Introduce API for platform hub compliance policies

[denys-octopus]

Background

We want to allow user to manage compliance policies via go-client.

Part of MAS-6 (I want to create a new policy in Platform Hub)

Result

This PR introduces new package with exposed function to add new compliance policy. Other functionalities will be added in next pull requests.

Example of usage

// Create new
draft := platformhubpolicies.PolicyDraft{
    GitRef:          "refs/heads/main",
    Slug:            "my_policy",
    Name:            "My policy",
    ScopeRego:       scope,
    ConditionsRego:  conditions,
    ViolationAction: "block",
}
createdPolicy, _ := platformhubpolicies.Add(octopusClient, draft, "Create new policy commit message")

// Get By Slug and Update
policy, _ := platformhubpolicies.GetBySlug(octopusClient, createdPolicy.GetGitRef(), createdPolicy.GetSlug())
policy.SetName("My policy Updated")
policy.SetViolationAction("warn")

updatedPolicy, _ := platformhubpolicies.Update(octopusClient, policy, "Update policy commit message")

// List policies
policiesResult, _ := platformhubpolicies.List(octopusClient, platformhubpolicies.PoliciesQuery{
    GitRef: "refs/heads/main",
    Skip:   0,
    Take:   30,
})

for _, p := range policiesResult.Policies {
    fmt.Printf("%s (slug: %s, action: %s)\n", p.GetName(), p.GetSlug(), p.GetViolationAction())
}

// Publish
publishedVersion1, _ := platformhubpolicies.Publish(octopusClient, updatedPolicy, "1.0.0")
publishedVersion2, _ := platformhubpolicies.Publish(octopusClient, updatedPolicy, "2.0.0")

// Activate published version
activatedVersion, _ := platformhubpolicies.ActivateVersion(octopusClient, publishedVersion2)

// List published versions
versionsResult, _ := platformhubpolicies.ListVersions(octopusClient, platformhubpolicies.PublishedPoliciesQuery{
    Slug: "my_policy",
    Skip: 0,
    Take: 20,
})

for _, v := range versionsResult.Items {
    fmt.Printf("%s v%s (active: %t)\n", v.GetSlug(), v.GetVersion(), v.IsActivated())
}

[shaun-od]

Just a couple of notes, can we check with the owners of the GO client if they need to review as well.

[shaun-od]

LGTM other than there is a comment about whether the publish should be on the policy entity instead? Lets chat about it.

[shaun-od]

LGTM from my perspective. There is one change we are going to make but I'm happy with either approach.

[liam-mackie]

Minor notes around the PlatformHubPolicyVersion which are nits - might be good to discuss, but it's a difference of opinion, rather than a real reason to block the PR.

[shaun-od]

A couple of things to look at, happy to chat if needed

[shaun-od]

I am not sold on candidate as the suffix, would PolicyDraft be better but I am not sold on that name either.

[denys-octopus]

Renamed to PolicyDraft - for me, sounds more appropriate than ..Cadidate

[shaun-od]

how does a user create a key if they don't already have a policy created to get it by slug? I wonder whether this method should take the gitRef and slug as parameters? What do other things do when they have GetBySlug

[denys-octopus]

Yeah, changed to two separate arguments.

For example runbook Git operations passing all required values as separate arguments

[shaun-od]

LGTM