bugfix: empty securityContext breaks console process with nil

[pjuarezd]

What this fix?

If you set an empty spec.securityContext: {} in the tenant resource, the Operator console breaks with the error below and the process crashes when you click the Security tab.

The fix is simply about check for not nil values.

2023/08/21 23:22:58 server.go:3230: http: panic serving 10.217.0.1:44752: runtime error: invalid memory address or nil pointer dereference
goroutine 74 [running]:
net/http.(*conn).serve.func1()
	net/http/server.go:1850 +0xbf
panic({0x22af760, 0x54ea0a0})
	runtime/panic.go:890 +0x262
github.com/minio/operator/api.convertK8sSCToModelSC(0xc0008eb1f0)
	github.com/minio/operator/api/tenants_helper.go:67 +0x39
github.com/minio/operator/api.getTenantSecurity({0x4222e70, 0xc00131f440}, {0x4233270, 0xc00012e0c0}, 0xc000251800)
	github.com/minio/operator/api/tenant-handlers.go:386 +0x18d
github.com/minio/operator/api.getTenantSecurityResponse(0xc0009589c0, {0xc000c0b700, {0xc0000550a7, 0xe}, {0xc0000550be, 0xe}})
	github.com/minio/operator/api/certificate-handlers.go:87 +0x3f9
github.com/minio/operator/api.registerCertificateHandlers.func1({0xc000c0b700, {0xc0000550a7, 0xe}, {0xc0000550be, 0xe}}, 0x0?)
	github.com/minio/operator/api/certificate-handlers.go:39 +0x4d
github.com/minio/operator/api/operations/operator_api.TenantSecurityHandlerFunc.Handle(0xc00016f380?, {0xc000c0b700, {0xc0000550a7, 0xe}, {0xc0000550be, 0xe}}, 0xf8?)
	github.com/minio/operator/api/operations/operator_api/tenant_security.go:38 +0x4d
github.com/minio/operator/api/operations/operator_api.(*TenantSecurity).ServeHTTP(0xc00013c9f0, {0x42131b8, 0xc0012b41b0}, 0xc000c0b700)
	github.com/minio/operator/api/operations/operator_api/tenant_security.go:85 +0x2c3
github.com/go-openapi/runtime/middleware.NewOperationExecutor.func1({0x42131b8, 0xc0012b41b0}, 0xc000c0b700)
	github.com/go-openapi/runtime@v0.25.0/middleware/operation.go:28 +0x59
net/http.HandlerFunc.ServeHTTP(0xc001351120?, {0x42131b8?, 0xc0012b41b0?}, 0x16?)
	net/http/server.go:2109 +0x2f
github.com/go-openapi/runtime/middleware.NewRouter.func1({0x42131b8, 0xc0012b41b0}, 0xc000c0b500)
	github.com/go-openapi/runtime@v0.25.0/middleware/router.go:78 +0x257
net/http.HandlerFunc.ServeHTTP(0xc0013512e8?, {0x42131b8?, 0xc0012b41b0?}, 0x21929c0?)
	net/http/server.go:2109 +0x2f
github.com/go-openapi/runtime/middleware.Redoc.func1({0x42131b8, 0xc0012b41b0}, 0x412de2?)
	github.com/go-openapi/runtime@v0.25.0/middleware/redoc.go:72 +0x242
net/http.HandlerFunc.ServeHTTP(0x0?, {0x42131b8?, 0xc0012b41b0?}, 0x0?)
	net/http/server.go:2109 +0x2f
github.com/go-openapi/runtime/middleware.Spec.func1({0x42131b8, 0xc0012b41b0}, 0xc000be4780?)
	github.com/go-openapi/runtime@v0.25.0/middleware/spec.go:46 +0x18c
net/http.HandlerFunc.ServeHTTP(0x54f12c0?, {0x42131b8?, 0xc0012b41b0?}, 0x4?)
	net/http/server.go:2109 +0x2f
github.com/klauspost/compress/gzhttp.NewWrapper.func1.1({0x4213518, 0xc000be4780}, 0x0?)
	github.com/klauspost/compress@v1.15.15/gzhttp/compress.go:409 +0x362
net/http.HandlerFunc.ServeHTTP(0x4221498?, {0x4213518?, 0xc000be4780?}, 0x19?)
	net/http/server.go:2109 +0x2f
github.com/minio/operator/api.AuditLogMiddleware.func1({0x4221498?, 0xc0006fe540?}, 0xc000c0b500)
	github.com/minio/operator/api/configure_operator.go:215 +0x82
net/http.HandlerFunc.ServeHTTP(0x7fe222305878?, {0x4221498?, 0xc0006fe540?}, 0xc001562f50?)
	net/http/server.go:2109 +0x2f
github.com/minio/operator/api.proxyMiddleware.func1({0x4221498?, 0xc0006fe540?}, 0xc000c0b500?)
	github.com/minio/operator/api/configure_operator.go:146 +0xcc
net/http.HandlerFunc.ServeHTTP(0x2456860?, {0x4221498?, 0xc0006fe540?}, 0x2634eff?)
	net/http/server.go:2109 +0x2f
github.com/minio/operator/api.FileServerMiddleware.func1({0x4221498, 0xc0006fe540}, 0xc000c0b500)
	github.com/minio/operator/api/configure_operator.go:390 +0x19e
net/http.HandlerFunc.ServeHTTP(0x4222f18?, {0x4221498?, 0xc0006fe540?}, 0x41f8e70?)
	net/http/server.go:2109 +0x2f
github.com/minio/operator/api.ContextMiddleware.func1({0x4221498, 0xc0006fe540}, 0xc000c0b400)
	github.com/minio/operator/api/configure_operator.go:207 +0x332
net/http.HandlerFunc.ServeHTTP(0x4222e70?, {0x4221498?, 0xc0006fe540?}, 0x41f8ea0?)
	net/http/server.go:2109 +0x2f
github.com/minio/operator/api.AuthenticationMiddleware.func1({0x4221498, 0xc0006fe540}, 0xc000c0b300)
	github.com/minio/operator/api/configure_operator.go:246 +0x55f
net/http.HandlerFunc.ServeHTTP(0xc0007ecf00?, {0x4221498?, 0xc0006fe540?}, 0x7fe1fae600b8?)
	net/http/server.go:2109 +0x2f
github.com/unrolled/secure.(*Secure).Handler.func1({0x4221498, 0xc0006fe540}, 0x7fe1faaaa548?)
	github.com/unrolled/secure@v1.13.0/secure.go:203 +0x98
net/http.HandlerFunc.ServeHTTP(0x0?, {0x4221498?, 0xc0006fe540?}, 0x46856e?)
	net/http/server.go:2109 +0x2f
net/http.serverHandler.ServeHTTP({0xc0008f0360?}, {0x4221498, 0xc0006fe540}, 0xc000c0b300)
	net/http/server.go:2947 +0x30c
net/http.(*conn).serve(0xc000be4280, {0x4222f18, 0xc000462120})
	net/http/server.go:1991 +0x607
created by net/http.(*Server).Serve
	net/http/server.go:3102 +0x4db

[jiuker]

LGTM