Merge pull request #7423 from edolstra/legacy-cli-flakes

Support flake references in the old CLI
This commit is contained in:
Eelco Dolstra 2022-12-12 14:34:27 +01:00 committed by GitHub
commit 5a11c9b6f5
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9 changed files with 91 additions and 36 deletions

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@ -2,3 +2,15 @@
* The `repeat` and `enforce-determinism` options have been removed * The `repeat` and `enforce-determinism` options have been removed
since they had been broken under many circumstances for a long time. since they had been broken under many circumstances for a long time.
* You can now use [flake references] in the [old command line interface], e.g.
[flake references]: ../command-ref/new-cli/nix3-flake.md#flake-references
[old command line interface]: ../command-ref/main-commands.md
```
# nix-build flake:nixpkgs -A hello
# nix-build -I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05 \
'<nixpkgs>' -A hello
# NIX_PATH=nixpkgs=flake:nixpkgs nix-build '<nixpkgs>' -A hello
```

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@ -85,6 +85,23 @@ MixEvalArgs::MixEvalArgs()
-I nixpkgs=channel:nixos-21.05 -I nixpkgs=channel:nixos-21.05
-I nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz -I nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz
``` ```
You can also fetch source trees using flake URLs and add them to the
search path. For instance,
```
-I nixpkgs=flake:nixpkgs
```
specifies that the prefix `nixpkgs` shall refer to the source tree
downloaded from the `nixpkgs` entry in the flake registry. Similarly,
```
-I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05
```
makes `<nixpkgs>` refer to a particular branch of the
`NixOS/nixpkgs` repository on GitHub.
)", )",
.category = category, .category = category,
.labels = {"path"}, .labels = {"path"},
@ -142,14 +159,25 @@ Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
Path lookupFileArg(EvalState & state, std::string_view s) Path lookupFileArg(EvalState & state, std::string_view s)
{ {
if (isUri(s)) { if (EvalSettings::isPseudoUrl(s)) {
return state.store->toRealPath( auto storePath = fetchers::downloadTarball(
fetchers::downloadTarball( state.store, EvalSettings::resolvePseudoUrl(s), "source", false).first.storePath;
state.store, resolveUri(s), "source", false).first.storePath); return state.store->toRealPath(storePath);
} else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') { }
else if (hasPrefix(s, "flake:")) {
settings.requireExperimentalFeature(Xp::Flakes);
auto flakeRef = parseFlakeRef(std::string(s.substr(6)), {}, true, false);
auto storePath = flakeRef.resolve(state.store).fetchTree(state.store).first.storePath;
return state.store->toRealPath(storePath);
}
else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
Path p(s.substr(1, s.size() - 2)); Path p(s.substr(1, s.size() - 2));
return state.findFile(p); return state.findFile(p);
} else }
else
return absPath(std::string(s)); return absPath(std::string(s));
} }

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@ -402,7 +402,8 @@ static Strings parseNixPath(const std::string & s)
} }
if (*p == ':') { if (*p == ':') {
if (isUri(std::string(start2, s.end()))) { auto prefix = std::string(start2, s.end());
if (EvalSettings::isPseudoUrl(prefix) || hasPrefix(prefix, "flake:")) {
++p; ++p;
while (p != s.end() && *p != ':') ++p; while (p != s.end() && *p != ':') ++p;
} }
@ -2583,6 +2584,23 @@ Strings EvalSettings::getDefaultNixPath()
return res; return res;
} }
bool EvalSettings::isPseudoUrl(std::string_view s)
{
if (s.compare(0, 8, "channel:") == 0) return true;
size_t pos = s.find("://");
if (pos == std::string::npos) return false;
std::string scheme(s, 0, pos);
return scheme == "http" || scheme == "https" || scheme == "file" || scheme == "channel" || scheme == "git" || scheme == "s3" || scheme == "ssh";
}
std::string EvalSettings::resolvePseudoUrl(std::string_view url)
{
if (hasPrefix(url, "channel:"))
return "https://nixos.org/channels/" + std::string(url.substr(8)) + "/nixexprs.tar.xz";
else
return std::string(url);
}
EvalSettings evalSettings; EvalSettings evalSettings;
static GlobalConfig::Register rEvalSettings(&evalSettings); static GlobalConfig::Register rEvalSettings(&evalSettings);

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@ -590,6 +590,10 @@ struct EvalSettings : Config
static Strings getDefaultNixPath(); static Strings getDefaultNixPath();
static bool isPseudoUrl(std::string_view s);
static std::string resolvePseudoUrl(std::string_view url);
Setting<bool> enableNativeCode{this, false, "allow-unsafe-native-code-during-evaluation", Setting<bool> enableNativeCode{this, false, "allow-unsafe-native-code-during-evaluation",
"Whether builtin functions that allow executing native code should be enabled."}; "Whether builtin functions that allow executing native code should be enabled."};

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@ -643,6 +643,7 @@ formal
#include "filetransfer.hh" #include "filetransfer.hh"
#include "fetchers.hh" #include "fetchers.hh"
#include "store-api.hh" #include "store-api.hh"
#include "flake/flake.hh"
namespace nix { namespace nix {
@ -805,17 +806,28 @@ std::pair<bool, std::string> EvalState::resolveSearchPathElem(const SearchPathEl
std::pair<bool, std::string> res; std::pair<bool, std::string> res;
if (isUri(elem.second)) { if (EvalSettings::isPseudoUrl(elem.second)) {
try { try {
res = { true, store->toRealPath(fetchers::downloadTarball( auto storePath = fetchers::downloadTarball(
store, resolveUri(elem.second), "source", false).first.storePath) }; store, EvalSettings::resolvePseudoUrl(elem.second), "source", false).first.storePath;
res = { true, store->toRealPath(storePath) };
} catch (FileTransferError & e) { } catch (FileTransferError & e) {
logWarning({ logWarning({
.msg = hintfmt("Nix search path entry '%1%' cannot be downloaded, ignoring", elem.second) .msg = hintfmt("Nix search path entry '%1%' cannot be downloaded, ignoring", elem.second)
}); });
res = { false, "" }; res = { false, "" };
} }
} else { }
else if (hasPrefix(elem.second, "flake:")) {
settings.requireExperimentalFeature(Xp::Flakes);
auto flakeRef = parseFlakeRef(elem.second.substr(6), {}, true, false);
debug("fetching flake search path element '%s''", elem.second);
auto storePath = flakeRef.resolve(store).fetchTree(store).first.storePath;
res = { true, store->toRealPath(storePath) };
}
else {
auto path = absPath(elem.second); auto path = absPath(elem.second);
if (pathExists(path)) if (pathExists(path))
res = { true, path }; res = { true, path };

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@ -220,8 +220,6 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v
} else } else
url = state.forceStringNoCtx(*args[0], pos); url = state.forceStringNoCtx(*args[0], pos);
url = resolveUri(*url);
state.checkURI(*url); state.checkURI(*url);
if (name == "") if (name == "")

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@ -33,14 +33,6 @@ FileTransferSettings fileTransferSettings;
static GlobalConfig::Register rFileTransferSettings(&fileTransferSettings); static GlobalConfig::Register rFileTransferSettings(&fileTransferSettings);
std::string resolveUri(std::string_view uri)
{
if (uri.compare(0, 8, "channel:") == 0)
return "https://nixos.org/channels/" + std::string(uri.substr(8)) + "/nixexprs.tar.xz";
else
return std::string(uri);
}
struct curlFileTransfer : public FileTransfer struct curlFileTransfer : public FileTransfer
{ {
CURLM * curlm = 0; CURLM * curlm = 0;
@ -873,14 +865,4 @@ FileTransferError::FileTransferError(FileTransfer::Error error, std::optional<st
err.msg = hf; err.msg = hf;
} }
bool isUri(std::string_view s)
{
if (s.compare(0, 8, "channel:") == 0) return true;
size_t pos = s.find("://");
if (pos == std::string::npos) return false;
std::string scheme(s, 0, pos);
return scheme == "http" || scheme == "https" || scheme == "file" || scheme == "channel" || scheme == "git" || scheme == "s3" || scheme == "ssh";
}
} }

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@ -125,9 +125,4 @@ public:
FileTransferError(FileTransfer::Error error, std::optional<std::string> response, const Args & ... args); FileTransferError(FileTransfer::Error error, std::optional<std::string> response, const Args & ... args);
}; };
bool isUri(std::string_view s);
/* Resolve deprecated 'channel:<foo>' URLs. */
std::string resolveUri(std::string_view uri);
} }

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@ -473,3 +473,9 @@ nix store delete $(nix store add-path $badFlakeDir)
[[ $(nix path-info $(nix store add-path $flake1Dir)) =~ flake1 ]] [[ $(nix path-info $(nix store add-path $flake1Dir)) =~ flake1 ]]
[[ $(nix path-info path:$(nix store add-path $flake1Dir)) =~ simple ]] [[ $(nix path-info path:$(nix store add-path $flake1Dir)) =~ simple ]]
# Test fetching flakerefs in the legacy CLI.
[[ $(nix-instantiate --eval flake:flake3 -A x) = 123 ]]
[[ $(nix-instantiate --eval flake:git+file://$flake3Dir -A x) = 123 ]]
[[ $(nix-instantiate -I flake3=flake:flake3 --eval '<flake3>' -A x) = 123 ]]
[[ $(NIX_PATH=flake3=flake:flake3 nix-instantiate --eval '<flake3>' -A x) = 123 ]]