LegacySSHStore: Add remote-store option

This is primarily useful for testing, e.g.

  $ nix copy --to 'ssh://localhost?remote-store=/tmp/nix' ...

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index 02d91ded04cd..f9b0b42c83d3 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -17,6 +17,7 @@ struct LegacySSHStore : public Store
     const Setting<Path> sshKey{this, "", "ssh-key", "path to an SSH private key"};
     const Setting<bool> compress{this, false, "compress", "whether to compress the connection"};
     const Setting<Path> remoteProgram{this, "nix-store", "remote-program", "path to the nix-store executable on the remote system"};
+    const Setting<std::string> remoteStore{this, "", "remote-store", "URI of the store on the remote system"};
 
     // Hack for getting remote build log output.
     const Setting<int> logFD{this, -1, "log-fd", "file descriptor to which SSH's stderr is connected"};
@@ -56,7 +57,9 @@ struct LegacySSHStore : public Store
     ref<Connection> openConnection()
     {
         auto conn = make_ref<Connection>();
-        conn->sshConn = master.startCommand(fmt("%s --serve --write", remoteProgram));
+        conn->sshConn = master.startCommand(
+            fmt("%s --serve --write", remoteProgram)
+            + (remoteStore.get() == "" ? "" : " --store " + shellEscape(remoteStore.get())));
         conn->to = FdSink(conn->sshConn->in.get());
         conn->from = FdSource(conn->sshConn->out.get());