Proces Controller Object

src/main/java/JobServ/JobServClient.java

@@ -51,7 +51,7 @@ public class JobServClient {
      * Spawns a new blockingStub for network operations with the server
      */
     public JobServClient(ManagedChannel channel) {
-	this.channel = channel;
+        this.channel = channel;
         blockingStub = ShellServerGrpc.newBlockingStub(this.channel);
     }
 
@@ -146,8 +146,8 @@ public class JobServClient {
     /*
      * sends PID to server
      * returns process exit code
-     * returns a 0-255 return code or 277 if still running
-     * or 278 if error in API
+     * returns a 0-255 return code or 256 if still running
+     * or 257 if error in API
      */
     public int getProcessReturn(int pid) {
         logger.info("[+] Requesting return code of a job");
@@ -162,7 +162,7 @@ public class JobServClient {
             response = blockingStub.getReturn(request);
         } catch (StatusRuntimeException e) {
             logger.log(Level.WARNING, "(API Failure) Failed to get return code: " + e.getStatus());
-            return 278;
+            return 257;
         }
 
         return response.getProcessReturnCode();
@@ -211,14 +211,13 @@ public class JobServClient {
 
         JobServClient client;
         try {
-	    SslContextBuilder builder = GrpcSslContexts.forClient();
-	    builder.trustManager(new File(args[2]));
-	    builder.keyManager(new File(args[1]), new File(args[0]));
+            SslContextBuilder builder = GrpcSslContexts.forClient();
+            builder.trustManager(new File(args[2]));
+            builder.keyManager(new File(args[1]), new File(args[0]));
 
-	    ManagedChannel channel = NettyChannelBuilder.forAddress(args[3], Integer.parseInt(args[4]))
-		.sslContext(builder.build())
-		.build();
-	    
+            ManagedChannel channel = NettyChannelBuilder.forAddress(args[3], Integer.parseInt(args[4]))
+                .sslContext(builder.build())
+                .build();
             client = new JobServClient(channel);
 
         // Likely bad port
@@ -226,7 +225,7 @@ public class JobServClient {
             System.out.println("Invalid Port");
             return;
 
-	// bad cert or key format
+        // bad cert or key format
         } catch (SSLException e) {
             System.out.println(e.getMessage());
             return;
@@ -253,19 +252,19 @@ public class JobServClient {
 
             case "output":
                 candidatePid = getPidArg(args, 6);
-		if (candidatePid < 0) {
-		    break;
-		}
+                if (candidatePid < 0) {
+                    break;
+                }
 
                 String processOutput = client.getProcessOutput(candidatePid);
                 System.out.println(processOutput);
                 break;
-
+                
             case "status":
                 candidatePid = getPidArg(args, 6);
-		if (candidatePid < 0) {
-		    break;
-		}
+                if (candidatePid < 0) {
+                    break;
+                }
 
                 Boolean processStatus = client.getProcessStatus(candidatePid);
                 System.out.printf("Process is currently running? %b\n", processStatus);
@@ -273,9 +272,9 @@ public class JobServClient {
 
             case "kill":
                 candidatePid = getPidArg(args, 6);
-		if (candidatePid < 0) {
-		    break;
-		}
+                if (candidatePid < 0) {
+                    break;
+                }
 
                 client.killProcess(candidatePid);
                 System.out.println("End process request recieved!");
@@ -283,9 +282,9 @@ public class JobServClient {
 
             case "return":
                 candidatePid = getPidArg(args, 6);
-		if (candidatePid < 0) {
-		    break;
-		}
+                if (candidatePid < 0) {
+                    break;
+                }
 
                 int returnCode = client.getProcessReturn(candidatePid);
 
@@ -314,15 +313,15 @@ public class JobServClient {
      * returns -1 (an invalid PID) if bad index or unparsable int
      */
     private static int getPidArg(String[] args, int index) {
-	if (args.length < index) {
-	    System.out.println("Improper formatting, try client --help");
-	    return -1;
-	}
+        if (args.length < index) {
+            System.out.println("Improper formatting, try client --help");
+            return -1;
+        }
 
         try {
             return Integer.parseInt(args[6]);
-	    
-	} catch (InputMismatchException e) {
+            
+        } catch (InputMismatchException e) {
             System.out.println(args[6] + " is not a valid int, much less a valid pid");
             return -1;
         }

src/main/java/JobServ/ProcessController.java

@@ -0,0 +1,101 @@
+/*
+ * ProcessController
+ *
+ * v1.0
+ *
+ * May 22, 2019
+ */
+
+package JobServ;
+
+/*
+ * ProcessController
+ * This class wraps a java Process object with metadata
+ * such as translated PID that exist for this specific API
+ * as well as general metadata like IO streams.
+ */
+class ProcessController {
+    // incremented in constructor
+    private static int nextPid = 0;
+    private int pid;
+
+    // TODO: add an api endpoint for streaming client input into
+    // interactive processes (out of scope for initial API)
+    private OutputStream output;
+    private InputStream input;
+    private Scanner outputScanner;
+
+    private Process process;
+
+    /*
+     * Constructor
+     * Takes a command and spawns it in a new process
+     * Redirects IO streams and assigns a fake PID
+     */
+    public ProcessController(String command) throws IOException {
+        this.pid = ProcessController.nextPid;
+        ProcessController.nextPid += 1;
+
+        this.process = Runtime.exec(command);
+        this.output = this.process.getOutputStream();
+        this.input = this.process.getInputStream();
+        this.outputScanner = new Scanner(this.input);
+        this.outputScanner.useDelimieter("\\A");
+    }
+
+    /*
+     * getStatus()
+     * returns whether or not the process is running
+     * this isnt a very direct way of getting the information
+     * The alternative is to use reflection to get into the private UNIXProcess class
+     * for the PID and to check that against 'ps' or a similar command
+     *
+     * TODO: (for future release) return thread state
+     */
+    public Boolean getStatus() {
+        try {
+            process.exitValue();
+            return true;
+        } catch (IllegalThreadStateException e) {
+            return false;
+        }
+    }
+
+    /*
+     * getReturn()
+     * returns the exit code of the process
+     * or 256 if process is still running
+     * (unix/posix defines an exit code as a uint8, so 256 is fair game)
+     */
+    public int getReturn() {
+        try {
+            return process.exitValue();
+        } catch (IllegalThreadStateException e) {
+            return 256;
+        }
+    }
+
+    /*
+     * getOutput()
+     * gets new output from stream
+     * (TODO: investigate whether this would better be done by )
+     */
+    public String getOutput() {
+        String out = "";
+        while(scanner.hasNext()) {
+            out += scanner.next();
+        }
+
+        return out;
+    }
+
+    /*
+     * kill()
+     * Cleans up resources and destroys process
+     */
+    public void kill() {
+        this.input.close();
+        this.output.close();
+        process.destroy();
+    }
+}