From 0afcdb2a33c630ba4b2f882c4fad670e06ee3d98 Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Wed, 17 Jun 2020 16:23:26 -0700
Subject: [PATCH] Add symlink SearchPath type

---
 pinch.py         | 45 ++++++++++++++++++++++++++++++++++++++-------
 tests/symlink.sh | 25 +++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 7 deletions(-)
 create mode 100755 tests/symlink.sh

diff --git a/pinch.py b/pinch.py
index 9b845e3..37d37a7 100644
--- a/pinch.py
+++ b/pinch.py
@@ -11,6 +11,7 @@ import shlex
 import shutil
 import subprocess
 import sys
+import tarfile
 import tempfile
 import types
 import urllib.parse
@@ -97,6 +98,12 @@ class AliasPin(NamedTuple):
     pass
 
 
+class SymlinkPin(NamedTuple):
+    @property
+    def release_name(self) -> str:
+        return 'link'
+
+
 class GitPin(NamedTuple):
     git_revision: str
     release_name: str
@@ -109,7 +116,15 @@ class ChannelPin(NamedTuple):
     tarball_sha256: str
 
 
-Pin = Union[AliasPin, GitPin, ChannelPin]
+Pin = Union[AliasPin, SymlinkPin, GitPin, ChannelPin]
+
+
+def copy_to_nix_store(v: Verification, filename: str) -> str:
+    v.status('Putting tarball in Nix store')
+    process = subprocess.run(
+        ['nix-store', '--add', filename], stdout=subprocess.PIPE)
+    v.result(process.returncode == 0)
+    return process.stdout.decode().strip()
 
 
 class AliasSearchPath(NamedTuple):
@@ -120,6 +135,22 @@ class AliasSearchPath(NamedTuple):
         return AliasPin()
 
 
+class SymlinkSearchPath(NamedTuple):
+    path: str
+
+    # pylint: disable=no-self-use
+    def pin(self, _: Verification, __: Optional[Pin]) -> SymlinkPin:
+        return SymlinkPin()
+
+    def fetch(self, v: Verification, _: Pin) -> str:
+        with tempfile.TemporaryDirectory() as td:
+            archive_filename = os.path.join(td, 'link.tar.gz')
+            os.symlink(self.path, os.path.join(td, 'link'))
+            with tarfile.open(archive_filename, mode='x:gz') as t:
+                t.add(os.path.join(td, 'link'), arcname='link')
+            return copy_to_nix_store(v, archive_filename)
+
+
 class GitSearchPath(NamedTuple):
     git_ref: str
     git_repo: str
@@ -168,7 +199,10 @@ class ChannelSearchPath(NamedTuple):
             v, pin.tarball_url, Digest16(pin.tarball_sha256))
 
 
-SearchPath = Union[AliasSearchPath, GitSearchPath, ChannelSearchPath]
+SearchPath = Union[AliasSearchPath,
+                   SymlinkSearchPath,
+                   GitSearchPath,
+                   ChannelSearchPath]
 TarrableSearchPath = Union[GitSearchPath, ChannelSearchPath]
 
 
@@ -513,11 +547,7 @@ def git_get_tarball(
             git.wait()
             v.result(git.returncode == 0 and xz.returncode == 0)
 
-        v.status('Putting tarball in Nix store')
-        process = subprocess.run(
-            ['nix-store', '--add', output_filename], stdout=subprocess.PIPE)
-        v.result(process.returncode == 0)
-        store_tarball = process.stdout.decode().strip()
+        store_tarball = copy_to_nix_store(v, output_filename)
 
         os.makedirs(os.path.dirname(cache_file), exist_ok=True)
         open(cache_file, 'w').write(store_tarball)
@@ -614,6 +644,7 @@ def read_config_section(
         'alias': (AliasSearchPath, AliasPin),
         'channel': (ChannelSearchPath, ChannelPin),
         'git': (GitSearchPath, GitPin),
+        'symlink': (SymlinkSearchPath, SymlinkPin),
     }
     SP, P = mapping[conf['type']]
     _, all_fields = filter_dict(dict(conf.items()), set(['type']))
diff --git a/tests/symlink.sh b/tests/symlink.sh
new file mode 100755
index 0000000..7f4c354
--- /dev/null
+++ b/tests/symlink.sh
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+. ./tests/lib/test-setup.sh
+
+foo_setup
+
+cat >> "$conf" <<EOF
+[bar]
+type = symlink
+path = /etc/nixos
+EOF
+
+python3 ./pinch.py pin "$conf"
+
+actual_env_command=`python3 ./pinch.py update --dry-run "$conf"`
+
+expected_env_command_RE='^nix-env --profile /nix/var/nix/profiles/per-user/[^/]+/channels --show-trace --file '\''<nix/unpack-channel.nix>'\'' --install --from-expression '\''f: f \{ name = "link"; channelName = "bar"; src = builtins.storePath "'"$NIX_STORE_DIR"'/.{32}-link.tar.gz"; \}'\'' '\''f: f \{ name = "(repo-[0-9]{10}-[0-9a-f]{11})"; channelName = "foo"; src = builtins.storePath "'"$NIX_STORE_DIR"'/.{32}-\1.tar.xz"; \}'\''$'
+
+if echo "$actual_env_command" | egrep "$expected_env_command_RE" > /dev/null;then
+  echo PASS
+else
+  echo "Output:   $actual_env_command"
+  echo "does not match RE: $expected_env_command_RE"
+  exit 1
+fi
-- 
2.44.1