Merge 4452d36181 into f9afc1e68c

src/libexpr/primops/fetchGitArchive.cc

@@ -0,0 +1,135 @@
+#include "primops.hh"
+#include "store-api.hh"
+#include "cache.hh"
+#include "tarfile.hh"
+#include "archive.hh"
+
+
+namespace nix {
+
+static void prim_fetchGitArchive(EvalState & state, const PosIdx pos, Value * * args, Value & v)
+{
+    std::optional<Hash> expectedHash;
+    std::optional<std::string> remote;
+    std::string name = "source";
+    std::string format = "tar.gz";
+    std::string version = "HEAD";
+
+    state.forceValue(*args[0], pos);
+    for (auto & attr : *args[0]->attrs) {
+        std::string_view n(state.symbols[attr.name]);
+        if (n == "name")
+            name = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the name of the git archive we should fetch");
+        else if (n == "sha256")
+            expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the sha256 of the git archive we should fetch"), htSHA256);
+        else if (n == "remote")
+            remote.emplace(state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the remote of the git archive we should fetch"));
+        else if (n == "format")
+            format = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the format of the git archive we should fetch");
+        else if (n == "version")
+            version = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the version of the git archive we should fetch");
+        else
+            state.debugThrowLastTrace(EvalError({
+                .msg = hintfmt("unsupported argument '%s' to 'fetchGitArchive'", n),
+                .errPos = state.positions[attr.pos]
+            }));
+    }
+
+    if (!remote) {
+        state.debugThrowLastTrace(EvalError({
+            .msg = hintfmt("missing required argument 'remote' to 'fetchGitArchive'"),
+            .errPos = state.positions[pos]
+        }));
+    }
+    if (evalSettings.pureEval && !expectedHash) {
+        state.debugThrowLastTrace(EvalError({
+            .msg = hintfmt("in pure evaluation mode, 'fetchGitArchive' requires a 'sha256' argument"),
+            .errPos = state.positions[pos]
+        }));
+    }
+    if (expectedHash) {
+        auto expectedPath = state.store->makeFixedOutputPath(FileIngestionMethod::Recursive, *expectedHash, name, {});
+        if (state.store->isValidPath(expectedPath)) {
+            state.allowAndSetStorePathString(expectedPath, v);
+            return;
+        }
+    }
+
+    auto inAttrs = fetchers::Attrs({
+        {"type", "git-archive"},
+        {"name", name},
+        {"remote", *remote},
+        {"version", version},
+        {"format", format}
+    });
+
+    if (auto res = fetchers::getCache()->lookup(state.store, inAttrs)) {
+        auto infoAttrs = res->first;
+        auto storePath = res->second;
+        state.allowAndSetStorePathString(storePath, v);
+        return;
+    }
+
+    auto [errorCode, programOutput] = runProgram(RunOptions {
+        .program = "git",
+        .args = {"archive", "--format=" + format, "--remote=" + *remote, version},
+        .mergeStderrToStdout = true
+    });
+    if (errorCode) {
+        state.debugThrowLastTrace(EvalError({
+            .msg = hintfmt("git archive failed with exit code %i:\n" + programOutput, errorCode),
+            .errPos = state.positions[pos]
+        }));
+    }
+
+    auto tarSource = StringSource(programOutput);
+    auto tmpDir = createTempDir();
+    AutoDelete(tmpDir, true);
+    unpackTarfile(tarSource, tmpDir);
+
+    PathFilter filter = [](const Path &) { return true; };
+    auto storePath = state.store->addToStore(name, tmpDir, FileIngestionMethod::Recursive, htSHA256, filter);
+    if (expectedHash) {
+        auto narHash = state.store->queryPathInfo(storePath)->narHash;
+        if (narHash != *expectedHash) {
+            state.debugThrowLastTrace(EvalError({
+                .msg = hintfmt(
+                    "hash mismatch in git archive downloaded from (remote) :\n  specified: %s\n  got:       %s",
+                    expectedHash->to_string(Base32, true),
+                    narHash.to_string(Base32, true)
+                ),
+                .errPos = state.positions[pos]
+            }));
+        }
+    }
+    state.allowAndSetStorePathString(storePath, v);
+
+    auto infoAttrs = fetchers::Attrs({});
+    bool locked = (bool) expectedHash;
+    fetchers::getCache()->add(state.store, inAttrs, infoAttrs, storePath, locked);
+}
+
+static RegisterPrimOp primop_fetchGitArchive({
+    .name = "fetchGitArchive",
+    .args = {"args"},
+    .doc = R"(
+      Fetch a git archive using the git-archive command.
+      See https://git-scm.com/docs/git-archive
+      *args* is an attribute set with the following attributes:
+      - `name`
+      - `remote`
+      - `format`
+      - `version`
+      - `sha256`
+
+      To fetch a version from a private repository over SSH:
+      ```nix
+      builtins.fetchGitArchive {
+      remote = "git@gitlab.com:my-secret/repository.git";
+      version = "v1.2.3";
+      }
+      ```
+    )",
+    .fun = prim_fetchGitArchive,
+});
+}