Go Template Playground

This website is running only from the browser and it uses go templates on WASM to render the templates.

Go Template Examples

For loop

Iterate over a slice and print each element.

{{ range $index, $element := .data.items }}
{{- mustToPrettyJson $element }}
{{ end }}

If statement

Check functions eq, ne, lt, le, gt, ge but arguments should be comparable types and result is boolean.

result: 10

{{if eq (int .result) 10 -}}
Result is 10
{{- else if eq (int .result) 0 -}}
Result is 0
{{- else -}}
unknown
{{- end}}

Output:

Result is 10

Range with number

Generates a sequence of integers from 0 up to (but not including) the given number.

{{ range $x := 5 }}
{{- $x }}
{{ end }}

With

Use with to limit the scope of a variable inside of a template. If we want to reach outer scope, we can use $. syntax.

{{ with .name -}}
Item {{ . }} value is {{ $.value }}
{{- end }}

Function References

Helm functions

Sprig Functions

abbrev(int, string) string

{{ abbrev 10 "Hello World" }}
    Output: Hello W...

abbrevboth(int, int, string) string

{{ abbrevboth 5 10 "1234 5678 9123" }}
    Output: ...5678...

add([]interface {}) int64

{{ add 1 2 3 4 5 }}
    Output: 15

add1(interface {}) int64

{{ add1 1 }}
    Output: 2

add1f(interface {}) float64

{{ add1f 1.1 }}
    Output: 2.1

addf([]interface {}) float64

{{ addf 1.1 2.2 3.3 4.4 5.5 }}
    Output: 16.5

adler32sum(string) string

{{ adler32sum "Hello World" }}
    Output: 403375133

ago(interface {}) string

Timestamp to human readable time ago.

{{ ago 1687989601 }}
    Output: 11s

all([]interface {}) bool

{{ all true true false }}
    Output: false

any([]interface {}) bool

{{ any true true false }}
    Output: true

append(interface {}, interface {}) []interface {}

First argument must be a slice.

{{ append . "add" }}
    Output: [1 add]

atoi(string) int

{{ atoi "123" }}
    Output: 123

b32dec(string) string

{{ b32dec "MZXW6YTBOI======" }}
    Output: foobar

b32enc(string) string

{{ b32enc "foobar" }}
    Output: MZXW6YTBOI======

b64dec(string) string

{{ b64dec "SGVsbG8gV29ybGQ=" }}
    Output: Hello World

b64enc(string) string

{{ b64enc "Hello World" }}
    Output: SGVsbG8gV29ybGQ=

base(string) string

path.Base function.

{{ base "/foo/bar/baz.js" }}
    Output: baz.js

bcrypt(string) string

golang.org/x/crypto/bcrypt package's GenerateFromPassword function.

{{ bcrypt "Hello World" }}
    Output: $2a$10$dTu/HetKKYglHR1bs9mBFeGkOFgIMAabTdC0TNPh5ucVJLQLTfVYG

biggest(interface {}, []interface {}) int64

{{ biggest 1 2 3 4 5 }}
    Output: 5

buildCustomCert(string, string) (sprig.certificate, error)

camelcase(string) string

{{ camelcase "hello_world" }}
    Output: HelloWorld

cat([]interface {}) string

{{ cat "Hello" "World" }}
    Output: Hello World

ceil(interface {}) float64

{{ ceil 1.1 }}
    Output: 2

chunk(int, interface {}) [][]interface {}

{{ chunk 2 (list 1 2 3 4 5) }}
    Output: [[1 2] [3 4] [5]]

clean(string) string

path.Clean function.

{{ clean "/foo/bar/.." }}
    Output: /foo

coalesce([]interface {}) interface {}

Returns the first non-empty value.

{{ coalesce "" "Hello World" }}
    Output: Hello World

compact(interface {}) []interface {}

concat([]interface {}) interface {}

contains(string, string) bool

strings.Contains function but arguments are reversed.

{{ contains "World" "Hello World" }}
    Output: true

date(string, interface {}) string

Date can be a time.Time or an int, int32, int64.

{{ date "2006-01-02" 1690151142 }}
    Output: 2023-07-24

dateInZone(string, interface {}, string) string

dateModify(string, time.Time) time.Time

date_in_zone(string, interface {}, string) string

date_modify(string, time.Time) time.Time

decryptAES(string, string) (string, error)

deepCopy(interface {}) interface {}

deepEqual(interface {}, interface {}) bool

default(interface {}, []interface {}) interface {}

derivePassword(uint32, string, string, string, string) string

dict([]interface {}) map[string]interface {}

{{ dict "a" 1 "b" 2 }}
    Output: map[a:1 b:2]

dig([]interface {}) (interface {}, error)

dir(string) string

path.Dir function.

{{ dir "/foo/bar/baz.js" }}
    Output: /foo/bar

div(interface {}, interface {}) int64

divf(interface {}, []interface {}) float64

duration(interface {}) string

{{ duration "3600" }}
    Output: 1h0m0s

durationRound(interface {}) string

empty(interface {}) bool

{{ empty "" }}
    Output: true

encryptAES(string, string) (string, error)

env(string) string

{{ env "HOME" }}
    Output: /home/rytsh

expandenv(string) string

{{ expandenv "$HOME" }}
    {{ expandenv "${USER}" }}
    Output:
    /home/rytsh
    rytsh

ext(string) string

path.Ext function.

{{ ext "/foo/bar/baz.js" }}
    Output: .js

fail(string) (string, error)

{{ fail "FAILED PROGRAM" }}
    Output: program fail, exit code 1

first(interface {}) interface {}

float64(interface {}) float64

floor(interface {}) float64

fromJson(string) interface {}

genCA(string, int) (sprig.certificate, error)

genCAWithKey(string, int, string) (sprig.certificate, error)

genPrivateKey(string) string

genSelfSignedCert(string, []interface {}, []interface {}, int) (sprig.certificate, error)

genSelfSignedCertWithKey(string, []interface {}, []interface {}, int, string) (sprig.certificate, error)

genSignedCert(string, []interface {}, []interface {}, int, sprig.certificate) (sprig.certificate, error)

genSignedCertWithKey(string, []interface {}, []interface {}, int, sprig.certificate, string) (sprig.certificate, error)

get(map[string]interface {}, string) interface {}

getHostByName(string) string

has(interface {}, interface {}) bool

hasKey(map[string]interface {}, string) bool

hasPrefix(string, string) bool

hasSuffix(string, string) bool

hello() string

htmlDate(interface {}) string

htmlDateInZone(interface {}, string) string

htpasswd(string, string) string