Import
import "github.com/thiagonache/terraformtest"
Summary
Terraformtest is a lightweight terraform tester written in Go for unit and integration tests.
Features
- Remove code paperwork to write tests.
- No JSON query required for testing resources.
- Terraform resources are abstract in a Go generic struct.
- Test number of resources wanted in a plan.
- Test if a wanted resource exist in a plan.
- Test if all wanted resources exist in a plan and vice-versa.
Motivation
Testing your plan
-
Run plan with plan in binary
terraform plan -out /tmp/mymodule.plan
-
Convert binary plan into JSON file.
terraform show -json /tmp/mymodule.plan > /any/path/i/want/mymodule.plan.json
Test if plan contains one or more resources
func TestContainsResource(t *testing.T) {
testCases := []struct {
desc, planJSONPath string
wantResource terraformtest.Resource
}{
{
// Test description
desc: "Test EIP",
// Path for Terraform plan with resources to be tested in JSON format.
planJSONPath: "testdata/terraform-aws-101.plan.json",
wantResource: terraformtest.Resource{
// Resource address as show in the output of terraform plan command.
Address: "module.vpc.aws_eip.nat[0]",
// Metadata represents the resource type and the resource name in the resource declaration.
// Eg.: resource "aws_eip" "nat" {
Metadata: map[string]string{
"type": "aws_eip",
"name": "nat",
},
// Values are the resources key => value. Anything inside of the planned_values in the JSON file.
Values: map[string]string{
"vpc": "true",
"timeouts": "",
},
},
},
{
desc: "Test DB Subnet Group",
planJSONPath: "testdata/terraform-aws-101.plan.json",
wantResource: terraformtest.Resource{
Address: "module.db.module.db_subnet_group.aws_db_subnet_group.this[0]",
Metadata: map[string]string{
"type": "aws_db_subnet_group",
"name": "this",
},
Values: map[string]string{
"name_prefix": "demodb-",
},
},
},
}
for _, tC := range testCases {
t.Run(tC.desc, func(t *testing.T) {
// Read the Terraform JSON plan file
p, err := terraformtest.ReadPlan(tC.planJSONPath)
if err != nil {
t.Fatal(err)
}
// Get the resourceSet (map of resources in the plan)
gotRS := p.Resources
// Test if the resource wanted is present in the plan
if !gotRS.Contains(tC.wantResource) {
// If does not contain, output the diff
t.Error(gotRS.Diff())
}
})
}
// Set the total number of resources the plan must have
wantNumResources := 40
items := p.Resources.Resources
// Test if number of resources in the plan is equal to number of resources wanted
if len(items) != wantNumResources {
t.Errorf("want %d resources in plan, got %d", wantNumResources, len(items))
}
}
Test if plan is equal (have all the resources wanted)
The difference between Contains and Equal is that Equal requires all resources
to be declared in the slice of wanted Resource. If there's one item in the plan
that doesn't exist in the resourceSet or vice-versa it fails.
func TestEqual(t *testing.T) {
wantRS := []terraformtest.Resource{
{
Address: "module.nomad_job.nomad_job.test_job",
Metadata: map[string]string{
"type": "nomad_job",
"name": "test_job",
},
Values: map[string]string{
"name": "unit-test",
"datacenters": `["dc1"]`,
},
},
}
p, err := terraformtest.ReadPlan("testdata/terraform.plan.json")
if err != nil {
t.Fatal(err)
}
gotRS := p.Resources
if !terraformtest.Equal(wantRS, &gotRS) {
t.Error(gotRS.Diff())
}
}