Running container as functions

Run an existing container image as a function with the container executor via fission function run-container, without an environment or builder.
Support for running containers as functions is in alpha. We plan to improve the experience over the coming releases, and your feedback is most welcome.

Fission can run an existing container image as a function using the container executor type. This is useful when you already have a containerized HTTP service and want to invoke it through Fission’s router and triggers. For how this executor compares to poolmgr and newdeploy, see Controlling Function Execution.

Running container image with Fission

fission function run-container provides required options to run an existing container image as a Fission function.

$ fission function run-container --name cn-hello --image gcr.io/google-samples/node-hello:1.0 --port 8080
function 'cn-hello' created

List functions to see the one just created:

$ fission function list
NAME     ENV    EXECUTORTYPE MINSCALE MAXSCALE MINCPU MAXCPU MINMEMORY MAXMEMORY TARGETCPU SECRETS CONFIGMAPS
cn-hello        container    1        1        0      0      0         0         80

Test the container function:

$ fission fn test --name cn-hello
Hello Kubernetes!

The container details live in spec.podspec of the Function spec. A function with the container executor type must include a pod spec; the API server rejects it otherwise. To explore the available fields:

kubectl explain functions.spec.podspec

You can also generate a function spec with the Fission CLI.

$ fission spec init
Creating fission spec directory 'specs'
$ fission function run-container --name cn-hello --image gcr.io/google-samples/node-hello:1.0 --port 8080 --spec
Saving Function 'default/cn-hello' to 'specs/function-cn-hello.yaml'
$ cat specs/function-cn-hello.yaml
apiVersion: fission.io/v1
kind: Function
metadata:
  creationTimestamp: null
  name: cn-hello
  namespace: default
spec:
  InvokeStrategy:
    ExecutionStrategy:
      ExecutorType: container
      MaxScale: 1
      MinScale: 1
      SpecializationTimeout: 120
      TargetCPUPercent: 80
    StrategyType: execution
  environment:
    name: ""
    namespace: ""
  functionTimeout: 60
  idletimeout: 120
  package:
    packageref:
      name: ""
      namespace: ""
  podspec:
    containers:
    - image: gcr.io/google-samples/node-hello:1.0
      name: cn-hello
      ports:
      - containerPort: 8080
        name: http-env
      resources: {}
  resources: {}

Running Next.js app container with Fission

You can run a sample Next.js-based app with the same executor.

$ fission fn run-container --name=nextapp --image fission/next-sample-app:1.0.0 --port 3000
function 'nextapp' created
$ fission route create --name nextapp --function nextapp --prefix /nextapp --keepprefix
trigger 'nextapp' created

Visit the app at http://<router_url>/nextapp/.

You can refer to the source for this application here.

Command options

The CLI provides short aliases: use fission fn runc for fission function run-container, and fission fn updatec for fission function update-container.

Run fission fn run-container --help to see all options for creating container-based functions.

Last modified July 18, 2026: docs(usage): Tufte clarity pass across usage guides (#311) (a06056f)