Create nix add-derivation command

src/nix/add-derivation.cc

@@ -0,0 +1,63 @@
+// FIXME: rename to 'nix plan add' or 'nix derivation add'?
+
+#include "command.hh"
+#include "common-args.hh"
+#include "store-api.hh"
+#include "archive.hh"
+#include "derivations.hh"
+#include <nlohmann/json.hpp>
+
+using namespace nix;
+using json = nlohmann::json;
+
+struct CmdAddDerivation : MixDryRun, StoreCommand
+{
+    Path path;
+    std::optional<std::string> namePart;
+
+    CmdAddDerivation()
+    {
+        addFlag({
+            .longName = "name",
+            .shortName = 'n',
+            .description = "Override the name component of the derivation path. It defaults to the base name of *path*.",
+            .labels = {"name"},
+            .handler = {&namePart},
+        });
+    }
+
+    std::string description() override
+    {
+        return "Add a store derivation";
+    }
+
+    std::string doc() override
+    {
+        return
+          #include "add-derivation.md"
+          ;
+    }
+
+    Category category() override { return catUtility; }
+
+    void run(ref<Store> store) override
+    {
+        if (!namePart) namePart = baseNameOf(path);
+        auto & name = *namePart;
+
+        auto json = nlohmann::json::parse(drainFD(STDIN_FILENO));
+
+        auto drv = Derivation::fromJSON(*store, name, json);
+        drv.name = name;
+
+        auto drvPath = writeDerivation(*store, drv, NoRepair, /* read only */ true);
+
+        drv.checkInvariants(*store, drvPath);
+
+        writeDerivation(*store, drv, NoRepair, dryRun);
+
+        logger->cout("%s", store->printStorePath(drvPath));
+    }
+};
+
+static auto rCmdAddDerivation = registerCommand<CmdAddDerivation>("add-derivation");

src/nix/add-derivation.md

@@ -0,0 +1,17 @@
+R""(
+
+# Description
+
+This command reads from the given path a JSON representation of a
+[store derivation] to which *installables* evaluate. Store derivations
+are used internally by Nix. They are store paths with extension `.drv`
+that represent the build-time dependency graph to which a Nix
+expression evaluates.
+
+[store derivation]: ../../glossary.md#gloss-store-derivation
+
+The JSON format is documented under the [`show-derivation`] command.
+
+[`show-derivation`]: ./nix3-show-derivation.md
+
+)""

tests/ca/derivation-json.sh

@@ -0,0 +1,14 @@
+source common.sh
+
+export NIX_TESTS_CA_BY_DEFAULT=1
+
+drvPath=$(nix-instantiate ../simple.nix)
+
+nix show-derivation $drvPath | jq .[] > $TEST_HOME/simple.json
+
+drvPath2=$(nix add-derivation --name simple < $TEST_HOME/simple.json)
+
+[[ "$drvPath" = "$drvPath2" ]]
+
+# Content-addressed derivations can be renamed.
+nix add-derivation --name foo < $TEST_HOME/simple.json

tests/derivation-json.sh

@@ -0,0 +1,12 @@
+source common.sh
+
+drvPath=$(nix-instantiate simple.nix)
+
+nix show-derivation $drvPath | jq .[] > $TEST_HOME/simple.json
+
+drvPath2=$(nix add-derivation --name simple < $TEST_HOME/simple.json)
+
+[[ "$drvPath" = "$drvPath2" ]]
+
+# Input addressed derivations cannot be renamed.
+expectStderr 1 nix add-derivation --name foo < $TEST_HOME/simple.json | grepQuiet "has incorrect output"

tests/local.mk

@@ -99,6 +99,8 @@ nix_tests = \
   eval-store.sh \
   why-depends.sh \
   ca/why-depends.sh \
+  derivation-json.sh \
+  ca/derivation-json.sh \
   import-derivation.sh \
   ca/import-derivation.sh \
   nix_path.sh \