buildx/docs/bake-stdlib.md

title
Bake standard library functions

Name	Description
absolute	If the given number is negative then returns its positive equivalent, or otherwise returns the given number unchanged.
add	Returns the sum of the two given numbers.
and	Applies the logical AND operation to the given boolean values.
base64decode	Decodes a string containing a base64 sequence.
base64encode	Encodes a string to a base64 sequence.
basename	Returns the last element of a path.
bcrypt	Computes a hash of the given string using the Blowfish cipher.
byteslen	Returns the total number of bytes in the given buffer.
bytesslice	Extracts a subslice from the given buffer.
can	Tries to evaluate the expression given in its first argument.
ceil	Returns the smallest whole number that is greater than or equal to the given value.
chomp	Removes one or more newline characters from the end of the given string.
chunklist	Splits a single list into multiple lists where each has at most the given number of elements.
cidrhost	Calculates a full host IP address within a given IP network address prefix.
cidrnetmask	Converts an IPv4 address prefix given in CIDR notation into a subnet mask address.
cidrsubnet	Calculates a subnet address within a given IP network address prefix.
cidrsubnets	Calculates many consecutive subnet addresses at once, rather than just a single subnet extension.
coalesce	Returns the first of the given arguments that isn't null, or raises an error if there are no non-null arguments.
coalescelist	Returns the first of the given sequences that has a length greater than zero.
compact	Removes all empty string elements from the given list of strings.
concat	Concatenates together all of the given lists or tuples into a single sequence, preserving the input order.
contains	Returns true if the given value is a value in the given list, tuple, or set, or false otherwise.
convert	Converts a value to a specified type constraint, using HCL's customdecode extension for type expression support.
csvdecode	Parses the given string as Comma Separated Values (as defined by RFC 4180) and returns a map of objects representing the table of data, using the first row as a header row to define the object attributes.
dirname	Returns the directory of a path.
distinct	Removes any duplicate values from the given list, preserving the order of remaining elements.
divide	Divides the first given number by the second.
element	Returns the element with the given index from the given list or tuple, applying the modulo operation to the given index if it's greater than the number of elements.
equal	Returns true if the two given values are equal, or false otherwise.
flatten	Transforms a list, set, or tuple value into a tuple by replacing any given elements that are themselves sequences with a flattened tuple of all of the nested elements concatenated together.
floor	Returns the greatest whole number that is less than or equal to the given value.
format	Constructs a string by applying formatting verbs to a series of arguments, using a similar syntax to the C function "printf".
formatdate	Formats a timestamp given in RFC 3339 syntax into another timestamp in some other machine-oriented time syntax, as described in the format string.
formatlist	Constructs a list of strings by applying formatting verbs to a series of arguments, using a similar syntax to the C function "printf".
greaterthan	Returns true if and only if the second number is greater than the first.
greaterthanorequalto	Returns true if and only if the second number is greater than or equal to the first.
hasindex	Returns true if if the given collection can be indexed with the given key without producing an error, or false otherwise.
homedir	Returns the current user's home directory.
indent	Adds a given number of spaces after each newline character in the given string.
index	Returns the element with the given key from the given collection, or raises an error if there is no such element.
indexof	Finds the element index for a given value in a list.
int	Discards any fractional portion of the given number.
join	Concatenates together the elements of all given lists with a delimiter, producing a single string.
jsondecode	Parses the given string as JSON and returns a value corresponding to what the JSON document describes.
jsonencode	Returns a string containing a JSON representation of the given value.
keys	Returns a list of the keys of the given map in lexicographical order.
length	Returns the number of elements in the given collection.
lessthan	Returns true if and only if the second number is less than the first.
lessthanorequalto	Returns true if and only if the second number is less than or equal to the first.
log	Returns the logarithm of the given number in the given base.
lookup	Returns the value of the element with the given key from the given map, or returns the default value if there is no such element.
lower	Returns the given string with all Unicode letters translated to their lowercase equivalents.
max	Returns the numerically greatest of all of the given numbers.
md5	Computes the MD5 hash of a given string and encodes it with hexadecimal digits.
merge	Merges all of the elements from the given maps into a single map, or the attributes from given objects into a single object.
min	Returns the numerically smallest of all of the given numbers.
modulo	Divides the first given number by the second and then returns the remainder.
multiply	Returns the product of the two given numbers.
negate	Multiplies the given number by -1.
not	Applies the logical NOT operation to the given boolean value.
notequal	Returns false if the two given values are equal, or true otherwise.
or	Applies the logical OR operation to the given boolean values.
parseint	Parses the given string as a number of the given base, or raises an error if the string contains invalid characters.
pow	Returns the given number raised to the given power (exponentiation).
range	Returns a list of numbers spread evenly over a particular range.
regex	Applies the given regular expression pattern to the given string and returns information about a single match, or raises an error if there is no match.
regex_replace	Applies the given regular expression pattern to the given string and replaces all matches with the given replacement string.
regexall	Applies the given regular expression pattern to the given string and returns a list of information about all non-overlapping matches, or an empty list if there are no matches.
replace	Replaces all instances of the given substring in the given string with the given replacement string.
reverse	Returns the given string with all of its Unicode characters in reverse order.
reverselist	Returns the given list with its elements in reverse order.
rsadecrypt	Decrypts an RSA-encrypted ciphertext.
sanitize	Replaces all non-alphanumeric characters with a underscore, leaving only characters that are valid for a Bake target name.
sethaselement	Returns true if the given set contains the given element, or false otherwise.
setintersection	Returns the intersection of all given sets.
setproduct	Calculates the cartesian product of two or more sets.
setsubtract	Returns the relative complement of the two given sets.
setsymmetricdifference	Returns the symmetric difference of the two given sets.
setunion	Returns the union of all given sets.
sha1	Computes the SHA1 hash of a given string and encodes it with hexadecimal digits.
sha256	Computes the SHA256 hash of a given string and encodes it with hexadecimal digits.
sha512	Computes the SHA512 hash of a given string and encodes it with hexadecimal digits.
signum	Returns 0 if the given number is zero, 1 if the given number is positive, or -1 if the given number is negative.
slice	Extracts a subslice of the given list or tuple value.
sort	Applies a lexicographic sort to the elements of the given list.
split	Produces a list of one or more strings by splitting the given string at all instances of a given separator substring.
strlen	Returns the number of Unicode characters (technically: grapheme clusters) in the given string.
substr	Extracts a substring from the given string.
subtract	Returns the difference between the two given numbers.
timeadd	Adds the duration represented by the given duration string to the given RFC 3339 timestamp string, returning another RFC 3339 timestamp.
timestamp	Returns a string representation of the current date and time.
title	Replaces one letter after each non-letter and non-digit character with its uppercase equivalent.
trim	Removes consecutive sequences of characters in "cutset" from the start and end of the given string.
trimprefix	Removes the given prefix from the start of the given string, if present.
trimspace	Removes any consecutive space characters (as defined by Unicode) from the start and end of the given string.
trimsuffix	Removes the given suffix from the start of the given string, if present.
try	Variadic function that tries to evaluate all of is arguments in sequence until one succeeds, in which case it returns that result, or returns an error if none of them succeed.
upper	Returns the given string with all Unicode letters translated to their uppercase equivalents.
urlencode	Applies URL encoding to a given string.
uuidv4	Generates and returns a Type-4 UUID in the standard hexadecimal string format.
uuidv5	Generates and returns a Type-5 UUID in the standard hexadecimal string format.
values	Returns the values of elements of a given map, or the values of attributes of a given object, in lexicographic order by key or attribute name.
zipmap	Constructs a map from a list of keys and a corresponding list of values, which must both be of the same length.

Examples

add

# docker-bake.hcl
target "webapp-dev" {
  dockerfile = "Dockerfile.webapp"
  tags = ["docker.io/username/webapp:latest"]
  args = {
    buildno = "${add(123, 1)}"
  }
}