resource/aws_lambda_function: Add support for lambda_function vpc_config update

[stack72]

Fixes: #1073

Changing to not ForceNew on any chances to vpc_config

Also, updates to dead_letter_config were supported in the code, but
the schema said that it would ForceNew on changes. So removed this
restriction

[Ninir]

LGTM! :)

Just left a question, since I may not have the answer at the moment! 😄

Tests are passing, except one, but not related to this PR.

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSLambdaFunction_'      
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSLambdaFunction_ -timeout 120m
=== RUN   TestAccAWSLambdaFunction_importLocalFile
--- PASS: TestAccAWSLambdaFunction_importLocalFile (36.93s)
=== RUN   TestAccAWSLambdaFunction_importLocalFile_VPC
--- PASS: TestAccAWSLambdaFunction_importLocalFile_VPC (38.61s)
=== RUN   TestAccAWSLambdaFunction_importS3
--- PASS: TestAccAWSLambdaFunction_importS3 (34.91s)
=== RUN   TestAccAWSLambdaFunction_basic
--- PASS: TestAccAWSLambdaFunction_basic (33.76s)
=== RUN   TestAccAWSLambdaFunction_updateRuntime
--- PASS: TestAccAWSLambdaFunction_updateRuntime (45.12s)
=== RUN   TestAccAWSLambdaFunction_expectFilenameAndS3Attributes
--- PASS: TestAccAWSLambdaFunction_expectFilenameAndS3Attributes (13.35s)
=== RUN   TestAccAWSLambdaFunction_envVariables
--- PASS: TestAccAWSLambdaFunction_envVariables (76.47s)
=== RUN   TestAccAWSLambdaFunction_encryptedEnvVariables
--- PASS: TestAccAWSLambdaFunction_encryptedEnvVariables (67.73s)
=== RUN   TestAccAWSLambdaFunction_versioned
--- PASS: TestAccAWSLambdaFunction_versioned (34.12s)
=== RUN   TestAccAWSLambdaFunction_DeadLetterConfig
--- PASS: TestAccAWSLambdaFunction_DeadLetterConfig (32.94s)
=== RUN   TestAccAWSLambdaFunction_DeadLetterConfigUpdated
--- PASS: TestAccAWSLambdaFunction_DeadLetterConfigUpdated (46.52s)
=== RUN   TestAccAWSLambdaFunction_nilDeadLetterConfig
--- PASS: TestAccAWSLambdaFunction_nilDeadLetterConfig (14.62s)
=== RUN   TestAccAWSLambdaFunction_tracingConfig
--- PASS: TestAccAWSLambdaFunction_tracingConfig (39.72s)
=== RUN   TestAccAWSLambdaFunction_VPC
--- PASS: TestAccAWSLambdaFunction_VPC (28.35s)
=== RUN   TestAccAWSLambdaFunction_VPCUpdate
--- PASS: TestAccAWSLambdaFunction_VPCUpdate (45.24s)
=== RUN   TestAccAWSLambdaFunction_VPC_withInvocation
--- FAIL: TestAccAWSLambdaFunction_VPC_withInvocation (22.98s)
	testing.go:428: Step 0 error: Check failed: Check 2/2 error: AccessDeniedException: The role defined for the function cannot be assumed by Lambda.
			status code: 403, request id: 4c787308-6623-11e7-a93c-b1f86a08b491
=== RUN   TestAccAWSLambdaFunction_s3
--- PASS: TestAccAWSLambdaFunction_s3 (30.79s)
=== RUN   TestAccAWSLambdaFunction_localUpdate
--- PASS: TestAccAWSLambdaFunction_localUpdate (41.85s)
=== RUN   TestAccAWSLambdaFunction_localUpdate_nameOnly
--- PASS: TestAccAWSLambdaFunction_localUpdate_nameOnly (42.12s)
=== RUN   TestAccAWSLambdaFunction_s3Update_basic
--- PASS: TestAccAWSLambdaFunction_s3Update_basic (57.16s)
=== RUN   TestAccAWSLambdaFunction_s3Update_unversioned
--- PASS: TestAccAWSLambdaFunction_s3Update_unversioned (43.68s)
=== RUN   TestAccAWSLambdaFunction_runtimeValidation_noRuntime
--- PASS: TestAccAWSLambdaFunction_runtimeValidation_noRuntime (32.91s)
=== RUN   TestAccAWSLambdaFunction_runtimeValidation_nodeJs
--- PASS: TestAccAWSLambdaFunction_runtimeValidation_nodeJs (35.92s)
=== RUN   TestAccAWSLambdaFunction_runtimeValidation_nodeJs43
--- PASS: TestAccAWSLambdaFunction_runtimeValidation_nodeJs43 (33.05s)
=== RUN   TestAccAWSLambdaFunction_runtimeValidation_python27
--- PASS: TestAccAWSLambdaFunction_runtimeValidation_python27 (35.92s)
=== RUN   TestAccAWSLambdaFunction_runtimeValidation_java8
--- PASS: TestAccAWSLambdaFunction_runtimeValidation_java8 (34.10s)
=== RUN   TestAccAWSLambdaFunction_tags
--- PASS: TestAccAWSLambdaFunction_tags (65.32s)
=== RUN   TestAccAWSLambdaFunction_runtimeValidation_python36
--- PASS: TestAccAWSLambdaFunction_runtimeValidation_python36 (33.33s)

[Ninir]

Without looking too much into the Terraform core, could this be something other than nil, like empty or so?
(Just wondering if the check is needed, since the check above guard us from nil structures, but may be missing something)

[stack72]

This is just an extra panic guard :)

[ghost]

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. Thanks!