Add timeout and retry to framework version of provider by bendbennett · Pull Request #151 · hashicorp/terraform-provider-http

bendbennett · 2022-07-01T13:43:20Z

Closes: #149

One consequence of adding an option to retry is that it raises the question of when a retry should be initiated.

The implementation in this PR will only retry if an error is generated when a request is made.

An option might be to add an additional attribute to retry to allow specifying which status codes, for instance, should also trigger a retry, something like:

retry = {
	attempts = 2
	status_codes = .....
}

However, adding an attribute to allow defining which response status codes should trigger a retry seems slightly odd given that status code checking is removed in #142

detro

LGTM, and I left a couple of comments/reflections

Should we also support setting delay between retries?
I'm conflicted around the error-code-driven retry: the default behaviour of retryinghttp, that involves checking 5xx, has strong merits, grounded in practicality.

detro · 2022-07-05T12:17:53Z

+	retryClient.CheckRetry = func(ctx context.Context, resp *http.Response, err error) (bool, error) {
+		if err == nil {
+			return false, nil
+		}
+
+		return true, fmt.Errorf("retrying as request generated error: %w", err)
+	}


To me this is a sane approach.
Given we made a choice of letting user deal with error codes themselves, it feels like an actual client error is the only case when retrying make sense.

I have taken a second to look at how the retryablehttp client does it, and they have this:

// Check the response code. We retry on 500-range responses to allow // the server time to recover, as 500's are typically not permanent // errors and may relate to outages on the server side. This will catch // invalid response codes as well, like 0 and 999. if resp.StatusCode == 0 || (resp.StatusCode >= 500 && resp.StatusCode != http.StatusNotImplemented) { return true, fmt.Errorf("unexpected HTTP status %s", resp.Status) }

While I agree that it feels rather odd to ignore error codes, while also checking them, here they are making a fair point: most of 5xx errors are usually temporary issues on the server side of things. Yes, post-conditions will allow TF execution to stop in case of error, but for this class of issues (temporary server-side issues), it would end up having to fail the overall TF execution, and then the user has to find a way to retry.

I'm frankly on the fence about this. Both side of this argument have merits.

Yep. Agreed. I'm on the fence too.

detro · 2022-07-05T12:20:01Z

+
+			"retry": {
+				Description: "Retry request configuration.",
+				Attributes: tfsdk.SingleNestedAttributes(map[string]tfsdk.Attribute{


One thing that sometimes helps is to introduce a delay between attempts - maybe an exponential-back-off?. Similarly proposed here: #87

The retryablehttp client has an exponential backoff by default and a default minimum wait between retries of 1 sec.

We could expose the RetryWaitMin (and RetryWaitMax)? One of the reasons for using a SingleNestedAttribute for retry configuration was because of the possibility of needing to expose additional configuration.

Even better if it's easy to expose and it's nicely "tucked away" in the nested object

bflad · 2022-08-01T18:26:25Z

+			"retry": {
+				Description: "Retry request configuration.",
+				Attributes: tfsdk.SingleNestedAttributes(map[string]tfsdk.Attribute{


Since we're still on protocol version 5, this will need to be migrated to Blocks for now -- Nesting: tfsdk.BlockNestingModeList with MaxItems: 1 would be the closest we can get there. 🙁 (It could technically be an Object attribute, but then it'd lose all the "nice" things the framework can provide for the nested attributes).

bflad · 2022-08-01T18:42:05Z


-	client := &http.Client{}
+	retryClient := retryablehttp.NewClient()
+	retryClient.Logger = levelledLogger{ctx}


Aside: This leaves us with an interesting inflection point with terraform-plugin-log. We recently updated the http.Transport in sdk/v2 helper/logging for terraform-plugin-log support: https://www.terraform.io/plugin/sdkv2/logging/http-transport

We thought that it might be the case that framework providers could use something similar and that the answer there might be copying that http.Transport implementation into a new terraform-plugin-log package, since its extending Go standard library functionality and tightly coupled with terraform-plugin-log functionality.

That said, the logging implementation of go-retryablehttp partially overlaps/conflicts with some of that http.Transport implementation if we were to try an also use it here. For example, retryablehttp saves some information in differently named fields and it would always create duplicate log entries for sending/receiving requests unless we overwrite RequestLogHook/ResponseLogHook. The terraform-plugin-log http.Transport implementation also creates a transaction ID for correlating entries easier.

I'm not sure if its worth looking into this further, but wanted to raise it in case it seems like an area we should explore more. I think go-retryablehttp is a really good choice in general since it bakes in a lot of goodies, just not sure about the logging side of things.

Created hashicorp/terraform-plugin-log#91 to discuss some ideas.

bendbennett · 2023-02-03T17:36:39Z

+
+ENHANCEMENTS:
+
+* data-source/http: `retry` with nested `attempts` has been added ([#151](https://github.com/hashicorp/terraform-provider-http/pull/151).


Needs updating to incorporate min_delay and max_delay.

bendbennett · 2023-02-03T17:38:55Z

 			},

+			"request_timeout": schema.Int64Attribute{
+				Description: "The request timeout in milliseconds.",


We could use a custom time.Duration type here.

bendbennett · 2023-02-03T17:39:05Z

+						},
+					},
+					"min_delay": schema.Int64Attribute{
+						Description: "The minimum delay between retry requests in milliseconds.",


We could use a custom time.Duration type here.

bendbennett · 2023-02-03T17:39:13Z

+						},
+					},
+					"max_delay": schema.Int64Attribute{
+						Description: "The maximum delay between retry requests in milliseconds.",


We could use a custom time.Duration type here.

Co-authored-by: Vincent Chenal <vincent.chenal@protonmail.com>

F21 · 2023-04-11T03:46:51Z

Any chance someone can review and merge this if it's ready? This feature would be really useful for a terraform project I am currently working on.

bendbennett · 2023-04-11T06:34:04Z

Hi @F21 👋

We are currently reviewing this PR and should have an update regarding when it might be merged and released shortly.

austinvalle

lgtm, great work! 👍🏻

bflad

Looks good to me 🚀

github-actions · 2024-05-25T15:37:17Z

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active contributions.
If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.

github-actions Bot added dependencies size/XL documentation labels Jul 1, 2022

bendbennett added this to the v3.1.0 milestone Jul 1, 2022

bendbennett marked this pull request as ready for review July 1, 2022 14:37

bendbennett requested a review from a team as a code owner July 1, 2022 14:37

Base automatically changed from bendbennett/issues-93 to main July 1, 2022 16:28

detro approved these changes Jul 5, 2022

View reviewed changes

bendbennett force-pushed the bendbennett/issues-149 branch 2 times, most recently from c7cebe4 to e974f5a Compare July 5, 2022 14:46

bflad reviewed Aug 1, 2022

View reviewed changes

bflad mentioned this pull request Aug 1, 2022

Consider tflog http.Transport Implementation hashicorp/terraform-plugin-log#91

Open

bendbennett modified the milestones: v3.1.0, v3.2.0 Aug 22, 2022

bendbennett removed this from the v3.2.0 milestone Oct 27, 2022

bendbennett force-pushed the bendbennett/issues-149 branch from 29da528 to 6f95f1f Compare February 3, 2023 17:16

bendbennett commented Feb 3, 2023

View reviewed changes

bendbennett force-pushed the bendbennett/issues-149 branch 3 times, most recently from 1c016ee to 3ff90d2 Compare February 9, 2023 17:00

Adding optional request_timeout and retry attributes (#149)

936b3c8

Co-authored-by: Vincent Chenal <vincent.chenal@protonmail.com>

bendbennett force-pushed the bendbennett/issues-149 branch from 3ff90d2 to 4d22215 Compare April 6, 2023 07:08

Fixing ExpectError in tests (#149)

ccc248e

bendbennett force-pushed the bendbennett/issues-149 branch from 4d22215 to ccc248e Compare April 6, 2023 07:28

Merge branch 'main' into bendbennett/issues-149

c855f2c

Updates following code review (#149)

bfd1df5

austinvalle approved these changes Apr 11, 2023

View reviewed changes

bflad approved these changes Apr 11, 2023

View reviewed changes

bflad added the enhancement label Apr 11, 2023

bflad added this to the v3.3.0 milestone Apr 11, 2023

bendbennett merged commit ae33628 into main Apr 12, 2023

bendbennett deleted the bendbennett/issues-149 branch April 12, 2023 06:10

This was referenced Apr 18, 2023

Provide retry option on http datasource #87

Closed

add optional timeout to client #71

Closed

github-actions Bot locked as resolved and limited conversation to collaborators May 25, 2024


		ENHANCEMENTS:

		* data-source/http: `retry` with nested `attempts` has been added ([#151](https://github.com/hashicorp/terraform-provider-http/pull/151).

Conversation

bendbennett commented Jul 1, 2022 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

detro left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

bflad Aug 1, 2022 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

F21 commented Apr 11, 2023 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

bendbennett commented Apr 11, 2023

Uh oh!

austinvalle left a comment

Choose a reason for hiding this comment

Uh oh!

bflad left a comment

Choose a reason for hiding this comment

Uh oh!

github-actions Bot commented May 25, 2024

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

bendbennett commented Jul 1, 2022 •

edited

Loading

bflad Aug 1, 2022 •

edited

Loading

F21 commented Apr 11, 2023 •

edited

Loading