00141d460}, 0xc0005fe100)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/authentication_middleware.go:127 +0x467\ngithub.com/influxdata/influxdb/v2/kit/transport/http.SetCORS.func1({0x4077400, 0xc00141d460}, 0xc0005fe100)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/kit/transport/http/middleware.go:36 +0x308\nnet/http.HandlerFunc.ServeHTTP(0xc000964240, {0x4077400, 0xc00141d460}, 0xc0011a0921)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/kit/transport/http.SkipOptions.func1({0x4077400, 0xc00141d460}, 0xc0005fe100)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/kit/transport/http/middleware.go:81 +0xb9\nnet/http.HandlerFunc.ServeHTTP(0x33d8a90, {0x4077400, 0xc00141d460}, 0x18)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/http.(*PlatformHandler).ServeHTTP(0xc0027da340, {0x4077400, 0xc00141d460}, 0xc0005fe100)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/platform_handler.go:81 +0x1d2\ngithub.com/go-chi/chi.(*Mux).Mount.func1({0x4077400, 0xc00141d460}, 0xc0005fe100)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/mux.go:298 +0x13b\nnet/http.HandlerFunc.ServeHTTP(0x203000, {0x4077400, 0xc00141d460}, 0xc00141d440)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/kit/transport/http.Metrics.func1.1({0x407c1d0, 0xc000668fc0}, 0xc0005fe100)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/kit/transport/http/middleware.go:66 +0x1e2\nnet/http.HandlerFunc.ServeHTTP(0xc0004c1830, {0x407c1d0, 0xc000668fc0}, 0x7f22d9a28318)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/kit/transport/http.Trace.func1.1({0x407c1d0, 0xc000668fc0}, 0x2)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/kit/transport/http/middleware.go:106 +0x30c\nnet/http.HandlerFunc.ServeHTTP(0xc0027e0180, {0x407c1d0, 0xc000668fc0}, 0xc000654c78)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/go-chi/chi.(*ChainHandler).ServeHTTP(0x3c2d5a0, {0x407c1d0, 0xc000668fc0}, 0xc0013f4bd5)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/chain.go:31 +0x2c\ngithub.com/go-chi/chi.(*Mux).routeHTTP(0xc0027dc180, {0x407c1d0, 0xc000668fc0}, 0xc0005fe000)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/mux.go:431 +0x1f9\nnet/http.HandlerFunc.ServeHTTP(0x88, {0x407c1d0, 0xc000668fc0}, 0x90)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/influxdata/influxdb/v2/http.(*AddHeader).Middleware.func1({0x407c1d0, 0xc000668fc0}, 0x53c4e01)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/handler.go:102 +0x77\nnet/http.HandlerFunc.ServeHTTP(0x40a6b18, {0x407c1d0, 0xc000668fc0}, 0x53c4e90)\n\t/home/circleci/.tools/go/src/net/http/server.go:2046 +0x2f\ngithub.com/go-chi/chi.(*Mux).ServeHTTP(0xc0027dc180, {0x407c1d0, 0xc000668fc0}, 0xc000531f00)\n\t/home/circleci/go/pkg/mod/github.com/go-chi/chi@v4.1.0+incompatible/mux.go:86 +0x3c2\ngithub.com/influxdata/influxdb/v2/http.(*Handler).ServeHTTP(0x0, {0x407c1d0, 0xc000668fc0}, 0x40)\n\t/home/circleci/go/src/github.com/influxdata/influxdb/http/handler.go:166 +0x2f\nnet/http.serverHandler.ServeHTTP({0x4072558}, {0x407c1d0, 0xc000668fc0}, 0xc000531f00)\n\t/home/circleci/.tools/go/src/net/http/server.go:2878 +0x43b\nnet/http.(*conn).serve(0xc0006d2b40, {0x40a6bc0, 0xc0027e03f0})\n\t/home/circleci/.tools/go/src/net/http/server.go:1929 +0xb08\ncreated by net/http.(*Server).Serve\n\t/home/circleci/.tools/go/src/net/http/server.go:3033 +0x4e8\n"

Reproduce the omission through the /api/v2/notificationRules endpoint, then trace the request through http/notification_rule.go and notification/rule/service.go. Inspect increaseDur and generateFluxASTStatuses in notification/rule/rule.go, along with notification/rule/http.go; done means omitting every no longer causes a nil-pointer panic and produces the intended validation or creation result.