HttpBinaryCacheStore: Support upsertFile with PUT.

Some servers, such as Artifactory, allow uploading with PUT and BASIC
auth. This allows nix copy to work to upload binaries to those
servers.

Worked on together with @adelbertc

3 files changed, 38 insertions, 4 deletions

diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index ef417685f..4b37826c4 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -22,6 +22,7 @@
 #include <thread>
 #include <cmath>
 #include <random>
+#include <algorithm>
 
 using namespace std::string_literals;
 
@@ -91,6 +92,8 @@ struct CurlDownloader : public Downloader
         {
             if (!request.expectedETag.empty())
                 requestHeaders = curl_slist_append(requestHeaders, ("If-None-Match: " + request.expectedETag).c_str());
+            if (!request.mimeType.empty())
+                requestHeaders = curl_slist_append(requestHeaders, ("Content-Type: " + request.mimeType).c_str());
         }
 
         ~DownloadItem()
@@ -185,6 +188,22 @@ struct CurlDownloader : public Downloader
             return 0;
         }
 
+        size_t readOffset = 0;
+        int readCallback(char *buffer, size_t size, size_t nitems)
+        {
+            if (readOffset == request.data->length())
+                return 0;
+            auto count = std::min(size * nitems, request.data->length() - readOffset);
+            memcpy(buffer, request.data->data() + readOffset, count);
+            readOffset += count;
+            return count;
+        }
+
+        static int readCallbackWrapper(char *buffer, size_t size, size_t nitems, void * userp)
+        {
+            return ((DownloadItem *) userp)->readCallback(buffer, size, nitems);
+        }
+
         long lowSpeedTimeout = 300;
 
         void init()
@@ -225,6 +244,13 @@ struct CurlDownloader : public Downloader
             if (request.head)
                 curl_easy_setopt(req, CURLOPT_NOBODY, 1);
 
+            if (request.data) {
+                curl_easy_setopt(req, CURLOPT_UPLOAD, 1L);
+                curl_easy_setopt(req, CURLOPT_READFUNCTION, readCallbackWrapper);
+                curl_easy_setopt(req, CURLOPT_READDATA, this);
+                curl_easy_setopt(req, CURLOPT_INFILESIZE_LARGE, (curl_off_t) request.data->length());
+            }
+
             if (request.verifyTLS) {
                 if (settings.caFile != "")
                     curl_easy_setopt(req, CURLOPT_CAINFO, settings.caFile.c_str());
@@ -265,7 +291,7 @@ struct CurlDownloader : public Downloader
             }
 
             if (code == CURLE_OK &&
-                (httpStatus == 200 || httpStatus == 304 || httpStatus == 226 /* FTP */ || httpStatus == 0 /* other protocol */))
+                (httpStatus == 200 || httpStatus == 201 || httpStatus == 204 || httpStatus == 304 || httpStatus == 226 /* FTP */ || httpStatus == 0 /* other protocol */))
             {
                 result.cached = httpStatus == 304;
                 done = true;
diff --git a/src/libstore/download.hh b/src/libstore/download.hh
index f2d65ad8d..0a278a05e 100644
--- a/src/libstore/download.hh
+++ b/src/libstore/download.hh
@@ -18,9 +18,11 @@ struct DownloadRequest
     unsigned int baseRetryTimeMs = 250;
     ActivityId parentAct;
     bool decompress = true;
+    std::shared_ptr<std::string> data;
+    std::string mimeType;
 
-    DownloadRequest(const std::string & uri)
-        : uri(uri), parentAct(curActivity) { }
+    DownloadRequest(const std::string & uri, std::shared_ptr<std::string> data = nullptr, std::string mimeType = "")
+        : uri(uri), parentAct(curActivity), data(std::move(data)), mimeType(std::move(mimeType)) { }
 };
 
 struct DownloadResult
diff --git a/src/libstore/http-binary-cache-store.cc b/src/libstore/http-binary-cache-store.cc
index 057337685..93bd3e5d5 100644
--- a/src/libstore/http-binary-cache-store.cc
+++ b/src/libstore/http-binary-cache-store.cc
@@ -67,7 +67,13 @@ protected:
         const std::string & data,
         const std::string & mimeType) override
     {
-        throw UploadToHTTP("uploading to an HTTP binary cache is not supported");
+        auto data_ = std::make_shared<string>(data);
+        auto req = DownloadRequest(cacheUri + "/" + path, data_, mimeType);
+        try {
+            getDownloader()->download(req);
+        } catch (DownloadError & e) {
+            throw UploadToHTTP(format("uploading to HTTP binary cache at %1% not supported: %2%") % cacheUri % e.msg());
+        }
     }
 
     void getFile(const std::string & path,