87 lines
2.2 KiB
Plaintext
87 lines
2.2 KiB
Plaintext
---
|
|
layout: guides
|
|
sidebar_current: workflow-tips-and-tricks-isotime-template-function
|
|
page_title: Using the isotime template function - Guides
|
|
description: |-
|
|
It can be a bit confusing to figure out how to format your isotime using the
|
|
golang reference date string. Here is a small guide and some examples.
|
|
---
|
|
|
|
# Using the Isotime template function with a format string
|
|
|
|
The way you format isotime in golang is a bit nontraditional compared to how
|
|
you may be used to formatting datetime strings.
|
|
|
|
Full docs and examples for the golang time formatting function can be found
|
|
[here](https://golang.org/pkg/time/#example_Time_Format)
|
|
|
|
However, the formatting basics are worth describing here. From the [golang docs](https://golang.org/pkg/time/#pkg-constants):
|
|
|
|
> These are predefined layouts for use in Time.Format and time.Parse. The
|
|
> reference time used in the layouts is the specific time:
|
|
>
|
|
> Mon Jan 2 15:04:05 MST 2006
|
|
>
|
|
> which is Unix time 1136239445. Since MST is GMT-0700, the reference time
|
|
> can be thought of as
|
|
>
|
|
> 01/02 03:04:05PM '06 -0700
|
|
>
|
|
> To define your own format, write down what the reference time would look like
|
|
> formatted your way; see the values of constants like ANSIC, StampMicro or
|
|
> Kitchen for examples. The model is to demonstrate what the reference time
|
|
> looks like so that the Format and Parse methods can apply the same
|
|
> transformation to a general time value.
|
|
|
|
So what does that look like in a Packer template function?
|
|
|
|
```json
|
|
{
|
|
"variables": {
|
|
"myvar": "packer-{{isotime \"2006-01-02 03:04:05\"}}"
|
|
},
|
|
"builders": [
|
|
{
|
|
"type": "null",
|
|
"communicator": "none"
|
|
}
|
|
],
|
|
"provisioners": [
|
|
{
|
|
"type": "shell-local",
|
|
"inline": ["echo {{ user `myvar`}}"]
|
|
}
|
|
]
|
|
}
|
|
```
|
|
|
|
You can switch out the variables section above with the following examples to
|
|
get different timestamps:
|
|
|
|
Date only, not time:
|
|
|
|
```json
|
|
"variables":
|
|
{
|
|
"myvar": "packer-{{isotime \"2006-01-02\"}}"
|
|
}
|
|
```
|
|
|
|
A timestamp down to the millisecond:
|
|
|
|
```json
|
|
"variables":
|
|
{
|
|
"myvar": "packer-{{isotime \"Jan-_2-15:04:05.000\"}}"
|
|
}
|
|
```
|
|
|
|
Or just the time as it would appear on a digital clock:
|
|
|
|
```json
|
|
"variables":
|
|
{
|
|
"myvar": "packer-{{isotime \"3:04PM\"}}"
|
|
}
|
|
```
|