Support revision control systems via plugins

2013-05-25 15:36:58 -04:00
parent 5e0542d3af
commit 1f1615e80b
15 changed files with 588 additions and 513 deletions
--- a/src/lib/Hydra/Plugin/GitInput.pm
+++ b/src/lib/Hydra/Plugin/GitInput.pm
@@ -0,0 +1,148 @@
+package Hydra::Plugin::GitInput;
+
+use strict;
+use parent 'Hydra::Plugin';
+use Digest::SHA qw(sha256_hex);
+use File::Path;
+use Hydra::Helper::Nix;
+use Nix::Store;
+
+sub supportedInputTypes {
+    my ($self, $inputTypes) = @_;
+    $inputTypes->{'git'} = 'Git checkout';
+}
+
+sub fetchInput {
+    my ($self, $type, $name, $value) = @_;
+
+    return undef if $type ne "git";
+
+    (my $uri, my $branch, my $deepClone) = split ' ', $value;
+    $branch = defined $branch ? $branch : "master";
+
+    my $timestamp = time;
+    my $sha256;
+    my $storePath;
+
+    my $cacheDir = getSCMCacheDir . "/git";
+    mkpath($cacheDir);
+    my $clonePath = $cacheDir . "/" . sha256_hex($uri);
+
+    my $stdout = ""; my $stderr = ""; my $res;
+    if (! -d $clonePath) {
+        # Clone everything and fetch the branch.
+        # TODO: Optimize the first clone by using "git init $clonePath" and "git remote add origin $uri".
+        ($res, $stdout, $stderr) = captureStdoutStderr(600, "git", "clone", "--branch", $branch, $uri, $clonePath);
+        die "error cloning git repo at `$uri':\n$stderr" if $res;
+    }
+
+    chdir $clonePath or die $!; # !!! urgh, shouldn't do a chdir
+
+    # This command force the update of the local branch to be in the same as
+    # the remote branch for whatever the repository state is.  This command mirror
+    # only one branch of the remote repository.
+    ($res, $stdout, $stderr) = captureStdoutStderr(600,
+        "git", "fetch", "-fu", "origin", "+$branch:$branch");
+    ($res, $stdout, $stderr) = captureStdoutStderr(600,
+        "git", "fetch", "-fu", "origin") if $res;
+    die "error fetching latest change from git repo at `$uri':\n$stderr" if $res;
+
+    ($res, $stdout, $stderr) = captureStdoutStderr(600,
+        ("git", "rev-parse", "$branch"));
+    die "error getting revision number of Git branch '$branch' at `$uri':\n$stderr" if $res;
+
+    my ($revision) = split /\n/, $stdout;
+    die "error getting a well-formated revision number of Git branch '$branch' at `$uri':\n$stdout"
+        unless $revision =~ /^[0-9a-fA-F]+$/;
+
+    my $ref = "refs/heads/$branch";
+
+    # If deepClone is defined, then we look at the content of the repository
+    # to determine if this is a top-git branch.
+    if (defined $deepClone) {
+
+        # Checkout the branch to look at its content.
+        ($res, $stdout, $stderr) = captureStdoutStderr(600, "git", "checkout", "$branch");
+        die "error checking out Git branch '$branch' at `$uri':\n$stderr" if $res;
+
+        if (-f ".topdeps") {
+            # This is a TopGit branch.  Fetch all the topic branches so
+            # that builders can run "tg patch" and similar.
+            ($res, $stdout, $stderr) = captureStdoutStderr(600,
+                "tg", "remote", "--populate", "origin");
+            print STDERR "warning: `tg remote --populate origin' failed:\n$stderr" if $res;
+        }
+    }
+
+    # Some simple caching: don't check a uri/branch/revision more than once.
+    # TODO: Fix case where the branch is reset to a previous commit.
+    my $cachedInput ;
+    ($cachedInput) = $self->{db}->resultset('CachedGitInputs')->search(
+        {uri => $uri, branch => $branch, revision => $revision},
+        {rows => 1});
+
+    if (defined $cachedInput && isValidPath($cachedInput->storepath)) {
+        $storePath = $cachedInput->storepath;
+        $sha256 = $cachedInput->sha256hash;
+        $revision = $cachedInput->revision;
+    } else {
+        # Then download this revision into the store.
+        print STDERR "checking out Git branch $branch from $uri\n";
+        $ENV{"NIX_HASH_ALGO"} = "sha256";
+        $ENV{"PRINT_PATH"} = "1";
+        $ENV{"NIX_PREFETCH_GIT_LEAVE_DOT_GIT"} = "0";
+        $ENV{"NIX_PREFETCH_GIT_DEEP_CLONE"} = "";
+
+        if (defined $deepClone) {
+            # Checked out code often wants to be able to run `git
+            # describe', e.g., code that uses Gnulib's `git-version-gen'
+            # script.  Thus, we leave `.git' in there.  Same for
+            # Subversion (e.g., libgcrypt's build system uses that.)
+            $ENV{"NIX_PREFETCH_GIT_LEAVE_DOT_GIT"} = "1";
+
+            # Ask for a "deep clone" to allow "git describe" and similar
+            # tools to work.  See
+            # http://thread.gmane.org/gmane.linux.distributions.nixos/3569
+            # for a discussion.
+            $ENV{"NIX_PREFETCH_GIT_DEEP_CLONE"} = "1";
+        }
+
+        ($res, $stdout, $stderr) = captureStdoutStderr(600, "nix-prefetch-git", $clonePath, $revision);
+        die "cannot check out Git repository branch '$branch' at `$uri':\n$stderr" if $res;
+
+        ($sha256, $storePath) = split ' ', $stdout;
+
+        txn_do($self->{db}, sub {
+            $self->{db}->resultset('CachedGitInputs')->update_or_create(
+                { uri => $uri
+                , branch => $branch
+                , revision => $revision
+                , sha256hash => $sha256
+                , storepath => $storePath
+                });
+            });
+    }
+
+    # For convenience in producing readable version names, pass the
+    # number of commits in the history of this revision (‘revCount’)
+    # the output of git-describe (‘gitTag’), and the abbreviated
+    # revision (‘shortRev’).
+    my $revCount = `git rev-list $revision | wc -l`; chomp $revCount;
+    die "git rev-list failed" if $? != 0;
+    my $gitTag = `git describe --always $revision`; chomp $gitTag;
+    die "git describe failed" if $? != 0;
+    my $shortRev = `git rev-parse --short $revision`; chomp $shortRev;
+    die "git rev-parse failed" if $? != 0;
+
+    return
+        { uri => $uri
+        , storePath => $storePath
+        , sha256hash => $sha256
+        , revision => $revision
+        , revCount => int($revCount)
+        , gitTag => $gitTag
+        , shortRev => $shortRev
+        };
+}
+
+1;