rancher-template

rancher-template is a utility to get stacks info from rancher metadata service and execute golang templates to generate files.

It's included at docker rawmind/rancher-tools at /opt/tools/rancher-template

Build statically

git clone -v <version> https://github.com/rawmind0/rancher-metadata.git
cd rancher-metadata
go get
CGO_ENABLED=0 GOOS=linux go build -a -ldflags '-extldflags "-static"' -o rancher-template

Versions

• 0.3-2

Usage

Rancher-template get stacks info from rancher metadata service and execute golang templates to generate files.

It refresh data in real time, updating templates if content change. An action could also be defined, command to be exectued when template content changes. E.g. Restart a service if config changes.

These are options and parameters that could be set. Env vars overwrite parameters values.

Usage of rancher-template:
  -debug
      Run in debug mode. Env var `RANCHER_TEMPLATE_DEBUG`
  -logfile string
      Rancher template log fie. (default "/opt/tools/rancher-template/log/rancher-template.log"). Env var `RANCHER_TEMPLATE_LOGFILE`
  -prefix string
      Rancher metadata prefix. (default "2016-07-29"). Env var `RANCHER_TEMPLATE_PREFIX`
  -refresh int
      Rancher metadata refresh time in seconds. (default 300). Env var `RANCHER_TEMPLATE_REFRESH`
  -self
      Get self stack data or all. Env var `RANCHER_TEMPLATE_SELF`
  -templates string
      Template files, wildcard allowed between quotes. (default "/opt/tools/rancher-template/etc/*.yml"). Env var `RANCHER_TEMPLATE_FILES`
  -url string
      Rancher metadata url. (default "http://rancher-metadata.rancher.internal"). Env var `RANCHER_TEMPLATE_URL`

Custom functions

Added some custom functions to golang templates

• "split" func split(s, sep string) []string
• "replace" func replace(s, old, new string) []string
• "tolower" func(s string) string
• "contains": func (s, c string) bool
• "ishealthy" func (s string) bool
• "isrunning": func (s string) bool

Templates

Templates should be configured with an yaml file, that rancher-template reads. This config yml file format..

destination: <destination file>
source: <template file>
action: <command> 

• destination set the file to write template execution
• source set golang template file
• action command to execute if template has changed. Optional

Templates get rancher.stacks data from Rancher metadata. You could get all stacks or just selfstack.

Template example to list Stack name, service name and service label if has specific values.

{{- range $stack := . }}
Stack name {{.Name}}
  {{- range $service := .Services }}
  Service name {{.Name}}
    {{- $traefik_label := (index .Labels "traefik.enable") -}}
    {{- if or (eq $traefik_label "true") (eq $traefik_label "stack") }}
    labels {{$traefik_label}}
    {{- end -}}
  {{- end -}}
{{- end }}