private def setUpBastionSSH()

in src/main/scala/com/gu/ssm/Main.scala [87:124]
38 lines of code
2 McCabe index (conditional complexity)

  private def setUpBastionSSH(
    awsClients: AWSClients,
    executionTarget: ExecutionTarget,
    user: String,
    sism: SingleInstanceSelectionMode,
    onlyUsePrivateIP: Boolean,
    rawOutput: Boolean,
    bastionInstance: ExecutionTarget,
    bastionPortNumberOpt: Option[Int],
    bastionUser: String,
    targetInstancePortNumberOpt: Option[Int],
    useAgent: Option[Boolean],
    preferredAlgs: List[String]): ProgramResult = {
    val fProgramResult = for {
      sshArtifacts <- Attempt.fromEither(SSH.createKey())
      (privateKeyFile, publicKey) = sshArtifacts
      bastionConfig <- IO.getSSMConfig(awsClients.ec2Client, awsClients.stsClient, bastionInstance)
      bastionInstance <- Attempt.fromEither(Logic.getSSHInstance(bastionConfig.targets, sism))
      bastionAddPublicKeyCommand = SSH.addPublicKeyCommand(user, publicKey) + SSH.outputHostKeysCommand()
      bastionRemovePublicKeyCommand = SSH.removePublicKeyCommand(user, publicKey)
      bastionAddress <- Attempt.fromEither(Logic.getAddress(bastionInstance, onlyUsePrivateIP))
      targetConfig <- IO.getSSMConfig(awsClients.ec2Client, awsClients.stsClient, executionTarget)
      targetInstance <- Attempt.fromEither(Logic.getSSHInstance(targetConfig.targets, sism))
      targetAddress <- Attempt.fromEither(Logic.getAddress(targetInstance, true))
      targetAddPublicKeyCommand = SSH.addTaintedCommand(targetConfig.name) + SSH.addPublicKeyCommand(user, publicKey) + SSH.outputHostKeysCommand()
      targetRemovePublicKeyCommand = SSH.removePublicKeyCommand(user, publicKey)
      bastionResult <- IO.executeOnInstance(bastionInstance.id, bastionConfig.name, bastionAddPublicKeyCommand, awsClients.ssmClient)
      _ <- IO.executeOnInstanceAsync(bastionInstance.id, bastionConfig.name, bastionRemovePublicKeyCommand, awsClients.ssmClient)
      _ <- IO.tagAsTainted(targetInstance.id, targetConfig.name, awsClients.ec2Client)
      targetResult <- IO.executeOnInstance(targetInstance.id, targetConfig.name, targetAddPublicKeyCommand, awsClients.ssmClient)
      _ <- IO.executeOnInstanceAsync(targetInstance.id, targetConfig.name, targetRemovePublicKeyCommand, awsClients.ssmClient)
      bastionHostKey <- Attempt.fromEither(Logic.getHostKeyEntry(bastionResult, preferredAlgs))
      targetHostKey <- Attempt.fromEither(Logic.getHostKeyEntry(targetResult, preferredAlgs))
      hostKeyFile <- SSH.writeHostKey((bastionAddress, bastionHostKey), (targetAddress, targetHostKey))
    } yield SSH.sshCmdBastion(rawOutput)(privateKeyFile, bastionInstance, targetInstance, user, bastionAddress, targetAddress, bastionPortNumberOpt, bastionUser, targetInstancePortNumberOpt, useAgent, Some(hostKeyFile))
    val programResult = Await.result(fProgramResult.asFuture, Duration.Inf)
    ProgramResult.convertErrorToResult(programResult.map(UI.sshOutput(rawOutput)))
  }