New Resource: Dataflow Job #855

nat-henderson · 2017-12-14T00:52:57Z

A long time ago, in a galaxy far, far away (prior to the provider split), @dasch created a PR hashicorp/terraform#14174 to close hashicorp/terraform#13537. @danawillow reviewed it, and it was nearly done, but the provider split happened, the PR was closed, and the issue was abandoned. This PR revives it, updates it in a minor way, and addresses one of @danawillow's remaining comments about the notion of existence.

I'm pretty new myself, so I'm not sure this is the right final state for this resource ("existence" is a weird notion for a dataflow job), but I think it's the closest to the original intent of the PR and I think it's a valid and useful way to do this.

@dasch and @k4y3ff are two people who have said that they have a use case in mind for this resource - what do you folks think?

If merged, this PR closes #81.

A dataflow job exists when it is in a nonterminal state, and does not exist if it is in a terminal state (or a non-running state which can only transition into terminal states).

nat-henderson · 2017-12-14T00:53:39Z

00:36 $ make testacc TEST=./google TESTARGS='-run=TestAccDataflow*'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./google -v -run=TestAccDataflow* -timeout 120m
=== RUN   TestAccDataflowJobCreate
--- PASS: TestAccDataflowJobCreate (8.43s)
PASS
ok      github.com/terraform-providers/terraform-provider-google/google 8.446s

danawillow

Woo thanks for reviving this @ndmckinley! Overall structure looks good, just a few comments.

danawillow · 2018-01-04T00:18:37Z

google/resource_dataflow_job.go

+		return err
+	}
+
+	jobName := d.Get("name").(string)


eh may as well just inline these in env and request

danawillow · 2018-01-04T00:19:15Z

google/resource_dataflow_job.go

+	jobName := d.Get("name").(string)
+	gcsPath := d.Get("template_gcs_path").(string)
+	tempLocation := d.Get("temp_gcs_location").(string)
+	zone := d.Get("zone").(string)


should probably be getZone now

danawillow · 2018-01-04T00:41:23Z

google/resource_dataflow_job.go

+		return err
+	}
+
+	d.SetId(job.Id)


For compute resources that are asynchronous, we usually follow this order:

Send the request

Set the Id

Wait on the request

If there's an error, set the id to ""

Since dataflow seems to use a synchronous API, we can't follow that exact pattern, but I still think setting the id before sending the request is probably the way to go:

If the Terraform process quits for whatever reason when the request is running, the request will have already been sent, so it means that the resource does exist in GCP. With the id in the state file already, we can read the information back when we call the read() function on plan, and we don't lose out on anything. If the id didn't get saved, then Terraform would think it needed to recreate it.

If the Terraform process quits (for whatever reason) exactly between when we set the id and when we make the request, then when it does the refresh on plan it would just see that it doesn't actually exist and set the id back to empty.

If the Terraform process doesn't quit then it doesn't really matter when the id gets set.

Anyway that's a long explanation for a tiny change that doesn't make a difference 99% of the time, but now you know :)

Unfortunately the ID here is created on the server side and not delivered back to us until the create has already succeeded. Think it's worth trying to use an async api instead?

danawillow · 2018-01-04T00:49:59Z

google/resource_dataflow_job.go

+	"google.golang.org/api/googleapi"
+)
+
+var dataflowTerminalStatesMap = map[string]bool{


Since bool's zero-value is false, there's no difference between a key that exists in the map but has a value of false and one not in the map at all, so if you wanted to you could remove all the falses from here. (according to the internet, the convention of how to do sets in go is to use a map[string]struct{}, although I'm pretty sure the reason for an empty struct instead of a bool is because it takes up less memory, and for a set this small the memory savings aren't going to make any difference at all)

Stack Overflow tells me that map[string]bool is the right way to go if you can afford the memory overhead for syntax convenience reasons.

https://softwareengineering.stackexchange.com/questions/177428/sets-data-structure-in-golang

(I prefer struct{} to bool when creating a set, as I feel it's clearer--the value can't have any meaning, which prevents future maintainers from accidentally thinking the bool means something--but it's such a minor preference I'm not super interested in enforcing it on anyone. I just find the semantic reasoning to be more persuasive than the memory savings.)

In this case I think the code gets uglier if I need to check existence of a key rather than the value of the key. Since go only provides comma-ok notation for that, I can't really see how to use it in the second condition of a loop without some ugly repeating-myself. I don't mind changing it - and if you know a trick, I'd love to learn it - but my mild preference is to leave it as is.

Ah, yes, the for does complicate this. I, personally, would move the Read out of the for loop's definition, something like https://play.golang.org/p/BIxXBPs--vM

But now I'm really in the weeds, and honestly this is such a slight preference thing, I'm happy to defer to what you think.

Fair enough, done.

danawillow · 2018-01-04T01:00:10Z

google/resource_dataflow_job.go

+			// If we have an error and it's not a google-specific error, we should go ahead and return.
+			return err
+		} else if ok && strings.Contains(gerr.Message, "not yet ready for canceling") {
+			time.Sleep(5 * time.Second)


So usually for something that requires checking a bunch of times if something is in a certain state, we would use a StateChangeConf (see all the _operation.go files for examples), which handles things like timeouts and backoff and whatnot. Is there a way to know just based on read whether the job is ready for canceling, or is it something you can only know by trying it and seeing if it works?

You can only know by trying it, it seems to me.

danawillow · 2018-01-04T01:05:19Z

google/resource_dataflow_job.go

+	tempLocation := d.Get("temp_gcs_location").(string)
+	zone := d.Get("zone").(string)
+	maxWorkers := d.Get("max_workers").(int)
+	params := expandDataflowParamsStringMap(d.Get("parameters").(map[string]interface{}))


you can use expandStringMap from utils.go for this

danawillow · 2018-01-04T01:14:24Z

vendor/vendor.json

@@ -1,6 +1,6 @@
 {
 	"comment": "",
-	"ignore": "appengine test github.com/hashicorp/nomad/ github.com/hashicorp/terraform/backend",
+	"ignore": "test",


why this change?

No idea - govendor did it for me. I'll put it back.

danawillow · 2018-01-04T01:21:23Z

google/resource_dataflow_job.go

+	} else {
+		d.Set("state", job.CurrentState)
+	}
+


Generally it's a good idea to set as many fields as you have access to on read, not just computed ones. This helps detect any drift between what Terraform thinks is true and what GCP thinks is true.

danawillow · 2018-01-04T01:22:13Z

google/resource_dataflow_job.go

@@ -0,0 +1,210 @@
+package google


You'll also want to add documentation in website/docs/r/

I added this last night but forgot to comment.

nat-henderson · 2018-01-09T02:29:27Z

@paddycarver For the tests to pass on CI server you'll need to enable the Dataflow API for the test project:

https://console.developers.google.com/apis/api/dataflow.googleapis.com/overview?project=hc-terraform-testing

If you prefer I can stick a "google_project_service" resource on there to have the test re-enable it automatically.

paddycarver · 2018-01-09T02:55:32Z

I've got a note now to enable the service for CI tomorrow. I'd rather the tests not try to set up their own environment, honestly, though... I think we just need a longer talk about testing and CI, and the ergonomics and developer experience around them. It's on my shortlist :)

paddycarver · 2018-01-10T00:11:29Z

API enabled for CI :)

nat-henderson · 2018-01-10T00:13:59Z

Thanks! I'm running it now. It passes locally, so it ought to work. :)

edit: Aha, great, it does pass.

danawillow · 2018-01-10T19:10:55Z

google/resource_dataflow_job.go

+		log.Printf("[DEBUG] Removing resource '%s' because it is in state %s.\n", job.Name, job.CurrentState)
+		d.SetId("")
+		return nil
+	} else {


nit: no need for this "else" (https://github.com/golang/go/wiki/CodeReviewComments#indent-error-flow)

Ah, good point, thanks.

danawillow · 2018-01-10T19:20:34Z

google/resource_dataflow_job_test.go

+)
+
+func TestAccDataflowJobCreate(t *testing.T) {
+


add t.Parallel()

danawillow · 2018-01-10T19:21:37Z

website/docs/r/dataflow_job.html.markdown

+```hcl
+resource "google_dataflow_job" "big_data_job" {
+    name = "dataflow-job"
+	template_gcs_path = "gs://my-bucket/templates/template_file"


nit: alignment (tabs vs spaces)

Oh no! Thanks, switched to spaces.

danawillow · 2018-01-10T19:23:13Z

website/docs/r/dataflow_job.html.markdown

+The following arguments are supported:
+
+* `name` - (Required) A unique name for the resource, required by Dataflow.
+    Changing this forces a new resource to be created.


I would remove this line since changing any of the fields forces a new resource to be created.

danawillow · 2018-01-10T19:25:35Z

website/docs/r/dataflow_job.html.markdown

+
+## Attributes Reference
+
+In addition to the above, the resource provides `state` - the current state of the resource, selected from the [JobState enum](https://cloud.google.com/dataflow/docs/reference/rest/v1b3/projects.jobs#Job.JobState)


Eh even though there's just one let's still make a list here so it's easy to scan the left side of the page for attributes

Add support for Google Dataflow jobs Note: A dataflow job exists when it is in a nonterminal state, and does not exist if it is in a terminal state (or a non-running state which can only transition into terminal states). See doc for more detail.

Allow resource_*_iam_bindings with no members

ghost · 2020-03-30T13:55:04Z

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. If you feel I made an error 🤖 🙉 , please reach out to my human friends 👉 hashibot-feedback@hashicorp.com. Thanks!

dasch and others added 4 commits December 13, 2017 22:08

Add support for Google Dataflow jobs

8869170

govendor fetch google.golang.org/api/dataflow/v1b3

ba23a52

Make this old PR compile by resolving name conflict.

9fb15bd

Revise the notion of dataflow resource's "existence"

7487f51

A dataflow job exists when it is in a nonterminal state, and does not exist if it is in a terminal state (or a non-running state which can only transition into terminal states).

paddycarver requested review from danawillow, paddycarver and rosbo December 14, 2017 23:16

danawillow suggested changes Jan 4, 2018

View reviewed changes

nat-henderson added 4 commits January 9, 2018 01:08

revert govendor change, test tweaks, minor simplifications.

52ffad0

Added doc.

6529289

Add doc to index.

c2b1b01

Switch to struct{} set instead of bool set.

6956ec6

danawillow reviewed Jan 10, 2018

View reviewed changes

docs updates and parallelizing test

844310c

danawillow approved these changes Jan 10, 2018

View reviewed changes

nat-henderson added 2 commits January 10, 2018 14:09

Merge branch 'master' into dataflow

0f047a6

Fix indent - the web editor changed it.

828909f

nat-henderson merged commit f50d4a1 into hashicorp:master Jan 10, 2018

nat-henderson deleted the dataflow branch January 10, 2018 22:38

modular-magician pushed a commit to modular-magician/terraform-provider-google that referenced this pull request Sep 27, 2019

Merge pull request hashicorp#855 from modular-magician/codegen-pr-1926

2da4126

Allow resource_*_iam_bindings with no members

ghost locked and limited conversation to collaborators Mar 30, 2020


		## Attributes Reference

		In addition to the above, the resource provides `state` - the current state of the resource, selected from the [JobState enum](https://cloud.google.com/dataflow/docs/reference/rest/v1b3/projects.jobs#Job.JobState)

New Resource: Dataflow Job #855

New Resource: Dataflow Job #855

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nat-henderson commented Dec 14, 2017

nat-henderson commented Dec 14, 2017

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nat-henderson commented Jan 9, 2018

paddycarver commented Jan 9, 2018

paddycarver commented Jan 10, 2018

nat-henderson commented Jan 10, 2018 • edited Loading

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ghost commented Mar 30, 2020

nat-henderson commented Jan 10, 2018 •

edited

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