Make <nix/fetchurl.nix> a builtin builder

This ensures that 1) the derivation doesn't change when Nix changes;
2) the derivation closure doesn't contain Nix and its dependencies; 3)
we don't have to rely on ugly chroot hacks.

3 files changed, 1 insertions, 259 deletions

diff --git a/src/libexpr/download.cc b/src/libexpr/download.cc
deleted file mode 100644
index 9bf3e13aa9..0000000000
--- a/src/libexpr/download.cc
+++ /dev/null
@@ -1,236 +0,0 @@
-#include "download.hh"
-#include "util.hh"
-#include "globals.hh"
-#include "hash.hh"
-#include "store-api.hh"
-
-#include <curl/curl.h>
-
-namespace nix {
-
-struct Curl
-{
-    CURL * curl;
-    string data;
-    string etag, status, expectedETag;
-
-    struct curl_slist * requestHeaders;
-
-    static size_t writeCallback(void * contents, size_t size, size_t nmemb, void * userp)
-    {
-        Curl & c(* (Curl *) userp);
-        size_t realSize = size * nmemb;
-        c.data.append((char *) contents, realSize);
-        return realSize;
-    }
-
-    static size_t headerCallback(void * contents, size_t size, size_t nmemb, void * userp)
-    {
-        Curl & c(* (Curl *) userp);
-        size_t realSize = size * nmemb;
-        string line = string((char *) contents, realSize);
-        printMsg(lvlVomit, format("got header: %1%") % trim(line));
-        if (line.compare(0, 5, "HTTP/") == 0) { // new response starts
-            c.etag = "";
-            auto ss = tokenizeString<vector<string>>(line, " ");
-            c.status = ss.size() >= 2 ? ss[1] : "";
-        } else {
-            auto i = line.find(':');
-            if (i != string::npos) {
-                string name = trim(string(line, 0, i));
-                if (name == "ETag") { // FIXME: case
-                    c.etag = trim(string(line, i + 1));
-                    /* Hack to work around a GitHub bug: it sends
-                       ETags, but ignores If-None-Match. So if we get
-                       the expected ETag on a 200 response, then shut
-                       down the connection because we already have the
-                       data. */
-                    printMsg(lvlDebug, format("got ETag: %1%") % c.etag);
-                    if (c.etag == c.expectedETag && c.status == "200") {
-                        printMsg(lvlDebug, format("shutting down on 200 HTTP response with expected ETag"));
-                        return 0;
-                    }
-                }
-            }
-        }
-        return realSize;
-    }
-
-    static int progressCallback(void * clientp, double dltotal, double dlnow, double ultotal, double ulnow)
-    {
-        return _isInterrupted;
-    }
-
-    Curl()
-    {
-        requestHeaders = 0;
-
-        curl = curl_easy_init();
-        if (!curl) throw Error("unable to initialize curl");
-
-        curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
-        curl_easy_setopt(curl, CURLOPT_CAINFO, getEnv("SSL_CERT_FILE", "/etc/ssl/certs/ca-certificates.crt").c_str());
-        curl_easy_setopt(curl, CURLOPT_USERAGENT, ("Nix/" + nixVersion).c_str());
-        curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
-
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writeCallback);
-        curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *) &curl);
-
-        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, headerCallback);
-        curl_easy_setopt(curl, CURLOPT_HEADERDATA, (void *) &curl);
-
-        curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, progressCallback);
-        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0);
-    }
-
-    ~Curl()
-    {
-        if (curl) curl_easy_cleanup(curl);
-        if (requestHeaders) curl_slist_free_all(requestHeaders);
-    }
-
-    bool fetch(const string & url, const string & expectedETag = "")
-    {
-        curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
-
-        data.clear();
-
-        if (requestHeaders) {
-            curl_slist_free_all(requestHeaders);
-            requestHeaders = 0;
-        }
-
-        if (!expectedETag.empty()) {
-            this->expectedETag = expectedETag;
-            requestHeaders = curl_slist_append(requestHeaders, ("If-None-Match: " + expectedETag).c_str());
-        }
-
-        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, requestHeaders);
-
-        CURLcode res = curl_easy_perform(curl);
-        checkInterrupt();
-        if (res == CURLE_WRITE_ERROR && etag == expectedETag) return false;
-        if (res != CURLE_OK)
-            throw DownloadError(format("unable to download ‘%1%’: %2% (%3%)")
-                % url % curl_easy_strerror(res) % res);
-
-        long httpStatus = 0;
-        curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &httpStatus);
-        if (httpStatus == 304) return false;
-
-        return true;
-    }
-};
-
-
-DownloadResult downloadFile(string url, string expectedETag)
-{
-    DownloadResult res;
-    Curl curl;
-    if (curl.fetch(url, expectedETag)) {
-        res.cached = false;
-        res.data = curl.data;
-    } else
-        res.cached = true;
-    res.etag = curl.etag;
-    return res;
-}
-
-
-Path downloadFileCached(const string & url, bool unpack)
-{
-    Path cacheDir = getEnv("XDG_CACHE_HOME", getEnv("HOME", "") + "/.cache") + "/nix/tarballs";
-    createDirs(cacheDir);
-
-    string urlHash = printHash32(hashString(htSHA256, url));
-
-    Path dataFile = cacheDir + "/" + urlHash + ".info";
-    Path fileLink = cacheDir + "/" + urlHash + "-file";
-
-    Path storePath;
-
-    string expectedETag;
-
-    int ttl = settings.get("tarball-ttl", 60 * 60);
-    bool skip = false;
-
-    if (pathExists(fileLink) && pathExists(dataFile)) {
-        storePath = readLink(fileLink);
-        store->addTempRoot(storePath);
-        if (store->isValidPath(storePath)) {
-            auto ss = tokenizeString<vector<string>>(readFile(dataFile), "\n");
-            if (ss.size() >= 3 && ss[0] == url) {
-                time_t lastChecked;
-                if (string2Int(ss[2], lastChecked) && lastChecked + ttl >= time(0))
-                    skip = true;
-                else if (!ss[1].empty()) {
-                    printMsg(lvlDebug, format("verifying previous ETag ‘%1%’") % ss[1]);
-                    expectedETag = ss[1];
-                }
-            }
-        } else
-            storePath = "";
-    }
-
-    string name;
-    auto p = url.rfind('/');
-    if (p != string::npos) name = string(url, p + 1);
-
-    if (!skip) {
-
-        if (storePath.empty())
-            printMsg(lvlInfo, format("downloading ‘%1%’...") % url);
-        else
-            printMsg(lvlInfo, format("checking ‘%1%’...") % url);
-
-        try {
-            auto res = downloadFile(url, expectedETag);
-
-            if (!res.cached)
-                storePath = store->addTextToStore(name, res.data, PathSet(), false);
-
-            assert(!storePath.empty());
-            replaceSymlink(storePath, fileLink);
-
-            writeFile(dataFile, url + "\n" + res.etag + "\n" + int2String(time(0)) + "\n");
-        } catch (DownloadError & e) {
-            if (storePath.empty()) throw;
-            printMsg(lvlError, format("warning: %1%; using cached result") % e.msg());
-        }
-    }
-
-    if (unpack) {
-        Path unpackedLink = cacheDir + "/" + baseNameOf(storePath) + "-unpacked";
-        Path unpackedStorePath;
-        if (pathExists(unpackedLink)) {
-            unpackedStorePath = readLink(unpackedLink);
-            store->addTempRoot(unpackedStorePath);
-            if (!store->isValidPath(unpackedStorePath))
-                unpackedStorePath = "";
-        }
-        if (unpackedStorePath.empty()) {
-            printMsg(lvlInfo, format("unpacking ‘%1%’...") % url);
-            Path tmpDir = createTempDir();
-            AutoDelete autoDelete(tmpDir, true);
-            // FIXME: this requires GNU tar for decompression.
-            runProgram("tar", true, {"xf", storePath, "-C", tmpDir, "--strip-components", "1"}, "");
-            unpackedStorePath = store->addToStore(name, tmpDir, true, htSHA256, defaultPathFilter, false);
-        }
-        replaceSymlink(unpackedStorePath, unpackedLink);
-        return unpackedStorePath;
-    }
-
-    return storePath;
-}
-
-
-bool isUri(const string & s)
-{
-    size_t pos = s.find("://");
-    if (pos == string::npos) return false;
-    string scheme(s, 0, pos);
-    return scheme == "http" || scheme == "https" || scheme == "file";
-}
-
-
-}
diff --git a/src/libexpr/download.hh b/src/libexpr/download.hh
deleted file mode 100644
index 28c9117e42..0000000000
--- a/src/libexpr/download.hh
+++ /dev/null
@@ -1,22 +0,0 @@
-#pragma once
-
-#include "types.hh"
-#include <string>
-
-namespace nix {
-
-struct DownloadResult
-{
-    bool cached;
-    string data, etag;
-};
-
-DownloadResult downloadFile(string url, string expectedETag = "");
-
-Path downloadFileCached(const string & url, bool unpack);
-
-MakeError(DownloadError, Error)
-
-bool isUri(const string & s);
-
-}
diff --git a/src/libexpr/local.mk b/src/libexpr/local.mk
index 35e84980a6..4c1f4de191 100644
--- a/src/libexpr/local.mk
+++ b/src/libexpr/local.mk
@@ -8,7 +8,7 @@ libexpr_SOURCES := $(wildcard $(d)/*.cc) $(d)/lexer-tab.cc $(d)/parser-tab.cc
 
 libexpr_LIBS = libutil libstore libformat
 
-libexpr_LDFLAGS = -ldl -lcurl
+libexpr_LDFLAGS = -ldl
 
 # The dependency on libgc must be propagated (i.e. meaning that
 # programs/libraries that use libexpr must explicitly pass -lgc),