IAM examples using SDK for Kotlin

Create functions that wrap IAM user actions.

suspend fun main(args: Array<String>) {
    val usage = """
    Usage:
        <username> <policyName> <roleName> <roleSessionName> <fileLocation> <bucketName> 

    Where:
        username - The name of the IAM user to create. 
        policyName - The name of the policy to create. 
        roleName - The name of the role to create. 
        roleSessionName - The name of the session required for the assumeRole operation. 
        fileLocation - The file location to the JSON required to create the role (see Readme). 
        bucketName - The name of the Amazon S3 bucket from which objects are read. 
    """

    if (args.size != 6) {
        println(usage)
        exitProcess(1)
    }

    val userName = args[0]
    val policyName = args[1]
    val roleName = args[2]
    val roleSessionName = args[3]
    val fileLocation = args[4]
    val bucketName = args[5]

    createUser(userName)
    println("$userName was successfully created.")

    val polArn = createPolicy(policyName)
    println("The policy $polArn was successfully created.")

    val roleArn = createRole(roleName, fileLocation)
    println("$roleArn was successfully created.")
    attachRolePolicy(roleName, polArn)

    println("*** Wait for 1 MIN so the resource is available.")
    delay(60000)
    assumeGivenRole(roleArn, roleSessionName, bucketName)

    println("*** Getting ready to delete the AWS resources.")
    deleteRole(roleName, polArn)
    deleteUser(userName)
    println("This IAM Scenario has successfully completed.")
}

suspend fun createUser(usernameVal: String?): String? {
    val request =
        CreateUserRequest {
            userName = usernameVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.createUser(request)
        return response.user?.userName
    }
}

suspend fun createPolicy(policyNameVal: String?): String {
    val policyDocumentValue: String =
        "{" +
            "  \"Version\": \"2012-10-17\"," +
            "  \"Statement\": [" +
            "    {" +
            "        \"Effect\": \"Allow\"," +
            "        \"Action\": [" +
            "            \"s3:*\"" +
            "       ]," +
            "       \"Resource\": \"*\"" +
            "    }" +
            "   ]" +
            "}"

    val request =
        CreatePolicyRequest {
            policyName = policyNameVal
            policyDocument = policyDocumentValue
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.createPolicy(request)
        return response.policy?.arn.toString()
    }
}

suspend fun createRole(
    rolenameVal: String?,
    fileLocation: String?,
): String? {
    val jsonObject = fileLocation?.let { readJsonSimpleDemo(it) } as JSONObject

    val request =
        CreateRoleRequest {
            roleName = rolenameVal
            assumeRolePolicyDocument = jsonObject.toJSONString()
            description = "Created using the AWS SDK for Kotlin"
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.createRole(request)
        return response.role?.arn
    }
}

suspend fun attachRolePolicy(
    roleNameVal: String,
    policyArnVal: String,
) {
    val request =
        ListAttachedRolePoliciesRequest {
            roleName = roleNameVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.listAttachedRolePolicies(request)
        val attachedPolicies = response.attachedPolicies

        // Ensure that the policy is not attached to this role.
        val checkStatus: Int
        if (attachedPolicies != null) {
            checkStatus = checkMyList(attachedPolicies, policyArnVal)
            if (checkStatus == -1) {
                return
            }
        }

        val policyRequest =
            AttachRolePolicyRequest {
                roleName = roleNameVal
                policyArn = policyArnVal
            }
        iamClient.attachRolePolicy(policyRequest)
        println("Successfully attached policy $policyArnVal to role $roleNameVal")
    }
}

fun checkMyList(
    attachedPolicies: List<AttachedPolicy>,
    policyArnVal: String,
): Int {
    for (policy in attachedPolicies) {
        val polArn = policy.policyArn.toString()

        if (polArn.compareTo(policyArnVal) == 0) {
            println("The policy is already attached to this role.")
            return -1
        }
    }
    return 0
}

suspend fun assumeGivenRole(
    roleArnVal: String?,
    roleSessionNameVal: String?,
    bucketName: String,
) {
    val stsClient =
        StsClient {
            region = "us-east-1"
        }

    val roleRequest =
        AssumeRoleRequest {
            roleArn = roleArnVal
            roleSessionName = roleSessionNameVal
        }

    val roleResponse = stsClient.assumeRole(roleRequest)
    val myCreds = roleResponse.credentials
    val key = myCreds?.accessKeyId
    val secKey = myCreds?.secretAccessKey
    val secToken = myCreds?.sessionToken

    val staticCredentials =
        StaticCredentialsProvider {
            accessKeyId = key
            secretAccessKey = secKey
            sessionToken = secToken
        }

    // List all objects in an Amazon S3 bucket using the temp creds.
    val s3 =
        S3Client {
            credentialsProvider = staticCredentials
            region = "us-east-1"
        }

    println("Created a S3Client using temp credentials.")
    println("Listing objects in $bucketName")

    val listObjects =
        ListObjectsRequest {
            bucket = bucketName
        }

    val response = s3.listObjects(listObjects)
    response.contents?.forEach { myObject ->
        println("The name of the key is ${myObject.key}")
        println("The owner is ${myObject.owner}")
    }
}

suspend fun deleteRole(
    roleNameVal: String,
    polArn: String,
) {
    val iam = IamClient { region = "AWS_GLOBAL" }

    // First the policy needs to be detached.
    val rolePolicyRequest =
        DetachRolePolicyRequest {
            policyArn = polArn
            roleName = roleNameVal
        }

    iam.detachRolePolicy(rolePolicyRequest)

    // Delete the policy.
    val request =
        DeletePolicyRequest {
            policyArn = polArn
        }

    iam.deletePolicy(request)
    println("*** Successfully deleted $polArn")

    // Delete the role.
    val roleRequest =
        DeleteRoleRequest {
            roleName = roleNameVal
        }

    iam.deleteRole(roleRequest)
    println("*** Successfully deleted $roleNameVal")
}

suspend fun deleteUser(userNameVal: String) {
    val iam = IamClient { region = "AWS_GLOBAL" }
    val request =
        DeleteUserRequest {
            userName = userNameVal
        }

    iam.deleteUser(request)
    println("*** Successfully deleted $userNameVal")
}

@Throws(java.lang.Exception::class)
fun readJsonSimpleDemo(filename: String): Any? {
    val reader = FileReader(filename)
    val jsonParser = JSONParser()
    return jsonParser.parse(reader)
}

suspend fun attachIAMRolePolicy(
    roleNameVal: String,
    policyArnVal: String,
) {
    val request =
        ListAttachedRolePoliciesRequest {
            roleName = roleNameVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.listAttachedRolePolicies(request)
        val attachedPolicies = response.attachedPolicies

        // Ensure that the policy is not attached to this role.
        val checkStatus: Int
        if (attachedPolicies != null) {
            checkStatus = checkList(attachedPolicies, policyArnVal)
            if (checkStatus == -1) {
                return
            }
        }

        val policyRequest =
            AttachRolePolicyRequest {
                roleName = roleNameVal
                policyArn = policyArnVal
            }
        iamClient.attachRolePolicy(policyRequest)
        println("Successfully attached policy $policyArnVal to role $roleNameVal")
    }
}

fun checkList(
    attachedPolicies: List<AttachedPolicy>,
    policyArnVal: String,
): Int {
    for (policy in attachedPolicies) {
        val polArn = policy.policyArn.toString()

        if (polArn.compareTo(policyArnVal) == 0) {
            println("The policy is already attached to this role.")
            return -1
        }
    }
    return 0
}

suspend fun createIAMAccessKey(user: String?): String {
    val request =
        CreateAccessKeyRequest {
            userName = user
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.createAccessKey(request)
        return response.accessKey?.accessKeyId.toString()
    }
}

suspend fun createIAMAccountAlias(alias: String) {
    val request =
        CreateAccountAliasRequest {
            accountAlias = alias
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        iamClient.createAccountAlias(request)
        println("Successfully created account alias named $alias")
    }
}

suspend fun createIAMPolicy(policyNameVal: String?): String {
    val policyDocumentVal =
        "{" +
            "  \"Version\": \"2012-10-17\"," +
            "  \"Statement\": [" +
            "    {" +
            "        \"Effect\": \"Allow\"," +
            "        \"Action\": [" +
            "            \"dynamodb:DeleteItem\"," +
            "            \"dynamodb:GetItem\"," +
            "            \"dynamodb:PutItem\"," +
            "            \"dynamodb:Scan\"," +
            "            \"dynamodb:UpdateItem\"" +
            "       ]," +
            "       \"Resource\": \"*\"" +
            "    }" +
            "   ]" +
            "}"

    val request =
        CreatePolicyRequest {
            policyName = policyNameVal
            policyDocument = policyDocumentVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.createPolicy(request)
        return response.policy?.arn.toString()
    }
}

suspend fun createIAMUser(usernameVal: String?): String? {
    val request =
        CreateUserRequest {
            userName = usernameVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.createUser(request)
        return response.user?.userName
    }
}

suspend fun deleteKey(
    userNameVal: String,
    accessKey: String,
) {
    val request =
        DeleteAccessKeyRequest {
            accessKeyId = accessKey
            userName = userNameVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        iamClient.deleteAccessKey(request)
        println("Successfully deleted access key $accessKey from $userNameVal")
    }
}

suspend fun deleteIAMAccountAlias(alias: String) {
    val request =
        DeleteAccountAliasRequest {
            accountAlias = alias
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        iamClient.deleteAccountAlias(request)
        println("Successfully deleted account alias $alias")
    }
}

suspend fun deleteIAMPolicy(policyARNVal: String?) {
    val request =
        DeletePolicyRequest {
            policyArn = policyARNVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        iamClient.deletePolicy(request)
        println("Successfully deleted $policyARNVal")
    }
}

suspend fun deleteIAMUser(userNameVal: String) {
    val request =
        DeleteUserRequest {
            userName = userNameVal
        }

    // To delete a user, ensure that the user's access keys are deleted first.
    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        iamClient.deleteUser(request)
        println("Successfully deleted user $userNameVal")
    }
}

suspend fun detachPolicy(
    roleNameVal: String,
    policyArnVal: String,
) {
    val request =
        DetachRolePolicyRequest {
            roleName = roleNameVal
            policyArn = policyArnVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        iamClient.detachRolePolicy(request)
        println("Successfully detached policy $policyArnVal from role $roleNameVal")
    }
}

suspend fun getIAMPolicy(policyArnVal: String?) {
    val request =
        GetPolicyRequest {
            policyArn = policyArnVal
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.getPolicy(request)
        println("Successfully retrieved policy ${response.policy?.policyName}")
    }
}

suspend fun listKeys(userNameVal: String?) {
    val request =
        ListAccessKeysRequest {
            userName = userNameVal
        }
    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.listAccessKeys(request)
        response.accessKeyMetadata?.forEach { md ->
            println("Retrieved access key ${md.accessKeyId}")
        }
    }
}

suspend fun listAliases() {
    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.listAccountAliases(ListAccountAliasesRequest {})
        response.accountAliases?.forEach { alias ->
            println("Retrieved account alias $alias")
        }
    }
}

suspend fun listAllUsers() {
    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        val response = iamClient.listUsers(ListUsersRequest { })
        response.users?.forEach { user ->
            println("Retrieved user ${user.userName}")
            val permissionsBoundary = user.permissionsBoundary
            if (permissionsBoundary != null) {
                println("Permissions boundary details ${permissionsBoundary.permissionsBoundaryType}")
            }
        }
    }
}

suspend fun updateIAMUser(
    curName: String?,
    newName: String?,
) {
    val request =
        UpdateUserRequest {
            userName = curName
            newUserName = newName
        }

    IamClient { region = "AWS_GLOBAL" }.use { iamClient ->
        iamClient.updateUser(request)
        println("Successfully updated user to $newName")
    }
}