Add Amazon SQS Connector

.gitignore

@@ -21,3 +21,6 @@
 
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
+
+target/
+ballerina.conf

Ballerina.toml

@@ -0,0 +1,8 @@
+[project]
+org-name = "wso2"
+version = "0.1.4"
+authors = ["WSO2"]
+keywords = ["amazon", "sqs", "mq"]
+repository = "https://github.com/wso2-ballerina/module-amazonsqs"
+license = "Apache-2.0"
+

amazonsqs/Module.md

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+Connects to Amazon SQS service.
+
+# Module Overview
+
+## Compatibility
+| Ballerina Language Version 
+| -------------------------- 
+| 0.990.3                    
+
+## Sample
+
+```ballerina
+import ballerina/config;
+import ballerina/io;
+import wso2/amazonrekn;
+import wso2/amazoncommons;
+
+amazonsqs:Configuration configuration = {
+    accessKey: config:getAsString("ACCESS_KEY_ID"),
+    secretKey: config:getAsString("SECRET_ACCESS_KEY"),
+    region: config:getAsString("REGION"),
+    accountNumber: config:getAsString("ACCOUNT_NUMBER")
+};
+
+amazonsqs:Client sqsClient = new(config);
+
+public function main() {
+    map<string> attributes = {};
+    attributes["VisibilityTimeout"] = "400";
+    attributes["FifoQueue"] = "true";
+
+    string|error response = sqsClient->createQueue("demo.fifo", attributes);
+    if(response is string && response.hasPrefix("http")) {
+        log:printInfo("Created queue: \n" + response);
+    }
+}
+```

amazonsqs/amazonsqs_connector.bal

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+// Copyright (c) 2019 WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+//
+// WSO2 Inc. licenses this file to you under the Apache License,
+// Version 2.0 (the "License"); you may not use this file except
+// in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import ballerina/crypto;
+import ballerina/encoding;
+import ballerina/http;
+import ballerina/internal;
+import ballerina/io;
+import ballerina/system;
+import ballerina/time;
+import wso2/amazoncommons;
+import ballerina/log;
+
+
+# Object to initialize the connection with Amazon SQS.
+#
+# + accessKey - The Amazon API access key
+# + secretKey - The Amazon API secret key
+# + region - The Amazon API Region
+# + acctNum - The account number of the SQS service
+public type Client client object {
+
+    http:Client clientEp;
+    string accessKey;
+    string secretKey;
+    string region;
+    string acctNum;
+    string host;
+
+    public function __init(Configuration config) {
+        self.accessKey = config.accessKey;
+        self.secretKey = config.secretKey;
+        self.acctNum = config.accountNumber;
+        self.region = config.region;
+        self.host = SQS_SERVICE_NAME + "." + self.region + "." + AMAZON_HOST;
+        self.clientEp = new("https://" + self.host);
+    }
+
+    public remote function createQueue(string queueName, map<string> attributes) returns string|error;
+
+    public remote function sendMessage(string messageBody, string queueResourcePath, map<string> attributes) 
+        returns OutboundMessage|error;
+
+    public remote function receiveMessage(string queueResourcePath, map<string> attributes) 
+        returns InboundMessage[]|error;
+
+    public remote function deleteMessage(string queueResourcePath, string receiptHandle) returns boolean|error;
+
+};
+
+# Creates a new queue in SQS
+#
+# + queueName - Name of the queue to be created 
+# + attributes - Other attribute parameters 
+# + return - If success, URL of the created queue, else returns error
+public remote function Client.createQueue(string queueName, map<string> attributes) returns string|error{
+
+    string amzTarget = "AmazonSQSv20121105.CreateQueue";
+    string endpoint = "/";
+    string payload =  "";
+    payload = payload + "Action=CreateQueue";
+    payload = payload + "&Version=2012-11-05";
+    payload = payload + "&QueueName=" + queueName;
+    int attributeNumber = 1;
+    foreach var (k, v) in attributes {
+        payload = payload + "&Attribute." + attributeNumber + ".Name=" + k;
+        payload = payload + "&Attribute." + attributeNumber + ".Value=" + v;
+        attributeNumber = attributeNumber + 1;
+    }
+
+    http:Request request = check generatePOSTRequest(self.accessKey, self.secretKey, self.host, amzTarget, 
+        endpoint, self.region, payload);
+    var httpResponse = self.clientEp->post(endpoint, request);
+    json|error response = handleResponse(httpResponse);
+    if(response is json){
+        return jsonToCreatedQueueUrl(response);
+    } else {
+        return response;
+    }
+
+}
+
+# Send a new message to a SQS queue
+#
+# + messageBody - Message body string to be sent 
+# + queueResourcePath - Resource path to the queue from the host address. e.g.: /610968236798/myQueue.fifo
+# + attributes - Non-mandatory parameters for sending a message 
+# + return - If success, details of the sent message, else returns error
+public remote function Client.sendMessage(string messageBody, string queueResourcePath, map<string> attributes) 
+    returns OutboundMessage|error {
+
+    string amzTarget = "AmazonSQSv20121105.SendMessage";
+    string payload =  "";
+    payload = payload + "Action=SendMessage";
+    payload = payload + "&MessageBody=" + check http:encode(messageBody, "UTF-8");
+
+    int attributeNumber = 1;
+    foreach var (k, v) in attributes {
+        payload = payload + "&" + k + "=" + v;
+        attributeNumber = attributeNumber + 1;
+    }
+
+    http:Request request = check generatePOSTRequest(self.accessKey, self.secretKey, self.host, amzTarget, 
+        queueResourcePath, self.region, payload);
+    var httpResponse = self.clientEp->post(queueResourcePath, request);
+    json|error response = handleResponse(httpResponse);
+    if(response is json){
+        return jsonToOutboundMessage(response);
+    } else {
+        return response;
+    }
+
+}
+
+# Receive the message(s) from the queue
+#
+# + queueResourcePath - Resource path to the queue from the host address. e.g.: /610968236798/myQueue.fifo 
+# + attributes - Non-mandatory parameters for receiving a message
+# + return - If success, details of the received message, else returns error
+public remote function Client.receiveMessage(string queueResourcePath, map<string> attributes) 
+    returns InboundMessage[]|error {
+
+    string amzTarget = "AmazonSQSv20121105.ReceiveMessage";
+    string payload =  "";
+    payload = payload + "&Action=ReceiveMessage";
+    int attributeNumber = 1;
+    foreach var (k, v) in attributes {
+        payload = payload + "&" + k + "=" + v;
+        attributeNumber = attributeNumber + 1;
+    }
+
+    http:Request request = check generatePOSTRequest(self.accessKey, self.secretKey, self.host, amzTarget, 
+        queueResourcePath, self.region, payload);
+    var httpResponse = self.clientEp->post(queueResourcePath, request);
+    json|error response = handleResponse(httpResponse);
+    if(response is json){
+        return jsonToInboundMessages(response);
+    } else {
+        return response;
+    }
+
+}
+
+# Delete the message(s) from the queue for the given receiptHandle
+#
+# + queueResourcePath - Resource path to the queue from the host address. e.g.: /610968236798/myQueue.fifo
+# + receiptHandle - Receipt Handle parameter for the message(s) to be deleted
+# + return - Whether the message(s) were successfully deleted or whether an error occurred
+public remote function Client.deleteMessage(string queueResourcePath, string receiptHandle) returns boolean|error {
+
+    string amzTarget = "AmazonSQSv20121105.DeleteMessage";
+    string receiptHandleEncoded = check http:encode(receiptHandle, "UTF-8");
+    string payload =  "";
+    payload = payload + "Action=DeleteMessage";
+    payload = payload + "&ReceiptHandle=" + receiptHandleEncoded;
+
+    http:Request request = check generatePOSTRequest(self.accessKey, self.secretKey, self.host, 
+        amzTarget, queueResourcePath, self.region, payload);
+    var httpResponse = self.clientEp->post(queueResourcePath, request);
+    json|error response = handleResponse(httpResponse);
+    if (response is json) {
+        if (response.DeleteMessageResponse != null) {
+            return true;
+        } else {
+            return false;
+        }
+    } else {
+        return response;
+    }
+
+}
+
+# Configuration provided for the client
+#
+# + accessKey - accessKey of Amazon Account 
+# + secretKey - secretKey of Amazon Account
+# + region - region of SQS Queue
+# + accountNumber - account number of the SQS queue
+public type Configuration record {
+    string accessKey;
+    string secretKey;
+    string region;
+    string accountNumber;
+};

amazonsqs/amazonsqs_constants.bal

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+// Copyright (c) 2019 WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+//
+// WSO2 Inc. licenses this file to you under the Apache License,
+// Version 2.0 (the "License"); you may not use this file except
+// in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+const SQS_SERVICE_NAME = "sqs";
+const SQS_CONTENT_TYPE = "application/x-www-form-urlencoded";
+
+const HOST = "Host";
+const X_AMZ_CONTENT_SHA256 = "X-Amz-Content-Sha256";
+const UNSIGNED_PAYLOAD = "UNSIGNED-PAYLOAD";
+const AMAZONSQS_ERROR_CODE = "(wso2/amazonsqs)AmazonsqsError";
+const AMAZON_HOST = "amazonaws.com";
+
+const ISO8601_BASIC_DATE_FORMAT = "yyyyMMdd'T'HHmmss'Z'";
+const SHORT_DATE_FORMAT = "yyyyMMdd";
+const X_AMZ_DATE = "X-Amz-Date";
+const X_AMZ_SECURITY_TOKEN = "X-Amz-Security-Token";
+const UTF_8 = "UTF-8";
+const CONTENT_TYPE = "Content-Type";
+const AWS4_HMAC_SHA256 = "AWS4-HMAC-SHA256";
+const SERVICE_NAME = "sqs";
+const TERMINATION_STRING = "aws4_request";
+const AWS4 = "AWS4";
+const CREDENTIAL = "Credential";
+const SIGNED_HEADER = " SignedHeaders";
+const SIGNATURE = " Signature";
+const AUTHORIZATION = "Authorization";
+const PUT = "PUT";
+const POST = "POST";
+const GET = "GET";
+
+const string STATUS_CODE = "status code";
+const string COLON_SYMBOL = ":";
+const string SEMICOLON_SYMBOL = ";";
+const string WHITE_SPACE = " ";
+const string MESSAGE = "message";
+const string NEW_LINE = "\n";
+const string ERROR = "error";
+
+const string EMPTY_STRING = "";