Re: Templating/automating configuration

[Alexis Letessier <alexis.letessier () gmail com>]

Go templates: http://golang.org <http://golang.org/> Fast and simple with gRPC and other good stuff like kelsey’s confd 
(a daemon that watches for changes and update templates)

% go doc text/template
package template // import "text/template"

Package template implements data-driven templates for generating textual
output.

To generate HTML output, see package html/template, which has the same
interface as this package but automatically secures HTML output against
certain attacks.

Templates are executed by applying them to a data structure. Annotations in
the template refer to elements of the data structure (typically a field of a
struct or a key in a map) to control execution and derive values to be
displayed. Execution of the template walks the structure and sets the
cursor, represented by a period '.' and called "dot", to the value at the
current location in the structure as execution proceeds.

The input text for a template is UTF-8-encoded text in any format.
"Actions"--data evaluations or control structures--are delimited by "{{" and
"}}"; all text outside actions is copied to the output unchanged. Except for
raw strings, actions may not span newlines, although comments can.

Once parsed, a template may be executed safely in parallel.

Here is a trivial example that prints "17 items are made of wool".

    type Inventory struct {
        Material string
        Count    uint
    }
    sweaters := Inventory{"wool", 17}
    tmpl, err := template.New("test").Parse("{{.Count}} items are made of {{.Material}}")
    if err != nil { panic(err) }
    err = tmpl.Execute(os.Stdout, sweaters)
    if err != nil { panic(err) }

Alexis

> On 6 Jun 2017, at 15:22, Graham Johnston <johnstong () westmancom com> wrote:
>
> Short of complete SDN, for those of you that have some degree of configuration templating and/or automation tools 
> what is it that you run? I'm envisioning some sort of tool that let's me define template snippets of configuration 
> and aids in their deployment to devices. I'm okay doing the heaving lifting in defining everything, I'm just looking 
> for the tool that stitches it together and hopefully makes things a little less error prone for those who aren't as 
> adept.
>
> Graham Johnston
> Network Planner
> Westman Communications Group
> 204.717.2829
> johnstong () westmancom com<mailto:johnstong () westmancom com>