How do you check if a terraform string contains another string?
For example, I want to treat terraform workspaces with "tmp" in the name specially (e.g. allowing rds instances to be deleted without a snapshot), so something like this:
locals
{
is_tmp = "${"tmp" in terraform.workspace}"
}
As far as I can tell, the substr interpolation function doesn't accomplish this.
For terraform 0.12.xx apparently you are suppose to use regexall to do this.
From the manual for terraform 0.12.XX:
regexall() documentation
regexall can also be used to test whether a particular string matches a given pattern, by testing whether the length of the resulting list of matches is greater than zero.
Example from the manual:
> length(regexall("[a-z]+", "1234abcd5678efgh9"))
2
> length(regexall("[a-z]+", "123456789")) > 0
false
Example applied to your case in terraform 0.12.xx syntax should be something like:
locals
{
is_tmp = length(regexall(".*tmp.*", terraform.workspace)) > 0
}
It also specifically says in the manual not to use "regex" but instead use regexall.
If the given pattern does not match at all, the regex raises an error. To test whether a given pattern matches a string, use regexall and test that the result has length greater than zero.
As stated above this is because you will actually get an exception error when you try to use it in the later versions of 0.12.xx that are out now when you run plan. This is how I found this out and why I posted the new answer back here.
You can indirectly check for substrings using replace, e.g.
locals
{
is_tmp = "${replace(terraform.workspace, "tmp", "") != terraform.workspace}"
}
Like #MechaStorm, with Terrafor 0.12.7+ you can use regex to return a Boolean value if your string contains a particular substring
locals {
is_tmp = contains(regex("^(?:.*(tmp))?.*$",terraform.workspace),"tmp")
}
The regex query returns a list of capture groups for any characters before tmp, tmp if found, any characters after tmp. Then contains looks for "tmp" in the list and returns true or false. I am using this type of logic in my own terraform.
Length of the list produced by split function is greater than one when separtor is a substring.
locals {
is_tmp = length(split("tmp", terraform.workspace)) > 1
}
Use replace( string, search, replace ) as in the snippet:
// string contains ABBA = result is ABBA
output "match" {
value = "${ replace("xxxABBAyyy", "/(?:.*)(ABBA)(?:.*)/", "$1") }"
}
// string doesn't contain ABBA = result is original string
output "no_match" {
value = "${ replace("xxxBABAyyy", "/(?:.*)(ABBA)(?:.*)/", "$1")}"
}
// string contains ABBA (ingorecase) = result is AbBA
output "equals_ignorecase" {
value = "${ replace("xxxAbBAyyy", "/(?:.*)((?i)ABBA)(?:.*)/", "$1")}"
}
An output of terraform apply is:
Outputs:
equals_ignorecase = AbBA
match = ABBA
no_match = xxxBABAyyy
In terraform 0.12.7, we now have regex . This may help simplify some code and make it readable to some (perhaps?)
> regex("[a-z]+", "53453453.345345aaabbbccc23454")
aaabbbccc
I use this way to check if bucket name start with test-tmp
eg. test-tmp, test-tmp-app1, test-tmp-db1 etc..
is_test_bucket = can(regex("^(test-tmp){1}($|-{1}.*$)", var.bucket_name))
Something that makes sense reading, IMHO:
locals {
is_tmp = can(regex("tmp", terraform.workspace))
}
This works because the regex function will raise an error if no matches are found.
Bonus: since Terraform 1.3.x, there are the new startswith and endswith functions that can be handy in a good amount of cases.
Related
I have text like this:
Forecaster Strongly disagree \n\nSomething else is going to happen\n\nExample:-\n\n#:hashtag/424 \n#:hashtag/2818 ",
I need to get 424 and 2818 (which are ids) and find titles for those ids and replace #:hashtag/424 with #Title1
How do I manipulate string for this?
You can use a regular expression like this:
RegExp exp = RegExp(r'#:hashtag\/(\d+)');
String test = "Forecaster Strongly disagree \n\nSomething else is going to happen\n\nExample:-\n\n#:hashtag/424 \n#:hashtag/2818";
final matches = exp.allMatches(test);
if(matches.isNotEmpty){
print (matches.first[0]!.split('/').last);
}
//prints 424
some additional null checks will probably be nececssary depending on what you can expect from the input string
To replace the IDs you could use the replaceAllMapped method like this:
test.replaceAllMapped(exp, (match) => match[0]!.split('/').first + '/#Title1');
I have the following string value that comes from a YAML file. I want to extract the first two parts of the string within the terraform file. Let me know how it can be done. I tried the split function.
String: "sg:dev:crm"
Expected value: "sg:dev"
Tried: split(":","sg:dev:crm")[1,2] // This doesn't work
You would have to split it into two separate values and concatenate them. For example:
locals {
sg = "sg:dev:crm"
split_sg = split(":","sg:dev:crm")
wanted_str = "${local.split_sg[0]}:${local.split_sg[1]}"
}
Also, you tried referencing wrong indexes after you split the string because indexes start from 0, and sg is at index 0 while dev is at index 1.
Is there a way I can check if a variable in Terraform contains a specific substring, i.e. en environment prefix such as eu- or us-? Please, see the following to better understand what I want to do.
contains("eu-<...>", var.environment) ? do-something : do-something-else
<...> could be anything.
You can achieve this with regexall:
length(regexall("eu-", var.environment)) > 0
For example:
variable environment {
default = "eu-dev-environment"
}
locals {
contains = length(regexall("eu-", var.environment)) > 0
}
The value for contains will be true in this case.
I have a regular expression that I use several times in a script, where a single word gets changed but the rest of the expression remains the same. Normally I handle this by just creating a regular expression string with a format like the following example:
# Simple regex looking for exact string match
$regexTemplate = '^{0}$'
# Later on...
$someString = 'hello'
$someString -match ( $regexTemplate -f 'hello' ) # ==> True
However, I've written a more complex expression where I need to insert a variable into the expression template and... well regex syntax and string formatting syntax begin to clash:
$regexTemplate = '(?<=^\w{2}-){0}(?=-\d$)'
$awsRegion = 'us-east-1'
$subRegion = 'east'
$awsRegion -match ( $regexTemplate -f $subRegion ) # ==> Error
Which results in the following error:
InvalidOperation: Error formatting a string: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.
I know what the issue is, it's seeing one of my expression quantifiers as a replacement token. Rather than opt for a string-interpolation approach or replace {0} myself, is there a way I can tell PowerShell/.NET to only replace the 0-indexed token? Or is there another way to achieve the desired output using format strings?
If a string template includes { and/or } characters, you need to double these so they do not interfere with the numbered placeholders.
Try
$regexTemplate = '(?<=^\w{{2}}-){0}(?=-\d$)'
i am fighting with a string splitting. I want to split string by wildcards into a slice, but this slice should contain this wildcards as well.
For example: /applications/{name}/tokens/{name} should be split into [/applications/ {name} /tokens/ {name}] etc.
Here is a sample code i wrote, but it is not working correctly, and i don't feel good about it either.
https://play.golang.org/p/VMOsJeaI4l
There are some example routes to be tested. Method splitPath split path into parts and display both: before and after.
Here is a solution:
var validPathRe = regexp.MustCompile("^(/{[[:alpha:]]+}|/[-_.[:alnum:]]+)+$")
var splitPathRe = regexp.MustCompile("({[[:alpha:]]+}|[-_.[:alnum:]]+)")
func splitPath(path string) parts{
var retPaths parts
if !validPathRe.MatchString(path) {
return retPaths
}
retPaths = splitPathRe.FindAllString(path, -1)
return retPaths
}
I made this by creating two regular expressions, one to check if the path was valid or not, the other to extract the various parts of the path and return them. If the path is not valid it will return an empty list. The return of this will look like this:
splitPath("/path/{to}/your/file.txt")
["path" "{to}" "your" "file.txt"]
This doesn't include the '/' character because you already know that all strings in the return but the last string is a directory and the last string is the file name. Because of the validity check you can assume this.