client: option to surface connection errors to callers #3430
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This commit allows blocking clients to receive a more informative error message than "context deadline exceeded", which is especially helpful in tracking down persistent client misconfiguration (such as an invalid TLS certificate, an invalid server that's refusing connections, etc.)
Rather than introducing a sudden interface change, provide an option for consumers to opt in to the new interface.
dfawley
reviewed
Mar 13, 2020
dialoptions.go
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| // WithReturnLastError returns a DialOption which makes the client connection | ||
| // return the last connection error that occurred instead of a context.DeadlineExceeded error. | ||
| // Implies WithBlock() | ||
| func WithReturnLastError() DialOption { |
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Please add an experimental tag for now (see other experimental dial options).
dialoptions.go
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| @@ -298,6 +299,16 @@ func WithBlock() DialOption { | |||
| }) | |||
| } | |||
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| // WithReturnLastError returns a DialOption which makes the client connection | |||
| // return the last connection error that occurred instead of a context.DeadlineExceeded error. | |||
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Please clarify that this returns the connection error string in addition to the context error, not instead of the context error.
dialoptions.go
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| @@ -298,6 +299,16 @@ func WithBlock() DialOption { | |||
| }) | |||
| } | |||
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| // WithReturnLastError returns a DialOption which makes the client connection | |||
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Regarding the name, WithReturnConnectionError is preferable to us.
Additionally, clarify documentation around what exactly it does.
dfawley
approved these changes
Apr 9, 2020
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Thank you for the PR! |
This was referenced Apr 14, 2020
timbunce
reviewed
Mar 5, 2021
| case err == nil || !cc.dopts.returnLastError: | ||
| conn, err = nil, ctx.Err() | ||
| default: | ||
| conn, err = nil, fmt.Errorf("%v: %v", ctx.Err(), err) |
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Wouldn't it be better for the second %v to be %w here, so the error is wrapped and thus available for introspection?
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This commit allows blocking clients to receive a more informative error
message than "context deadline exceeded", which is especially helpful in
tracking down persistent client misconfiguration (such as an invalid TLS
certificate, an invalid server that's refusing connections, etc.)