Write your own Runners

Not quite what you need yet? Let’s customize the output!

Runners?

Whenever you type bpmon run you execute a Runner. This is nothing but a go text/template and some meta data. There are default runner (such as the one named default which will run if no runner is specified) which you can list via the --list flag:

$ bpmon run --list
verbose
	Print all check results in a long format and human readable
issues
	Print failed check results in a short format and human readable
issues_verbose
	Print failed check results in a long format and human readable
default
	Print all check results in a short format and human readable

Try them out by specifying the Runner you want to execute. For example bpmon run issues will only print failed business processes, bpmon run verbose prints a ton of details.

If you want to dig into the details of these predefined runners have a look at their source.

Since we are obviousely only rendering some templates we can easily build our own runners…

Learning by Example: Generate a status.html with a Runner

Wouldn’t it be nice to render some web page that shows the current business process status? Here we go…

Create two files in the directory $BPMON_BASE/runners/status/. The first file cmd.yaml contains some meta data:

---
description: |
  This renders a html file to stdout that represents the current status.

The second file cmd.template it the template:

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>status.html</title>
        <style>
.content { width: 70%; margin: 0 auto; }
.bp { margin: 20px; padding: 20px; padding-right: 0; }
.kpi { padding: 10px; padding-left: 30px; padding-right: 0; padding-bottom: 20px; margin-top: 10px; }
.svc { padding: 10px; padding-left: 30px; padding-right: 0; margin-top: 10px; }
.bp.ok { background-color: #8cd98c; }
.kpi.ok { background-color: #66cc66; }
.svc.ok { background-color: #40bf40; }
.bp.nok { background-color: #ff6666; }
.kpi.nok { background-color: #ff3333; }
.svc.nok { background-color: #ff0000; }
.bp.unknown { background-color: #d966ff; }
.kpi.unknown { background-color: #cc33ff; }
.svc.unknown { background-color: #bf00ff; }
.bp>.title, .kpi>.title { font-weight: 700; }
.kpi>.title, .svc>.title { font-size: 14px; }
        </style>
    </head>
    <body>
        <div class="content">
            {{ range $index, $bp := .BP }}
            {{$status := "unknown"}}{{if eq $bp.Status 0}}{{$status = "ok"}}{{else if eq $bp.Status 1}}{{$status = "nok"}}{{end}}
            <div class="bp {{$status}}" id="{{$bp.ID}}">
                <div class="title">BP {{$bp.Name}}</div>
                {{- range $index, $kpi := .Children }}
                {{$status := "unknown"}}{{if eq $kpi.Status 0}}{{$status = "ok"}}{{else if eq $kpi.Status 1}}{{$status = "nok"}}{{end}}
                <div class="kpi {{$status}}" id="{{$kpi.ID}}">
                    <div class="title">KPI {{$kpi.Name}}</div>
                    {{- range $index, $svc := .Children }}
                    {{$status := "unknown"}}{{if eq $svc.Status 0}}{{$status = "ok"}}{{else if eq $svc.Status 1}}{{$status = "nok"}}{{end}}
                    <div class="svc {{$status}}" id="{{$svc.ID}}">
                        <div class="title">SVC {{$svc.Name}}</div>
                        {{if ne $status "ok"}}<div class="output">{{$svc.Output}}</div>{{end}}
                    </div>
                    {{- end -}}
                </div>
                {{ end -}}
            </div>
            {{ end -}}
        </div>
    </body>
</html>

Wanna see?

$ bpmon run status > status.html && firefox status.html; rm status.html

Now you can imagine the possibilities. Do you want to trigger pagerduty via API if a business process is failed? Create a runner that renders a bash script and schedule via bpmon run myrunner | bash.

Meet your friends

Now the biggest hassle when buildung templates is to know the data you have available. To give you a hand we have added some funcions to the templating engine to help you inspect the data:

Function Description Usage
pretty Print the data in a human readable format {{ pretty . }}
json Print the data as JSON object {{ json . }}
yaml Print as YAML object {{ yaml . }}
spew Print with a lot of details regarding data type and such {{ spew . }}
describe Print the data structure rather than the data itself {{ describe . }}

Remember those functions, they might get handy. You can try them out easily via an AdHoc Runner:

bpmon run --adhoc "{{ pretty . }}"
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