create a application like system

[ripienaar]

mco applications were ruby plugins that was used to build CLI tools, primarily they were used to render results differently and less frequently about doing multiple chained requests (puppet runall)

For a large portion of things really all thats needed now is a way to construct complex choria req commands.

I imagine that:

someapp machine report check_load --lt 1.0.0

Would just do, and it would be enough:

choria req choria_util machine_state name=check_load --reply-filter 'ok() && semver(data("version"), "< 1.0.0")'

If there was a way to create dynamically a cli thats essentially just macros around rpc, kv, external commands etc it would allow them to make a local utility that has easy to discover features without that is just a wrapper.

$ ./myco --help
usage: ./myco [<flags>] <command> [<args> ...]

A thing that does Foo

Flags:
  --help  Show context-sensitive help (also try --help-long and --help-man).

Commands:
  help [<command>...]
    Show help.

  machines [<flags>] <machine>
    Query Autonomous Agents

$ ./myco machines --help
usage: ./myco machines [<flags>] <machine>

Query Autonomous Agents

Flags:
  --help         Show context-sensitive help (also try --help-long and --help-man).
  --not=VERSION  Matches instances that are not this version
  --le=VERSION   Matches instances that are older than or same as
  --lt=VERSION   Matches instances that are older than
  --ge=VERSION   Matches instances that are newer than or same as
  --gt=VERSION   Matches instances that are older than
  --eq=VERSION   Matches instances that are same as

Args:
  <machine>  Autonomous Agent to report on

$ ./myco machines check_bacula_fd --eq 1.0.0
2022/05/09 14:40:35 choria req choria_util machine_state name=check_bacula_fd --filter-replies ok() && semver(data("version"), "= 1.0.0")
Discovering nodes using the choria method .... 29

29 / 29    0s [==============================================================================] 100%

...

Summary of Name:

   check_bacula_fd: 16

Summary of State:

   OK: 16

Summary of Version:

   1.0.0: 16

Finished processing 29 / 29 hosts in 1.304s

This could be defined using a YAML file like this:

name: Foo Thing
description: A thing that does Foo
version: 0.0.1
author: R.I.Pienaar <[email protected]>
commands:
  - name: machines
    description: Query Autonomous Agents
    std_filter: true
    request:
      agent: choria_util
      action: machine_state
      params:
        name: "{{.Arguments.machine}}"

    args:
      - name: machine
        description: Autonomous Agent to report on
        required: true

    flags:
      - name: not
        description: Matches instances that are not this version
        place_holder: VERSION
        filter: ok() && semver(data("version"), "!= {{.Flags.not}}")

      - name: le
        description: Matches instances that are older than or same as
        place_holder: VERSION
        filter: ok() && semver(data("version"), "<= {{.Flags.le}}")

      - name: lt
        description: Matches instances that are older than
        place_holder: VERSION
        filter: ok() && semver(data("version"), "< {{.Flags.lt}}")

      - name: ge
        description: Matches instances that are newer than or same as
        place_holder: VERSION
        filter: ok() && semver(data("version"), ">= {{.Flags.ge}}")

      - name: gt
        description: Matches instances that are older than
        place_holder: VERSION
        filter: ok() && semver(data("version"), "> {{.Flags.gt}}")

      - name: eq
        description: Matches instances that are same as
        place_holder: VERSION
        filter: ok() && semver(data("version"), "= {{.Flags.eq}}")

[ripienaar]

#1666 adds a super basic version of this with no input validation etc,

-rwxr-xr-x 1 rip rip 37412864 May 10 18:06 choria
lrwxrwxrwx 1 rip rip        6 May 10 17:58 mycorp -> choria
-rw-r--r-- 1 rip rip     3601 May 10 15:23 mycorp.yaml

Simply symlink mycorp to the choria binary and create mycorp.yaml in either ., ~/config/choria/builder/ or /etc/choria/builder. It also supports loading a config from those directories in config.yaml

% ./mycorp
usage: mycorp [<flags>] <command> [<args> ...]

A thing that does Foo

Flags:
  --help  Show context-sensitive help (also try --help-long and --help-man).

Commands:
  help [<command>...]
    Show help.

  fleet info [<flags>]
    Get Choria Versions, broker distribution and more

  provisioning reprovision [<flags>]
    Re-provision running nodes

    Reprovisioning will remove the node from the network and reset it's configuration to factory default, it will then get a new configuration, credentials and more from the Choria Provisioner.

  provisioning restart [<flags>]
    Restarts running nodes

  provisioner force-election
    Force a leader election

  provisioner leader
    Obtain the name of the current cluster leader

  machines [<flags>] <machine>
    Query Autonomous Agents

[ripienaar]

Draft docs PR here choria-io/website#90

[ripienaar]

Some notes on enhancements while trying to build something with this:

• should have a discovery type that can show matching hosts
• should template parse filters
• -S filters should have semver match also
• kv should have an optional array of map[string]string for keys, so on a get you can do keys: {B1: K1, B2: K2} and it should render all the keys in a table or something
• should support boolean flags
• kv should have JSON output via a --json flag thats always added
• setting std_filters shouldnt disable filters, they should merge, you may only want to hit all machines of a class and then allow users to add additional filters like country/location/dc/cluster etc. You may also want to force a certain discovery method etc
• standard command should have a confirm option that will prompt people to confirm, should be a string used in the prompt
• rpc command should have a confirm option that will prompt when an empty filter is given, should be a string used in the prompt
• kv should have history
• kv put should be able to read a file - should actually be a template function to a read a file

[ripienaar]

Closing this, future enhancements as new issues.