Put functional tests in `tests/functional`

I think it is bad for these reasons when `tests/` contains a mix of
functional and integration tests

 - Concepts is harder to understand, the documentation makes a good
   unit vs functional vs integration distinction, but when the
   integration tests are just two subdirs within `tests/` this is not
   clear.

 - Source filtering in the `flake.nix` is more complex. We need to
   filter out some of the dirs from `tests/`, rather than simply pick
   the dirs we want and take all of them. This is a good sign the
   structure of what we are trying to do is not matching the structure
   of the files.

With this change we have a clean:
```shell-session
$ git show 'HEAD:tests'
tree HEAD:tests

functional/
installer/
nixos/
```

(cherry picked from commit 68c81c737571794f7246db53fb4774e94fcf4b7e)

1 files changed, 286 insertions, 0 deletions

diff --git a/tests/functional/binary-cache.sh b/tests/functional/binary-cache.sh
new file mode 100644
index 000000000..7c64a115c
--- /dev/null
+++ b/tests/functional/binary-cache.sh
@@ -0,0 +1,286 @@
+source common.sh
+
+needLocalStore "'--no-require-sigs' can’t be used with the daemon"
+
+# We can produce drvs directly into the binary cache
+clearStore
+clearCacheCache
+nix-instantiate --store "file://$cacheDir" dependencies.nix
+
+# Create the binary cache.
+clearStore
+clearCache
+outPath=$(nix-build dependencies.nix --no-out-link)
+
+nix copy --to file://$cacheDir $outPath
+
+# Test copying build logs to the binary cache.
+expect 1 nix log --store file://$cacheDir $outPath 2>&1 | grep 'is not available'
+nix store copy-log --to file://$cacheDir $outPath
+nix log --store file://$cacheDir $outPath | grep FOO
+rm -rf $TEST_ROOT/var/log/nix
+expect 1 nix log $outPath 2>&1 | grep 'is not available'
+nix log --substituters file://$cacheDir $outPath | grep FOO
+
+# Test copying build logs from the binary cache.
+nix store copy-log --from file://$cacheDir $(nix-store -qd $outPath)^'*'
+nix log $outPath | grep FOO
+
+basicDownloadTests() {
+    # No uploading tests bcause upload with force HTTP doesn't work.
+
+    # By default, a binary cache doesn't support "nix-env -qas", but does
+    # support installation.
+    clearStore
+    clearCacheCache
+
+    nix-env --substituters "file://$cacheDir" -f dependencies.nix -qas \* | grep -- "---"
+
+    nix-store --substituters "file://$cacheDir" --no-require-sigs -r $outPath
+
+    [ -x $outPath/program ]
+
+
+    # But with the right configuration, "nix-env -qas" should also work.
+    clearStore
+    clearCacheCache
+    echo "WantMassQuery: 1" >> $cacheDir/nix-cache-info
+
+    nix-env --substituters "file://$cacheDir" -f dependencies.nix -qas \* | grep -- "--S"
+    nix-env --substituters "file://$cacheDir" -f dependencies.nix -qas \* | grep -- "--S"
+
+    x=$(nix-env -f dependencies.nix -qas \* --prebuilt-only)
+    [ -z "$x" ]
+
+    nix-store --substituters "file://$cacheDir" --no-require-sigs -r $outPath
+
+    nix-store --check-validity $outPath
+    nix-store -qR $outPath | grep input-2
+
+    echo "WantMassQuery: 0" >> $cacheDir/nix-cache-info
+}
+
+
+# Test LocalBinaryCacheStore.
+basicDownloadTests
+
+
+# Test HttpBinaryCacheStore.
+export _NIX_FORCE_HTTP=1
+basicDownloadTests
+
+
+# Test whether Nix notices if the NAR doesn't match the hash in the NAR info.
+clearStore
+
+nar=$(ls $cacheDir/nar/*.nar.xz | head -n1)
+mv $nar $nar.good
+mkdir -p $TEST_ROOT/empty
+nix-store --dump $TEST_ROOT/empty | xz > $nar
+
+expect 1 nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result 2>&1 | tee $TEST_ROOT/log
+grepQuiet "hash mismatch" $TEST_ROOT/log
+
+mv $nar.good $nar
+
+
+# Test whether this unsigned cache is rejected if the user requires signed caches.
+clearStore
+clearCacheCache
+
+if nix-store --substituters "file://$cacheDir" -r $outPath; then
+    echo "unsigned binary cache incorrectly accepted"
+    exit 1
+fi
+
+
+# Test whether fallback works if a NAR has disappeared. This does not require --fallback.
+clearStore
+
+mv $cacheDir/nar $cacheDir/nar2
+
+nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result
+
+mv $cacheDir/nar2 $cacheDir/nar
+
+
+# Test whether fallback works if a NAR is corrupted. This does require --fallback.
+clearStore
+
+mv $cacheDir/nar $cacheDir/nar2
+mkdir $cacheDir/nar
+for i in $(cd $cacheDir/nar2 && echo *); do touch $cacheDir/nar/$i; done
+
+(! nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result)
+
+nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result --fallback
+
+rm -rf $cacheDir/nar
+mv $cacheDir/nar2 $cacheDir/nar
+
+
+# Test whether building works if the binary cache contains an
+# incomplete closure.
+clearStore
+
+rm -v $(grep -l "StorePath:.*dependencies-input-2" $cacheDir/*.narinfo)
+
+nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result 2>&1 | tee $TEST_ROOT/log
+grepQuiet "copying path.*input-0" $TEST_ROOT/log
+grepQuiet "copying path.*input-2" $TEST_ROOT/log
+grepQuiet "copying path.*top" $TEST_ROOT/log
+
+
+# Idem, but without cached .narinfo.
+clearStore
+clearCacheCache
+
+nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result 2>&1 | tee $TEST_ROOT/log
+grepQuiet "don't know how to build" $TEST_ROOT/log
+grepQuiet "building.*input-1" $TEST_ROOT/log
+grepQuiet "building.*input-2" $TEST_ROOT/log
+grepQuiet "copying path.*input-0" $TEST_ROOT/log
+grepQuiet "copying path.*top" $TEST_ROOT/log
+
+
+# Create a signed binary cache.
+clearCache
+clearCacheCache
+
+nix key generate-secret --key-name test.nixos.org-1 > $TEST_ROOT/sk1
+publicKey=$(nix key convert-secret-to-public < $TEST_ROOT/sk1)
+
+nix key generate-secret --key-name test.nixos.org-1 > $TEST_ROOT/sk2
+badKey=$(nix key convert-secret-to-public < $TEST_ROOT/sk2)
+
+nix key generate-secret --key-name foo.nixos.org-1 > $TEST_ROOT/sk3
+otherKey=$(nix key convert-secret-to-public < $TEST_ROOT/sk3)
+
+_NIX_FORCE_HTTP= nix copy --to file://$cacheDir?secret-key=$TEST_ROOT/sk1 $outPath
+
+
+# Downloading should fail if we don't provide a key.
+clearStore
+clearCacheCache
+
+(! nix-store -r $outPath --substituters "file://$cacheDir")
+
+
+# And it should fail if we provide an incorrect key.
+clearStore
+clearCacheCache
+
+(! nix-store -r $outPath --substituters "file://$cacheDir" --trusted-public-keys "$badKey")
+
+
+# It should succeed if we provide the correct key.
+nix-store -r $outPath --substituters "file://$cacheDir" --trusted-public-keys "$otherKey $publicKey"
+
+
+# It should fail if we corrupt the .narinfo.
+clearStore
+
+cacheDir2=$TEST_ROOT/binary-cache-2
+rm -rf $cacheDir2
+cp -r $cacheDir $cacheDir2
+
+for i in $cacheDir2/*.narinfo; do
+    grep -v References $i > $i.tmp
+    mv $i.tmp $i
+done
+
+clearCacheCache
+
+(! nix-store -r $outPath --substituters "file://$cacheDir2" --trusted-public-keys "$publicKey")
+
+# If we provide a bad and a good binary cache, it should succeed.
+
+nix-store -r $outPath --substituters "file://$cacheDir2 file://$cacheDir" --trusted-public-keys "$publicKey"
+
+
+unset _NIX_FORCE_HTTP
+
+
+# Test 'nix verify --all' on a binary cache.
+nix store verify -vvvvv --all --store file://$cacheDir --no-trust
+
+
+# Test local NAR caching.
+narCache=$TEST_ROOT/nar-cache
+rm -rf $narCache
+mkdir $narCache
+
+[[ $(nix store cat --store "file://$cacheDir?local-nar-cache=$narCache" $outPath/foobar) = FOOBAR ]]
+
+rm -rfv "$cacheDir/nar"
+
+[[ $(nix store cat --store "file://$cacheDir?local-nar-cache=$narCache" $outPath/foobar) = FOOBAR ]]
+
+(! nix store cat --store file://$cacheDir $outPath/foobar)
+
+
+# Test NAR listing generation.
+clearCache
+
+outPath=$(nix-build --no-out-link -E '
+  with import ./config.nix;
+  mkDerivation {
+    name = "nar-listing";
+    buildCommand = "mkdir $out; echo foo > $out/bar; ln -s xyzzy $out/link";
+  }
+')
+
+nix copy --to file://$cacheDir?write-nar-listing=1 $outPath
+
+diff -u \
+    <(jq -S < $cacheDir/$(basename $outPath | cut -c1-32).ls) \
+    <(echo '{"version":1,"root":{"type":"directory","entries":{"bar":{"type":"regular","size":4,"narOffset":232},"link":{"type":"symlink","target":"xyzzy"}}}}' | jq -S)
+
+
+# Test debug info index generation.
+clearCache
+
+outPath=$(nix-build --no-out-link -E '
+  with import ./config.nix;
+  mkDerivation {
+    name = "debug-info";
+    buildCommand = "mkdir -p $out/lib/debug/.build-id/02; echo foo > $out/lib/debug/.build-id/02/623eda209c26a59b1a8638ff7752f6b945c26b.debug";
+  }
+')
+
+nix copy --to "file://$cacheDir?index-debug-info=1&compression=none" $outPath
+
+diff -u \
+    <(cat $cacheDir/debuginfo/02623eda209c26a59b1a8638ff7752f6b945c26b.debug | jq -S) \
+    <(echo '{"archive":"../nar/100vxs724qr46phz8m24iswmg9p3785hsyagz0kchf6q6gf06sw6.nar","member":"lib/debug/.build-id/02/623eda209c26a59b1a8638ff7752f6b945c26b.debug"}' | jq -S)
+
+# Test against issue https://github.com/NixOS/nix/issues/3964
+#
+expr='
+  with import ./config.nix;
+  mkDerivation {
+    name = "multi-output";
+    buildCommand = "mkdir -p $out; echo foo > $doc; echo $doc > $out/docref";
+    outputs = ["out" "doc"];
+  }
+'
+outPath=$(nix-build --no-out-link -E "$expr")
+docPath=$(nix-store -q --references $outPath)
+
+# $ nix-store -q --tree $outPath
+# ...-multi-output
+# +---...-multi-output-doc
+
+nix copy --to "file://$cacheDir" $outPath
+
+hashpart() {
+  basename "$1" | cut -c1-32
+}
+
+# break the closure of out by removing doc
+rm $cacheDir/$(hashpart $docPath).narinfo
+
+nix-store --delete $outPath $docPath
+# -vvv is the level that logs during the loop
+timeout 60 nix-build --no-out-link -E "$expr" --option substituters "file://$cacheDir" \
+  --option trusted-binary-caches "file://$cacheDir"  --no-require-sigs