Kapp

Example Workflow

Install kapp following the install instructions.

In this example, we are installing an example app from the kapp repository.

Note that in the changes summary we see that all the resources to be deployed are new.

$ kapp deploy -a app1 -f examples/simple-app-example/config-1.yml Target cluster 'https://x.x.x.x' (nodes: gke-dk-jan-9-pool-1-d01bcd06-bgie, 4+) Changes Namespace Name Kind Conds. Age Op Op st. 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 2:12:59PM: ---- applying 2 changes [0/2 done] ---- 2:13:00PM: create service/simple-app (v1) namespace: default 2:13:01PM: create deployment/simple-app (apps/v1) namespace: default 2:13:01PM: ---- waiting on 2 changes [0/2 done] ---- 2:13:01PM: ok: reconcile service/simple-app (v1) namespace: default 2:13:01PM: ongoing: reconcile deployment/simple-app (apps/v1) namespace: default 2:13:01PM: ^ Waiting for 1 unavailable replicas 2:13:01PM: L ok: waiting on replicaset/simple-app-7f9c78ccd8 (apps/v1) namespace: default 2:13:01PM: L ongoing: waiting on pod/simple-app-7f9c78ccd8-h7wlc (v1) namespace: default 2:13:01PM: ^ Pending: ContainerCreating 2:13:01PM: ---- waiting on 1 changes [1/2 done] ---- 2:13:03PM: ok: reconcile deployment/simple-app (apps/v1) namespace: default 2:13:03PM: ---- applying complete [2/2 done] ---- 2:13:03PM: ---- waiting complete [2/2 done] ---- Succeeded

The ls command shows a list of all apps stored in the current namespace. Apps themselves can span multiple namespaces and cluster scope.

$ kapp ls Target cluster 'https://x.x.x.x' (nodes: gke-dk-jan-9-pool-1-d01bcd06-bgie, 4+) Apps in namespace 'default' Name Namespaces Lcs Lca app1 default true 25s Lcs: Last Change Successful Lca: Last Change Age 1 apps Succeeded

Now let's update from one app configuration to another using the deploy command.

In this example, since --diff-changes is used, kapp will show a detailed diff against versions of the resources that exist in the cluster. The first two resource diffs indicate they are brand new and will be created. The next resource in the diff will be updated according to the changes shown. Finally, the last resource diff shows it will be deleted.

As above, the deploy will then display a list of changes before continuing. Once the user has chosen to continue, we see a series of progress logs and finally a success message.

$ kapp deploy -a app1 -f examples/simple-app-example/config-2.yml --diff-changes Target cluster 'https://x.x.x.x' (nodes: gke-dk-jan-9-pool-1-d01bcd06-bgie, 4+) @@ create service/simple-app-node (v1) namespace: default @@ 0 + apiVersion: v1 1 + kind: Service 2 + metadata: 3 + labels: 4 + kapp.k14s.io/app: "1594663909283037000" 5 + kapp.k14s.io/association: v1.6e43c1cd2c7173a969d84f77ad6a72c2 6 + name: simple-app-node 7 + namespace: default 8 + spec: 9 + ports: 10 + - nodePort: 31111 11 + port: 80 12 + targetPort: 80 13 + selector: 14 + kapp.k14s.io/app: "1594663909283037000" 15 + simple-app: "" 16 + type: NodePort 17 + @@ create configmap/simple-app (v1) namespace: default @@ 0 + apiVersion: v1 1 + data: 2 + hello_msg: friend 3 + kind: ConfigMap 4 + metadata: 5 + labels: 6 + kapp.k14s.io/app: "1594663909283037000" 7 + kapp.k14s.io/association: v1.afcdfc989e2a0b3f3e526dc1c4176060 8 + name: simple-app 9 + namespace: default 10 + @@ update deployment/simple-app (apps/v1) namespace: default @@ ... 29, 29 - name: HELLO_MSG 30 - value: stranger 30 + valueFrom: 31 + configMapKeyRef: 32 + key: hello_msg 33 + name: simple-app 31, 34 image: docker.io/dkalinin/k8s-simple-app@sha256:4c8b96d4fffdfae29258d94a22ae4ad1f... 32, 35 name: simple-app @@ delete service/simple-app (v1) namespace: default @@ 0 - apiVersion: v1 1 - kind: Service 2 - metadata: 3 - creationTimestamp: "2020-07-13T18:12:59Z" 4 - labels: 5 - kapp.k14s.io/app: "1594663909283037000" 6 - kapp.k14s.io/association: v1.462a95c01b2a0bdc4d5acadc4a22dd74 7 - name: simple-app 8 - namespace: default 9 - resourceVersion: "69009086" 10 - selfLink: /api/v1/namespaces/default/services/simple-app 11 - uid: 4e8bb148-2de4-46b3-a2e1-53dacbaaff34 12 - spec: 13 - clusterIP: 10.76.6.94 14 - ports: 15 - - port: 80 16 - targetPort: 80 17 - selector: 18 - kapp.k14s.io/app: "1594663909283037000" 19 - simple-app: "" 20 - status: 21 - loadBalancer: {} 22 - Changes Namespace Name Kind Conds. Age Op Op st. Wait to Rs Ri default simple-app ConfigMap - - create - reconcile - - ^ simple-app Deployment 2/2 t 2m update - reconcile ok - ^ simple-app Service - 2m delete - delete ok - ^ simple-app-node Service - - create - reconcile - - Op: 2 create, 1 delete, 1 update, 0 noop, 0 exists Wait to: 3 reconcile, 1 delete, 0 noop Continue? [yN]: 2:21:15PM: ---- applying 2 changes [0/4 done] ---- 2:21:15PM: delete service/simple-app (v1) namespace: default 2:21:15PM: create configmap/simple-app (v1) namespace: default 2:21:15PM: ---- waiting on 2 changes [0/4 done] ---- 2:21:15PM: ok: delete service/simple-app (v1) namespace: default 2:21:15PM: ok: reconcile configmap/simple-app (v1) namespace: default 2:21:15PM: ---- applying 2 changes [2/4 done] ---- 2:21:15PM: create service/simple-app-node (v1) namespace: default 2:21:17PM: update deployment/simple-app (apps/v1) namespace: default 2:21:17PM: ---- waiting on 2 changes [2/4 done] ---- 2:21:17PM: ok: reconcile service/simple-app-node (v1) namespace: default 2:21:17PM: ongoing: reconcile deployment/simple-app (apps/v1) namespace: default 2:21:17PM: ^ Waiting for 1 unavailable replicas 2:21:17PM: L ok: waiting on replicaset/simple-app-8558f78495 (apps/v1) namespace: default 2:21:17PM: L ok: waiting on replicaset/simple-app-7f9c78ccd8 (apps/v1) namespace: default 2:21:17PM: L ok: waiting on pod/simple-app-8558f78495-zqwxt (v1) namespace: default 2:21:17PM: L ongoing: waiting on pod/simple-app-7f9c78ccd8-h7wlc (v1) namespace: default 2:21:17PM: ^ Deleting 2:21:17PM: ---- waiting on 1 changes [3/4 done] ---- 2:21:18PM: ok: reconcile deployment/simple-app (apps/v1) namespace: default 2:21:18PM: ---- applying complete [4/4 done] ---- 2:21:18PM: ---- waiting complete [4/4 done] ---- Succeeded

The inspect command can be used to view a list of live objects associated with given app. --tree view optionally shows simple parent-child resource relationships.

$ kapp inspect -a app1 --tree Target cluster 'https://x.x.x.x' (nodes: gke-dk-jan-9-pool-1-d01bcd06-bgie, 4+) Resources in app 'app' Namespace Name Kind Owner Conds. Rs Ri Age default simple-app Deployment kapp 2/2 t ok - 8m default L simple-app-7f9c78ccd8 ReplicaSet cluster - ok - 8m default L simple-app-8558f78495 ReplicaSet cluster - ok - 28s default L.. simple-app-8558f78495-zqwxt Pod cluster 4/4 t ok - 28s default simple-app-node Service kapp - ok - 28s default L simple-app-node Endpoints cluster - ok - 28s default simple-app ConfigMap kapp - ok - 28s Rs: Reconcile state Ri: Reconcile information 7 resources Succeeded

The logs command starts streaming logs from all Pods associated with the given app.

$ kapp logs -f -a app1 Target cluster 'https://x.x.x.x' (nodes: gke-dk-jan-9-pool-1-d01bcd06-bgie, 4+) # starting tailing 'simple-app-8558f78495-zqwxt > simple-app' logs simple-app-8558f78495-zqwxt > simple-app | 2020/07/13 18:21:16 Server started ^C

The delete command finds all resources in the cluster associated with the given app, issues delete operation, and waits for them be be deleted.

$ kapp delete -a app1 Target cluster 'https://x.x.x.x' (nodes: gke-dk-jan-9-pool-1-d01bcd06-bgie, 4+) Changes Namespace Name Kind Conds. Age Op Op st. Wait to Rs Ri default simple-app ConfigMap - 1m delete - delete ok - ^ simple-app Deployment 2/2 t 10m delete - delete ok - ^ simple-app-7f9c78ccd8 ReplicaSet - 10m - - delete ok - ^ simple-app-8558f78495 ReplicaSet - 1m - - delete ok - ^ simple-app-8558f78495-zqwxt Pod 4/4 t 1m - - delete ok - ^ simple-app-8558f78495-zqwxt PodMetrics - 0s - - delete ok - ^ simple-app-node Endpoints - 1m - - delete ok - ^ simple-app-node Service - 1m delete - delete ok - Op: 0 create, 3 delete, 0 update, 5 noop, 0 exists Wait to: 0 reconcile, 8 delete, 0 noop Continue? [yN]: y 2:23:24PM: ---- applying 8 changes [0/8 done] ---- 2:23:24PM: noop endpoints/simple-app-node (v1) namespace: default 2:23:24PM: noop replicaset/simple-app-7f9c78ccd8 (apps/v1) namespace: default 2:23:24PM: noop pod/simple-app-8558f78495-zqwxt (v1) namespace: default 2:23:24PM: noop podmetrics/simple-app-8558f78495-zqwxt (metrics.k8s.io/v1beta1) namespace: default 2:23:24PM: noop replicaset/simple-app-8558f78495 (apps/v1) namespace: default 2:23:24PM: delete deployment/simple-app (apps/v1) namespace: default 2:23:24PM: delete service/simple-app-node (v1) namespace: default 2:23:24PM: delete configmap/simple-app (v1) namespace: default 2:23:24PM: ---- waiting on 8 changes [0/8 done] ---- 2:23:24PM: ongoing: delete replicaset/simple-app-7f9c78ccd8 (apps/v1) namespace: default 2:23:24PM: ok: delete endpoints/simple-app-node (v1) namespace: default 2:23:24PM: ok: delete configmap/simple-app (v1) namespace: default 2:23:24PM: ongoing: delete replicaset/simple-app-8558f78495 (apps/v1) namespace: default 2:23:24PM: ongoing: delete pod/simple-app-8558f78495-zqwxt (v1) namespace: default 2:23:24PM: ok: delete service/simple-app-node (v1) namespace: default 2:23:24PM: ok: delete deployment/simple-app (apps/v1) namespace: default 2:23:24PM: ongoing: delete podmetrics/simple-app-8558f78495-zqwxt (metrics.k8s.io/v1beta1) namespa... 2:23:24PM: ---- waiting on 4 changes [4/8 done] ---- 2:23:26PM: ok: delete replicaset/simple-app-8558f78495 (apps/v1) namespace: default 2:23:26PM: ok: delete replicaset/simple-app-7f9c78ccd8 (apps/v1) namespace: default 2:23:26PM: ---- waiting on 2 changes [6/8 done] ---- 2:23:27PM: ok: delete podmetrics/simple-app-8558f78495-zqwxt (metrics.k8s.io/v1beta1) namespace: d... 2:23:27PM: ok: delete pod/simple-app-8558f78495-zqwxt (v1) namespace: default 2:23:27PM: ---- applying complete [8/8 done] ---- 2:23:27PM: ---- waiting complete [8/8 done] ---- Succeeded