Experimentally allow forcing `nix-daemon` trust; use this to test

We finally test the status quo of remote build trust in a number of
ways. We create a new experimental feature on `nix-daemon` to do so.

PR #3921, which improves the situation with trustless remote building,
will build upon these changes. This code / tests was pull out of there
to make this, so everything is easier to review, and in particular we
test before and after so the new behavior in that PR is readily apparent
from the testsuite diff alone.

8 files changed, 84 insertions, 0 deletions

diff --git a/tests/build-remote-trustless-after.sh b/tests/build-remote-trustless-after.sh
new file mode 100644
index 000000000..19f59e6ae
--- /dev/null
+++ b/tests/build-remote-trustless-after.sh
@@ -0,0 +1,2 @@
+outPath=$(readlink -f $TEST_ROOT/result)
+grep 'FOO BAR BAZ' ${remoteDir}/${outPath}
diff --git a/tests/build-remote-trustless-should-fail-0.sh b/tests/build-remote-trustless-should-fail-0.sh
new file mode 100644
index 000000000..5e3d5ae07
--- /dev/null
+++ b/tests/build-remote-trustless-should-fail-0.sh
@@ -0,0 +1,29 @@
+source common.sh
+
+enableFeatures "daemon-trust-override"
+
+restartDaemon
+
+[[ $busybox =~ busybox ]] || skipTest "no busybox"
+
+unset NIX_STORE_DIR
+unset NIX_STATE_DIR
+
+# We first build a dependency of the derivation we eventually want to
+# build.
+nix-build build-hook.nix -A passthru.input2 \
+  -o "$TEST_ROOT/input2" \
+  --arg busybox "$busybox" \
+  --store "$TEST_ROOT/local" \
+  --option system-features bar
+
+# Now when we go to build that downstream derivation, Nix will fail
+# because we cannot trustlessly build input-addressed derivations with
+# `inputDrv` dependencies.
+
+file=build-hook.nix
+prog=$(readlink -e ./nix-daemon-untrusting.sh)
+proto=ssh-ng
+
+expectStderr 1 source build-remote-trustless.sh \
+    | grepQuiet "you are not privileged to build input-addressed derivations"
diff --git a/tests/build-remote-trustless-should-pass-0.sh b/tests/build-remote-trustless-should-pass-0.sh
new file mode 100644
index 000000000..2a7ebd8c6
--- /dev/null
+++ b/tests/build-remote-trustless-should-pass-0.sh
@@ -0,0 +1,9 @@
+source common.sh
+
+# Remote trusts us
+file=build-hook.nix
+prog=nix-store
+proto=ssh
+
+source build-remote-trustless.sh
+source build-remote-trustless-after.sh
diff --git a/tests/build-remote-trustless-should-pass-1.sh b/tests/build-remote-trustless-should-pass-1.sh
new file mode 100644
index 000000000..516bdf092
--- /dev/null
+++ b/tests/build-remote-trustless-should-pass-1.sh
@@ -0,0 +1,9 @@
+source common.sh
+
+# Remote trusts us
+file=build-hook.nix
+prog=nix-daemon
+proto=ssh-ng
+
+source build-remote-trustless.sh
+source build-remote-trustless-after.sh
diff --git a/tests/build-remote-trustless-should-pass-3.sh b/tests/build-remote-trustless-should-pass-3.sh
new file mode 100644
index 000000000..40f81da5a
--- /dev/null
+++ b/tests/build-remote-trustless-should-pass-3.sh
@@ -0,0 +1,14 @@
+source common.sh
+
+enableFeatures "daemon-trust-override"
+
+restartDaemon
+
+# Remote doesn't trusts us, but this is fine because we are only
+# building (fixed) CA derivations.
+file=build-hook-ca-fixed.nix
+prog=$(readlink -e ./nix-daemon-untrusting.sh)
+proto=ssh-ng
+
+source build-remote-trustless.sh
+source build-remote-trustless-after.sh
diff --git a/tests/build-remote-trustless.sh b/tests/build-remote-trustless.sh
new file mode 100644
index 000000000..9df44e0c5
--- /dev/null
+++ b/tests/build-remote-trustless.sh
@@ -0,0 +1,14 @@
+requireSandboxSupport
+[[ $busybox =~ busybox ]] || skipTest "no busybox"
+
+unset NIX_STORE_DIR
+unset NIX_STATE_DIR
+
+remoteDir=$TEST_ROOT/remote
+
+# Note: ssh{-ng}://localhost bypasses ssh. See tests/build-remote.sh for
+# more details.
+nix-build $file -o $TEST_ROOT/result --max-jobs 0 \
+  --arg busybox $busybox \
+  --store $TEST_ROOT/local \
+  --builders "$proto://localhost?remote-program=$prog&remote-store=${remoteDir}%3Fsystem-features=foo%20bar%20baz - - 1 1 foo,bar,baz"
diff --git a/tests/local.mk b/tests/local.mk
index 6cb466e8e..7c3b42599 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -70,6 +70,10 @@ nix_tests = \
   check-reqs.sh \
   build-remote-content-addressed-fixed.sh \
   build-remote-content-addressed-floating.sh \
+  build-remote-trustless-should-pass-0.sh \
+  build-remote-trustless-should-pass-1.sh \
+  build-remote-trustless-should-pass-3.sh \
+  build-remote-trustless-should-fail-0.sh \
   nar-access.sh \
   pure-eval.sh \
   eval.sh \
diff --git a/tests/nix-daemon-untrusting.sh b/tests/nix-daemon-untrusting.sh
new file mode 100755
index 000000000..bcdb70989
--- /dev/null
+++ b/tests/nix-daemon-untrusting.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+exec nix-daemon --force-untrusted "$@"