child_process: Add gid/uid flags to spawn config

This is mostly working, but not completely ideal for two reasons.

1. Rather than emitting an error on the ChildProcess object when the
setgid/setuid fails, it is simply printing the error to stderr and
exiting.  The same happens with the cwd, so that's not completely
terrible.

2. I don't have a good test for this.  It fails with an EPERM if you try
to change the uid or gid as a non-root user.

1 files changed, 41 insertions, 0 deletions

diff --git a/test/disabled/test-child-process-uid-gid.js b/test/disabled/test-child-process-uid-gid.js
new file mode 100644
index 0000000000..71513c0e0e
--- /dev/null
+++ b/test/disabled/test-child-process-uid-gid.js
@@ -0,0 +1,41 @@
+// must be run as sudo, otherwise the gid/uid setting will fail.
+var child_process = require("child_process"),
+    constants = require("constants"),
+    passwd = require("fs").readFileSync("/etc/passwd", "utf8"),
+    myUid = process.getuid(),
+    myGid = process.getgid();
+
+// get a different user.
+// don't care who it is, as long as it's not root
+passwd = passwd.trim().split(/\n/);
+for (var i = 0, l = passwd.length; i < l; i ++) {
+  if (passwd[i].charAt(0) === "#") continue;
+  passwd[i] = passwd[i].split(":");
+  var otherName = passwd[i][0];
+  var otherUid = +passwd[i][2];
+  var otherGid = +passwd[i][3];
+  if (otherUid && otherUid !== myUid &&
+      otherGid && otherGid !== myGid &&
+      otherUid > 0) {
+    break;
+  }
+}
+if (!otherUid && !otherGid) throw new Error("failed getting passwd info.");
+
+console.error("name, id, gid = %j", [otherName, otherUid, otherGid]);
+
+var whoNumber = child_process.spawn("id",[], {uid:otherUid,gid:otherGid}),
+    assert = require("assert");
+
+whoNumber.stdout.buf = "byNumber:";
+whoNumber.stdout.on("data", onData);
+function onData (c) { this.buf += c; }
+
+whoNumber.on("exit", onExit);
+function onExit (code) {
+  var buf = this.stdout.buf;
+  console.log(buf);
+  var expr = new RegExp("^byNumber:uid="+otherUid+"\\("+
+                        otherName+"\\) gid="+otherGid+"\\(");
+  assert.ok(buf.match(expr), "uid and gid should match "+otherName);
+}