Factor out abstract syntax for Store URIs

Need to decouple parsing from actually opening a store for Machine
configs.

Co-authored-by: Théophane Hufschmitt <7226587+thufschmitt@users.noreply.github.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
This commit is contained in:
John Ericson 2024-01-23 14:23:03 -05:00
parent 1d6c2316a9
commit c036d75f9e
4 changed files with 236 additions and 132 deletions

View file

@ -8,7 +8,6 @@
#include "util.hh"
#include "nar-info-disk-cache.hh"
#include "thread-pool.hh"
#include "url.hh"
#include "references.hh"
#include "archive.hh"
#include "callback.hh"
@ -1267,109 +1266,63 @@ Derivation Store::readInvalidDerivation(const StorePath & drvPath)
namespace nix {
/* Split URI into protocol+hierarchy part and its parameter set. */
std::pair<std::string, Store::Params> splitUriAndParams(const std::string & uri_)
{
auto uri(uri_);
Store::Params params;
auto q = uri.find('?');
if (q != std::string::npos) {
params = decodeQuery(uri.substr(q + 1));
uri = uri_.substr(0, q);
}
return {uri, params};
}
static bool isNonUriPath(const std::string & spec)
{
return
// is not a URL
spec.find("://") == std::string::npos
// Has at least one path separator, and so isn't a single word that
// might be special like "auto"
&& spec.find("/") != std::string::npos;
}
std::shared_ptr<Store> openFromNonUri(const std::string & uri, const Store::Params & params)
{
// TODO reenable on Windows once we have `LocalStore` and
// `UDSRemoteStore`.
if (uri == "" || uri == "auto") {
auto stateDir = getOr(params, "state", settings.nixStateDir);
if (access(stateDir.c_str(), R_OK | W_OK) == 0)
return std::make_shared<LocalStore>(params);
else if (pathExists(settings.nixDaemonSocketFile))
return std::make_shared<UDSRemoteStore>(params);
#if __linux__
else if (!pathExists(stateDir)
&& params.empty()
&& !isRootUser()
&& !getEnv("NIX_STORE_DIR").has_value()
&& !getEnv("NIX_STATE_DIR").has_value())
{
/* If /nix doesn't exist, there is no daemon socket, and
we're not root, then automatically set up a chroot
store in ~/.local/share/nix/root. */
auto chrootStore = getDataDir() + "/nix/root";
if (!pathExists(chrootStore)) {
try {
createDirs(chrootStore);
} catch (Error & e) {
return std::make_shared<LocalStore>(params);
}
warn("'%s' does not exist, so Nix will use '%s' as a chroot store", stateDir, chrootStore);
} else
debug("'%s' does not exist, so Nix will use '%s' as a chroot store", stateDir, chrootStore);
return std::make_shared<LocalStore>("local", chrootStore, params);
}
#endif
else
return std::make_shared<LocalStore>(params);
} else if (uri == "daemon") {
return std::make_shared<UDSRemoteStore>(params);
} else if (uri == "local") {
return std::make_shared<LocalStore>(params);
} else if (isNonUriPath(uri)) {
return std::make_shared<LocalStore>("local", absPath(uri), params);
} else {
return nullptr;
}
}
ref<Store> openStore(const std::string & uri_,
ref<Store> openStore(const std::string & uri,
const Store::Params & extraParams)
{
auto params = extraParams;
try {
auto parsedUri = parseURL(uri_);
params.insert(parsedUri.query.begin(), parsedUri.query.end());
return openStore(StoreReference::parse(uri, extraParams));
}
auto baseURI = parsedUri.authority.value_or("") + parsedUri.path;
ref<Store> openStore(StoreReference && storeURI)
{
auto & params = storeURI.params;
for (auto implem : *Implementations::registered) {
if (implem.uriSchemes.count(parsedUri.scheme)) {
auto store = implem.create(parsedUri.scheme, baseURI, params);
if (store) {
experimentalFeatureSettings.require(store->experimentalFeature());
store->init();
store->warnUnknownSettings();
return ref<Store>(store);
}
auto store = std::visit(overloaded {
[&](const StoreReference::Auto &) -> std::shared_ptr<Store> {
auto stateDir = getOr(params, "state", settings.nixStateDir);
if (access(stateDir.c_str(), R_OK | W_OK) == 0)
return std::make_shared<LocalStore>(params);
else if (pathExists(settings.nixDaemonSocketFile))
return std::make_shared<UDSRemoteStore>(params);
#if __linux__
else if (!pathExists(stateDir)
&& params.empty()
&& !isRootUser()
&& !getEnv("NIX_STORE_DIR").has_value()
&& !getEnv("NIX_STATE_DIR").has_value())
{
/* If /nix doesn't exist, there is no daemon socket, and
we're not root, then automatically set up a chroot
store in ~/.local/share/nix/root. */
auto chrootStore = getDataDir() + "/nix/root";
if (!pathExists(chrootStore)) {
try {
createDirs(chrootStore);
} catch (Error & e) {
return std::make_shared<LocalStore>(params);
}
warn("'%s' does not exist, so Nix will use '%s' as a chroot store", stateDir, chrootStore);
} else
debug("'%s' does not exist, so Nix will use '%s' as a chroot store", stateDir, chrootStore);
return std::make_shared<LocalStore>("local", chrootStore, params);
}
}
}
catch (BadURL &) {
auto [uri, uriParams] = splitUriAndParams(uri_);
params.insert(uriParams.begin(), uriParams.end());
#endif
else
return std::make_shared<LocalStore>(params);
},
[&](const StoreReference::Specified & g) {
for (auto implem : *Implementations::registered)
if (implem.uriSchemes.count(g.scheme))
return implem.create(g.scheme, g.authority, params);
if (auto store = openFromNonUri(uri, params)) {
experimentalFeatureSettings.require(store->experimentalFeature());
store->warnUnknownSettings();
return ref<Store>(store);
}
}
throw Error("don't know how to open Nix store with scheme '%s'", g.scheme);
},
}, storeURI.variant);
throw Error("don't know how to open Nix store '%s'", uri_);
experimentalFeatureSettings.require(store->experimentalFeature());
store->warnUnknownSettings();
store->init();
return ref<Store> { store };
}
std::list<ref<Store>> getDefaultSubstituters()

View file

@ -13,6 +13,7 @@
#include "path-info.hh"
#include "repair-flag.hh"
#include "store-dir-config.hh"
#include "store-reference.hh"
#include "source-path.hh"
#include <nlohmann/json_fwd.hpp>
@ -65,7 +66,7 @@ MakeError(Unsupported, Error);
MakeError(SubstituteGone, Error);
MakeError(SubstituterDisabled, Error);
MakeError(InvalidStoreURI, Error);
MakeError(InvalidStoreReference, Error);
struct Realisation;
struct RealisedPath;
@ -102,7 +103,7 @@ typedef std::map<StorePath, std::optional<ContentAddress>> StorePathCAMap;
struct StoreConfig : public StoreDirConfig
{
typedef std::map<std::string, std::string> Params;
using Params = StoreReference::Params;
using StoreDirConfig::StoreDirConfig;
@ -859,34 +860,13 @@ OutputPathMap resolveDerivedPath(Store &, const DerivedPath::Built &, Store * ev
/**
* @return a Store object to access the Nix store denoted by
* uri (slight misnomer...).
*
* @param uri Supported values are:
*
* - local: The Nix store in /nix/store and database in
* /nix/var/nix/db, accessed directly.
*
* - daemon: The Nix store accessed via a Unix domain socket
* connection to nix-daemon.
*
* - unix://<path>: The Nix store accessed via a Unix domain socket
* connection to nix-daemon, with the socket located at <path>.
*
* - auto or : Equivalent to local or daemon depending on
* whether the user has write access to the local Nix
* store/database.
*
* - file://<path>: A binary cache stored in <path>.
*
* - https://<path>: A binary cache accessed via HTTP.
*
* - s3://<path>: A writable binary cache stored on Amazon's Simple
* Storage Service.
*
* - ssh://[user@]<host>: A remote Nix store accessed by running
* nix-store --serve via SSH.
*
* You can pass parameters to the store type by appending
* ?key=value&key=value&... to the URI.
*/
ref<Store> openStore(StoreReference && storeURI);
/**
* Opens the store at `uri`, where `uri` is in the format expected by `StoreReference::parse`
*/
ref<Store> openStore(const std::string & uri = settings.storeUri.get(),
const Store::Params & extraParams = Store::Params());
@ -957,11 +937,6 @@ std::optional<ValidPathInfo> decodeValidPathInfo(
std::istream & str,
std::optional<HashResult> hashGiven = std::nullopt);
/**
* Split URI into protocol+hierarchy part and its parameter set.
*/
std::pair<std::string, Store::Params> splitUriAndParams(const std::string & uri);
const ContentAddress * getDerivationCA(const BasicDerivation & drv);
std::map<DrvOutput, StorePath> drvOutputReferences(

View file

@ -0,0 +1,92 @@
#include <regex>
#include "error.hh"
#include "url.hh"
#include "store-reference.hh"
#include "file-system.hh"
namespace nix {
static bool isNonUriPath(const std::string & spec)
{
return
// is not a URL
spec.find("://") == std::string::npos
// Has at least one path separator, and so isn't a single word that
// might be special like "auto"
&& spec.find("/") != std::string::npos;
}
StoreReference StoreReference::parse(const std::string & uri, const StoreReference::Params & extraParams)
{
auto params = extraParams;
try {
auto parsedUri = parseURL(uri);
params.insert(parsedUri.query.begin(), parsedUri.query.end());
auto baseURI = parsedUri.authority.value_or("") + parsedUri.path;
return {
.variant =
Specified{
.scheme = std::move(parsedUri.scheme),
.authority = std::move(baseURI),
},
.params = std::move(params),
};
} catch (BadURL &) {
auto [baseURI, uriParams] = splitUriAndParams(uri);
params.insert(uriParams.begin(), uriParams.end());
if (baseURI == "" || baseURI == "auto") {
return {
.variant = Auto{},
.params = std::move(params),
};
} else if (baseURI == "daemon") {
return {
.variant =
Specified{
.scheme = "unix",
.authority = "",
},
.params = std::move(params),
};
} else if (baseURI == "local") {
return {
.variant =
Specified{
.scheme = "local",
.authority = "",
},
.params = std::move(params),
};
} else if (isNonUriPath(baseURI)) {
return {
.variant =
Specified{
.scheme = "local",
.authority = absPath(baseURI),
},
.params = std::move(params),
};
}
}
throw UsageError("Cannot parse Nix store '%s'", uri);
}
/* Split URI into protocol+hierarchy part and its parameter set. */
std::pair<std::string, StoreReference::Params> splitUriAndParams(const std::string & uri_)
{
auto uri(uri_);
StoreReference::Params params;
auto q = uri.find('?');
if (q != std::string::npos) {
params = decodeQuery(uri.substr(q + 1));
uri = uri_.substr(0, q);
}
return {uri, params};
}
}

View file

@ -0,0 +1,84 @@
#pragma once
///@file
#include <variant>
#include "types.hh"
namespace nix {
/**
* A parsed Store URI (URI is a slight misnomer...), parsed but not yet
* resolved to a specific instance and query parms validated.
*
* Supported values are:
*
* - local: The Nix store in /nix/store and database in
* /nix/var/nix/db, accessed directly.
*
* - daemon: The Nix store accessed via a Unix domain socket
* connection to nix-daemon.
*
* - unix://<path>: The Nix store accessed via a Unix domain socket
* connection to nix-daemon, with the socket located at <path>.
*
* - auto or : Equivalent to local or daemon depending on
* whether the user has write access to the local Nix
* store/database.
*
* - file://<path>: A binary cache stored in <path>.
*
* - https://<path>: A binary cache accessed via HTTP.
*
* - s3://<path>: A writable binary cache stored on Amazon's Simple
* Storage Service.
*
* - ssh://[user@]<host>: A remote Nix store accessed by running
* nix-store --serve via SSH.
*
* You can pass parameters to the store type by appending
* ?key=value&key=value&... to the URI.
*/
struct StoreReference
{
using Params = std::map<std::string, std::string>;
/**
* Special store reference `""` or `"auto"`
*/
struct Auto
{
inline bool operator==(const Auto & rhs) const = default;
inline auto operator<=>(const Auto & rhs) const = default;
};
/**
* General case, a regular `scheme://authority` URL.
*/
struct Specified
{
std::string scheme;
std::string authority;
bool operator==(const Specified & rhs) const = default;
auto operator<=>(const Specified & rhs) const = default;
};
typedef std::variant<Auto, Specified> Variant;
Variant variant;
Params params;
bool operator==(const StoreReference & rhs) const = default;
auto operator<=>(const StoreReference & rhs) const = default;
static StoreReference parse(const std::string & uri, const Params & extraParams = Params{});
};
/**
* Split URI into protocol+hierarchy part and its parameter set.
*/
std::pair<std::string, StoreReference::Params> splitUriAndParams(const std::string & uri);
}