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Type:
Bug
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Resolution: Fixed
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Priority:
Major - P3
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Affects Version/s: None
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Component/s: Networking
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Labels:
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Fully Compatible
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ALL
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Service Arch 2019-10-07, Service Arch 2019-10-21, Service Arch 2019-11-18, Service Arch 2019-12-02, Service Arch 2019-12-16, Service Arch 2019-12-30, Service Arch 2020-01-13, Service Arch 2020-01-27, Service Arch 2020-02-10, Service Arch 2020-03-23
Tested on k8s by setting the ipv6 parameter to true or false in the mongodb.conf file:
# network interfaces net: port: 27017 unixDomainSocket: enabled: true pathPrefix: /opt/bitnami/mongodb/tmp ipv6: true bindIpAll: true
In some k8s cluster, mongodb service is not running because of the following error (from mongodb.log):
2019-06-21T14:09:17.987+0000 I CONTROL [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none' 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] MongoDB starting : pid=36 port=27017 dbpath=/opt/bitnami/mongodb/data/db 64-bit host=carlosrh-mongo-mongodb-76bc884646-ztpxl 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] db version v4.0.10 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] git version: c389e7f69f637f7a1ac3cc9fae843b635f20b766 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.1.0j 20 Nov 2018 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] allocator: tcmalloc 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] modules: none 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] build environment: 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] distmod: debian92 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] distarch: x86_64 2019-06-21T14:09:17.992+0000 I CONTROL [initandlisten] target_arch: x86_64 2019-06-21T14:09:17.993+0000 I CONTROL [initandlisten] options: { config: "/opt/bitnami/mongodb/conf/mongodb.conf", net: { bindIpAll: true, ipv6: true, port: 27017, unixDomainSocket: { enabled: true, pathPrefix: "/opt/bitnami/mongodb/tmp" } }, processManagement: { fork: false, pidFilePath: "/opt/bitnami/mongodb/tmp/mongodb.pid" }, security: { authorization: "disabled" }, setParameter: { enableLocalhostAuthBypass: "true" }, storage: { dbPath: "/opt/bitnami/mongodb/data/db", directoryPerDB: false, journal: { enabled: true } }, systemLog: { destination: "file", logAppend: true, logRotate: "reopen", path: "/opt/bitnami/mongodb/logs/mongodb.log", quiet: false, verbosity: 0 } } 2019-06-21T14:09:17.995+0000 I STORAGE [initandlisten] exception in initAndListen std::exception: open: Address family not supported by protocol, terminating 2019-06-21T14:09:17.996+0000 I CONTROL [initandlisten] now exiting 2019-06-21T14:09:17.996+0000 I CONTROL [initandlisten] shutting down with code:100
This message is very descriptive:
2019-06-21T14:09:17.995+0000 I STORAGE [initandlisten] exception in initAndListen std::exception: open: Address family not supported by protocol, terminating
Although the host has disabled IPv6, it is expected that MongoDB will try to use IPv4 in its absence, in fact, we tried it when using this parameter for the first time, so why in some k8s cluster works and not in others?
We can disable IPv6 support by running
sudo sysctl -w net.ipv6.conf.*.disable_ipv6=1
in this case, mongodb server does not complain about unsupported address family when IPv6 is enabled in the configs. This reflects with our earlier findings as we had used the same method to disable IPv6.
Continuing on our investigation, we found that the alternate way of disabling IPv6 support is to pass
ipv6.disable=1
as a bootarg to the Linux kernel and with this, we were able to see the unsupported address family error with mongodb.
With these findings, we cannot make the assumption that IPv6 enabled in the mongodb configs by default will always work regardless of whether the underlying host supports IPv6 or not.