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Install an Application

This walkthrough demonstrates how to install an example application on Kubernetes with kapp-controller. The example application is an HTTP server. You will use examples/simple-app-git directory for the YAML configuration.

You can use kapp or another tool such as kubectl to deploy the following YAML examples:

Install kapp-controller onto your cluster.
Install examples/default-ns-rbac.yml.
It creates default-ns-sa service account to change resources within the default namespace. The App CR in the next step uses the service account.
```
$ kapp deploy -a default-ns-rbac -f https://raw.githubusercontent.com/carvel-dev/kapp-controller/develop/examples/rbac/default-ns.yml
```

Install examples/simple-app-git/1.yml App CR.

It specifies how to fetch, template, and deploy the example application.

$ kapp deploy -a simple-app -f https://raw.githubusercontent.com/k14s/kapp-controller/develop/examples/simple-app-git/1.yml
# or... kubectl apply -f https://raw.githubusercontent.com/k14s/kapp-controller/develop/examples/simple-app-git/1.yml

Changes

Namespace  Name        Kind  Conds.  Age  Op      Wait to    Rs  Ri
default    simple-app  App   -       -    create  reconcile  -   -

Op:      1 create, 0 delete, 0 update, 0 noop, 0 exists
Wait to: 1 reconcile, 0 delete, 0 noop

Continue? [yN]: y

5:20:27PM: ---- applying 1 changes [0/1 done] ----
5:20:27PM: create app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:20:27PM: ---- waiting on 1 changes [0/1 done] ----
5:20:27PM: ongoing: reconcile app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:20:33PM: ok: reconcile app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:20:33PM: ---- applying complete [1/1 done] ----
5:20:33PM: ---- waiting complete [1/1 done] ----

Succeeded

Run kubectl get app to verify that the app is deployed.

Verify the status of the App CR.

Note: As of kapp-controller v0.31.0, inspect is deactivated by default. See App CR spec for more details.

$ kapp inspect -a simple-app --status
# or... kubectl get app simple-app -oyaml

Resources in app 'simple-app'

Namespace  default
Name       simple-app
Kind       App
Status     conditions:
           - status: "True"
             type: ReconcileSucceeded
           deploy:
             exitCode: 0
             finished: true
             startedAt: "2019-12-02T22:20:28Z"
             stdout: |-
               Changes
               Namespace  Name        Kind        Conds.  Age  Op      Wait to    Rs  Ri
               default    simple-app  Deployment  -       -    create  reconcile  -   -
               ^          simple-app  Service     -       -    create  reconcile  -   -
               Op:      2 create, 0 delete, 0 update, 0 noop, 0 exists
               Wait to: 2 reconcile, 0 delete, 0 noop
               10:20:28PM: ---- applying 2 changes [0/2 done] ----
               10:20:28PM: create service/simple-app (v1) namespace: default
               10:20:28PM: create deployment/simple-app (apps/v1) namespace: default
               10:20:29PM: ---- waiting on 2 changes [0/2 done] ----
               10:20:29PM: ok: reconcile service/simple-app (v1) namespace: default
               10:20:29PM: ongoing: reconcile deployment/simple-app (apps/v1) namespace: default
               10:20:29PM:  ^ Waiting for 1 unavailable replicas
               10:20:29PM:  L ok: waiting on replicaset/simple-app-6fb57f844b (apps/v1) namespace: default
               10:20:29PM:  L ongoing: waiting on pod/simple-app-6fb57f844b-jk7d8 (v1) namespace: default
               10:20:29PM:     ^ Pending: ContainerCreating
               10:20:29PM: ---- waiting on 1 changes [1/2 done] ----
               10:20:31PM: ok: reconcile deployment/simple-app (apps/v1) namespace: default
               10:20:31PM: ---- applying complete [2/2 done] ----
               10:20:31PM: ---- waiting complete [2/2 done] ----
               Succeeded
             updatedAt: "2019-12-02T22:20:31Z"
           fetch:
             exitCode: 0
             startedAt: "2019-12-02T22:20:27Z"
             updatedAt: "2019-12-02T22:20:27Z"
           inspect:
             exitCode: 0
             stdout: |-
               Resources in app 'simple-app-ctrl'
               Namespace  Name                              Kind        Owner    Conds.  Rs  Ri  Age
               default    simple-app                        Deployment  kapp     2/2 t   ok  -   4s
               default     L simple-app-6fb57f844b          ReplicaSet  cluster  -       ok  -   4s
               default     L.. simple-app-6fb57f844b-jk7d8  Pod         cluster  4/4 t   ok  -   4s
               default    simple-app                        Service     kapp     -       ok  -   4s
               default     L simple-app                     Endpoints   cluster  -       ok  -   4s
               Rs: Reconcile state
               Ri: Reconcile information
               5 resources
               Succeeded
             updatedAt: "2019-12-02T22:20:32Z"
           observedGeneration: 2
           template:
             exitCode: 0
             updatedAt: "2019-12-02T22:20:28Z"

1 resources

Succeeded

The output shows the overall status of the application, including the latest deploy output (status.deploy.stdout) and the latest inspect output (status.inspect.stdout). Based on the inspect output you can see that the app included a Deployment and a Service.

Update simple-app App CR to reconfigure it.

This example changes data values for ytt templates.

$ kapp deploy -a simple-app -f https://raw.githubusercontent.com/k14s/kapp-controller/develop/examples/simple-app-git/2.yml -c
# or... kubectl apply -f https://raw.githubusercontent.com/k14s/kapp-controller/develop/examples/simple-app-git/2.yml

--- update app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
  ...
 23, 23     template:
 24     -   - ytt: {}
     24 +   - ytt:
     25 +       inline:
     26 +         pathsFrom:
     27 +         - secretRef:
     28 +             name: simple-app-values
 25, 29   status:
 26, 30     conditions:
--- create secret/simple-app-values (v1) namespace: default
      0 + apiVersion: v1
      1 + kind: Secret
      2 + metadata:
      3 +   labels:
      4 +     kapp.k14s.io/app: "1575325198404867000"
      5 +     kapp.k14s.io/association: v1.7a671029ad7db07aa797301eac59e9ad
      6 +   name: simple-app-values
      7 +   namespace: default
      8 + stringData:
      9 +   values2.yml: |
     10 +     #@data/values
     11 +     ---
     12 +     hello_msg: updated
     13 +

Changes

Namespace  Name               Kind    Conds.  Age  Op      Wait to    Rs  Ri
default    simple-app         App     1/1 t   2m   update  reconcile  ok  -
^          simple-app-values  Secret  -       -    create  reconcile  -   -

Op:      1 create, 0 delete, 1 update, 0 noop, 0 exists
Wait to: 2 reconcile, 0 delete, 0 noop

Continue? [yN]: y

5:23:13PM: ---- applying 2 changes [0/2 done] ----
5:23:13PM: update app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:23:13PM: create secret/simple-app-values (v1) namespace: default
5:23:14PM: ---- waiting on 2 changes [0/2 done] ----
5:23:14PM: ongoing: reconcile app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:23:14PM: ok: reconcile secret/simple-app-values (v1) namespace: default
5:23:14PM: ---- waiting on 1 changes [1/2 done] ----
5:23:17PM: ok: reconcile app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:23:17PM: ---- applying complete [2/2 done] ----
5:23:17PM: ---- waiting complete [2/2 done] ----

Succeeded

Delete the simple-app App CR.

$ kapp delete -a simple-app
# or... kubectl delete -f https://raw.githubusercontent.com/k14s/kapp-controller/develop/examples/simple-app-git/2.yml

Changes

Namespace  Name               Kind    Conds.  Age  Op      Wait to  Rs  Ri
default    simple-app         App     1/1 t   6m   delete  delete   ok  -
^          simple-app-values  Secret  -       3m   delete  delete   ok  -

Op:      0 create, 2 delete, 0 update, 0 noop, 0 exists
Wait to: 0 reconcile, 2 delete, 0 noop

Continue? [yN]: y

5:26:25PM: ---- applying 2 changes [0/2 done] ----
5:26:25PM: delete secret/simple-app-values (v1) namespace: default
5:26:25PM: delete app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:26:26PM: ---- waiting on 2 changes [0/2 done] ----
5:26:26PM: ok: delete secret/simple-app-values (v1) namespace: default
5:26:26PM: ongoing: delete app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:26:26PM: ---- waiting on 1 changes [1/2 done] ----
5:26:30PM: ok: delete app/simple-app (kappctrl.k14s.io/v1alpha1) namespace: default
5:26:30PM: ---- applying complete [2/2 done] ----
5:26:30PM: ---- waiting complete [2/2 done] ----

Succeeded

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