I have a list of users with characteristics like this and I want to create a local variable that includes the names of the users in the "maker" group.
variable "users" {
type = map(object({
groups = list(string)
}))
default = {
"kevin.mccallister" = {
groups = ["kids", "maker"],
},
"biff" = {
groups = ["kids", "teens", "bully"],
},
}
}
I want to write the local like this, but it complains
Error: Invalid 'for' expression ... Key expression is required when
building an object.
locals {
makers_list = flatten({
for user, attr in var.users: user
if contains(attr.groups, "makers")
})
}
How can I take that map of objects and get out a list of names based on group affiliation?
flatten() is not required for this. Also, the {} is pushing this to build an object. You can instead build a list using [] and then it will create a list of the users filtered by their group association.
makers_list = [
for user, attr in var.users: user
if contains(attr.groups, "makers")
]
Related
I am interested to see if anyone knows of any better alternative to using conditional count statements in Terraform. By "conditional count statement", I mean a statement where depending a condition like a variable input, count will evaluate to create either 0 or 1 of a resource.
A simple example:
resource "xxxxxxxx" "example" {
count = var.example != null ? 1 : 0
}
Here, the resource will only be created if var.example has a value (is not null), otherwise it will not get created.
Conditional counts usually work ok in practice, but sometimes in more complex uses than the one above it introduces a risk of getting an error during Terraform Plan where it cannot evaluate the result of the count pre-apply.
The "count" value depends on resource attributes that cannot be determined
until apply, so Terraform cannot predict how many instances will be created.
To work around this, use the -target argument to first apply only the
resources that the count depends on.
Is there any better way to achieve the same effect of creating resources on a conditional basis in Terraform?
Keeping in mind that your terraform config not shown I've used a general example of for_each instead of count.
This is an example of how 2 CNAME records will be created using & in this example terraform modules are used but the same can be done directly on terraform resources.
locals {
cname_records = {
"email" = ["email.domain.net."]
"imap" = ["imap.domain.net."]
}
}
module "aws_route53_record_CNAME" {
source = "app.terraform.io/terraform-cloud-org/route53-record/aws"
version = "1.0.0"
for_each = local.cname_records
records = each.value
name = each.key
zone_id = "YOUR-HOSTED-ZONE-ID"
type = "CNAME"
ttl = "300"
}
It varies by case, but there are some cases where you need to get around this. There is a clever trick, but it seems obtuse in the single item (binary exists or not) case. But in a case where there are actually multiple items, this should help.
This is a completely contrived example but I actually use the method quite a bit. In short, a list of things not known until apply, can be replaced by a list of objects with a key you don't care about. The purpose is that for_each doesn't mind if the value is unknown at plan-time, only if the key is.
Consider the following root module with these four modules.
main.tf
resource "aws_s3_bucket" "this" {
bucket = "h4s-test-bucket"
}
# module "with_count" { # cannot be determined until apply
# source = "./with-count"
# x = aws_s3_bucket.this.id
# }
module "with_for_each_over_item" { # handy workaround
source = "./with-for-each-over-item"
x = aws_s3_bucket.this.id
}
output "with_for_each_over_item" {
value = module.with_for_each_over_item
}
# module "with_for_each_list" { # cannot be determined until apply
# source = "./with-for-each-list"
# x = [aws_s3_bucket.this.id]
# }
module "with_for_each_list_better" { # handy workaround
source = "./with-for-each-list-better"
x = [{ y = aws_s3_bucket.this.id }]
}
output "with_for_each_list_better" {
value = module.with_for_each_list_better
}
module "with_for_each_list_best" { # handier workaround
source = "./with-for-each-list-best"
x = [aws_s3_bucket.this.id]
}
output "with_for_each_list_best" {
value = module.with_for_each_list_best
}
with-count/main.tf (problematic)
variable "x" {
type = string
default = null
}
resource "null_resource" "this" {
count = var.x != null ? 1 : 0
}
output "this" {
value = null_resource.this
}
with-for-each-over-item/main.tf (handy workaround)
variable "x" {
type = string
default = null
}
resource "null_resource" "this" {
for_each = { for i, v in [var.x] : i => v }
}
output "this" {
value = null_resource.this
}
with-for-each-list/main.tf (problematic)
variable "x" {
type = list(string)
default = []
}
resource "null_resource" "this" {
for_each = toset(var.x)
}
output "this" {
value = null_resource.this
}
with-for-each-list-better/main.tf (handy workaround)
variable "x" {
type = list(object({ y = string }))
default = []
}
resource "null_resource" "this" {
for_each = { for i, v in var.x : i => v }
}
output "this" {
value = null_resource.this
}
with-for-each-list-best/main.tf (handiest workaround)
variable "x" {
type = list(string)
default = []
}
resource "null_resource" "this" {
for_each = { for i, v in var.x : i => v }
}
output "this" {
value = null_resource.this
}
Summary
In cases where the variable has a value not known at plan-time, consider using an object where the key is known.
I got such a map
Map<String, List<Object>>
when I use
map.toSortedMap(comparator)
and comparing values by keys I got sorted map but amount of objects in each value list is also changed (reduced). It's super strange. Under the hood toSortedMap method creates TreeMap with the given comparator, I don't know TreeMap internals but I assume that any map should not change values but only manipulate with the keys. Is this something that is ok for TreeMap or is it a bug in Kotlin library?
Edit
Code I get this issue on:
val categoriesKeys = listOf("key1", "key2", etc)
val categoriesKeysOrdersMap = mapOf("key1" to 0, "key2" to 1, etc)
val model = listOf(MyModel(..), MyModel(..), etc)
val categoryKeyToModelsMap = categoriesKeys
.asSequence()
.map { key ->
key to model.filter {
it.categories?.contains(key) == true
}
}
.filter { it.second.isNotEmpty() }
.toMap()
.toSortedMap(compareBy { categoriesKeysOrdersMap[it] })
On toMap step I have the map I want but not sorted, but after toSortedMap my data is messed up. Comparator compares by int value from categoriesKeysOrdersMap using key from category.
I have some json, for examle:
data = {
"name":"Bob","age":"20",
"name":"Jo","age":"21",
"name":"Jo","age":"22",
"name":"Nick","age":"23"
}
Next, I use crossfilter, create dimension and filter it:
let ndx = crossfilter(data);
let dim = ndx.dimension(d => d.name).filter(d !== "Jo");
//try to get filtered values
let filtered = dim.top(Infinity); // -> return 2 values where 'name'!='Jo'
//"name":"Bob","age":"20"
//"name":"Nick","age":"23"
let myGroup = dim.group(d => {
if(d === 'Jo') {
//Why we come here? This values must be filtered already
}
})
How can I filter my dimension and don't have these values on 'dim.group'?
Not sure what version you are using, but in the current version of Crossfilter, when a new group is created all records are first added to the group and then filtered records are removed. So the group accessor will be run at least once for all records.
Why do we do this? Because for certain types of grouping logic, it is important for the group to "see" a full picture of all records that are in scope.
It is possible that the group accessor is run over all records (even filtered ones) anyway in order to build the group index, but I don't remember.
Using Scala, MongoDB, Casbah.
Given a random list of strings:
val names = {
val listBuffer = new ListBuffer[String]
for(n <- 1 to (new Random().nextInt(5) + 1)){
val name = ((new Random().nextInt(26) + 65).asInstanceOf[Char]).toString
listBuffer += name
}
listBuffer.toList
}
Given a MongoDB document structure:
"_id": <uuid>
"name": <string>
How do I find all documents that have a name equal to an entry in my list using a single single MongoDBCollection.find() statement? (i.e using $or)
Thanks,
- Don
MongoDB has conditional operator $in that lets test if a field's value is in a list of values (documentation)
collection.find({name: {$in: ["aaa", "bbb", "ccc"]}})
In Casbah this will look like
collection.find("name" $in names)
I've looked at this other question, but can't get my select box to work correctly:
Binding initial/default value of dropdown (select) list
I've got the following Game object:
function Game(visitingTeamDetails, homeTeamDetails, game) {
if (arguments.length > 0) {
this.VisitingTeamDetails = visitingTeamDetails;
this.HomeTeamDetails = homeTeamDetails;
this.GameId = ko.observable(game.GameId);
this.HomeTeamName = ko.observable(game.HomeTeamName);
this.VisitingTeamName = ko.observable(game.VisitingTeamName);
this.SportTypeName = ko.observable(game.SportTypeName);
this.HomeAccountName = ko.observable(game.HomeAccountName);
this.VisitingAccountName = ko.observable(game.VisitingAccountName);
this.GameDateString = ko.observable(game.GameDateString);
this.GameTimeString = ko.observable(game.GameTimeString);
this.AvailableSportTypes = ko.observableArray(game.Sports);
this.sportTypeFunction = function () {
for (sportType in this.AvailableSportTypes()) {
if (this.AvailableSportTypes()[sportType].Name == this.SportTypeName()) {
return this.AvailableSportTypes()[sportType];
}
}
return null;
};
this.SportType = ko.observable(game.SportType);
}
}
SportType is an object with Name and SportTypeId.
I have the following template:
<td rowspan="3"><select data-bind="options: AvailableSportTypes, value: SportType, optionsText:'Name', optionsCaption: 'Choose...'" class="sportType"></select></td>
AvailableSportTypes is a list of SportType.
The list is coming in with the names of the SportTypes in the drop down list, but I can't make the initial selection be SportType. I wrote sportTypeFunction to show myself that the data was coming in correctly, and it would select the correct value, but changing my selection in the drop down would not update SportType.
I'm sure I'm doing something wrong. Anyone see it?
Thanks
When game.SportType gets passed in, it needs to be a reference to the an item in the game.AvailableSportTypes and not just an object that looks the same.
Basically two objects are not equal unless they are actually a reference to the same object.
var a = { name: "test" },
b = { name: "test" };
alert(a === b); //false
So, you would need to call your function to locate the correct object in the array and set it as the value of your observable.
Not that it is way better, but in KO 1.3 you can extend .fn of observables, observableArrays, and dependentObservables to add additional functionality.
Here is a sample: http://jsfiddle.net/rniemeyer/ZP79w