Getting Started Guide
Abstract
- the ability to follow a microservices-based approach, where some components are built with .NET and others with Java, but all can run on a common, supported platform in Red Hat Enterprise Linux and OpenShift Container Platform.
- the capacity to more easily develop new .NET Core workloads on Microsoft Windows. Customers can deploy and run on either Red Hat Enterprise Linux or Windows Server.
- a heterogeneous data center, where the underlying infrastructure is capable of running .NET applications without having to rely solely on Windows Server.
Chapter 1. .NET Core 2.0 on Red Hat Enterprise Linux Copy linkLink copied to clipboard!
This Getting Started Guide describes how to install .NET Core 2.0 on Red Hat Enterprise Linux (RHEL). See Red Hat Enterprise Linux documentation for more information about Red Hat Enterprise Linux 7.
1.1. Install and Register Red Hat Enterprise Linux Copy linkLink copied to clipboard!
Install RHEL 7 using one of the following images:
Register the system by following the appropriate steps in Registering and Unregistering a System in the Red Hat Subscription Management document.
You can also use the following command to register the system.
sudo subscription-manager register
$ sudo subscription-manager registerCopy to Clipboard Copied! Toggle word wrap Toggle overflow Display a list of all subscriptions that are available for your system and identify the pool ID for the subscription.
sudo subscription-manager list --available
$ sudo subscription-manager list --availableCopy to Clipboard Copied! Toggle word wrap Toggle overflow This command displays the subscription name, unique identifier, expiration date, and other details related to it. The pool ID is listed on a line beginning with Pool ID.
Attach the subscription that provides access to the
dotNET on RHELrepository. Use the pool ID you identified in the previous step.sudo subscription-manager attach --pool=<appropriate pool ID from the subscription>
$ sudo subscription-manager attach --pool=<appropriate pool ID from the subscription>Copy to Clipboard Copied! Toggle word wrap Toggle overflow Enable the .NET Core channel for Red Hat Enterprise 7 Server, Red Hat Enterprise 7 Workstation, or HPC Compute Node with one of the following commands, respectively.
sudo subscription-manager repos --enable=rhel-7-server-dotnet-rpms sudo subscription-manager repos --enable=rhel-7-workstation-dotnet-rpms sudo subscription-manager repos --enable=rhel-7-hpc-node-dotnet-rpms
$ sudo subscription-manager repos --enable=rhel-7-server-dotnet-rpms $ sudo subscription-manager repos --enable=rhel-7-workstation-dotnet-rpms $ sudo subscription-manager repos --enable=rhel-7-hpc-node-dotnet-rpmsCopy to Clipboard Copied! Toggle word wrap Toggle overflow Verify the list of subscriptions attached to your system.
sudo subscription-manager list --consumed
$ sudo subscription-manager list --consumedCopy to Clipboard Copied! Toggle word wrap Toggle overflow Install the scl tool.
sudo yum install scl-utils
$ sudo yum install scl-utilsCopy to Clipboard Copied! Toggle word wrap Toggle overflow
1.2. Install .NET Core Copy linkLink copied to clipboard!
Install .NET Core 2.0 and all of its dependencies.
sudo yum install rh-dotnet20 -y
$ sudo yum install rh-dotnet20 -yCopy to Clipboard Copied! Toggle word wrap Toggle overflow Enable the
rh-dotnet20Software Collection environment so you can rundotnetcommands in the bash shell.NoteThis procedure installs the .NET Core 2.0 SDK. A .NET Core 2.1 SDK is also available, which you can install via
sudo yum install rh-dotnet20-dotnet-sdk-2.1. It can be installed and used side-by-side with the 2.0 SDK. By default, the 2.1 SDK takes precedence if you install both. You can use a global.json to explicitly select one or the other.scl enable rh-dotnet20 bash
$ scl enable rh-dotnet20 bashCopy to Clipboard Copied! Toggle word wrap Toggle overflow NoteThis command does not persist; it creates a new shell, and the
dotnetcommand is only available within that shell. If you log out, use another shell, or open up a new terminal, thedotnetcommand is no longer enabled.WarningRed Hat does not recommend permanently enabling
rh-dotnet20because it may affect other programs. For example,rh-dotnet20includes a version oflibcurlthat differs from the base RHEL version. This may lead to issues in programs that do not expect a different verison oflibcurl. If you want to permanently enablerh-dotnetfor yourself, add the following line to your~/.bashrcfile.source scl_source enable rh-dotnet20Run the following command to prove the installation succeeded.
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
1.3. Create an Application Copy linkLink copied to clipboard!
If you want to run the classic "Hello World" test case, create the following directory.
mkdir hello-world
$ mkdir hello-worldCopy to Clipboard Copied! Toggle word wrap Toggle overflow Navigate to the
hello-worlddirectory.cd hello-world
$ cd hello-worldCopy to Clipboard Copied! Toggle word wrap Toggle overflow Create a project.
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Pull the dependencies needed for the project.
dotnet build
$ dotnet buildCopy to Clipboard Copied! Toggle word wrap Toggle overflow Run the project.
dotnet run Hello World!
$ dotnet run Hello World!Copy to Clipboard Copied! Toggle word wrap Toggle overflow
1.4. Publish Applications Copy linkLink copied to clipboard!
The .NET Core 2.0 applications can be published to use a shared system-wide version of .NET Core or to include .NET Core. These two deployment types are called framework-dependent deployment (FDD) and self-contained deployment (SCD), respectively.
For RHEL, we recommend publishing by FDD. This method ensures the application is using an up-to-date version of .NET Core, built by Red Hat, that includes a specific set of native dependencies. These native libraries are part of the dotnet Software Collection. On the other hand, SCD uses a runtime built by Microsoft and uses the global Red Hat Enterprise Linux libraries. There are known issues when using .NET Core with these libraries.
1.4.1. Publish .NET Core Applications Copy linkLink copied to clipboard!
Use the following command to publish an application using the FDD.
dotnet publish -f netcoreapp2.0 -c Release
$ dotnet publish -f netcoreapp2.0 -c ReleaseCopy to Clipboard Copied! Toggle word wrap Toggle overflow If the application will only be used on RHEL, you can trim the dependencies needed for other platforms by using these commands.
dotnet restore -r rhel.7-x64 dotnet publish -f netcoreapp2.0 -c Release -r rhel.7-x64 --self-contained false
$ dotnet restore -r rhel.7-x64 $ dotnet publish -f netcoreapp2.0 -c Release -r rhel.7-x64 --self-contained falseCopy to Clipboard Copied! Toggle word wrap Toggle overflow Enable the Software Collection and pass the application assembly name to the
dotnetcommand to run the application on a RHEL system.scl enable rh-dotnet20 -- dotnet <app>.dll
$ scl enable rh-dotnet20 -- dotnet <app>.dllCopy to Clipboard Copied! Toggle word wrap Toggle overflow This command can be added to a script that is published with the application. Add the following script to your project and update the ASSEMBLY variable.
Copy to Clipboard Copied! Toggle word wrap Toggle overflow To include the script when publishing, add this ItemGroup to the
csprojfile.<ItemGroup> <None Update="<scriptname>" Condition="'$(RuntimeIdentifier)' == 'rhel.7-x64' and '$(SelfContained)' == 'false'" CopyToPublishDirectory="PreserveNewest" /> </ItemGroup><ItemGroup> <None Update="<scriptname>" Condition="'$(RuntimeIdentifier)' == 'rhel.7-x64' and '$(SelfContained)' == 'false'" CopyToPublishDirectory="PreserveNewest" /> </ItemGroup>Copy to Clipboard Copied! Toggle word wrap Toggle overflow
1.4.2. Publish ASP.NET Core Applications Copy linkLink copied to clipboard!
By default, ASP.NET Core 2.0 web applications are published with a dependency on a runtime store. This is a set of packages that are expected to be available on the runtime system. They are not included with the published application. RHEL does not include the ASP.NET runtime store, so the applications must be published, including all dependencies. This can be done by setting the PublishWithAspNetCoreTargetManifest property to false in the project file.
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Alternatively, this property can be set when publishing the application.
dotnet publish -f netcoreapp2.0 -c Release -r rhel.7-x64 --self-contained false /p:PublishWithAspNetCoreTargetManifest=false
$ dotnet publish -f netcoreapp2.0 -c Release -r rhel.7-x64 --self-contained false /p:PublishWithAspNetCoreTargetManifest=falseCopy to Clipboard Copied! Toggle word wrap Toggle overflow
1.5. Run Applications on Docker Copy linkLink copied to clipboard!
This section shows how to use the dotnet/dotnet-20-runtime-rhel7 image to run your application inside a Docker container. It requires you to have the docker binary installed, the docker daemon running, and the rh-dotnet20 Software Collection enabled.
Create and navigate to the following directory.
mkdir mvc_runtime_example && cd mvc_runtime_example
$ mkdir mvc_runtime_example && cd mvc_runtime_exampleCopy to Clipboard Copied! Toggle word wrap Toggle overflow Create a new project.
dotnet new mvc --no-restore
$ dotnet new mvc --no-restoreCopy to Clipboard Copied! Toggle word wrap Toggle overflow Pull all dependencies.
dotnet restore -r rhel.7-x64
$ dotnet restore -r rhel.7-x64Copy to Clipboard Copied! Toggle word wrap Toggle overflow Publish the project.
dotnet publish -f netcoreapp2.0 -c Release -r rhel.7-x64 \ --self-contained false /p:PublishWithAspNetCoreTargetManifest=false
$ dotnet publish -f netcoreapp2.0 -c Release -r rhel.7-x64 \ --self-contained false /p:PublishWithAspNetCoreTargetManifest=falseCopy to Clipboard Copied! Toggle word wrap Toggle overflow Create a file called
Dockerfileand add the following contents.Copy to Clipboard Copied! Toggle word wrap Toggle overflow Build your image.
sudo docker build -t dotnet-20-runtime-example .
$ sudo docker build -t dotnet-20-runtime-example .Copy to Clipboard Copied! Toggle word wrap Toggle overflow Run your image.
sudo docker run -d -p8080:8080 dotnet-20-runtime-example
$ sudo docker run -d -p8080:8080 dotnet-20-runtime-exampleCopy to Clipboard Copied! Toggle word wrap Toggle overflow - View the result in a browser: http://127.0.0.1:8080
Chapter 2. .NET Core 2.0 on Red Hat OpenShift Container Platform Copy linkLink copied to clipboard!
2.1. Install Image Streams Copy linkLink copied to clipboard!
The .NET Core image streams definition can be defined globally in the openshift namespace or locally in your specific project.
If you are a system administrator or otherwise have sufficient permissions, change to the
openshiftproject. Using theopenshiftproject allows you to globally update the image stream definitions.oc project openshift
$ oc project openshiftCopy to Clipboard Copied! Toggle word wrap Toggle overflow If you do not have permissions to use the
openshiftproject, you can still update your project definitions starting with Step 2.Run the following command to list all available .NET Core image versions.
oc describe is dotnet
$ oc describe is dotnetCopy to Clipboard Copied! Toggle word wrap Toggle overflow The output shows installed images or the message
Error from server (NotFound)if no images are installed.To pull the images, OpenShift needs credentials for authenticating with the
registry.redhat.ioserver. These credentials are stored in a secret.NoteFor OpenShift 3.11 and later, a secret is preconfigured for the
openshiftnamespace.Enter the following command to list secrets. The first column shows the secret name.
oc get secret | grep kubernetes.io/dockercfg
$ oc get secret | grep kubernetes.io/dockercfgCopy to Clipboard Copied! Toggle word wrap Toggle overflow To check the contents of a secret, you can decode the
.dockercfgor.dockercfgjsondata from Base64 format. This allows you to see if you already have credentials for theregistry.redhat.ioserver. Enter the following command to show the.dockercfgsection in a secret.oc get secret <secret-name> -o yaml | grep .dockercfg .dockercfg: eyJyZWdpc3RyeS5yZWRoYXQuaW8iOnsidXNlcm5hbWUiOiIqKioqKioqKiIsInBhc3N3b3JkIjoiKioqKioqKioiLCJlbWFpbCI6InVudXNlZCIsImF1dGgiOiJLaW9xS2lvcUtpbzZLaW9xS2lvcUtpbz0ifX0=
$ oc get secret <secret-name> -o yaml | grep .dockercfg .dockercfg: eyJyZWdpc3RyeS5yZWRoYXQuaW8iOnsidXNlcm5hbWUiOiIqKioqKioqKiIsInBhc3N3b3JkIjoiKioqKioqKioiLCJlbWFpbCI6InVudXNlZCIsImF1dGgiOiJLaW9xS2lvcUtpbzZLaW9xS2lvcUtpbz0ifX0=Copy to Clipboard Copied! Toggle word wrap Toggle overflow Copy and paste the output in the following command to convert it from Base64 format. The example below shows the credentials for the
registry.redhat.ioserver.echo eyJyZWdpc3RyeS5yZWRoYXQuaW8iOnsidXNlcm5hbWUiOiIqKioqKioqKiIsInBhc3N3b3JkIjoiKioqKioqKioiLCJlbWFpbCI6InVudXNlZCIsImF1dGgiOiJLaW9xS2lvcUtpbzZLaW9xS2lvcUtpbz0ifX0= | base64 -d {"registry.redhat.io":{"username":"********","password":"********","email":"unused","auth":"KioqKioqKio6KioqKioqKio="}}$ echo eyJyZWdpc3RyeS5yZWRoYXQuaW8iOnsidXNlcm5hbWUiOiIqKioqKioqKiIsInBhc3N3b3JkIjoiKioqKioqKioiLCJlbWFpbCI6InVudXNlZCIsImF1dGgiOiJLaW9xS2lvcUtpbzZLaW9xS2lvcUtpbz0ifX0= | base64 -d {"registry.redhat.io":{"username":"********","password":"********","email":"unused","auth":"KioqKioqKio6KioqKioqKio="}}Copy to Clipboard Copied! Toggle word wrap Toggle overflow You need to add a secret if there is no secret listed with credentials for the
registry.redhat.ioserver.Red Hat account credentials are used for
registry.redhat.ioaccess. If you are a customer with entitlements to Red Hat products, you already have account credentials to use. These are typically the same credentials used to log in to the Red Hat Customer Portal. To verify your Red Hat credentials, enter the following command and attempt to log in.docker login registry.redhat.io
$ docker login registry.redhat.ioCopy to Clipboard Copied! Toggle word wrap Toggle overflow If you cannot log in, you first need to get an account with Red Hat. See Red Hat Container Registry Authentication for additional information. If you can log in, enter the following commands to create the secret.
Copy to Clipboard Copied! Toggle word wrap Toggle overflow After creating the secret, enter the following command to import new image streams.
oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/dotnet_imagestreams.json
$ oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/dotnet_imagestreams.jsonCopy to Clipboard Copied! Toggle word wrap Toggle overflow If image streams were already installed, use the
replacecommand to update the image stream definitions.oc replace -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/dotnet_imagestreams.json
$ oc replace -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/dotnet_imagestreams.jsonCopy to Clipboard Copied! Toggle word wrap Toggle overflow
2.2. Deploy Applications Copy linkLink copied to clipboard!
Run the following commands to deploy the ASP.NET Core application, which is in the
appfolder on thedotnetcore-2.0branch of theredhat-developer/s2i-dotnetcore-exGitHub repository.oc new-app --name=exampleapp 'dotnet:2.0~https://github.com/redhat-developer/s2i-dotnetcore-ex#dotnetcore-2.0' --build-env DOTNET_STARTUP_PROJECT=app
$ oc new-app --name=exampleapp 'dotnet:2.0~https://github.com/redhat-developer/s2i-dotnetcore-ex#dotnetcore-2.0' --build-env DOTNET_STARTUP_PROJECT=appCopy to Clipboard Copied! Toggle word wrap Toggle overflow As suggested by the output of the
new-appcommand, you can track progress of the build using theoc logscommand.oc logs -f bc/exampleapp
$ oc logs -f bc/exampleappCopy to Clipboard Copied! Toggle word wrap Toggle overflow Once the build is finished, you can see the deployed application.
oc logs -f dc/exampleapp
$ oc logs -f dc/exampleappCopy to Clipboard Copied! Toggle word wrap Toggle overflow At this point, the application is accessible within the project. To make it accessible externally, use the
oc exposecommand. You can then useoc get routesto find the URL.oc expose svc/exampleapp oc get routes
$ oc expose svc/exampleapp $ oc get routesCopy to Clipboard Copied! Toggle word wrap Toggle overflow
2.3. Environment Variables Copy linkLink copied to clipboard!
The .NET Core images support a number of environment variables to control the build behavior of your .NET Core application. These variables can be set as part of the build configuration, or they can be added to an .s2i/environment file in the application source code repository.
| Variable Name | Description | Default |
|---|---|---|
| DOTNET_STARTUP_PROJECT |
Used to select the project to run. This must be a project file (for example, |
|
| DOTNET_SDK_VERSION |
Used to select the default sdk version when building. If there is a global.json file in the source repository, that takes precedence. When set to | Lowest sdk version available in the image |
| DOTNET_ASSEMBLY_NAME |
Used to select the assembly to run. This must not include the .dll extension. Set this to the output assembly name specified in |
Name of the |
| DOTNET_RESTORE_SOURCES |
Used to specify the space-separated list of NuGet package sources used during the restore operation. This overrides all of the sources specified in the | |
| DOTNET_NPM_TOOLS | Used to specify a list of NPM packages to install before building the application. | |
| DOTNET_TEST_PROJECTS |
Used to specify the list of test projects to test. This must be project files or folders containing a single project file. | |
| DOTNET_VERBOSITY |
Used to specify the verbosity of the dotnet build commands. When set, the environment variables are printed at the start of the build. This variable can be set to one of the msbuild verbosity values ( | |
| DOTNET_CONFIGURATION | Used to run the application in Debug or Release mode. This value should be either Release or Debug. |
|
| ASPNETCORE_URLS |
This variable is set to | |
| HTTP_PROXY, HTTPS_PROXY | Configures the HTTP/HTTPS proxy used when building and running the application. | |
| NPM_MIRROR | Use a custom NPM registry mirror to download packages during the build process. | |
| DOTNET_ASPNET_STORE | Publish assuming the runtime image contains the ASP.NET Core runtime store. |
|
2.4. Sample Applications Copy linkLink copied to clipboard!
Three sample applications are available:
- dotnet-example: This is the default model–view–controller (MVC) application.
- dotnet-runtime-example: This shows how to build an MVC application using a chained build and the .NET runtime image.
- dotnet-pgsql-persistent: This is the Microsoft ASP.NET Core MusicStore sample application using a PostgreSQL backend.
To add the samples using the OpenShift Web Console, browse to your project and click Add to project. You can filter for dotnet. If the samples do not show up, you can add them to your installation by running the following commands.
oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/templates/dotnet-example.json oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/templates/dotnet-runtime-example.json oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/templates/dotnet-pgsql-persistent.json
$ oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/templates/dotnet-example.json
$ oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/templates/dotnet-runtime-example.json
$ oc create -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/master/templates/dotnet-pgsql-persistent.json
2.5. Create a Runtime Image Copy linkLink copied to clipboard!
The .NET Core runtime image contains the files sufficient to run a .NET application, but not to build one. As such, you must provide an already published application for the runtime image. This can be a static application inside of an image that layers on top of the runtime image or a new image can be built that is fed the application from a build image. This last method is commonly referred to as chaining builds.
Deploying a build chain requires a more in-depth configuration than a simple application build. At a minimum, a build chain needs:
- a build config for the build image
- a build config for the runtime image
- an inline dockerfile for the runtime image
- a deployment config that uses the runtime image
The following elements are optional but recommended:
- an internal image stream
- a trigger for the build image based on the source project
- a trigger for the runtime build based on the build image
See dotnet-runtime-example template for an example of such a configuration.
In this template, we define a *-build and a *-runtime build config. The build image builds from a GitHub project and has a trigger to rebuild automatically when the project changes or when the base image (in this case, dotnet-20-rhel7) updates.
The runtime image builds from the dotnet-20-runtime-rhel7 base image but pulls a tar.gz file from the build image that contains the build project. That is done using this source definition in the build config.
The runtime image also has triggers to rebuild automatically when build image is updated in the projects internal image stream or when the dotnet-20-runtime-rhel7 base image updates.
There is also a deployment defined for the runtime image. A deployment is not necessary for the build image.
The use of these triggers means that any object in the chain will be rebuilt as necessary when images or code is updated.
Appendix A. Revision History Copy linkLink copied to clipboard!
| Date | Version | Author | Changes |
|---|---|---|---|
| 08/21/2017 | 2.0 | Les Williams | Generally available |
| 08/30/2017 | 2.0 | Les Williams | Revised DOTNET_STARTUP_PROJECT and DOTNET_TEST_PROJECTS entries in Section 2.3 |
| 09/13/2017 | 2.0 | Les Williams | Revised Section 1.2 to include a note about how to permanently enable rh-dotnet20 |
| 02/14/2018 | 2.0 | Les Williams | Revised Section 2.2 to resolve BZ 1500230; added quoting for zsh and other shells |
| 02/28/2018 | 2.0.3 | Les Williams | Revised to include SDK 2.0 and 2.1 |
| 06/07/2018 | 2.0.3 | Toby Drake | Updated list of environment variables based on s2i-dotnetcore 2.0 build on github |
| 08/27/2018 | 2.0.3 | Toby Drake | Backported Install Stream section updates from .NET Core 2.1 |