Running applications

Red Hat build of MicroShift 4.12

Running applications in MicroShift

Red Hat OpenShift Documentation Team

Abstract

This document provides details about how to run applications in MicroShift.

Chapter 1. Application deployment with Red Hat build of MicroShift

You can use the kustomize configuration management tool to deploy applications. Read through the following procedure for an example of how this tool works in Red Hat build of MicroShift.

1.1. How manifests work with kustomize

The kustomize configuration management tool is integrated with Red Hat build of MicroShift. At every start, Red Hat build of MicroShift searches the /etc/microshift/manifests and /usr/lib/microshift/ manifest directories for a kustomization.yaml file. If it finds one, Red Hat build of MicroShift automatically runs the equivalent of the kubectl apply -k command to apply the identified manifests to the cluster.

Location	Intent
`/etc/microshift/manifests`	Read-write location for configuration management systems or development.
`/usr/lib/microshift/manifests`	Read-only location for embedding configuration manifests on OSTree-based systems.

1.2. Using manifests example

This example demonstrates automatic deployment of a BusyBox container using kustomize manifests in the /etc/microshift/manifests directory.

Procedure

Create the BusyBox manifest files by running the following commands:

Define the directory location:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
MANIFEST_DIR=/etc/microshift/manifests
```
```
$ MANIFEST_DIR=/etc/microshift/manifests
```
Make the directory:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
sudo mkdir -p ${MANIFEST_DIR}
```
```
$ sudo mkdir -p ${MANIFEST_DIR}
```

Place the YAML file in the directory:

Copy to Clipboard Toggle word wrap

sudo tee ${MANIFEST_DIR}/busybox.yaml &>/dev/null <<EOF

apiVersion: v1
kind: Namespace
metadata:
  name: busybox
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: busybox-deployment
spec:
  selector:
    matchLabels:
      app: busybox
  template:
    metadata:
      labels:
        app: busybox
    spec:
      containers:
      - name: busybox
        image: BUSYBOX_IMAGE
        command:
          - sleep
          - "3600"
EOF

$ sudo tee ${MANIFEST_DIR}/busybox.yaml &>/dev/null <<EOF

apiVersion: v1
kind: Namespace
metadata:
  name: busybox
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: busybox-deployment
spec:
  selector:
    matchLabels:
      app: busybox
  template:
    metadata:
      labels:
        app: busybox
    spec:
      containers:
      - name: busybox
        image: BUSYBOX_IMAGE
        command:
          - sleep
          - "3600"
EOF

Next, create the kustomize manifest files by running the following commands:

Place the YAML file in the directory:

Copy to Clipboard Toggle word wrap

sudo tee ${MANIFEST_DIR}/kustomization.yaml &>/dev/null <<EOF
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: busybox
resources:
  - busybox.yaml
images:
  - name: BUSYBOX_IMAGE
    newName: registry.k8s.io/busybox
EOF

$ sudo tee ${MANIFEST_DIR}/kustomization.yaml &>/dev/null <<EOF
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: busybox
resources:
  - busybox.yaml
images:
  - name: BUSYBOX_IMAGE
    newName: registry.k8s.io/busybox
EOF

Restart Red Hat build of MicroShift to apply the manifests by running the following command:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
sudo systemctl restart microshift
```
```
$ sudo systemctl restart microshift
```
Apply the manifests and start the busybox pod by running the following command:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
oc get pods -n busybox
```
```
$ oc get pods -n busybox
```

Chapter 2. How Operators work with Red Hat build of MicroShift

You can use Operators with Red Hat build of MicroShift to create applications that monitor the running services in your cluster. Operators can manage applications and their resources, such as deploying a database or message bus. As customized software running inside your cluster, Operators can be used to implement and automate common operations.

Operators offer a more localized configuration experience and integrate with Kubernetes APIs and CLI tools such as kubectl and oc. Operators are designed specifically for your applications. Operators enable you to configure components instead of modifying a global configuration file.

Red Hat build of MicroShift applications are generally expected to be deployed in static environments. However, Operators are available if helpful in your use case. To determine an Operator’s compatibility with Red Hat build of MicroShift, check the Operator’s documentation.

To minimize the footprint of Red Hat build of MicroShift, Operators are installed directly with manifests instead of using the Operator Lifecycle Manager (OLM). The following examples provide instructions on how you can use the kustomize configuration management tool with Red Hat build of MicroShift to deploy an application. Use the same steps to install Operators with manifests.

2.1. How manifests work with kustomize

Location	Intent
`/etc/microshift/manifests`	Read-write location for configuration management systems or development.
`/usr/lib/microshift/manifests`	Read-only location for embedding configuration manifests on OSTree-based systems.

2.2. Using manifests example

This example demonstrates automatic deployment of a BusyBox container using kustomize manifests in the /etc/microshift/manifests directory.

Procedure

Create the BusyBox manifest files by running the following commands:

Define the directory location:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
MANIFEST_DIR=/etc/microshift/manifests
```
```
$ MANIFEST_DIR=/etc/microshift/manifests
```
Make the directory:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
sudo mkdir -p ${MANIFEST_DIR}
```
```
$ sudo mkdir -p ${MANIFEST_DIR}
```

Place the YAML file in the directory:

Copy to Clipboard Toggle word wrap

sudo tee ${MANIFEST_DIR}/busybox.yaml &>/dev/null <<EOF

apiVersion: v1
kind: Namespace
metadata:
  name: busybox
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: busybox-deployment
spec:
  selector:
    matchLabels:
      app: busybox
  template:
    metadata:
      labels:
        app: busybox
    spec:
      containers:
      - name: busybox
        image: BUSYBOX_IMAGE
        command:
          - sleep
          - "3600"
EOF

$ sudo tee ${MANIFEST_DIR}/busybox.yaml &>/dev/null <<EOF

apiVersion: v1
kind: Namespace
metadata:
  name: busybox
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: busybox-deployment
spec:
  selector:
    matchLabels:
      app: busybox
  template:
    metadata:
      labels:
        app: busybox
    spec:
      containers:
      - name: busybox
        image: BUSYBOX_IMAGE
        command:
          - sleep
          - "3600"
EOF

Next, create the kustomize manifest files by running the following commands:

Place the YAML file in the directory:

Copy to Clipboard Toggle word wrap

sudo tee ${MANIFEST_DIR}/kustomization.yaml &>/dev/null <<EOF
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: busybox
resources:
  - busybox.yaml
images:
  - name: BUSYBOX_IMAGE
    newName: registry.k8s.io/busybox
EOF

$ sudo tee ${MANIFEST_DIR}/kustomization.yaml &>/dev/null <<EOF
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: busybox
resources:
  - busybox.yaml
images:
  - name: BUSYBOX_IMAGE
    newName: registry.k8s.io/busybox
EOF

Restart Red Hat build of MicroShift to apply the manifests by running the following command:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
sudo systemctl restart microshift
```
```
$ sudo systemctl restart microshift
```
Apply the manifests and start the busybox pod by running the following command:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
```
oc get pods -n busybox
```
```
$ oc get pods -n busybox
```

Legal Notice

The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version.

Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.

Red Hat, Red Hat Enterprise Linux, the Shadowman logo, the Red Hat logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.

Linux® is the registered trademark of Linus Torvalds in the United States and other countries.

Java® is a registered trademark of Oracle and/or its affiliates.

XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.

MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries.

Node.js® is an official trademark of Joyent. Red Hat is not formally related to or endorsed by the official Joyent Node.js open source or commercial project.

The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation's permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community.

All other trademarks are the property of their respective owners.

Running applications

Running applications in MicroShift

Chapter 1. Application deployment with Red Hat build of MicroShift

1.1. How manifests work with kustomize

1.2. Using manifests example

Chapter 2. How Operators work with Red Hat build of MicroShift

2.1. How manifests work with kustomize

2.2. Using manifests example

Legal Notice

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

Making open source more inclusive

About Red Hat

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links