diff --git a/cmd/in/unpack.go b/cmd/in/unpack.go index 9df86b7..73252bd 100644 --- a/cmd/in/unpack.go +++ b/cmd/in/unpack.go @@ -127,15 +127,28 @@ func extractLayer(dest string, layer v1.Layer, bar *mpb.Bar, chown bool) error { } if hdr.Typeflag == tar.TypeSymlink { - log.Warnf("symlinking to %s", hdr.Linkname) + log.Debugf("symlinking to %s", hdr.Linkname) } if hdr.Typeflag == tar.TypeLink { - log.Warnf("hardlinking to %s", hdr.Linkname) + log.Debugf("hardlinking to %s", hdr.Linkname) + } + + if fi, err := os.Lstat(path); err == nil { + if fi.IsDir() && hdr.Name == "." { + continue + } + + if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) { + log.Debugf("removing existing path") + if err := os.RemoveAll(path); err != nil { + return err + } + } } if err := tarfs.ExtractEntry(hdr, dest, tr, chown); err != nil { - log.Infof("extracting") + log.Debugf("extracting") return err } } diff --git a/go.mod b/go.mod index 2ecfd26..278708d 100644 --- a/go.mod +++ b/go.mod @@ -11,6 +11,7 @@ require ( github.com/google/go-containerregistry v0.0.0-20180801194910-5f7b0e489541 github.com/hpcloud/tail v1.0.0 // indirect github.com/kr/pretty v0.1.0 // indirect + github.com/kr/pty v1.1.2 // indirect github.com/mattn/go-colorable v0.0.9 // indirect github.com/mattn/go-isatty v0.0.3 // indirect github.com/onsi/ginkgo v1.6.0 @@ -19,10 +20,10 @@ require ( github.com/sirupsen/logrus v1.0.6 github.com/stretchr/testify v1.2.2 // indirect github.com/vbauerster/mpb v3.3.1+incompatible - golang.org/x/crypto v0.0.0-20180802221240-56440b844dfe // indirect + golang.org/x/crypto v0.0.0-20180807104621-f027049dab0a // indirect golang.org/x/net v0.0.0-20180801234040-f4c29de78a2a // indirect golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f // indirect - golang.org/x/sys v0.0.0-20180802203216-0ffbfd41fbef // indirect + golang.org/x/sys v0.0.0-20180806192500-2be389f392cd // indirect golang.org/x/text v0.3.0 // indirect gopkg.in/airbrake/gobrake.v2 v2.0.9 // indirect gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect diff --git a/go.sum b/go.sum index 72fb502..061a695 100644 --- a/go.sum +++ b/go.sum @@ -19,6 +19,7 @@ github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpO github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI= github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo= github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ= +github.com/kr/pty v1.1.2/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ= github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE= github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI= github.com/mattn/go-colorable v0.0.9 h1:UVL0vNpWh04HeJXV0KLcaT7r06gOH2l4OW6ddYRUIY4= @@ -39,12 +40,16 @@ github.com/vbauerster/mpb v3.3.1+incompatible h1:895YxWn6TBP+leAp2kml6H+Rccyo6kX github.com/vbauerster/mpb v3.3.1+incompatible/go.mod h1:zAHG26FUhVKETRu+MWqYXcI70POlC6N8up9p1dID7SU= golang.org/x/crypto v0.0.0-20180802221240-56440b844dfe h1:APBCFlxGVQi3YDSHtTbNXRZhDEuz9rrnVPXZA4YbUx8= golang.org/x/crypto v0.0.0-20180802221240-56440b844dfe/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4= +golang.org/x/crypto v0.0.0-20180807104621-f027049dab0a h1:PulT0Y50PcfTWomfsD39bSQyVrjjWdIuJKfyR4nOCJw= +golang.org/x/crypto v0.0.0-20180807104621-f027049dab0a/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4= golang.org/x/net v0.0.0-20180801234040-f4c29de78a2a h1:8fCF9zjAir2SP3N+axz9xs+0r4V8dqPzqsWO10t8zoo= golang.org/x/net v0.0.0-20180801234040-f4c29de78a2a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4= golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f h1:wMNYb4v58l5UBM7MYRLPG6ZhfOqbKu7X5eyFl8ZhKvA= golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= golang.org/x/sys v0.0.0-20180802203216-0ffbfd41fbef h1:ESfhYoBNk2UQGmavscFPKfwmc4ZTB2+UdQYsVw6Bq9M= golang.org/x/sys v0.0.0-20180802203216-0ffbfd41fbef/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= +golang.org/x/sys v0.0.0-20180806192500-2be389f392cd h1:KFYUs6SCkSktZ+xJWb5YbuSCJLLphbTsg0kvyirtlQ8= +golang.org/x/sys v0.0.0-20180806192500-2be389f392cd/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg= golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ= gopkg.in/airbrake/gobrake.v2 v2.0.9 h1:7z2uVWwn7oVeeugY1DtlPAy5H+KYgB1KeKTnqjNatLo= diff --git a/in_test.go b/in_test.go index 86f2952..5186512 100644 --- a/in_test.go +++ b/in_test.go @@ -153,7 +153,7 @@ var _ = Describe("In", func() { Describe("a hardlink that is later removed", func() { BeforeEach(func() { - req.Source.Repository = "concourse/test-image-symlinks" + req.Source.Repository = "concourse/test-image-removed-hardlinks" req.Version.Digest = latestDigest(req.Source.Repository) }) @@ -167,4 +167,22 @@ var _ = Describe("In", func() { Expect(stat.Mode() & os.ModeSymlink).To(BeZero()) }) }) + + Describe("layers that replace symlinks with regular files", func() { + BeforeEach(func() { + req.Source.Repository = "concourse/test-image-symlinks" + req.Version.Digest = latestDigest(req.Source.Repository) + }) + + It("removes the symlink and writes to a new file rather than trying to open and write to it (thereby overwriting its target)", func() { + Expect(cat(rootfsPath("a"))).To(Equal("symlinked\n")) + Expect(cat(rootfsPath("b"))).To(Equal("replaced\n")) + }) + }) }) + +func cat(path string) string { + bytes, err := ioutil.ReadFile(path) + Expect(err).ToNot(HaveOccurred()) + return string(bytes) +} diff --git a/testdata/removed-hardlinks/Dockerfile b/testdata/removed-hardlinks/Dockerfile new file mode 100644 index 0000000..aa44904 --- /dev/null +++ b/testdata/removed-hardlinks/Dockerfile @@ -0,0 +1,3 @@ +FROM alpine +RUN apk --no-cache add git +RUN rm /usr/bin/git diff --git a/testdata/symlinks/Dockerfile b/testdata/symlinks/Dockerfile index aa44904..533f7ff 100644 --- a/testdata/symlinks/Dockerfile +++ b/testdata/symlinks/Dockerfile @@ -1,3 +1,4 @@ FROM alpine -RUN apk --no-cache add git -RUN rm /usr/bin/git +RUN echo symlinked > a +RUN ln -s a b +RUN rm b && echo replaced > b