[Cialug] Columns of Data

[Jeffrey Ollie]

For the specific case of kubectl, yes, yes it can output JSON.  Just add
'-o=json' to the command line.

https://kubernetes.io/docs/reference/kubectl/cheatsheet/#formatting-output

It is definitely worth looking into any CLI command to see if it can output
it's data in a machine-readable format rather than human-readable output
that many commands produce. There are a lot of CLI commands that will do
that, because you're probably not the first one to ask for such a thing.


On Fri, Jul 31, 2020 at 12:04 PM Barry Von Ahsen <vonahsen at gmail.com> wrote:

> Not a sed/cut/awk option, but does it have a JSON output option you could
> dump into jq?
>
>
> -barry
>
>
>
>
> On 7/31/20, 10:18 AM, "Cialug on behalf of Todd Walton" <
> cialug-bounces at cialug.org on behalf of tdwalton at gmail.com> wrote:
>
>     Happy SysAdmin Day, everyone!
>
>     Here is an example bit of text coughed up by a Kubernetes command-line
> tool:
>
>     9m49s    Normal    Updated
>      machine/oo-r6sr3-worker-us-east-1d-nvfzh    Updated machine
>     oo-r6sr3-worker-us-east-1d-nvfzh
>     9m47s    Normal    Updated            machine/oo-r6sr3-master-1
>           Updated machine oo-r6sr3-master-1
>     9m46s    Normal    Updated
>      machine/oo-r6sr3-worker-us-east-1b-hsmsx    Updated machine
>     oo-r6sr3-worker-us-east-1b-hsmsx
>     9m46s    Normal    Updated
>      machine/oo-r6sr3-worker-us-east-1a-wk5cs    Updated machine
>     oo-r6sr3-worker-us-east-1a-wk5cs
>     9m46s    Normal    Updated
>      machine/oo-r6sr3-worker-us-east-1e-z9xlb    Updated machine
>     oo-r6sr3-worker-us-east-1e-z9xlb
>     9m44s    Normal    Updated            machine/oo-r6sr3-master-0
>           Updated machine oo-r6sr3-master-0
>     9m43s    Normal    Updated            machine/oo-r6sr3-master-2
>           Updated machine oo-r6sr3-master-2
>     9m43s    Normal    Updated
>      machine/oo-r6sr3-worker-us-east-1d-tfg6x    Updated machine
>     oo-r6sr3-worker-us-east-1d-tfg6x
>     9m43s    Normal    Updated
>      machine/oo-r6sr3-worker-us-east-1c-6l42j    Updated machine
>     oo-r6sr3-worker-us-east-1c-6l42j
>     59s      Normal    SuccessfulUpdate   clusterautoscaler/default
>           Updated ClusterAutoscaler deployment:
>     machine-api/cluster-autoscaler-default
>     4m7s     Normal    Pulled
>     pod/gateway-laravel-schedule-1296080-h43n6  Container image
>     "dockerregistry:4567/group/gateway/master:alpine-nodejs-fpm" already
>     present on machine
>
>     For the purpose of this email, don't mind about the semantics. This
> could
>     be anything. But do notice that the output is arranged into neat
> columns.
>     The first four columns are strings of non-space characters. The fifth
>     column, however, gives us trouble. It seeks to undermine the movement
> from
>     within, throwing a wrench into the works. Fifth columns, amiright?
>
>     Here's another example, this one taken from my /var/log/messages:
>
>     Jun 28 02:50:42 ilm01-ll-ttwalto NetworkManager[2238]: <info>  device
>     (wlp1s0): set-hw-addr: set MAC address to 9:7:8:9:2:F (scanning)
>     Jun 28 02:50:42 ilm01-ll-ttwalto kernel: IPv6: ADDRCONF(NETDEV_UP):
> wlp1s0:
>     link is not ready
>     Jun 28 02:50:42 ilm01-ll-ttwalto NetworkManager[2238]: <info>  device
>     (wlp1s0): supplicant interface state: inactive -> disabled
>     Jun 28 02:50:42 ilm01-ll-ttwalto NetworkManager[2238]: <info>  device
>     (wlp1s0): supplicant interface state: disabled -> inactive
>     Jun 28 02:55:57 ilm01-ll-ttwalto NetworkManager[2238]: <info>  device
>     (wlp1s0): set-hw-addr: set MAC address to 62:0F:6E:7A:B3:2C (scanning)
>     Jun 28 02:55:57 ilm01-ll-ttwalto kernel: IPv6: ADDRCONF(NETDEV_UP):
> wlp1s0:
>     link is not ready
>     Jun 28 02:55:57 ilm01-ll-ttwalto NetworkManager[2238]: <info>  device
>     (wlp1s0): supplicant interface state: inactive -> disabled
>
>     Here again the fifth column is making things difficult. Also the first
>     three could certainly stand to be one column, but at least they're
>     standard, predictable, and manipulable. Manipulable being what I'm
> looking
>     for.
>
>     This happens frequently, where a command or log outputs text in columns
>     that are not quite usefully arranged. How does one deal with columnar
> data
>     like this? I can't use 'cut'. What would I cut on that would capture
> the
>     first columns *and* keep the last one intact? I'm not sure how one
> would
>     easily use awk for this. Is there something like '{ print $5- }'?
> Meaning,
>     from column 5 onwards? I can't use "column -t" because that screws
>     everything up royally.
>
>     Another thing that trips me up. Sometimes I'll have a nice set of
>     comma-separated values but there'll be a comma in one of the fields.
> The
>     typical way of dealing with this in CSV files is to quote the entire
> field.
>     But that doesn't help me, the bash scripter.
>
>     Any suggestions for how to deal with stuff like this?
>
>     --
>     Todd
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-- 
Jeff Ollie
The majestik møøse is one of the mäni interesting furry animals in Sweden.