feature(service list): Print NAMESPACE column as the first column when --all-namespaces is specified

[toVersus]

/lint

Proposed Changes

kn service list should print NAMESPACE column when specifying --all-namespaces option, which follows the kubectl convention.

NAMESPACE should be displayed as the first column when --all-namespaces is specified

I know we can find a namespace we deployed our service by inspecting an URL column. It tells us a namespace by default because its FQDN is composed of {{.Name}}.{{.Namespace}}.{{.Domain}}. However, we can easily change this FQDN template by modifying domainTemplate field in config-network.yaml. In this case, we have no idea to see a namespace from the output of kn service list --all-namespace at a glance. Also, I think it is useful to see a bunch of services in the same namespace by sorting in alphabetical order.

• Print NAMESPACE as the first column when --all-namespaces is specified in kn service list command
• Show services in default namespace at the top of the list
• Add unit tests using fake services as well as mock framework

Before:

$ ./kn service list -A
NAME    URL                                GENERATION   AGE     CONDITIONS   READY   REASON
bar     http://bar-bar.example.com         1            73m     3 OK / 3     True
echo    http://echo-bar.example.com        1            73m     3 OK / 3     True
echo    http://echo-default.example.com    1            6h10m   3 OK / 3     True
echo    http://echo-foo.example.com        1            74m     3 OK / 3     True
foo     http://foo-default.example.com     1            6h9m    3 OK / 3     True
foo     http://foo-foo.example.com         1            74m     3 OK / 3     True
hello   http://hello-bar.example.com       1            72m     3 OK / 3     True
hello   http://hello-default.example.com   1            42h     3 OK / 3     True
hello   http://hello-foo.example.com       1            73m     3 OK / 3     True

After:

$ ./kn service list -A
NAMESPACE   NAME    URL                                GENERATION   AGE     CONDITIONS   READY   REASON
default     echo    http://echo-default.example.com    1            5h51m   3 OK / 3     True
default     foo     http://foo-default.example.com     1            5h51m   3 OK / 3     True
default     hello   http://hello-default.example.com   1            42h     3 OK / 3     True
bar         bar     http://bar-bar.example.com         1            54m     3 OK / 3     True
bar         echo    http://echo-bar.example.com        1            54m     3 OK / 3     True
bar         hello   http://hello-bar.example.com       1            54m     3 OK / 3     True
foo         echo    http://echo-foo.example.com        1            55m     3 OK / 3     True
foo         foo     http://foo-foo.example.com         1            56m     3 OK / 3     True
foo         hello   http://hello-foo.example.com       1            55m     3 OK / 3     True

[knative-prow-robot]

@toVersus: 1 warning.

In response to this:

/lint

Proposed Changes

kn service list should print NAMESPACE column when specifying --all-namespaces option, which follows the kubectl convention.

NAMESPACE should be displayed as the first column when --all-namespaces is specified

I know we can find a namespace we deployed our service by inspecting an URL column. It tells us a namespace by default because its FQDN is composed of {{.Name}}.{{.Namespace}}.{{.Domain}}. However, we can easily change this FQDN template by modifying domainTemplate field in config-network.yaml. In this case, we have no idea to see a namespace from the output of kn service list --all-namespace at a glance. Also, I think it is useful to see a bunch of services in the same namespace by sorting in alphabetical order.

• Print NAMESPACE as the first column when --all-namespaces is specified in kn service list command
• Show services in default namespace at the top of the list
• Add unit tests using fake services as well as mock framework

Before:

$ ./kn service list -A
NAME    URL                                GENERATION   AGE     CONDITIONS   READY   REASON
bar     http://bar-bar.example.com         1            73m     3 OK / 3     True
echo    http://echo-bar.example.com        1            73m     3 OK / 3     True
echo    http://echo-default.example.com    1            6h10m   3 OK / 3     True
echo    http://echo-foo.example.com        1            74m     3 OK / 3     True
foo     http://foo-default.example.com     1            6h9m    3 OK / 3     True
foo     http://foo-foo.example.com         1            74m     3 OK / 3     True
hello   http://hello-bar.example.com       1            72m     3 OK / 3     True
hello   http://hello-default.example.com   1            42h     3 OK / 3     True
hello   http://hello-foo.example.com       1            73m     3 OK / 3     True

After:

$ ./kn service list -A
NAMESPACE   NAME    URL                                GENERATION   AGE     CONDITIONS   READY   REASON
default     echo    http://echo-default.example.com    1            5h51m   3 OK / 3     True
default     foo     http://foo-default.example.com     1            5h51m   3 OK / 3     True
default     hello   http://hello-default.example.com   1            42h     3 OK / 3     True
bar         bar     http://bar-bar.example.com         1            54m     3 OK / 3     True
bar         echo    http://echo-bar.example.com        1            54m     3 OK / 3     True
bar         hello   http://hello-bar.example.com       1            54m     3 OK / 3     True
foo         echo    http://echo-foo.example.com        1            55m     3 OK / 3     True
foo         foo     http://foo-foo.example.com         1            56m     3 OK / 3     True
foo         hello   http://hello-foo.example.com       1            55m     3 OK / 3     True

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[knative-prow-robot]

Hi @toVersus. Thanks for your PR.

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[duglin]

Clearly including the NS in there is +1 :-)

I'm just wondering about people using kn within scripts and possibly parsing the output, and whether having the number of columns change based on whether -A is used or not is a good or bad thing. Meaning, should NAMESPACE be there even w/o -A? Honestly, I can't decide. It might depend on whether people consider the use of -A to make it a totally new command or just a variant of service list and the same "output processor" should work for both.

I do parse output from cmds like this a lot, but I don't know if I'm in a very small minority.

[toVersus]

@duglin I'm not an enthusiast to use kn within my custom scripts, so I'm not sure about this :)

Meaning, should NAMESPACE be there even w/o -A

I think it feels redundant because kn service list or kn service list -n <namespace> will only print the services in specific namespace. It is clear for the users without NAMESPACE column.

It might depend on whether people consider the use of -A to make it a totally new command or just a variant of service list and the same "output processor" should work for both.

IMO, the motivation of -A option is to ensure the human readability, which is the same as -o wide option. It is not designed for improving machine readability for the use in scripts, so it is acceptable to change the number of columns.

[navidshaikh]

Can we make this other way round and handle it in more generic way ?

As in, flags defined in HumanPrintFlags, gets added to all resource listing commands.

ToPrinter handles it for services, revisions and routes.

WDYT ?

[toVersus]

I'm not sure I can handle it in more generic way, but I changed to handle --all-namespace option in a similar way to kubectl get.

[navidshaikh]

Few things to clean up and a suggestion to add --with-namespace for kn service list command (not to be implemented right now but up for discussion).

[navidshaikh]

@toVersus a minor change request, we're good then. Thanks!

[navidshaikh]

/lgtm

[knative-prow-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: navidshaikh, toVersus

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[knative-metrics-robot]

The following is the coverage report on pkg/.
Say /test pull-knative-client-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/kn/commands/service/human_readable_flags.go	95.0%	92.5%	-2.5
pkg/kn/commands/service/service_list.go	87.5%	88.2%	0.7