Fixes creating aws_db_instance from snapshot with iops

[sklarsa]

The same PR as #5800 with an acceptance test added. Thanks to @dannosaur for finding and correcting the bug in the first place.

Changes proposed in this pull request:

Move the iops config element from the initial create to the secondary "modify" stage of the create (the initial iops value gets inherited from the snapshot, so this isn't required in the initial stage
Output from acceptance testing:

Stevens-MacBook-Pro-2:terraform-provider-aws steven$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage'
TF_ACC=1 go test ./aws -v -parallel 20 -run=TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage -timeout 120m
=== RUN   TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage
=== PAUSE TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage
=== CONT  TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage (1481.44s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	1481.491s

[sklarsa]

pinging @bflad since this is a bug affecting multiple users per the comments on #5800

[hernan82arg]

+1

[bflad]

LGTM, thanks @sklarsa 🚀 I'm not 100% sure this will cause slower restores in certain use cases, but a working setup is much better than the alternative. The extra acceptance test can be used to guard against future regressions should any optimization be needed, so thank you for adding it.

I'm going to merge #5800 first so @dannosaur gets proper attribution, then merge this afterwards.

Previous output from acceptance test (before code update):

--- FAIL: TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage (1508.07s)
    testing.go:538: Step 0 error: Error applying: 1 error occurred:
        	* aws_db_instance.test: 1 error occurred:
        	* aws_db_instance.test: error modifying DB Instance (tf-acc-test-6951710415450023739): InvalidParameterCombination: Both storage size and iops must be specified when modifying storage size or iops on an DB Instance that has iops

Output from acceptance testing:

--- PASS: TestAccAWSDBInstance_iamAuth (431.24s)
--- PASS: TestAccAWSDBInstance_kmsKey (440.56s)
--- PASS: TestAccAWSDBInstance_basic (493.29s)
--- PASS: TestAccAWSDBInstance_namePrefix (516.76s)
--- PASS: TestAccAWSDBInstance_generatedName (523.32s)
--- PASS: TestAccAWSDBInstance_DeletionProtection (525.94s)
--- PASS: TestAccAWSDBInstance_optionGroup (542.98s)
--- PASS: TestAccAWSDBInstance_IsAlreadyBeingDeleted (564.03s)
--- PASS: TestAccAWSDBInstance_FinalSnapshotIdentifier_SkipFinalSnapshot (768.31s)
--- PASS: TestAccAWSDBInstance_subnetGroup (915.58s)
--- PASS: TestAccAWSDBInstance_FinalSnapshotIdentifier (970.21s)
--- PASS: TestAccAWSDBInstance_S3Import (694.48s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_Monitoring (1345.59s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_AutoMinorVersionUpgrade (1353.66s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_AvailabilityZone (1404.82s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb (1445.31s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_IamDatabaseAuthenticationEnabled (1527.90s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_BackupWindow (1586.96s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_AllocatedStorage (1676.57s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_MaintenanceWindow (1776.92s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_Port (1311.26s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_ParameterGroupName (1411.21s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier (1329.88s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_AutoMinorVersionUpgrade (1087.99s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_VpcSecurityGroupIds (1383.85s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_BackupRetentionPeriod (1958.83s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_AllocatedStorage (1500.79s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_AvailabilityZone (1128.85s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_Io1Storage (1560.53s)
--- PASS: TestAccAWSDBInstance_ReplicateSourceDb_MultiAZ (1955.20s)
--- PASS: TestAccAWSDBInstance_portUpdate (512.81s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_BackupRetentionPeriod (1600.82s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_IamDatabaseAuthenticationEnabled (1168.50s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_MaintenanceWindow (1128.37s)
--- PASS: TestAccAWSDBInstance_separate_iops_update (674.50s)
--- PASS: TestAccAWSDBInstance_enhancedMonitoring (736.87s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_BackupWindow (1329.85s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_DeletionProtection (1505.73s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_Port (1097.28s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_VpcSecurityGroupIds_Tags (1049.80s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_Monitoring (1401.18s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_BackupRetentionPeriod_Unset (1722.40s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_ParameterGroupName (1249.43s)
--- PASS: TestAccAWSDBInstance_diffSuppressInitialState (459.67s)
--- PASS: TestAccAWSDBInstance_MinorVersion (490.58s)
--- PASS: TestAccAWSDBInstance_cloudwatchLogsExportConfiguration (514.64s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_Tags (1258.04s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_VpcSecurityGroupIds (1330.16s)
--- PASS: TestAccAWSDBInstance_EnabledCloudwatchLogsExports_Postgresql (580.76s)
--- PASS: TestAccAWSDBInstance_cloudwatchLogsExportConfigurationUpdate (766.75s)
--- PASS: TestAccAWSDBInstance_EnabledCloudwatchLogsExports_Oracle (742.12s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_MultiAZ (1853.22s)
--- PASS: TestAccAWSDBInstance_MSSQL_TZ (1530.71s)
--- PASS: TestAccAWSDBInstance_SnapshotIdentifier_MultiAZ_SQLServer (3588.27s)
--- PASS: TestAccAWSDBInstance_MSSQL_DomainSnapshotRestore (2908.84s)
--- PASS: TestAccAWSDBInstance_MSSQL_Domain (3423.36s)

[bflad]

This has been released in version 1.60.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[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!