String Notes — Orkestra

String notes manipulate text values. They cover the cases that come up constantly when building resource names, labels, and field values from CR data.

Reference

Note	Description
`toLower`	Convert a string to all lowercase or all uppercase.
`toUpper`	Convert a string to all lowercase or all uppercase.
`trimSpace`	Remove leading and trailing whitespace.
`trim`	Remove all leading and trailing occurrences of a cutset string.
`trimPrefix`	Remove a specific prefix or suffix if present.
`trimSuffix`	Remove a specific prefix or suffix if present.
`hasPrefix`	Return `true` if the string starts or ends with the given substring.
`hasSuffix`	Return `true` if the string starts or ends with the given substring.
`contains`	Return `true` if the string contains the substring.
`replace`	Replace all occurrences of `old` with `new` in `s`.
`split`	Split a string by a separator into a slice.
`join`	Join a slice of strings into a single string with a separator.
`repeat`	Repeat a string n times.
`camelToKebab`	Convert CamelCase or PascalCase to kebab-case.
`concat`	Join any number of strings together with no separator.
`truncate`	Truncate a string to at most `n` characters.

Examples

# toLower
# value: "{{ toLower .spec.environment }}"
# production → production
# PRODUCTION → production

# value: "{{ toUpper .spec.tier }}"
# premium → PREMIUM

# toUpper
# value: "{{ toLower .spec.environment }}"
# production → production
# PRODUCTION → production

# value: "{{ toUpper .spec.tier }}"
# premium → PREMIUM

# trimSpace
# value: "{{ trimSpace .spec.domain }}"
# "  example.com  " → "example.com"

# trim
# value: "{{ trim .spec.tag \"/\" }}"
# "/images/nginx/" → "images/nginx"

# trimPrefix
# value: "{{ trimPrefix .metadata.name \"app-\" }}"
# "app-frontend" → "frontend"

# value: "{{ trimSuffix .spec.image \":latest\" }}"
# "nginx:latest" → "nginx"

# trimSuffix
# value: "{{ trimPrefix .metadata.name \"app-\" }}"
# "app-frontend" → "frontend"

# value: "{{ trimSuffix .spec.image \":latest\" }}"
# "nginx:latest" → "nginx"

# hasPrefix
# value: "{{ hasPrefix .spec.image \"gcr.io/\" }}"
# "gcr.io/myproject/app:v1" → true

# hasSuffix
# value: "{{ hasPrefix .spec.image \"gcr.io/\" }}"
# "gcr.io/myproject/app:v1" → true

# contains
# value: "{{ contains .spec.environment \"prod\" }}"
# "production" → true
# "staging"    → false

# replace
# value: "{{ replace .spec.domain \".\" \"-\" }}"
# "my.app.example.com" → "my-app-example-com"

# split
# Extract the first tag from a comma-separated list
# value: "{{ index (split .spec.tags \",\") 0 }}"
# spec.tags: "latest,stable,v2" → "latest"

# join
# value: "{{ join .spec.hosts \", \" }}"
# ["api.example.com", "admin.example.com"] → "api.example.com, admin.example.com"

# repeat
# value: "{{ repeat \"ha\" 3 }}"
# → "hahaha"

# camelToKebab
# value: "{{ camelToKebab .spec.controllerName }}"
# "WebsiteOperator" → "website-operator"
# "myAppName"       → "my-app-name"

# concat
# value: "{{ concat \"*.\" .spec.domain }}"
# spec.domain: "api.example.com" → "*.api.example.com"

# value: "{{ concat .metadata.name \"-\" .spec.tier }}"
# name: "webapp", tier: "prod" → "webapp-prod"

# truncate
# value: "{{ truncate .metadata.name 63 }}"
# Names longer than 63 chars are clipped and get "..." appended.
# Names at or under 63 chars are returned unchanged.