lix/src/nix/flake.cc
John Ericson bc23a44c54 Make command infra less stateful and more regular
Already, we had classes like `BuiltPathsCommand` and `StorePathsCommand`
which provided alternative `run` virtual functions providing the
implementation with more arguments. This was a very nice and easy way to
make writing command; just fill in the virtual functions and it is
fairly clear what to do.

However, exception to this pattern were `Installable{,s}Command`. These
two classes instead just had a field where the installables would be
stored, and various side-effecting `prepare` and `load` machinery too
fill them in. Command would wish out those fields.

This isn't so clear to use.

What this commit does is make those command classes like the others,
with richer `run` functions.

Not only does this restore the pattern making commands easier to write,
it has a number of other benefits:

- `prepare` and `load` are gone entirely! One command just hands just
  hands off to the next.

- `useDefaultInstallables` because `defaultInstallables`. This takes
  over `prepare` for the one case that needs it, and provides enough
  flexiblity to handle `nix repl`'s idiosyncratic migration.

- We can use `ref` instead of `std::shared_ptr`. The former must be
  initialized (so it is like Rust's `Box` rather than `Option<Box>`,
  This expresses the invariant that the installable are in fact
  initialized much better.

  This is possible because since we just have local variables not
  fields, we can stop worrying about the not-yet-initialized case.

- Fewer lines of code! (Finally I have a large refactor that makes the
  number go down not up...)

- `nix repl` is now implemented in a clearer way.

The last item deserves further mention. `nix repl` is not like the other
installable commands because instead working from once-loaded
installables, it needs to be able to load them again and again.

To properly support this, we make a new superclass
`RawInstallablesCommand`. This class has the argument parsing and
completion logic, but does *not* hand off parsed installables but
instead just the raw string arguments.

This is exactly what `nix repl` needs, and allows us to instead of
having the logic awkwardly split between `prepare`,
`useDefaultInstallables,` and `load`, have everything right next to each
other. I think this will enable future simplifications of that argument
defaulting logic, but I am saving those for a future PR --- best to keep
code motion and more complicated boolean expression rewriting separate
steps.

The "diagnostic ignored `-Woverloaded-virtual`" pragma helps because C++
doesn't like our many `run` methods. In our case, we don't mind the
shadowing it all --- it is *intentional* that the derived class only
provides a `run` method, and doesn't call any of the overridden `run`
methods.

Helps with https://github.com/NixOS/rfcs/pull/134
2023-03-15 16:29:07 -04:00

1337 lines
50 KiB
C++

#include "command.hh"
#include "installable-flake.hh"
#include "common-args.hh"
#include "shared.hh"
#include "eval.hh"
#include "eval-inline.hh"
#include "flake/flake.hh"
#include "get-drvs.hh"
#include "store-api.hh"
#include "derivations.hh"
#include "outputs-spec.hh"
#include "attr-path.hh"
#include "fetchers.hh"
#include "registry.hh"
#include "eval-cache.hh"
#include "markdown.hh"
#include <nlohmann/json.hpp>
#include <queue>
#include <iomanip>
using namespace nix;
using namespace nix::flake;
using json = nlohmann::json;
class FlakeCommand : virtual Args, public MixFlakeOptions
{
std::string flakeUrl = ".";
public:
FlakeCommand()
{
expectArgs({
.label = "flake-url",
.optional = true,
.handler = {&flakeUrl},
.completer = {[&](size_t, std::string_view prefix) {
completeFlakeRef(getStore(), prefix);
}}
});
}
FlakeRef getFlakeRef()
{
return parseFlakeRef(flakeUrl, absPath(".")); //FIXME
}
LockedFlake lockFlake()
{
return flake::lockFlake(*getEvalState(), getFlakeRef(), lockFlags);
}
std::vector<std::string> getFlakesForCompletion() override
{
return {flakeUrl};
}
};
struct CmdFlakeUpdate : FlakeCommand
{
std::string description() override
{
return "update flake lock file";
}
CmdFlakeUpdate()
{
/* Remove flags that don't make sense. */
removeFlag("recreate-lock-file");
removeFlag("update-input");
removeFlag("no-update-lock-file");
removeFlag("no-write-lock-file");
}
std::string doc() override
{
return
#include "flake-update.md"
;
}
void run(nix::ref<nix::Store> store) override
{
settings.tarballTtl = 0;
lockFlags.recreateLockFile = true;
lockFlags.writeLockFile = true;
lockFlags.applyNixConfig = true;
lockFlake();
}
};
struct CmdFlakeLock : FlakeCommand
{
std::string description() override
{
return "create missing lock file entries";
}
CmdFlakeLock()
{
/* Remove flags that don't make sense. */
removeFlag("no-write-lock-file");
}
std::string doc() override
{
return
#include "flake-lock.md"
;
}
void run(nix::ref<nix::Store> store) override
{
settings.tarballTtl = 0;
lockFlags.writeLockFile = true;
lockFlags.applyNixConfig = true;
lockFlake();
}
};
static void enumerateOutputs(EvalState & state, Value & vFlake,
std::function<void(const std::string & name, Value & vProvide, const PosIdx pos)> callback)
{
auto pos = vFlake.determinePos(noPos);
state.forceAttrs(vFlake, pos, "while evaluating a flake to get its outputs");
auto aOutputs = vFlake.attrs->get(state.symbols.create("outputs"));
assert(aOutputs);
state.forceAttrs(*aOutputs->value, pos, "while evaluating the outputs of a flake");
auto sHydraJobs = state.symbols.create("hydraJobs");
/* Hack: ensure that hydraJobs is evaluated before anything
else. This way we can disable IFD for hydraJobs and then enable
it for other outputs. */
if (auto attr = aOutputs->value->attrs->get(sHydraJobs))
callback(state.symbols[attr->name], *attr->value, attr->pos);
for (auto & attr : *aOutputs->value->attrs) {
if (attr.name != sHydraJobs)
callback(state.symbols[attr.name], *attr.value, attr.pos);
}
}
struct CmdFlakeMetadata : FlakeCommand, MixJSON
{
std::string description() override
{
return "show flake metadata";
}
std::string doc() override
{
return
#include "flake-metadata.md"
;
}
void run(nix::ref<nix::Store> store) override
{
auto lockedFlake = lockFlake();
auto & flake = lockedFlake.flake;
if (json) {
nlohmann::json j;
if (flake.description)
j["description"] = *flake.description;
j["originalUrl"] = flake.originalRef.to_string();
j["original"] = fetchers::attrsToJSON(flake.originalRef.toAttrs());
j["resolvedUrl"] = flake.resolvedRef.to_string();
j["resolved"] = fetchers::attrsToJSON(flake.resolvedRef.toAttrs());
j["url"] = flake.lockedRef.to_string(); // FIXME: rename to lockedUrl
j["locked"] = fetchers::attrsToJSON(flake.lockedRef.toAttrs());
if (auto rev = flake.lockedRef.input.getRev())
j["revision"] = rev->to_string(Base16, false);
if (auto revCount = flake.lockedRef.input.getRevCount())
j["revCount"] = *revCount;
if (auto lastModified = flake.lockedRef.input.getLastModified())
j["lastModified"] = *lastModified;
j["path"] = store->printStorePath(flake.sourceInfo->storePath);
j["locks"] = lockedFlake.lockFile.toJSON();
logger->cout("%s", j.dump());
} else {
logger->cout(
ANSI_BOLD "Resolved URL:" ANSI_NORMAL " %s",
flake.resolvedRef.to_string());
logger->cout(
ANSI_BOLD "Locked URL:" ANSI_NORMAL " %s",
flake.lockedRef.to_string());
if (flake.description)
logger->cout(
ANSI_BOLD "Description:" ANSI_NORMAL " %s",
*flake.description);
logger->cout(
ANSI_BOLD "Path:" ANSI_NORMAL " %s",
store->printStorePath(flake.sourceInfo->storePath));
if (auto rev = flake.lockedRef.input.getRev())
logger->cout(
ANSI_BOLD "Revision:" ANSI_NORMAL " %s",
rev->to_string(Base16, false));
if (auto revCount = flake.lockedRef.input.getRevCount())
logger->cout(
ANSI_BOLD "Revisions:" ANSI_NORMAL " %s",
*revCount);
if (auto lastModified = flake.lockedRef.input.getLastModified())
logger->cout(
ANSI_BOLD "Last modified:" ANSI_NORMAL " %s",
std::put_time(std::localtime(&*lastModified), "%F %T"));
if (!lockedFlake.lockFile.root->inputs.empty())
logger->cout(ANSI_BOLD "Inputs:" ANSI_NORMAL);
std::set<ref<Node>> visited;
std::function<void(const Node & node, const std::string & prefix)> recurse;
recurse = [&](const Node & node, const std::string & prefix)
{
for (const auto & [i, input] : enumerate(node.inputs)) {
bool last = i + 1 == node.inputs.size();
if (auto lockedNode = std::get_if<0>(&input.second)) {
logger->cout("%s" ANSI_BOLD "%s" ANSI_NORMAL ": %s",
prefix + (last ? treeLast : treeConn), input.first,
(*lockedNode)->lockedRef);
bool firstVisit = visited.insert(*lockedNode).second;
if (firstVisit) recurse(**lockedNode, prefix + (last ? treeNull : treeLine));
} else if (auto follows = std::get_if<1>(&input.second)) {
logger->cout("%s" ANSI_BOLD "%s" ANSI_NORMAL " follows input '%s'",
prefix + (last ? treeLast : treeConn), input.first,
printInputPath(*follows));
}
}
};
visited.insert(lockedFlake.lockFile.root);
recurse(*lockedFlake.lockFile.root, "");
}
}
};
struct CmdFlakeInfo : CmdFlakeMetadata
{
void run(nix::ref<nix::Store> store) override
{
warn("'nix flake info' is a deprecated alias for 'nix flake metadata'");
CmdFlakeMetadata::run(store);
}
};
struct CmdFlakeCheck : FlakeCommand
{
bool build = true;
CmdFlakeCheck()
{
addFlag({
.longName = "no-build",
.description = "Do not build checks.",
.handler = {&build, false}
});
}
std::string description() override
{
return "check whether the flake evaluates and run its tests";
}
std::string doc() override
{
return
#include "flake-check.md"
;
}
void run(nix::ref<nix::Store> store) override
{
if (!build) {
settings.readOnlyMode = true;
evalSettings.enableImportFromDerivation.setDefault(false);
}
auto state = getEvalState();
lockFlags.applyNixConfig = true;
auto flake = lockFlake();
bool hasErrors = false;
auto reportError = [&](const Error & e) {
try {
throw e;
} catch (Error & e) {
if (settings.keepGoing) {
ignoreException();
hasErrors = true;
}
else
throw;
}
};
// FIXME: rewrite to use EvalCache.
auto resolve = [&] (PosIdx p) {
return state->positions[p];
};
auto argHasName = [&] (Symbol arg, std::string_view expected) {
std::string_view name = state->symbols[arg];
return
name == expected
|| name == "_"
|| (hasPrefix(name, "_") && name.substr(1) == expected);
};
auto checkSystemName = [&](const std::string & system, const PosIdx pos) {
// FIXME: what's the format of "system"?
if (system.find('-') == std::string::npos)
reportError(Error("'%s' is not a valid system type, at %s", system, resolve(pos)));
};
auto checkDerivation = [&](const std::string & attrPath, Value & v, const PosIdx pos) -> std::optional<StorePath> {
try {
auto drvInfo = getDerivation(*state, v, false);
if (!drvInfo)
throw Error("flake attribute '%s' is not a derivation", attrPath);
// FIXME: check meta attributes
return drvInfo->queryDrvPath();
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the derivation '%s'", attrPath));
reportError(e);
}
return std::nullopt;
};
std::vector<DerivedPath> drvPaths;
auto checkApp = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
try {
#if 0
// FIXME
auto app = App(*state, v);
for (auto & i : app.context) {
auto [drvPathS, outputName] = NixStringContextElem::parse(i);
store->parseStorePath(drvPathS);
}
#endif
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the app definition '%s'", attrPath));
reportError(e);
}
};
auto checkOverlay = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
try {
state->forceValue(v, pos);
if (!v.isLambda()
|| v.lambda.fun->hasFormals()
|| !argHasName(v.lambda.fun->arg, "final"))
throw Error("overlay does not take an argument named 'final'");
auto body = dynamic_cast<ExprLambda *>(v.lambda.fun->body);
if (!body
|| body->hasFormals()
|| !argHasName(body->arg, "prev"))
throw Error("overlay does not take an argument named 'prev'");
// FIXME: if we have a 'nixpkgs' input, use it to
// evaluate the overlay.
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the overlay '%s'", attrPath));
reportError(e);
}
};
auto checkModule = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
try {
state->forceValue(v, pos);
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the NixOS module '%s'", attrPath));
reportError(e);
}
};
std::function<void(const std::string & attrPath, Value & v, const PosIdx pos)> checkHydraJobs;
checkHydraJobs = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
try {
state->forceAttrs(v, pos, "");
if (state->isDerivation(v))
throw Error("jobset should not be a derivation at top-level");
for (auto & attr : *v.attrs) {
state->forceAttrs(*attr.value, attr.pos, "");
auto attrPath2 = concatStrings(attrPath, ".", state->symbols[attr.name]);
if (state->isDerivation(*attr.value)) {
Activity act(*logger, lvlChatty, actUnknown,
fmt("checking Hydra job '%s'", attrPath2));
checkDerivation(attrPath2, *attr.value, attr.pos);
} else
checkHydraJobs(attrPath2, *attr.value, attr.pos);
}
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the Hydra jobset '%s'", attrPath));
reportError(e);
}
};
auto checkNixOSConfiguration = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
try {
Activity act(*logger, lvlChatty, actUnknown,
fmt("checking NixOS configuration '%s'", attrPath));
Bindings & bindings(*state->allocBindings(0));
auto vToplevel = findAlongAttrPath(*state, "config.system.build.toplevel", bindings, v).first;
state->forceValue(*vToplevel, pos);
if (!state->isDerivation(*vToplevel))
throw Error("attribute 'config.system.build.toplevel' is not a derivation");
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the NixOS configuration '%s'", attrPath));
reportError(e);
}
};
auto checkTemplate = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
try {
Activity act(*logger, lvlChatty, actUnknown,
fmt("checking template '%s'", attrPath));
state->forceAttrs(v, pos, "");
if (auto attr = v.attrs->get(state->symbols.create("path"))) {
if (attr->name == state->symbols.create("path")) {
PathSet context;
auto path = state->coerceToPath(attr->pos, *attr->value, context, "");
if (!store->isInStore(path))
throw Error("template '%s' has a bad 'path' attribute");
// TODO: recursively check the flake in 'path'.
}
} else
throw Error("template '%s' lacks attribute 'path'", attrPath);
if (auto attr = v.attrs->get(state->symbols.create("description")))
state->forceStringNoCtx(*attr->value, attr->pos, "");
else
throw Error("template '%s' lacks attribute 'description'", attrPath);
for (auto & attr : *v.attrs) {
std::string_view name(state->symbols[attr.name]);
if (name != "path" && name != "description" && name != "welcomeText")
throw Error("template '%s' has unsupported attribute '%s'", attrPath, name);
}
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the template '%s'", attrPath));
reportError(e);
}
};
auto checkBundler = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
try {
state->forceValue(v, pos);
if (!v.isLambda())
throw Error("bundler must be a function");
// TODO: check types of inputs/outputs?
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking the template '%s'", attrPath));
reportError(e);
}
};
{
Activity act(*logger, lvlInfo, actUnknown, "evaluating flake");
auto vFlake = state->allocValue();
flake::callFlake(*state, flake, *vFlake);
enumerateOutputs(*state,
*vFlake,
[&](const std::string & name, Value & vOutput, const PosIdx pos) {
Activity act(*logger, lvlChatty, actUnknown,
fmt("checking flake output '%s'", name));
try {
evalSettings.enableImportFromDerivation.setDefault(name != "hydraJobs");
state->forceValue(vOutput, pos);
std::string_view replacement =
name == "defaultPackage" ? "packages.<system>.default" :
name == "defaultApp" ? "apps.<system>.default" :
name == "defaultTemplate" ? "templates.default" :
name == "defaultBundler" ? "bundlers.<system>.default" :
name == "overlay" ? "overlays.default" :
name == "devShell" ? "devShells.<system>.default" :
name == "nixosModule" ? "nixosModules.default" :
"";
if (replacement != "")
warn("flake output attribute '%s' is deprecated; use '%s' instead", name, replacement);
if (name == "checks") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
state->forceAttrs(*attr.value, attr.pos, "");
for (auto & attr2 : *attr.value->attrs) {
auto drvPath = checkDerivation(
fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
*attr2.value, attr2.pos);
if (drvPath && attr_name == settings.thisSystem.get()) {
drvPaths.push_back(DerivedPath::Built {
.drvPath = *drvPath,
.outputs = OutputsSpec::All { },
});
}
}
}
}
else if (name == "formatter") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
checkApp(
fmt("%s.%s", name, attr_name),
*attr.value, attr.pos);
}
}
else if (name == "packages" || name == "devShells") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
state->forceAttrs(*attr.value, attr.pos, "");
for (auto & attr2 : *attr.value->attrs)
checkDerivation(
fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
*attr2.value, attr2.pos);
}
}
else if (name == "apps") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
state->forceAttrs(*attr.value, attr.pos, "");
for (auto & attr2 : *attr.value->attrs)
checkApp(
fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
*attr2.value, attr2.pos);
}
}
else if (name == "defaultPackage" || name == "devShell") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
checkDerivation(
fmt("%s.%s", name, attr_name),
*attr.value, attr.pos);
}
}
else if (name == "defaultApp") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
checkApp(
fmt("%s.%s", name, attr_name),
*attr.value, attr.pos);
}
}
else if (name == "legacyPackages") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
checkSystemName(state->symbols[attr.name], attr.pos);
// FIXME: do getDerivations?
}
}
else if (name == "overlay")
checkOverlay(name, vOutput, pos);
else if (name == "overlays") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs)
checkOverlay(fmt("%s.%s", name, state->symbols[attr.name]),
*attr.value, attr.pos);
}
else if (name == "nixosModule")
checkModule(name, vOutput, pos);
else if (name == "nixosModules") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs)
checkModule(fmt("%s.%s", name, state->symbols[attr.name]),
*attr.value, attr.pos);
}
else if (name == "nixosConfigurations") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs)
checkNixOSConfiguration(fmt("%s.%s", name, state->symbols[attr.name]),
*attr.value, attr.pos);
}
else if (name == "hydraJobs")
checkHydraJobs(name, vOutput, pos);
else if (name == "defaultTemplate")
checkTemplate(name, vOutput, pos);
else if (name == "templates") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs)
checkTemplate(fmt("%s.%s", name, state->symbols[attr.name]),
*attr.value, attr.pos);
}
else if (name == "defaultBundler") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
checkBundler(
fmt("%s.%s", name, attr_name),
*attr.value, attr.pos);
}
}
else if (name == "bundlers") {
state->forceAttrs(vOutput, pos, "");
for (auto & attr : *vOutput.attrs) {
const auto & attr_name = state->symbols[attr.name];
checkSystemName(attr_name, attr.pos);
state->forceAttrs(*attr.value, attr.pos, "");
for (auto & attr2 : *attr.value->attrs) {
checkBundler(
fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
*attr2.value, attr2.pos);
}
}
}
else if (
name == "lib"
|| name == "darwinConfigurations"
|| name == "darwinModules"
|| name == "flakeModule"
|| name == "flakeModules"
|| name == "herculesCI"
|| name == "homeConfigurations"
|| name == "nixopsConfigurations"
)
// Known but unchecked community attribute
;
else
warn("unknown flake output '%s'", name);
} catch (Error & e) {
e.addTrace(resolve(pos), hintfmt("while checking flake output '%s'", name));
reportError(e);
}
});
}
if (build && !drvPaths.empty()) {
Activity act(*logger, lvlInfo, actUnknown, "running flake checks");
store->buildPaths(drvPaths);
}
if (hasErrors)
throw Error("some errors were encountered during the evaluation");
}
};
static Strings defaultTemplateAttrPathsPrefixes{"templates."};
static Strings defaultTemplateAttrPaths = {"templates.default", "defaultTemplate"};
struct CmdFlakeInitCommon : virtual Args, EvalCommand
{
std::string templateUrl = "templates";
Path destDir;
const LockFlags lockFlags{ .writeLockFile = false };
CmdFlakeInitCommon()
{
addFlag({
.longName = "template",
.shortName = 't',
.description = "The template to use.",
.labels = {"template"},
.handler = {&templateUrl},
.completer = {[&](size_t, std::string_view prefix) {
completeFlakeRefWithFragment(
getEvalState(),
lockFlags,
defaultTemplateAttrPathsPrefixes,
defaultTemplateAttrPaths,
prefix);
}}
});
}
void run(nix::ref<nix::Store> store) override
{
auto flakeDir = absPath(destDir);
auto evalState = getEvalState();
auto [templateFlakeRef, templateName] = parseFlakeRefWithFragment(templateUrl, absPath("."));
auto installable = InstallableFlake(nullptr,
evalState, std::move(templateFlakeRef), templateName, DefaultOutputs(),
defaultTemplateAttrPaths,
defaultTemplateAttrPathsPrefixes,
lockFlags);
auto cursor = installable.getCursor(*evalState);
auto templateDirAttr = cursor->getAttr("path");
auto templateDir = templateDirAttr->getString();
if (!store->isInStore(templateDir))
throw TypeError(
"'%s' was not found in the Nix store\n"
"If you've set '%s' to a string, try using a path instead.",
templateDir, templateDirAttr->getAttrPathStr());
std::vector<Path> changedFiles;
std::vector<Path> conflictedFiles;
std::function<void(const Path & from, const Path & to)> copyDir;
copyDir = [&](const Path & from, const Path & to)
{
createDirs(to);
for (auto & entry : readDirectory(from)) {
auto from2 = from + "/" + entry.name;
auto to2 = to + "/" + entry.name;
auto st = lstat(from2);
if (S_ISDIR(st.st_mode))
copyDir(from2, to2);
else if (S_ISREG(st.st_mode)) {
auto contents = readFile(from2);
if (pathExists(to2)) {
auto contents2 = readFile(to2);
if (contents != contents2) {
printError("refusing to overwrite existing file '%s'\n please merge it manually with '%s'", to2, from2);
conflictedFiles.push_back(to2);
} else {
notice("skipping identical file: %s", from2);
}
continue;
} else
writeFile(to2, contents);
}
else if (S_ISLNK(st.st_mode)) {
auto target = readLink(from2);
if (pathExists(to2)) {
if (readLink(to2) != target) {
printError("refusing to overwrite existing file '%s'\n please merge it manually with '%s'", to2, from2);
conflictedFiles.push_back(to2);
} else {
notice("skipping identical file: %s", from2);
}
continue;
} else
createSymlink(target, to2);
}
else
throw Error("file '%s' has unsupported type", from2);
changedFiles.push_back(to2);
notice("wrote: %s", to2);
}
};
copyDir(templateDir, flakeDir);
if (!changedFiles.empty() && pathExists(flakeDir + "/.git")) {
Strings args = { "-C", flakeDir, "add", "--intent-to-add", "--force", "--" };
for (auto & s : changedFiles) args.push_back(s);
runProgram("git", true, args);
}
auto welcomeText = cursor->maybeGetAttr("welcomeText");
if (welcomeText) {
notice("\n");
notice(renderMarkdownToTerminal(welcomeText->getString()));
}
if (!conflictedFiles.empty())
throw Error("Encountered %d conflicts - see above", conflictedFiles.size());
}
};
struct CmdFlakeInit : CmdFlakeInitCommon
{
std::string description() override
{
return "create a flake in the current directory from a template";
}
std::string doc() override
{
return
#include "flake-init.md"
;
}
CmdFlakeInit()
{
destDir = ".";
}
};
struct CmdFlakeNew : CmdFlakeInitCommon
{
std::string description() override
{
return "create a flake in the specified directory from a template";
}
std::string doc() override
{
return
#include "flake-new.md"
;
}
CmdFlakeNew()
{
expectArgs({
.label = "dest-dir",
.handler = {&destDir},
.completer = completePath
});
}
};
struct CmdFlakeClone : FlakeCommand
{
Path destDir;
std::string description() override
{
return "clone flake repository";
}
std::string doc() override
{
return
#include "flake-clone.md"
;
}
CmdFlakeClone()
{
addFlag({
.longName = "dest",
.shortName = 'f',
.description = "Clone the flake to path *dest*.",
.labels = {"path"},
.handler = {&destDir}
});
}
void run(nix::ref<nix::Store> store) override
{
if (destDir.empty())
throw Error("missing flag '--dest'");
getFlakeRef().resolve(store).input.clone(destDir);
}
};
struct CmdFlakeArchive : FlakeCommand, MixJSON, MixDryRun
{
std::string dstUri;
CmdFlakeArchive()
{
addFlag({
.longName = "to",
.description = "URI of the destination Nix store",
.labels = {"store-uri"},
.handler = {&dstUri}
});
}
std::string description() override
{
return "copy a flake and all its inputs to a store";
}
std::string doc() override
{
return
#include "flake-archive.md"
;
}
void run(nix::ref<nix::Store> store) override
{
auto flake = lockFlake();
StorePathSet sources;
sources.insert(flake.flake.sourceInfo->storePath);
// FIXME: use graph output, handle cycles.
std::function<nlohmann::json(const Node & node)> traverse;
traverse = [&](const Node & node)
{
nlohmann::json jsonObj2 = json ? json::object() : nlohmann::json(nullptr);
for (auto & [inputName, input] : node.inputs) {
if (auto inputNode = std::get_if<0>(&input)) {
auto storePath =
dryRun
? (*inputNode)->lockedRef.input.computeStorePath(*store)
: (*inputNode)->lockedRef.input.fetch(store).first.storePath;
if (json) {
auto& jsonObj3 = jsonObj2[inputName];
jsonObj3["path"] = store->printStorePath(storePath);
sources.insert(std::move(storePath));
jsonObj3["inputs"] = traverse(**inputNode);
} else {
sources.insert(std::move(storePath));
traverse(**inputNode);
}
}
}
return jsonObj2;
};
if (json) {
nlohmann::json jsonRoot = {
{"path", store->printStorePath(flake.flake.sourceInfo->storePath)},
{"inputs", traverse(*flake.lockFile.root)},
};
logger->cout("%s", jsonRoot);
} else {
traverse(*flake.lockFile.root);
}
if (!dryRun && !dstUri.empty()) {
ref<Store> dstStore = dstUri.empty() ? openStore() : openStore(dstUri);
copyPaths(*store, *dstStore, sources);
}
}
};
struct CmdFlakeShow : FlakeCommand, MixJSON
{
bool showLegacy = false;
bool showAllSystems = false;
CmdFlakeShow()
{
addFlag({
.longName = "legacy",
.description = "Show the contents of the `legacyPackages` output.",
.handler = {&showLegacy, true}
});
addFlag({
.longName = "all-systems",
.description = "Show the contents of outputs for all systems.",
.handler = {&showAllSystems, true}
});
}
std::string description() override
{
return "show the outputs provided by a flake";
}
std::string doc() override
{
return
#include "flake-show.md"
;
}
void run(nix::ref<nix::Store> store) override
{
evalSettings.enableImportFromDerivation.setDefault(false);
auto state = getEvalState();
auto flake = std::make_shared<LockedFlake>(lockFlake());
auto localSystem = std::string(settings.thisSystem.get());
std::function<bool(
eval_cache::AttrCursor & visitor,
const std::vector<Symbol> &attrPath,
const Symbol &attr)> hasContent;
// For frameworks it's important that structures are as lazy as possible
// to prevent infinite recursions, performance issues and errors that
// aren't related to the thing to evaluate. As a consequence, they have
// to emit more attributes than strictly (sic) necessary.
// However, these attributes with empty values are not useful to the user
// so we omit them.
hasContent = [&](
eval_cache::AttrCursor & visitor,
const std::vector<Symbol> &attrPath,
const Symbol &attr) -> bool
{
auto attrPath2(attrPath);
attrPath2.push_back(attr);
auto attrPathS = state->symbols.resolve(attrPath2);
const auto & attrName = state->symbols[attr];
auto visitor2 = visitor.getAttr(attrName);
if ((attrPathS[0] == "apps"
|| attrPathS[0] == "checks"
|| attrPathS[0] == "devShells"
|| attrPathS[0] == "legacyPackages"
|| attrPathS[0] == "packages")
&& (attrPathS.size() == 1 || attrPathS.size() == 2)) {
for (const auto &subAttr : visitor2->getAttrs()) {
if (hasContent(*visitor2, attrPath2, subAttr)) {
return true;
}
}
return false;
}
if ((attrPathS.size() == 1)
&& (attrPathS[0] == "formatter"
|| attrPathS[0] == "nixosConfigurations"
|| attrPathS[0] == "nixosModules"
|| attrPathS[0] == "overlays"
)) {
for (const auto &subAttr : visitor2->getAttrs()) {
if (hasContent(*visitor2, attrPath2, subAttr)) {
return true;
}
}
return false;
}
// If we don't recognize it, it's probably content
return true;
};
std::function<nlohmann::json(
eval_cache::AttrCursor & visitor,
const std::vector<Symbol> & attrPath,
const std::string & headerPrefix,
const std::string & nextPrefix)> visit;
visit = [&](
eval_cache::AttrCursor & visitor,
const std::vector<Symbol> & attrPath,
const std::string & headerPrefix,
const std::string & nextPrefix)
-> nlohmann::json
{
auto j = nlohmann::json::object();
auto attrPathS = state->symbols.resolve(attrPath);
Activity act(*logger, lvlInfo, actUnknown,
fmt("evaluating '%s'", concatStringsSep(".", attrPathS)));
try {
auto recurse = [&]()
{
if (!json)
logger->cout("%s", headerPrefix);
std::vector<Symbol> attrs;
for (const auto &attr : visitor.getAttrs()) {
if (hasContent(visitor, attrPath, attr))
attrs.push_back(attr);
}
for (const auto & [i, attr] : enumerate(attrs)) {
const auto & attrName = state->symbols[attr];
bool last = i + 1 == attrs.size();
auto visitor2 = visitor.getAttr(attrName);
auto attrPath2(attrPath);
attrPath2.push_back(attr);
auto j2 = visit(*visitor2, attrPath2,
fmt(ANSI_GREEN "%s%s" ANSI_NORMAL ANSI_BOLD "%s" ANSI_NORMAL, nextPrefix, last ? treeLast : treeConn, attrName),
nextPrefix + (last ? treeNull : treeLine));
if (json) j.emplace(attrName, std::move(j2));
}
};
auto showDerivation = [&]()
{
auto name = visitor.getAttr(state->sName)->getString();
if (json) {
std::optional<std::string> description;
if (auto aMeta = visitor.maybeGetAttr(state->sMeta)) {
if (auto aDescription = aMeta->maybeGetAttr(state->sDescription))
description = aDescription->getString();
}
j.emplace("type", "derivation");
j.emplace("name", name);
if (description)
j.emplace("description", *description);
} else {
logger->cout("%s: %s '%s'",
headerPrefix,
attrPath.size() == 2 && attrPathS[0] == "devShell" ? "development environment" :
attrPath.size() >= 2 && attrPathS[0] == "devShells" ? "development environment" :
attrPath.size() == 3 && attrPathS[0] == "checks" ? "derivation" :
attrPath.size() >= 1 && attrPathS[0] == "hydraJobs" ? "derivation" :
"package",
name);
}
};
if (attrPath.size() == 0
|| (attrPath.size() == 1 && (
attrPathS[0] == "defaultPackage"
|| attrPathS[0] == "devShell"
|| attrPathS[0] == "formatter"
|| attrPathS[0] == "nixosConfigurations"
|| attrPathS[0] == "nixosModules"
|| attrPathS[0] == "defaultApp"
|| attrPathS[0] == "templates"
|| attrPathS[0] == "overlays"))
|| ((attrPath.size() == 1 || attrPath.size() == 2)
&& (attrPathS[0] == "checks"
|| attrPathS[0] == "packages"
|| attrPathS[0] == "devShells"
|| attrPathS[0] == "apps"))
)
{
recurse();
}
else if (
(attrPath.size() == 2 && (attrPathS[0] == "defaultPackage" || attrPathS[0] == "devShell" || attrPathS[0] == "formatter"))
|| (attrPath.size() == 3 && (attrPathS[0] == "checks" || attrPathS[0] == "packages" || attrPathS[0] == "devShells"))
)
{
if (!showAllSystems && std::string(attrPathS[1]) != localSystem) {
if (!json)
logger->cout(fmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--all-systems' to show)", headerPrefix));
else {
logger->warn(fmt("%s omitted (use '--all-systems' to show)", concatStringsSep(".", attrPathS)));
}
} else {
if (visitor.isDerivation())
showDerivation();
else
throw Error("expected a derivation");
}
}
else if (attrPath.size() > 0 && attrPathS[0] == "hydraJobs") {
if (visitor.isDerivation())
showDerivation();
else
recurse();
}
else if (attrPath.size() > 0 && attrPathS[0] == "legacyPackages") {
if (attrPath.size() == 1)
recurse();
else if (!showLegacy){
if (!json)
logger->cout(fmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--legacy' to show)", headerPrefix));
else {
logger->warn(fmt("%s omitted (use '--legacy' to show)", concatStringsSep(".", attrPathS)));
}
} else if (!showAllSystems && std::string(attrPathS[1]) != localSystem) {
if (!json)
logger->cout(fmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--all-systems' to show)", headerPrefix));
else {
logger->warn(fmt("%s omitted (use '--all-systems' to show)", concatStringsSep(".", attrPathS)));
}
} else {
if (visitor.isDerivation())
showDerivation();
else if (attrPath.size() <= 2)
// FIXME: handle recurseIntoAttrs
recurse();
}
}
else if (
(attrPath.size() == 2 && attrPathS[0] == "defaultApp") ||
(attrPath.size() == 3 && attrPathS[0] == "apps"))
{
auto aType = visitor.maybeGetAttr("type");
if (!aType || aType->getString() != "app")
throw EvalError("not an app definition");
if (json) {
j.emplace("type", "app");
} else {
logger->cout("%s: app", headerPrefix);
}
}
else if (
(attrPath.size() == 1 && attrPathS[0] == "defaultTemplate") ||
(attrPath.size() == 2 && attrPathS[0] == "templates"))
{
auto description = visitor.getAttr("description")->getString();
if (json) {
j.emplace("type", "template");
j.emplace("description", description);
} else {
logger->cout("%s: template: " ANSI_BOLD "%s" ANSI_NORMAL, headerPrefix, description);
}
}
else {
auto [type, description] =
(attrPath.size() == 1 && attrPathS[0] == "overlay")
|| (attrPath.size() == 2 && attrPathS[0] == "overlays") ? std::make_pair("nixpkgs-overlay", "Nixpkgs overlay") :
attrPath.size() == 2 && attrPathS[0] == "nixosConfigurations" ? std::make_pair("nixos-configuration", "NixOS configuration") :
(attrPath.size() == 1 && attrPathS[0] == "nixosModule")
|| (attrPath.size() == 2 && attrPathS[0] == "nixosModules") ? std::make_pair("nixos-module", "NixOS module") :
std::make_pair("unknown", "unknown");
if (json) {
j.emplace("type", type);
} else {
logger->cout("%s: " ANSI_WARNING "%s" ANSI_NORMAL, headerPrefix, description);
}
}
} catch (EvalError & e) {
if (!(attrPath.size() > 0 && attrPathS[0] == "legacyPackages"))
throw;
}
return j;
};
auto cache = openEvalCache(*state, flake);
auto j = visit(*cache->getRoot(), {}, fmt(ANSI_BOLD "%s" ANSI_NORMAL, flake->flake.lockedRef), "");
if (json)
logger->cout("%s", j.dump());
}
};
struct CmdFlakePrefetch : FlakeCommand, MixJSON
{
CmdFlakePrefetch()
{
}
std::string description() override
{
return "download the source tree denoted by a flake reference into the Nix store";
}
std::string doc() override
{
return
#include "flake-prefetch.md"
;
}
void run(ref<Store> store) override
{
auto originalRef = getFlakeRef();
auto resolvedRef = originalRef.resolve(store);
auto [tree, lockedRef] = resolvedRef.fetchTree(store);
auto hash = store->queryPathInfo(tree.storePath)->narHash;
if (json) {
auto res = nlohmann::json::object();
res["storePath"] = store->printStorePath(tree.storePath);
res["hash"] = hash.to_string(SRI, true);
logger->cout(res.dump());
} else {
notice("Downloaded '%s' to '%s' (hash '%s').",
lockedRef.to_string(),
store->printStorePath(tree.storePath),
hash.to_string(SRI, true));
}
}
};
struct CmdFlake : NixMultiCommand
{
CmdFlake()
: MultiCommand({
{"update", []() { return make_ref<CmdFlakeUpdate>(); }},
{"lock", []() { return make_ref<CmdFlakeLock>(); }},
{"metadata", []() { return make_ref<CmdFlakeMetadata>(); }},
{"info", []() { return make_ref<CmdFlakeInfo>(); }},
{"check", []() { return make_ref<CmdFlakeCheck>(); }},
{"init", []() { return make_ref<CmdFlakeInit>(); }},
{"new", []() { return make_ref<CmdFlakeNew>(); }},
{"clone", []() { return make_ref<CmdFlakeClone>(); }},
{"archive", []() { return make_ref<CmdFlakeArchive>(); }},
{"show", []() { return make_ref<CmdFlakeShow>(); }},
{"prefetch", []() { return make_ref<CmdFlakePrefetch>(); }},
})
{
}
std::string description() override
{
return "manage Nix flakes";
}
std::string doc() override
{
return
#include "flake.md"
;
}
void run() override
{
if (!command)
throw UsageError("'nix flake' requires a sub-command.");
settings.requireExperimentalFeature(Xp::Flakes);
command->second->run();
}
};
static auto rCmdFlake = registerCommand<CmdFlake>("flake");