Using tflint with IntelliJ

I’ve recently been working on a Terraform code base which has grown organically overtime and also been worked on by a number of different people. This means there are naturally some aspects which can be improved upon.

Some really basic things which could be improved :

  • declare variable types
  • give useful descriptions for variables
  • remove unused variables (copy/paste from other places)
  • basic formatting consistency (terraform fmt)

tflint - as a tool can detect the first three with the relevant rules enabled.

What I wanted was this functionality available in the IDE I am using to edit the Terraform code as I can fix issues as I work on a specific module/environment.

Setup instructions

  1. Install tflint (I’m working on a Macbook)

    brew install tflint

  2. Ensure you have tflint setup correctly

    I have my tflint config file in this location ~/tflint.hcl and at the time of writing have the following rules enabled :

    config {
  plugin_dir = "~/.tflint.d/plugins"
  disabled_by_default = false
}
   
rule "terraform_comment_syntax" {
  enabled = true
}
   
rule "terraform_deprecated_index" {
  enabled = true
}
   
rule "terraform_documented_outputs" {
   enabled = true
}
   
rule "terraform_documented_variables" {
  enabled = true
}
   
rule "terraform_naming_convention" {
  enabled = false
}
   
rule "terraform_required_providers" {
  enabled = true
}
   
rule "terraform_required_version" {
  enabled = true
}
   
rule "terraform_deprecated_interpolation" {
  enabled = true
}
   
rule "terraform_typed_variables" {
  enabled = true
}
   
rule "terraform_unused_declarations" {
  enabled = true
}
   
plugin "aws" {
    enabled = true
    version = "0.12.0"
    source  = "github.com/terraform-linters/tflint-ruleset-aws"
}

    You can check it is working my manually running it against an example test.tf file with content below :

    variable "test" {
  description = "test variable"
}

    If you run the following command you should expect to see the warnings below if tflint is working correctly : tflint test.tf

    ➜  ~ tflint test.tf
2 issue(s) found:
   
Warning: `test` variable has no type (terraform_typed_variables)
   
  on /tmp/test.tf line 1:
   1: variable "test" {
   
Reference: https://github.com/terraform-linters/tflint/blob/v0.34.1/docs/rules/terraform_typed_variables.md
   
Warning: variable "test" is declared but not used (terraform_unused_declarations)
   
  on /tmp/test.tf line 1:
   1: variable "test" {
   
Reference: https://github.com/terraform-linters/tflint/blob/v0.34.1/docs/rules/terraform_unused_declarations.md

  3. Install IntelliJ

    Grab it from here IntelliJ Download Page

  4. Install the HCL and LSP IntelliJ Plugins

    • Navigate to Preferences -> Plugins
    • Search for HCL and install the Terraform and HCL plugin
    • Search for LSP and install the LSP Support plugin

    Your installed plugins should look similar to the screen grab below.

    Plugins

  5. Create an association for the language server

    Open Preferences -> Language & Frameworks -> Language Server Protocol -> Server Definitions

    Create an association as shown in the screenshot below :

    CreateAssociation

  6. Restart IntelliJ

  7. Load the same test.tf we used earlier and check we now get code highlighting of our issues without our IDE

    tflintInIntelliJ