Add customized path mounting in Bazel sandbox.

RELNOTES: New flag --sandbox_add_mount_pair to specify customized source:target path pairs to bind mount inside the sandbox.

--
Change-Id: Ifbacfc0e16bbaedcf5b6d3937799710f2cfa3d58
Reviewed-on: https://cr.bazel.build/7150
PiperOrigin-RevId: 142542381
MOS_MIGRATED_REVID=142542381

1 files changed, 12 insertions, 5 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxRunner.java b/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxRunner.java
index da50cda15a..97151e24ce 100644
--- a/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxRunner.java
+++ b/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxRunner.java
@@ -45,7 +45,8 @@ final class LinuxSandboxRunner extends SandboxRunner {
   private final Set<Path> writableDirs;
   private final Set<Path> inaccessiblePaths;
   private final Set<Path> tmpfsPaths;
-  private final Set<Path> bindMounts;
+  // a <target, source> mapping of paths to bind mount
+  private final Map<Path, Path> bindMounts;
   private final boolean sandboxDebug;
 
   LinuxSandboxRunner(
@@ -56,7 +57,7 @@ final class LinuxSandboxRunner extends SandboxRunner {
       Set<Path> writableDirs,
       Set<Path> inaccessiblePaths,
       Set<Path> tmpfsPaths,
-      Set<Path> bindMounts,
+      Map<Path, Path> bindMounts,
       boolean verboseFailures,
       boolean sandboxDebug) {
     super(sandboxExecRoot, verboseFailures);
@@ -155,9 +156,15 @@ final class LinuxSandboxRunner extends SandboxRunner {
       fileArgs.add(tmpfsPath.getPathString());
     }
 
-    for (Path bindMount : bindMounts) {
-      fileArgs.add("-b");
-      fileArgs.add(bindMount.getPathString());
+    for (ImmutableMap.Entry<Path, Path> bindMount : bindMounts.entrySet()) {
+      fileArgs.add("-M");
+      fileArgs.add(bindMount.getValue().getPathString());
+
+      // The file is mounted in a custom location inside the sandbox.
+      if (!bindMount.getKey().equals(bindMount.getValue())) {
+        fileArgs.add("-m");
+        fileArgs.add(bindMount.getKey().getPathString());
+      }
     }
 
     if (!allowNetwork) {