Merge pull request #4926 from vespa-engine/hakonhall/amend-program-output-parse-exceptions-with-command-and-output-snippet

Amend program output parse exceptions with command and output snippet

6 files changed, 97 insertions, 3 deletions

diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/ChildProcessException.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/ChildProcessException.java
index b84bd2d8fef..9f7aaab2060 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/ChildProcessException.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/ChildProcessException.java
@@ -26,13 +26,26 @@ public abstract class ChildProcessException extends RuntimeException {
      * @param possiblyHugeOutput The output of the command
      */
     protected ChildProcessException(String problem, String commandLine, String possiblyHugeOutput) {
-        super(makeSnippet(
+        super(makeSnippet(problem, commandLine, possiblyHugeOutput));
+    }
+
+    protected ChildProcessException(RuntimeException cause,
+                                    String problem,
+                                    String commandLine,
+                                    String possiblyHugeOutput) {
+        super(makeSnippet(problem, commandLine, possiblyHugeOutput), cause);
+    }
+
+    private static String makeSnippet(String problem,
+                               String commandLine,
+                               String possiblyHugeOutput) {
+        return makeSnippet(
                 problem,
                 commandLine,
                 possiblyHugeOutput,
                 MAX_OUTPUT_PREFIX,
                 MAX_OUTPUT_SUFFIX,
-                MAX_OUTPUT_SLACK));
+                MAX_OUTPUT_SLACK);
     }
 
     // Package-private instead of private for testing.
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLine.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLine.java
index 6c4de7ac1e3..9a8ed19e0ac 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLine.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLine.java
@@ -9,6 +9,7 @@ import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.function.Predicate;
@@ -66,11 +67,16 @@ public class CommandLine {
     public CommandLine add(String... arguments) { return add(Arrays.asList(arguments)); }
 
     /** Add arguments to the command. The first argument in the first call to add() is the program. */
-    public CommandLine add(List<String> arguments) {
+    public CommandLine add(Collection<String> arguments) {
         this.arguments.addAll(arguments);
         return this;
     }
 
+    /** Add arguments by splitting arguments by space. */
+    public CommandLine addTokens(String arguments) {
+        return add(arguments.split(" "));
+    }
+
     /**
      * Execute a shell-like program in a child process:
      *  - the program is recorded and logged as modifying the system, but see executeSilently().
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandResult.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandResult.java
index 12f0d546b36..e0e84242f78 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandResult.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandResult.java
@@ -3,6 +3,7 @@
 package com.yahoo.vespa.hosted.node.admin.task.util.process;
 
 import java.util.List;
+import java.util.function.Function;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -39,6 +40,7 @@ public class CommandResult {
         return getOutputLinesStream().collect(Collectors.toList());
     }
 
+    /** Returns the output lines as a stream, omitting trailing empty lines. */
     public Stream<String> getOutputLinesStream() {
         if (output.isEmpty()) {
             // For some reason an empty string => one-element list.
@@ -50,6 +52,36 @@ public class CommandResult {
     }
 
     /**
+     * Map this CommandResult to an instance of type R.
+     *
+     * If a RuntimeException is thrown by the mapper, it is wrapped in an
+     * UnexpectedOutputException2 that includes a snippet of the output in the message.
+     *
+     * This method is intended to be used as part of the verification of the output.
+     */
+    public <R> R map(Function<CommandResult, R> mapper) {
+        try {
+            return mapper.apply(this);
+        } catch (RuntimeException e) {
+            throw new UnexpectedOutputException2(e, "Failed to map output", commandLine.toString(), output);
+        }
+    }
+
+    /**
+     * Map the output to an instance of type R according to mapper, wrapping any
+     * RuntimeException in UnexpectedOutputException2 w/output snippet. See map() for details.
+     */
+    public <R> R mapOutput(Function<String, R> mapper) { return map(result -> mapper.apply(result.getOutput())); }
+
+    /**
+     * Map each output line to an instance of type R according to mapper, wrapping any
+     * RuntimeException in UnexpectedOutputException2 w/output snippet. See map() for details.
+     */
+    public <R> List<R> mapEachLine(Function<String, R> mapper) {
+        return map(result -> result.getOutputLinesStream().map(mapper).collect(Collectors.toList()));
+    }
+
+    /**
      * Convenience method for getting the CommandLine, whose execution resulted in
      * this CommandResult instance.
      *
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/TerminalImpl.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/TerminalImpl.java
index 422584b8ccd..8ec0d267f0d 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/TerminalImpl.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/TerminalImpl.java
@@ -19,6 +19,7 @@ public class TerminalImpl implements Terminal {
         this.processFactory = processFactory;
     }
 
+    @Override
     public CommandLine newCommandLine(TaskContext taskContext) {
         return new CommandLine(taskContext, processFactory);
     }
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/UnexpectedOutputException2.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/UnexpectedOutputException2.java
index e786452c0ef..82fae1aa70e 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/UnexpectedOutputException2.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/process/UnexpectedOutputException2.java
@@ -13,4 +13,14 @@ public class UnexpectedOutputException2 extends ChildProcessException {
     public UnexpectedOutputException2(String problem, String commandLine, String possiblyHugeOutput) {
         super("output was not of the expected format: " + problem, commandLine, possiblyHugeOutput);
     }
+
+    /**
+     * @param problem Problem description, e.g. "Output is not of the form ^NAME=VALUE$"
+     */
+    public UnexpectedOutputException2(RuntimeException cause,
+                                      String problem,
+                                      String commandLine,
+                                      String possiblyHugeOutput) {
+        super(cause, "output was not of the expected format: " + problem, commandLine, possiblyHugeOutput);
+    }
 }
diff --git a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLineTest.java b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLineTest.java
index dd6d9c8226d..397380461d6 100644
--- a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLineTest.java
+++ b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/process/CommandLineTest.java
@@ -49,6 +49,9 @@ public class CommandLineTest {
         List<CommandLine> commandLines = terminal.getTestProcessFactory().getMutableCommandLines();
         assertEquals(1, commandLines.size());
         assertTrue(commandLine == commandLines.get(0));
+
+        int lines = result.map(r -> r.getOutputLines().size());
+        assertEquals(2, lines);
     }
 
     @Test
@@ -112,4 +115,33 @@ public class CommandLineTest {
                     e.getMessage());
         }
     }
+
+    @Test
+    public void mapException() {
+        terminal.ignoreCommand("output");
+        CommandResult result = terminal.newCommandLine(context).add("program").execute();
+        IllegalArgumentException exception = new IllegalArgumentException("foo");
+        try {
+            result.mapOutput(output -> { throw exception; });
+            fail();
+        } catch (UnexpectedOutputException2 e) {
+            assertEquals("Command 'program 2>&1' output was not of the expected format: " +
+                    "Failed to map output: stdout/stderr: 'output'", e.getMessage());
+            assertTrue(e.getCause() == exception);
+        }
+    }
+
+    @Test
+    public void testMapEachLine() {
+        assertEquals(
+                1 + 2 + 3,
+                terminal.ignoreCommand("1\n2\n3\n")
+                        .newCommandLine(context)
+                        .add("foo")
+                        .execute()
+                        .mapEachLine(Integer::valueOf)
+                        .stream()
+                        .mapToInt(i -> i)
+                        .sum());
+    }
 }
\ No newline at end of file