Understanding Director command arguments with DSL

Icinga Web Modules Icinga Director
1

Hello,

I am working on building up a new Icinga2 Setup in our Environment, in which I want to try to automatize as much as possible.

In the last days I created a Master → Satellite → Agent setup to try migrating hand written configuration from our old Icinga2 Setup into Director. Now I reached a point, where I am not able to implement a CheckCommand into director that works like expected.

The old Config:

object CheckCommand "infiniband_rate" {
        import "plugin-check-command"
        command = [ PluginDir + "/check_ib_link" ]

        arguments = {
            "-a" = {
                description = "List of active port(s)"
                value = "$ib_port$"
            }
            "-d" = {
                description = "HCA device to check"
                value = "$ib_device$"
            }
            "-r" = {
                description = "Expected rate in Gb/sec."
                value = "$ib_rate$"
            }
        }
}

apply Service "infiniband" {
        import "generic-service"

        if ( "sys/infiniband/mlx4_port1_40" in host.vars.groups) {
           // infinband device mlx4, port 1, 40GB rate

              vars.ib_port = "1"
              vars.ib_device = "mlx4_0"
              vars.ib_rate = "40"

        } else if ( "sys/infiniband/mlx4_port1_56" in host.vars.groups) {
           // infinband device mlx4, port 1, 56GB rate

              vars.ib_port = "1"
              vars.ib_device = "mlx4_0"
              vars.ib_rate = "56"

        } else if ( "sys/infiniband/mlx5_port1_40" in host.vars.groups) {
           // infinband device mlx5, port 1, 40GB rate

              vars.ib_port = "1"
              vars.ib_device = "mlx5_0"
              vars.ib_rate = "40"

        } else if ( "sys/infiniband/mlx5_port1_56" in host.vars.groups) {
           // infinband device mlx5, port 1, 56GB rate

              vars.ib_port = "1"
              vars.ib_device = "mlx5_0"
              vars.ib_rate = "56"

        } else if ( "sys/infiniband/mlx5_port1_100" in host.vars.groups) {
           // infinband device mlx5, port 1, 100GB rate

              vars.ib_port = "1"
              vars.ib_device = "mlx5_0"
              vars.ib_rate = "100"

        } else if ( "sys/infiniband/mlx5_port2_100" in host.vars.groups) {
           // infinband device mlx5, port 2, 100GB rate

              vars.ib_port = "2"
              vars.ib_device = "mlx5_2"
              vars.ib_rate = "100"

        }


        display_name = "Infiniband interface " + host.vars.ib_port
        check_command = "infiniband_rate"


        if (host.name != NodeName) {
                command_endpoint = host.name
        }


        assign where "sys/infiniband" in host.vars.groups
}

The groups like sys/infiniband have been imported from our CMDB as dicts and looks now like:

 object Host "s002.domain.net" {
    import "generic-agent"

    display_name = "s002"
    address = "xxx.xxx.240.12"
    zone = "xxx"
    vars.centos = {
        centos7 = {
            cluster = true
        }
    }
    vars.redhatel = true
    vars.redhatel7 = true
    vars.server = true
    vars.sys = {
        icinga2 = {
            client = true
            zone = {
                xxx = true
            }
        }
        infiniband = {
            mlx5_port1_100 = true
        }
        openssh = true
        platform_mpi = true
        prometheus = true
        racadm = true
        resolver = true
    }
    vars.vendor = {
        dell = {
            poweredge = {
                c6525 = true
            }
        }
    }
}

I read somewhere on the internet, that conditions on custom host variables should be done inside the CheckCommando not on the ApplyService.

So, I try to do this, but I am failing to found the right syntax for the condition. Inside the Director Command preview it shows this:

object CheckCommand "infiniband_rate" {
    import "plugin-check-command"
    command = [ PluginDir + "/check_ib_link" ]
    arguments += {
        "-a" = {
            description = "List of active port(s)"
            required = true
            value = {{
                if (host.vars.sys.infiniband.mlx5_port2_100) {
              return "2"
            } else {
              return "1"
            }
            }}
        }
        "-d" = {
            description = "HCA device to check"
            required = true
            value = {{
                if (host.vars.sys.infiniband.mlx4_port1_40) {
              return "mlx4_0"
            } else if (host.vars.sys.infiniband.mlx4_port1_56) {
              return "mlx4_0"
            } else if (host.vars.sys.infiniband.mlx5_port1_40) {
              return "mlx5_0"
            } else if (host.vars.sys.infiniband.mlx5_port1_56) {
              return "mlx5_0"
            } else if (host.vars.sys.infiniband.mlx5_port1_100) {
              return "mlx5_0"
            } else if (host.vars.sys.infiniband.mlx5_port2_100) {       
              return "mlx5_2"
            }
            }}
        }
        "-r" = {
            description = "Expected rate in Gb/sec."
            required = true
            value = {{
                if (host.vars.sys.infiniband.mlx4_port1_40) {
              return "40"
            } else if (host.vars.sys.infiniband.mlx4_port1_56) {
              return "56"
            } else if (host.vars.sys.infiniband.mlx5_port1_40) {
              return "40"
            } else if (host.vars.sys.infiniband.mlx5_port1_56) {
              return "56"
            } else if (host.vars.sys.infiniband.mlx5_port1_100) {
              return "100"
            } else if (host.vars.sys.infiniband.mlx5_port2_100) {
              return "100"
            } else {
              return false
            }
            }}
        }
    }
}

They me be other elegant ways to do this inside Director, but I really want to understand how to call the custom vars here. I am also grateful for suggestion for other solutions.

For me it looks like that inside the command condition host.vars.sys.infiniband.mlx* is not available, but I saw similar examples on the net. So, I am wondering what I am do wrong here.

  • Director version (System - About):1.9.0
  • Icinga Web 2 version and modules (System - About): 2.9.5
  • Icinga 2 version (icinga2 --version): 2.13.2-1
  • Operating System and version: RockyLinux 8
  • Webserver, PHP versions:
    • Apache 2.4.37-41
    • PHP 7.4.19
2

Never done something like that before tbh.
But have you tried putting what you have into the Condition (set_if) field and change the condition format to “Icinga DSL” and return a variable. And then use that variable in the value field.

3

I think you need to use the macro function: Library Reference - Icinga 2

I have no example for exactly this at the moment, but an example that shows the general capabilities: Director - use function for timebased threshold - #4 by dgoetz

4

Thank you @log1c and @dgoetz for the replays.

I did some more testing and are more confused that before :confounded:

First I try to use set_if for setting an var and use it in the value field:

object CheckCommand "infiniband_rate" {
    import "plugin-check-command"
    command = [ PluginDir + "/check_ib_link" ]
    arguments += {
        "-a" = {
            description = "List of active port(s)"
            required = true
            value = "1"
        }
        "-d" = {
            description = "HCA device to check"
            required = true
            value = "1"
        }
        "-r" = {
            description = "Expected rate in Gb/sec."
            required = true
            set_if = {{
                var speed = "40"
            return speed
            }}
            value = "$speed$"
        }
    }
}

OUTPUT: Error: Non-optional macro ‘speed’ used in argument ‘-r’ is missing.
So even in such a simple example it not worked. I am sure I do miss here something… :unamused:

Next I try to test the conditions i wanted to use. So I started the icinga2 console. Here the code runs fine with the output I expected:

# icinga2 console
Icinga 2 (version: 2.13.2-1)
Type $help to view available commands.
<1> => host.vars.sys.infiniband.mlx5_port1_100 = true
null
<2> =>
null
<3> => var speed = host.vars.sys.infiniband.keys().join("").split("_")[2]
null
<4> => speed
"100"
<5> => host.vars
{
        sys = {
                infiniband = {
                        mlx5_port1_100 = true
                }
        }
}

When I try to port this into director, it fails.

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Here is the Preview of the command:

object CheckCommand "infiniband_rate" {
    import "plugin-check-command"
    command = [ PluginDir + "/check_ib_link" ]
    arguments += {
        "-a" = {
            description = "List of active port(s)"
            required = true
            value = "1"
        }
        "-d" = {
            description = "HCA device to check"
            required = true
            value = "1"
        }
        "-r" = {
            description = "Expected rate in Gb/sec."
            required = true
            set_if = {{
                var speed = host.vars.sys.infiniband.keys().join("").split("_")[2]
            return speed
            }}
            value = "$speed$"
        }
    }
}

From Icinga2 Docs I found an example of the set_if function where there are access the host.vars and use dictionary functions. In my case it does not work.

5

After alot of trail and error, I finally managed to get it work.

object CheckCommand "infiniband_rate" {
    import "plugin-check-command"
    command = [ PluginDir + "/check_ib_link" ]
    arguments += {
        "-a" = {
            description = "List of active port(s)"
            required = true
            value = {{
                var infiniband= macro("$host.vars.sys.infiniband$")
            return infiniband.keys().join("").split("_")[1].replace("port", "")
            
            }}
        }
        "-d" = {
            description = "HCA device to check"
            required = true
            value = {{
                var host_vars = macro("$host.vars$")
            var mlx_array = host_vars.sys.infiniband.keys().join("").split("_")
            if (mlx_array[0] == "mlx4") {
             return "mlx4_0"
            } else if (mlx_array[0] == "mlx5") {
              if (mlx_array[1] == "port1" ) {
                return "mlx5_0"
              } else {
                return "mlx5_2"
              }
            } 
            
            }}
        }
        "-r" = {
            description = "Expected rate in Gb/sec."
            required = true
            value = {{
                var host_vars = macro("$host.vars$")
            return host_vars.sys.infiniband.keys().join("").split("_")[2]
            }}
        }
    }
}

What took me the most time, was that parts of the documentation shows different examples but non of them did work from me.
Examle: https://icinga.com/docs/icinga-2/latest/doc/08-advanced-topics/#use-functions-in-command-arguments-set_if
I did a copy Paste, but I was not able to load the host_vars was always empty!

var host_vars = host.vars
log(host_vars)

When I do it with the macro function it works:

var host_vars = macro("$host.vars$")

So, can somebody explain me why I can not call the host.vars like in the example or is just the documentation here wrong?

6

I would classify this as bug in the documentation if it does not work like stated there. So can you do a pull request or at least open an issue? This would also allow a developer to look into and decide if it is expected to work like documented and it is an actual bug. There is also a chance that a bit of explanation is added why the one syntax works and there does not.

Someone tried to explain this to me in the past, but I am not sure if I understood and remember it correctly and so I do not try to explain it to prevent creating wrong knowledge! But this is why I pointed to the macro function initially.

7

Thank you @dgoetz
I opened an github issue. Lets see what the Devs will answer!

1 Like
8

Hi,

I suggest posting the link to the issue here as well, just for the sake of completeness :smiley:

I could imagine that the stuff from the docs not working could have something to to with the Director.
But that is just some wild guessing.

9

The Director is just generating DSL and if it looks like in the docs and not working, it is Icinga and not the Director to blame.

And for completeness: https://github.com/Icinga/icinga2/issues/9299

1 Like