CODEWITHSUNDEEP
monoasp.net-corecentos7
Ankesh
Ankesh

Reputation: 4885

Unable to launch a website using KestrelHttpServer (Error : Object reference not set to an instance of an object)

I have installed mono 3.10.0 from source in my Linux VM (Centos 7)

I have installed KVM using the link provided in ASP.NET home on Github 

curl -sSL https://raw.githubusercontent.com/aspnet/Home/master/kvminstall.sh | sh && source ~/.kre/kvm/kvm.sh

and kpm restore is working file and restoring all packages

but i am not able to run k kestrel in the HelloMvc samples from Asp.Net Home Github
I gives error 

System.NullReferenceException: Object reference not set to an instance of an object
  at Microsoft.AspNet.Server.Kestrel.Networking.Libuv.loop_size () [0x00000] in <filename unknown>:0 
  at Microsoft.AspNet.Server.Kestrel.Networking.UvLoopHandle.Init (Microsoft.AspNet.Server.Kestrel.Networking.Libuv uv) [0x00000] in <filename unknown>:0 
  at Microsoft.AspNet.Server.Kestrel.KestrelThread.ThreadStart (System.Object parameter) [0x00000] in <filename unknown>:0

I have also tried to isntall libuv from source still no luck

Edit

Steps Followed for libuv install :

wget http://dist.libuv.org/dist/v1.0.0-rc1/libuv-v1.0.0-rc2.tar.gz
tar -xvf libuv-v1.0.0-rc2.tar.gz
cd libuv-v1.0.0-rc2/
./gyp_uv.py -f make -Duv_library=shared_library
make -C out
sudo cp out/Debug/lib.target/libuv.so /usr/lib/libuv.so.1.0.0-rc2
sudo ln -s libuv.so.1.0.0-rc2 /usr/lib/libuv.so.1

Exception after installing Libuv again

System.ArgumentException: An element with the same key already exists in the dictionary.
  at System.Collections.Generic.Dictionary`2[TKey,TValue].Add (System.Collections.Generic.TKey key, System.Collections.Generic.TValue value) [0x00000] in <filename unknown>:0 
  at System.Linq.Enumerable.ToDictionary[DictionaryEntry,String,String] (IEnumerable`1 source, System.Func`2 keySelector, System.Func`2 elementSelector, IEqualityComparer`1 comparer) [0x00000] in <filename unknown>:0 
  at Microsoft.Framework.ConfigurationModel.EnvironmentVariablesConfigurationSource.Load (IDictionary envVariables) [0x00000] in <filename unknown>:0 
  at Microsoft.Framework.ConfigurationModel.EnvironmentVariablesConfigurationSource.Load () [0x00000] in <filename unknown>:0 
  at Microsoft.Framework.ConfigurationModel.Configuration.Add (IConfigurationSource configurationSource) [0x00000] in <filename unknown>:0 
  at Microsoft.Framework.ConfigurationModel.ConfigurationExtensions.AddEnvironmentVariables (IConfigurationSourceContainer configuration) [0x00000] in <filename unknown>:0 
  at Microsoft.AspNet.Hosting.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0 
  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0

Upvotes: 3

Views: 1272

Answers (3)

druss
druss

Reputation: 1880

You got an exception because you have two variables with the same name but in the different case. Dump all environment variables before start:

printenv > env.dump

find duplicated variables and before start unset one of them (save the original value before to restore it after)

Here is script init.d with example

Just save and unset variable:

TMP_SAVE_runlevel_VAR=$runlevel
unset runlevel

And the restore it:

export runlevel=$TMP_SAVE_runlevel_VAR

Upvotes: 1

agua from mars
agua from mars

Reputation: 17424

Take a look at http://olivierlefebvre.tumblr.com/post/101523386694/asp-vnext-alpa4-on-ubuntu

I fixed like that.

Step Used

git clone https://github.com/joyent/libuv.git
cd libuv
sh autogen.sh
./configure
make
make check
sudo make install

Final by adding a symlink to the lib

ln /usr/local/lib/libuv.so -sf ~/.kpm/packages/Microsoft.AspNet.Server.Kestrel/1.0.0-alpha4/native/darwin/universal/libuv.dylib

Upvotes: 2

Evert
Evert

Reputation: 162

Take a look at http://carolynvanslyck.com/blog/2014/09/dotnet-vnext-impressions/ the section on Kestrel.

wget http://dist.libuv.org/dist/v1.0.0-rc2/libuv-v1.0.0-rc2.tar.gz
tar -xvf libuv-v1.0.0-rc2.tar.gz
cd libuv-v1.0.0-rc2/
./gyp_uv.py -f make -Duv_library=shared_library
make -C out
sudo cp out/Debug/lib.target/libuv.so /usr/lib/libuv.so.1.0.0-rc2
sudo ln -s libuv.so.1.0.0-rc2 /usr/lib/libuv.so.1

This worked for me

Upvotes: 2

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