• terraform: Using for_each over tuples

  2 min read

  
  

  Let's imagine we have the following data structure:

  locals {
    queries = [
      {
        query  = "SELECT version()"
        engine = "postgresql"
      },
      {
        query  = "SELECT * FROM v$version"
        engine = "oracle"
      },
      (...)
    ]
  }
  

  If we want to use just some of the items on a resource we can use for_each through the resulting array of filtering the objects using a for:

  for_each = [ for item in local.queries: item if item.engine == "postgresql" ]
  

  22/06/2021

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• Kubernetes init containers

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  Kubernetes init containers are a special container that runs before the main containers on the Pod. They are usually used used for setting up the environment and populate some shared storage to be used for the actual containers.

  21/06/2021

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• Pod and Service DNS naming schema

  2 min read

  
  

  Kubernetes provides a DNS to be used to locate other pods or services instead of using it's IP address. The default cluster domain is cluster.local but we can change it if we like.

  18/06/2021

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• How to list installed applications on a kubernetes cluster using helm

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  Helm intends to be a package manager for kubernetes, as such it provides a way to list all the installed applicacions on the cluster

  17/06/2021

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• terraform setproduct: combine list of objects to generate all the possible combinations

  4 min read

  
  

  Let's imagine we want to create a security group with the following ingress rules:

  ingress_rules = [
      {
          protocol = "tcp"
          cidr_blocks = [ "1.1.1.1/32", "2.2.2.2/32" ]
      },
      {
          protocol = "tcp"
          cidr_blocks = [ "1.2.3.4/32" ]
      }
  ]
  

  For each of the following ports:

  services = ["80", "443", "8080"]
  

  We can use the terraform function setproduct() to calculate all the combinations of elements from the given sets. That's also called the Cartesian product. For this example it's going to be 2x3.

  16/06/2021

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