Option to output conversion to one file.

[cdrage]

Similar to helm and other k8s tools, we should be able to have the option to output to one file, rather than multiple files.

Or maybe we should make it the default that everything is outputted to one file? What do people think?

[OneCricketeer]

IMO, --one-file flag would be helpful only for saving that output file to some location without a loop to do the same...

kubectl apply can accept a directory of files, right? So, why need to combine?

I've always used kompose to get a rough idea of what I need to do. Then I convert to Charts, as I see fit.

[AhmedGrati]

@OneCricketeer For debugging purposes, you might occasionally need to display all the manifests in one file so that you don't have to switch between them when a problem arises. Therefore, IMO I see that the default behavior should remain the same, and we add the --one-file flag to save the output in one file.

[AhmedGrati]

After investigating this issue, I found that this functionality already exists, by using the --file flag. For example:

kompose convert -f docker-compose.yaml --out f.yaml

But the issue is that the output is not the correct one. In fact, for this docker-compose file:

version: "3.8"

services:
  front_end:
    image: gcr.io/google-samples/gb-frontend:v4
    ports:
      - "80:80"
    environment:
      - GET_HOSTS_FROM=dns
    labels:
      kompose.service.expose: lb
      kompose.service.expose.ingress-class-name: nginx

we'll have the following output:

apiVersion: v1
items:
  - apiVersion: v1
    kind: Service
    metadata:
      annotations:
        kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
        kompose.service.expose: lb
        kompose.service.expose.ingress-class-name: nginx
        kompose.version: 1.26.1 (HEAD)
      creationTimestamp: null
      labels:
        io.kompose.service: front-end
      name: front_end
    spec:
      ports:
        - name: "80"
          port: 80
          targetPort: 80
      selector:
        io.kompose.service: front-end
    status:
      loadBalancer: {}
  - apiVersion: apps/v1
    kind: Deployment
    metadata:
      annotations:
        kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
        kompose.service.expose: lb
        kompose.service.expose.ingress-class-name: nginx
        kompose.version: 1.26.1 (HEAD)
      creationTimestamp: null
      labels:
        io.kompose.service: front-end
      name: front-end
    spec:
      replicas: 1
      selector:
        matchLabels:
          io.kompose.service: front-end
      strategy: {}
      template:
        metadata:
          annotations:
            kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
            kompose.service.expose: lb
            kompose.service.expose.ingress-class-name: nginx
            kompose.version: 1.26.1 (HEAD)
          creationTimestamp: null
          labels:
            io.kompose.service: front-end
        spec:
          containers:
            - env:
                - name: GET_HOSTS_FROM
                  value: dns
              image: gcr.io/google-samples/gb-frontend:v4
              name: front-end
              ports:
                - containerPort: 80
              resources: {}
          restartPolicy: Always
    status: {}
  - apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      annotations:
        kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
        kompose.service.expose: lb
        kompose.service.expose.ingress-class-name: nginx
        kompose.version: 1.26.1 (HEAD)
      creationTimestamp: null
      labels:
        io.kompose.service: front-end
      name: front-end
    spec:
      ingressClassName: nginx
      rules:
        - host: lb
          http:
            paths:
              - backend:
                  service:
                    name: front-end
                    port:
                      number: 80
                path: /
                pathType: Prefix
    status:
      loadBalancer: {}
kind: List
metadata: {}

As you can see, the output file is not in the desired behavior, because we cannot use it directly by kubectl. What do you think @cdrage @hangyan?

[hangyan]

Yeah, we support that. But what do you mean by 'cannot use it diectly'?

[AhmedGrati]

Yeah, we support that. But what do you mean by 'cannot use it diectly'?

I mean that we cannot execute kubectl apply on that file.

[OneCricketeer]

Related

• Replace kind: List k8s resource with multi-document YAML cockpit-project/cockpituous#520
• Add note to api conventions about kind: List community#5903

[cdrage]

After investigating this issue, I found that this functionality already exists, by using the --file flag. For example:

kompose convert -f docker-compose.yaml --out f.yaml

But the issue is that the output is not the correct one. In fact, for this docker-compose file:

version: "3.8"

services:
  front_end:
    image: gcr.io/google-samples/gb-frontend:v4
    ports:
      - "80:80"
    environment:
      - GET_HOSTS_FROM=dns
    labels:
      kompose.service.expose: lb
      kompose.service.expose.ingress-class-name: nginx

we'll have the following output:

apiVersion: v1
items:
  - apiVersion: v1
    kind: Service
    metadata:
      annotations:
        kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
        kompose.service.expose: lb
        kompose.service.expose.ingress-class-name: nginx
        kompose.version: 1.26.1 (HEAD)
      creationTimestamp: null
      labels:
        io.kompose.service: front-end
      name: front_end
    spec:
      ports:
        - name: "80"
          port: 80
          targetPort: 80
      selector:
        io.kompose.service: front-end
    status:
      loadBalancer: {}
  - apiVersion: apps/v1
    kind: Deployment
    metadata:
      annotations:
        kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
        kompose.service.expose: lb
        kompose.service.expose.ingress-class-name: nginx
        kompose.version: 1.26.1 (HEAD)
      creationTimestamp: null
      labels:
        io.kompose.service: front-end
      name: front-end
    spec:
      replicas: 1
      selector:
        matchLabels:
          io.kompose.service: front-end
      strategy: {}
      template:
        metadata:
          annotations:
            kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
            kompose.service.expose: lb
            kompose.service.expose.ingress-class-name: nginx
            kompose.version: 1.26.1 (HEAD)
          creationTimestamp: null
          labels:
            io.kompose.service: front-end
        spec:
          containers:
            - env:
                - name: GET_HOSTS_FROM
                  value: dns
              image: gcr.io/google-samples/gb-frontend:v4
              name: front-end
              ports:
                - containerPort: 80
              resources: {}
          restartPolicy: Always
    status: {}
  - apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      annotations:
        kompose.cmd: /var/folders/jn/kphqd_553871ydfcs_2_5kbm0000gn/T/go-build1291552472/b001/exe/main convert -f docker-compose.yaml --out f.yaml
        kompose.service.expose: lb
        kompose.service.expose.ingress-class-name: nginx
        kompose.version: 1.26.1 (HEAD)
      creationTimestamp: null
      labels:
        io.kompose.service: front-end
      name: front-end
    spec:
      ingressClassName: nginx
      rules:
        - host: lb
          http:
            paths:
              - backend:
                  service:
                    name: front-end
                    port:
                      number: 80
                path: /
                pathType: Prefix
    status:
      loadBalancer: {}
kind: List
metadata: {}

As you can see, the output file is not in the desired behavior, because we cannot use it directly by kubectl. What do you think @cdrage @hangyan?

Yeah, we shouldn't be using List.

With Helm, you can export it and it just adds --- between each kind / section.

We should do the same with Kompose. You should be able to generate a single file using --- between each section.

[hangyan]

Agreed. --- is the best approach to do this.(i thought List can be applied before...）

[AhmedGrati]

/assign

[AhmedGrati]

Mark this as closed, solved by #1541.