Support hydra-build-products on binary cache stores

src/hydra-queue-runner/build-result.cc

@@ -2,26 +2,13 @@
 #include "store-api.hh"
 #include "util.hh"
 #include "regex.hh"
+#include "fs-accessor.hh"
 
 using namespace nix;
 
 
-static std::tuple<bool, string> secureRead(Path fileName)
-{
-    auto fail = std::make_tuple(false, "");
-
-    if (!pathExists(fileName)) return fail;
-
-    try {
-        /* For security, resolve symlinks. */
-        fileName = canonPath(fileName, true);
-        if (!isInStore(fileName)) return fail;
-        return std::make_tuple(true, readFile(fileName));
-    } catch (Error & e) { return fail; }
-}
-
-
-BuildOutput getBuildOutput(nix::ref<Store> store, const Derivation & drv)
+BuildOutput getBuildOutput(nix::ref<Store> store,
+    nix::ref<nix::FSAccessor> accessor, const Derivation & drv)
 {
     BuildOutput res;
 
@@ -41,7 +28,6 @@ BuildOutput getBuildOutput(nix::ref<Store> store, const Derivation & drv)
     /* Get build products. */
     bool explicitProducts = false;
 
-#if 0
     Regex regex(
         "(([a-zA-Z0-9_-]+)" // type (e.g. "doc")
         "[[:space:]]+"
@@ -53,14 +39,16 @@ BuildOutput getBuildOutput(nix::ref<Store> store, const Derivation & drv)
 
     for (auto & output : outputs) {
         Path failedFile = output + "/nix-support/failed";
-        if (pathExists(failedFile)) res.failed = true;
+        if (accessor->stat(failedFile).type == FSAccessor::Type::tRegular)
+            res.failed = true;
 
-        auto file = secureRead(output + "/nix-support/hydra-build-products");
-        if (!std::get<0>(file)) continue;
+        Path productsFile = output + "/nix-support/hydra-build-products";
+        if (accessor->stat(productsFile).type != FSAccessor::Type::tRegular)
+            continue;
 
         explicitProducts = true;
 
-        for (auto & line : tokenizeString<Strings>(std::get<1>(file), "\n")) {
+        for (auto & line : tokenizeString<Strings>(accessor->readFile(productsFile), "\n")) {
             BuildProduct product;
 
             Regex::Subs subs;
@@ -73,32 +61,28 @@ BuildOutput getBuildOutput(nix::ref<Store> store, const Derivation & drv)
 
             /* Ensure that the path exists and points into the Nix
                store. */
+            // FIXME: should we disallow products referring to other
+            // store paths, or that are outside the input closure?
             if (product.path == "" || product.path[0] != '/') continue;
-            try {
-                product.path = canonPath(product.path, true);
-            } catch (Error & e) { continue; }
-            if (!isInStore(product.path) || !pathExists(product.path)) continue;
+            product.path = canonPath(product.path);
+            if (!isInStore(product.path)) continue;
 
-            /*  FIXME: check that the path is in the input closure
-                of the build? */
+            auto st = accessor->stat(product.path);
+            if (st.type == FSAccessor::Type::tMissing) continue;
 
             product.name = product.path == output ? "" : baseNameOf(product.path);
 
-            struct stat st;
-            if (stat(product.path.c_str(), &st))
-                throw SysError(format("getting status of ‘%1%’") % product.path);
-
-            if (S_ISREG(st.st_mode)) {
+            if (st.type == FSAccessor::Type::tRegular) {
                 product.isRegular = true;
-                product.fileSize = st.st_size;
-                product.sha1hash = hashFile(htSHA1, product.path);
-                product.sha256hash = hashFile(htSHA256, product.path);
+                product.fileSize = st.fileSize;
+                auto contents = accessor->readFile(product.path);
+                product.sha1hash = hashString(htSHA1, contents);
+                product.sha256hash = hashString(htSHA256, contents);
             }
 
             res.products.push_back(product);
         }
     }
-#endif
 
     /* If no build products were explicitly declared, then add all
        outputs as a product of type "nix-build". */
@@ -110,31 +94,29 @@ BuildOutput getBuildOutput(nix::ref<Store> store, const Derivation & drv)
             product.subtype = output.first == "out" ? "" : output.first;
             product.name = storePathToName(product.path);
 
-#if 0
-            struct stat st;
-            if (stat(product.path.c_str(), &st))
-                throw SysError(format("getting status of ‘%1%’") % product.path);
-            if (S_ISDIR(st.st_mode))
-#endif
+            auto st = accessor->stat(product.path);
+            if (st.type == FSAccessor::Type::tMissing)
+                throw Error(format("getting status of ‘%1%’") % product.path);
+            if (st.type == FSAccessor::Type::tDirectory)
                 res.products.push_back(product);
         }
     }
 
-#if 0
     /* Get the release name from $output/nix-support/hydra-release-name. */
     for (auto & output : outputs) {
         Path p = output + "/nix-support/hydra-release-name";
-        if (!pathExists(p)) continue;
+        if (accessor->stat(p).type != FSAccessor::Type::tRegular) continue;
         try {
-            res.releaseName = trim(readFile(p));
+            res.releaseName = trim(accessor->readFile(p));
         } catch (Error & e) { continue; }
         // FIXME: validate release name
     }
 
     /* Get metrics. */
     for (auto & output : outputs) {
-        auto file = secureRead(output + "/nix-support/hydra-metrics");
-        for (auto & line : tokenizeString<Strings>(std::get<1>(file), "\n")) {
+        Path metricsFile = output + "/nix-support/hydra-metrics";
+        if (accessor->stat(metricsFile).type != FSAccessor::Type::tRegular) continue;
+        for (auto & line : tokenizeString<Strings>(accessor->readFile(metricsFile), "\n")) {
             auto fields = tokenizeString<std::vector<std::string>>(line);
             if (fields.size() < 2) continue;
             BuildMetric metric;
@@ -144,7 +126,6 @@ BuildOutput getBuildOutput(nix::ref<Store> store, const Derivation & drv)
             res.metrics[metric.name] = metric;
         }
     }
-#endif
 
     return res;
 }

src/hydra-queue-runner/build-result.hh

@@ -4,6 +4,7 @@
 
 #include "hash.hh"
 #include "derivations.hh"
+#include "store-api.hh"
 
 struct BuildProduct
 {
@@ -37,4 +38,5 @@ struct BuildOutput
     std::map<std::string, BuildMetric> metrics;
 };
 
-BuildOutput getBuildOutput(nix::ref<nix::Store> store, const nix::Derivation & drv);
+BuildOutput getBuildOutput(nix::ref<nix::Store> store,
+    nix::ref<nix::FSAccessor> accessor, const nix::Derivation & drv);

src/hydra-queue-runner/builder.cc

@@ -126,7 +126,7 @@ bool State::doBuildStep(nix::ref<Store> destStore, Step::ptr step,
             result.errorMsg = e.msg();
         }
 
-        if (result.success()) res = getBuildOutput(destStore, step->drv);
+        if (result.success()) res = getBuildOutput(destStore, destStore->getFSAccessor(), step->drv);
     }
 
     time_t stepStopTime = time(0);

src/hydra-queue-runner/queue-monitor.cc

@@ -159,7 +159,7 @@ bool State::getQueuedBuilds(Connection & conn, ref<Store> localStore,
            all valid. So we mark this as a finished, cached build. */
         if (!step) {
             Derivation drv = readDerivation(build->drvPath);
-            BuildOutput res = getBuildOutput(destStore, drv);
+            BuildOutput res = getBuildOutput(destStore, destStore->getFSAccessor(), drv);
 
             pqxx::work txn(conn);
             time_t now = time(0);