From cfcd1e1863ad4fb31476364bde64a70dc1f1196c Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Tue, 3 Aug 2021 14:07:28 -0400 Subject: Do not add an entry to /etc/hosts with `--net=host` To match Docker's behavior, in the `--net=host` case, we need to use the host's `/etc/hosts` file, unmodified (without adding an entry for the container). We will still respect hosts from `--add-host` but will not make any automatic changes. Fortuntely, this is strictly a matter of removal and refactoring as we already base our `/etc/hosts` on the host's version - just need to remove the code that added entries when net=host was set. Fixes #10319 Signed-off-by: Matthew Heon --- libpod/container_internal_linux.go | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) (limited to 'libpod') diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index bff64aa95..f30f622ac 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -1912,6 +1912,7 @@ func (c *Container) appendHosts(path string, netCtr *Container) (string, error) // and returns a string in a format that can be written to the host file func (c *Container) getHosts() string { var hosts string + if len(c.config.HostAdd) > 0 { for _, host := range c.config.HostAdd { // the host format has already been verified at this point @@ -1922,36 +1923,33 @@ func (c *Container) getHosts() string { hosts += c.cniHosts() - // If not making a network namespace, add our own hostname. + // Add hostname for slirp4netns if c.Hostname() != "" { if c.config.NetMode.IsSlirp4netns() { // When using slirp4netns, the interface gets a static IP slirp4netnsIP, err := GetSlirp4netnsIP(c.slirp4netnsSubnet) if err != nil { - logrus.Warn("failed to determine slirp4netnsIP: ", err.Error()) + logrus.Warnf("failed to determine slirp4netnsIP: %v", err.Error()) } else { hosts += fmt.Sprintf("# used by slirp4netns\n%s\t%s %s\n", slirp4netnsIP.String(), c.Hostname(), c.config.Name) } - } else { - hasNetNS := false - netNone := false - for _, ns := range c.config.Spec.Linux.Namespaces { - if ns.Type == spec.NetworkNamespace { - hasNetNS = true - if ns.Path == "" && !c.config.CreateNetNS { - netNone = true - } - break + } + + // Do we have a network namespace? + netNone := false + for _, ns := range c.config.Spec.Linux.Namespaces { + if ns.Type == spec.NetworkNamespace { + if ns.Path == "" && !c.config.CreateNetNS { + netNone = true } + break } - if !hasNetNS { - // 127.0.1.1 and host's hostname to match Docker - osHostname, _ := os.Hostname() - hosts += fmt.Sprintf("127.0.1.1 %s %s %s\n", osHostname, c.Hostname(), c.config.Name) - } - if netNone { - hosts += fmt.Sprintf("127.0.1.1 %s %s\n", c.Hostname(), c.config.Name) - } + } + + // If we are net=none (have a network namespace, but not connected to + // anything) add the container's name and hostname to localhost. + if netNone { + hosts += fmt.Sprintf("127.0.0.1 %s %s\n", c.Hostname(), c.config.Name) } } -- cgit v1.2.3-54-g00ecf