Store: Add a method for getting build logs

This allows various Store implementations to provide different ways to
get build logs. For example, BinaryCacheStore can get the build logs
from the binary cache.

Also, remove the log-servers option since we can use substituters for
this.

1 files changed, 5 insertions, 52 deletions

diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index 950c2a7c977f..024fa4168ebb 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -9,7 +9,6 @@
 #include "util.hh"
 #include "worker-protocol.hh"
 #include "xmlgraph.hh"
-#include "compression.hh"
 
 #include <iostream>
 #include <algorithm>
@@ -482,58 +481,12 @@ static void opReadLog(Strings opFlags, Strings opArgs)
 
     RunPager pager;
 
-    // FIXME: move getting logs into Store.
-    auto store2 = std::dynamic_pointer_cast<LocalFSStore>(store);
-    if (!store2) throw Error(format("store ‘%s’ does not support reading logs") % store->getUri());
-
     for (auto & i : opArgs) {
-        Path path = useDeriver(store->followLinksToStorePath(i));
-
-        string baseName = baseNameOf(path);
-        bool found = false;
-
-        for (int j = 0; j < 2; j++) {
-
-            Path logPath =
-                j == 0
-                ? (format("%1%/%2%/%3%/%4%") % store2->logDir % drvsLogDir % string(baseName, 0, 2) % string(baseName, 2)).str()
-                : (format("%1%/%2%/%3%") % store2->logDir % drvsLogDir % baseName).str();
-            Path logBz2Path = logPath + ".bz2";
-
-            if (pathExists(logPath)) {
-                /* !!! Make this run in O(1) memory. */
-                string log = readFile(logPath);
-                writeFull(STDOUT_FILENO, log);
-                found = true;
-                break;
-            }
-
-            else if (pathExists(logBz2Path)) {
-                std::cout << *decompress("bzip2", readFile(logBz2Path));
-                found = true;
-                break;
-            }
-        }
-
-        if (!found) {
-            for (auto & i : settings.logServers) {
-                string prefix = i;
-                if (!prefix.empty() && prefix.back() != '/') prefix += '/';
-                string url = prefix + baseName;
-                try {
-                    string log = runProgram(CURL, true, {"--fail", "--location", "--silent", "--", url});
-                    std::cout << "(using build log from " << url << ")" << std::endl;
-                    std::cout << log;
-                    found = true;
-                    break;
-                } catch (ExecError & e) {
-                    /* Ignore errors from curl. FIXME: actually, might be
-                       nice to print a warning on HTTP status != 404. */
-                }
-            }
-        }
-
-        if (!found) throw Error(format("build log of derivation ‘%1%’ is not available") % path);
+        auto path = store->followLinksToStorePath(i);
+        auto log = store->getBuildLog(path);
+        if (!log)
+            throw Error("build log of derivation ‘%s’ is not available", path);
+        std::cout << *log;
     }
 }