repository_ctx.execute: execute from the external repository root and allow to override the environment variables.

Fixes #1130
Fixes #1242

--
MOS_MIGRATED_REVID=124118789

2 files changed, 77 insertions, 10 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
index b4181aa449..ad2e7b60a8 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
@@ -13,6 +13,7 @@
 // limitations under the License.
 package com.google.devtools.build.lib.bazel.repository.skylark;
 
+import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.shell.BadExitStatusException;
 import com.google.devtools.build.lib.shell.Command;
@@ -23,9 +24,11 @@ import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.util.Preconditions;
 
+import java.io.File;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
 /**
  * A structure callable from Skylark that stores the result of repository_ctx.execute() method. It
@@ -89,9 +92,12 @@ final class SkylarkExecutionResult {
 
   /**
    * Returns a Builder that can be used to execute a command and build an execution result.
+   *
+   * @param environment pass through the list of environment variables from the client to be passed
+   * to the execution environment.
    */
-  public static Builder builder() {
-    return new Builder();
+  public static Builder builder(Map<String, String> environment) {
+    return new Builder(environment);
   }
 
   /**
@@ -100,9 +106,15 @@ final class SkylarkExecutionResult {
   static final class Builder {
 
     private final List<String> args = new ArrayList<>();
+    private File directory = null;
+    private final ImmutableMap.Builder<String, String> envBuilder = ImmutableMap.builder();
     private long timeout = -1;
     private boolean executed = false;
 
+    private Builder(Map<String, String> environment) {
+      envBuilder.putAll(environment);
+    }
+
     /**
      * Adds arguments to the list of arguments to pass to the command. The first argument is
      * expected to be the binary to execute. The subsequent arguments are the arguments passed
@@ -125,6 +137,25 @@ final class SkylarkExecutionResult {
     }
 
     /**
+     * Set the path to the directory to execute the result process. This method must be called
+     * before calling {@link #execute()}.
+     */
+    Builder setDirectory(File path) throws EvalException {
+      this.directory = path;
+      return this;
+    }
+
+    /**
+     * Add an environment variables to be added to the list of environment variables. For all
+     * key <code>k</code> of <code>variables</code>, the resulting process will have the variable
+     * <code>k=variables.get(k)</code> defined.
+     */
+    Builder addEnvironmentVariables(Map<String, String> variables) {
+      this.envBuilder.putAll(variables);
+      return this;
+    }
+
+    /**
      * Sets the timeout, in milliseconds, after which the executed command will be terminated.
      */
     Builder setTimeout(long timeout) {
@@ -140,6 +171,7 @@ final class SkylarkExecutionResult {
       Preconditions.checkArgument(timeout > 0, "Timeout must be set prior to calling execute().");
       Preconditions.checkArgument(!args.isEmpty(), "No command specified.");
       Preconditions.checkState(!executed, "Command was already executed, cannot re-use builder.");
+      Preconditions.checkNotNull(directory, "Directory must be set before calling execute().");
       executed = true;
 
       try {
@@ -147,7 +179,8 @@ final class SkylarkExecutionResult {
         for (int i = 0; i < args.size(); i++) {
           argsArray[i] = args.get(i);
         }
-        CommandResult result = new Command(argsArray).execute(new byte[]{}, timeout, false);
+        Command command = new Command(argsArray, envBuilder.build(), directory);
+        CommandResult result = command.execute(new byte[]{}, timeout, false);
         return new SkylarkExecutionResult(result);
       } catch (BadExitStatusException e) {
         return new SkylarkExecutionResult(e.getResult());
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java
index e4dd0293c8..35b4e71556 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryContext.java
@@ -293,23 +293,57 @@ public class SkylarkRepositoryContext {
     return osObject;
   }
 
+  private void createOutputDirectory() throws RepositoryFunctionException {
+    try {
+      if (!outputDirectory.exists()) {
+        makeDirectories(outputDirectory);
+        outputDirectory.createDirectory();
+      }
+    } catch (IOException e) {
+      throw new RepositoryFunctionException(e, Transience.TRANSIENT);
+    }
+  }
+
   @SkylarkCallable(
     name = "execute",
     doc =
         "Executes the command given by the list of arguments. The execution time of the command"
             + " is limited by <code>timeout</code> (in seconds, default 600 seconds). This method"
             + " returns an <code>exec_result</code> structure containing the output of the"
-            + " command."
+            + " command. The <code>environment</code> map can be used to override some environment"
+            + " variables to be passed to the process."
   )
-  public SkylarkExecutionResult execute(List<Object> arguments, long timeout) throws EvalException {
-    return SkylarkExecutionResult.builder()
-        .addArguments(arguments).setTimeout(timeout / 1000).execute();
+  public SkylarkExecutionResult execute(List<Object> arguments, Integer timeout,
+      Map<String, String> environment) throws EvalException, RepositoryFunctionException {
+    createOutputDirectory();
+    return SkylarkExecutionResult.builder(osObject.getEnvironmentVariables())
+        .addArguments(arguments)
+        .setDirectory(outputDirectory.getPathFile())
+        .addEnvironmentVariables(environment)
+        .setTimeout(timeout.longValue() * 1000)
+        .execute();
+  }
+
+  @SkylarkCallable(name = "execute", documented = false)
+  public SkylarkExecutionResult execute(List<Object> arguments)
+      throws EvalException, RepositoryFunctionException {
+    createOutputDirectory();
+    return SkylarkExecutionResult.builder(osObject.getEnvironmentVariables())
+        .setDirectory(outputDirectory.getPathFile())
+        .addArguments(arguments)
+        .setTimeout(600000)
+        .execute();
   }
 
   @SkylarkCallable(name = "execute", documented = false)
-  public SkylarkExecutionResult execute(List<Object> arguments) throws EvalException {
-    return SkylarkExecutionResult.builder()
-        .addArguments(arguments).setTimeout(600000).execute();
+  public SkylarkExecutionResult execute(List<Object> arguments, Integer timeout)
+      throws EvalException, RepositoryFunctionException {
+    createOutputDirectory();
+    return SkylarkExecutionResult.builder(osObject.getEnvironmentVariables())
+        .setDirectory(outputDirectory.getPathFile())
+        .addArguments(arguments)
+        .setTimeout(timeout.longValue() * 1000)
+        .execute();
   }
 
   @SkylarkCallable(