Passing In Variables At Runtime

[AdminTurnedDevOps]

Hey All,

Trying to figure out how to pass in variables at runtime. For example:

terraform apply --auto-approve -var name="value" -var location="value"

I set up a Variables interface to pass in the values (setting up the values of the variables by passing them in at runtime. Already have that covered).

		variables := map[string]interface{}{
			"name":                name,
			"resource_group_name": resourceGroupName,
			"location":            location,
			"node_count":          nodeCount,
			"k8s_version":         k8sVersion,
		}

		err = tf.Apply(context.Background())

[doyleish]

tfVarTempFile, _ := os.CreateTemp(os.TempDir(), "tempvars-*.tfvars.json")
defer os.Remove(tfVarTempFile.Name())
configBytes, _ := json.Marshal(variables)
tfVarTempFile.Write(configBytes)
tfVarTempFile.Close()
tf.Apply(context.TODO(), tfexec.VarFile(tfVarTempFile.Name()))

This is how I did it. Not amazing but not a ton of work either.
You could also do tfexec.Var("k=v") for all pairs in your map

[radeksimko]

There is a couple of ways you can pass variables in. Assuming you wish to keep the map and the map is in practice map[string]string (i.e. values are convertible to string).

	var varOpts []tfexec.ApplyOption
	for k, v := range variables {
		varOpts = append(varOpts, tfexec.Var(k+"="+v))
	}
	err = tf.Apply(ctx, varOpts...)

or you can hard code these, e.g.

	opts := []tfexec.ApplyOption{
		tfexec.Var("name=" + name),
		tfexec.Var("resource_group_name=" + resourceGroupName),
		tfexec.Var("location=" + location),
		tfexec.Var("node_count=" + nodeCount),
		tfexec.Var("k8s_version=" + k8sVersion),
	}

	err = tf.Apply(ctx, opts...)

In either case keep in mind that this is passed in as CLI flag with all the same restrictions that shell may come with. i.e. This should work fine for variables of primitive types (number, string, bool) as long as you format it or cast it correctly to string. Complex types will be better handled through tfvars files, as mentioned by @doyleish.