Evaluating template in workflow replaced << with &lt;<

[invidian]

Expected Behaviour

Workflow properly renders template without replacing any characters.

Current Behaviour

When template includes sequence like <<, it gets replaced into `<<.

Possible Solution

Use text/template instead of html/template when rendering workflows.

Steps to Reproduce (for bugs)

Unit test to reproduce:

func TestRenderTemplateNotHTML(t *testing.T) {
        validTemplate := `
version: "0.1"
name: hello_world_workflow
global_timeout: 600
tasks:
  - name: "hello world<<"
    worker: "{{.device_1}}"
    actions:
    - name: "hello_world"
      image: hello-world
      timeout: 60
`
        templateID := uuid.New().String()
        hwAddress := []byte("{\"device_1\":\"08:00:27:00:00:01\"}")

        result, err := RenderTemplate(templateID, validTemplate, hwAddress)
        if err != nil {
                t.Fatalf("rendering should not fail")
        }

        expected := "hello world<<"

        if !strings.Contains(result, expected) {
                t.Fatalf("Result should contain %q, got \n\n%s", expected, result)
        }
}

Context

https://twitter.com/_invidian/status/1339504259340091392

Found while working on tinkerbell/cluster-api-provider-tinkerbell#17.

Your Environment

Tinkerbell sandbox from version tinkerbell/playground@be40a7b.

[gianarb]

I agree with John Arundel https://twitter.com/bitfield/status/1339506837230632960 is not a bug it is a security-conscious decision.

I am joking thank you for opening this issue

[invidian]

Added sample unit test to reproduce. Perhaps one in the code could be more comprehensive.