From 7a04839ea53986a0175bf085e7d061ab8a32d59b Mon Sep 17 00:00:00 2001 From: Maximilian Bosch Date: Mon, 31 Jan 2022 22:05:28 +0100 Subject: ssh-ng: also store build logs to make them accessible by `nix log` Right now when building a derivation remotely via $ nix build -j0 -f . hello -L --builders 'ssh://builder' it's possible later to read through the entire build-log by running `nix log -f . hello`. This isn't possible however when using `ssh-ng` rather than `ssh`. The reason for that is that there are two different ways to transfer logs in Nix through e.g. an SSH tunnel (that are used by `ssh`/`ssh-ng` respectively): * `ssh://` receives its logs from the fd pointing to `builderOut`. This is directly passed to the "log-sink" (and to the logger on each `\n`), hence `nix log` works here. * `ssh-ng://` however expects JSON-like messages (i.e. `@nix {log data in here}`) and passes it directly to the logger without doing anything with the `logSink`. However it's certainly possible to extract log-lines from this format as these have their own message-type in the JSON payload (i.e. `resBuildLogLine`). This is basically what I changed in this patch: if the code-path for `builderOut` is not reached and a `logSink` is initialized, the message was successfully processed by the JSON logger (i.e. it's in the expected format) and the line is of the expected type (i.e. `resBuildLogLine`), the line will be written to the log-sink as well. Closes #5079 --- src/libstore/build/derivation-goal.cc | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc index 95da1841d..ef1135601 100644 --- a/src/libstore/build/derivation-goal.cc +++ b/src/libstore/build/derivation-goal.cc @@ -1175,10 +1175,10 @@ bool DerivationGoal::isReadDesc(int fd) return fd == hook->builderOut.readSide.get(); } - void DerivationGoal::handleChildOutput(int fd, std::string_view data) { - if (isReadDesc(fd)) + auto isWrittenToLog = isReadDesc(fd); + if (isWrittenToLog) { logSize += data.size(); if (settings.maxLogSize && logSize > settings.maxLogSize) { @@ -1207,7 +1207,14 @@ void DerivationGoal::handleChildOutput(int fd, std::string_view data) if (hook && fd == hook->fromHook.readSide.get()) { for (auto c : data) if (c == '\n') { - handleJSONLogMessage(currentHookLine, worker.act, hook->activities, true); + auto s = handleJSONLogMessage(currentHookLine, worker.act, hook->activities, true); + if (s && !isWrittenToLog && logSink) { + auto json = nlohmann::json::parse(std::string(currentHookLine, 5)); + if (json["type"] == resBuildLogLine) { + auto f = json["fields"]; + (*logSink)((f.size() > 0 ? f.at(0).get() : "") + "\n"); + } + } currentHookLine.clear(); } else currentHookLine += c; -- cgit v1.2.3