Add gateway to app server component checking

lib/plugin-loader.js

@@ -53,6 +53,8 @@ const APP_SERVER_COMP_ID = 'app-server';
 
 const AGENT_COMP_ID = 'zss';
 
+const APIML_GATEWAY_COMP_ID = 'gateway';
+
 const compsToCheck = {
   [APP_SERVER_COMP_ID]: {
     name: "App server",
@@ -72,6 +74,15 @@ const compsToCheck = {
     cpu: true,
     version: true,
     endpoints: true
+  },
+  [APIML_GATEWAY_COMP_ID]: {
+    name: "Gateway", 
+    id: APIML_GATEWAY_COMP_ID,
+
+    os: true,
+    cpu: false,
+    version: true,
+    endpoints: false
   }
 };
 
@@ -883,6 +894,7 @@ PluginLoader.prototype = {
     return new Promise((complete, fail)=> {
       let appServerComp = {};
       let agentComp = {};
+      let gatewayComp = {};
       const requestOptions = zluxUtil.getAgentRequestOptions(config, this.tlsOptions, false);
 
       appServerComp.os = process.platform; // Operating system
@@ -928,9 +940,9 @@ PluginLoader.prototype = {
             resolve();
           });
 
-        }).then(() => { /* Obtains and stores the endpoints exposed by the agent */
+        }).then(() => {
           requestOptions.path = '/server/agent/services';
-          return new Promise((resolve, reject) => { 
+          return new Promise((resolve, reject) => {
             httpApi.get(requestOptions, (res) => {
               const { statusCode } = res; // TODO: Check status code for bad status
               const contentType = res.headers['content-type'];
@@ -959,12 +971,64 @@ PluginLoader.prototype = {
               bootstrapLogger.severe(e.message);
               resolve(); // We don't want to reject here. Error gets caught down stream
             });
-          }).then(() => {
+          })
+        }).then(() => { /* Obtains and stores the endpoints exposed by the agent */
+          requestOptions.path = '/application/info';
+          if(config.node.mediationLayer &&
+            config.node.mediationLayer.enabled &&
+            config.node.mediationLayer.server){
+              requestOptions.host = config.node.mediationLayer.server.gatewayHostname
+              requestOptions.port = config.node.mediationLayer.server.gatewayPort
+          }
+          let timer = process.env.APIML_GATEWAY_TIMEOUT_MILLIS || 600000;
+          const GATEWAY_CHECK_RECONNECT_DELAY = 10000;
+          const end = Date.now() + GATEWAY_TIMEOUT_MILLIS;
+          return new Promise((resolve, reject) => {
+
+            const gatewayCheck = () => {
+              if (Date.now() > end) {
+                log.warn(`ZWED0045`, this.apimlHost, this.apimlPort);
+                return reject(new Error(`Call timeout when fetching gateway status from APIML`));
+              }
+
+              let req = httpApi.request(requestOptions, (res) => {
+                res.setEncoding('utf8');
+                let rawData = '';
+                res.on('data', (chunk) => { rawData += chunk; });
+                res.on('end', () => {
+                  try {
+                    const parsedData = JSON.parse(rawData);
+                    if (parsedData.build) {
+                      gatewayComp.os = parsedData.build.operatingSystem;
+                      gatewayComp.version = parsedData.build.version;
+                    } else {
+                      setTimeout(gatewayCheck, GATEWAY_CHECK_RECONNECT_DELAY);
+                    }
+                    resolve();
+                  } catch (e) {
+                    bootstrapLogger.severe(e.message);
+                    resolve(); // We don't want to reject here. Error gets caught down stream
+                  }
+                });
+              }).on('error', (e) => {
+                bootstrapLogger.severe(e.message);
+                setTimeout(gatewayCheck, GATEWAY_CHECK_RECONNECT_DELAY);
+                resolve(); // We don't want to reject here. Error gets caught down stream
+              });
+              req.setTimeout(timer, () => {
+                reject(new Error(`Call timeout when fetching gateway status from APIML`));
+              })
+              req.end();
+          } 
+          gatewayCheck();
+        })
+          .then(() => {
             /* TODO: before checking if dependencies are met, we must learn about the components that exist. doing this is not formalized
                currently, so we currently have a block per component to learn about their capabilities, version, environment, etc. perhaps in the 
                future zowe components could have metadata files and/or expected URLs for querying.*/
             envComps[AGENT_COMP_ID] = agentComp;
             envComps[APP_SERVER_COMP_ID] = appServerComp;
+            envComps[APIML_GATEWAY_COMP_ID] = gatewayComp;
             complete();
           }).catch((e)=> {fail(e);});
         }).catch((e)=>{fail(e);});