5 ms·

Docker dropping support for RHEL/CentOS6.x

69 points by visualphoenix 11y ago

armab 11y ago
That's strange. CentOS 6.x is still very popular.
- FooBarWidget 11y ago
  And shipping with kernel 2.6 and being 4 years old.
  - x5n1 11y ago
    yeah it makes sense the 2.6 kernel is too ancient. They have kept it patched up, but upward and onward!
- visualphoenix 11y ago
  Yeah it's huge in the enterprise. Not everyone has migrated to 7.x with systemd yet.
  - swinglock 11y ago
    Far from it, I would be surprised if even most RHEL installations ran RHEL 7 yet.
- dice 11y ago
  Hell, CentOS 5 is still pretty widely deployed (and supported by RH until 2017).
  - visualphoenix 11y ago
    And if you recall, RedHat touted Docker support in 6.5: http://www.redhat.com/en/about/press-releases/red-hat-launches-latest-version-of-red-hat-enterprise-linux-6 http://www.redhat.com/en/about/press-releases/red-hat-launch...
- justincormack 11y ago
  But it is very old, and does not support a lot of features that new software like docker needs. The enterprise release cycle is just too slow for software that is dependent on kernel features.
- astockwell 11y ago
  Compatibility with CentOS was a big driver to adopting Docker at my prior employer. It's benefits were made even more pronounced on semi-legacy systems like that.
  - visualphoenix 11y ago
    Completely agreed. It has been a huge help in the migration of legacy systems to containers while underlying monitoring and config infrastructure is being updated to support systemd.
    - huslage 11y ago
      You can still use 6.x as a base layer inside the container, just not on the host OS.
mcescalante 11y ago
For anyone else curious, Docker 1.8's target release date is August 4th, so basically in a month all support will be dropped for RHEL/Centos 6.x. Definitely a bit concerning to me. I'm quite interested to see how the whole Open Container Project pans out, and I'm pleased by the prospect of it, just hoping they successfully iron out some of the "Docker wrinkles" that have shown over the course of it's lifecycle in the last few years. No 6.x support from the get go doesn't necessarily put a great taste in my mouth, so far.
- visualphoenix 11y ago
  Super worrying to me too. 1.8 marked the move to Open Container Project. I guess this means Open Container Project won't be supporting 6.x. It would have been nice to get more than 1 month of notice.
  - deleted 11y ago
    [deleted]
  - niels_olson 11y ago
    Interesting sidelight: DoD uses RHEL almost exclusively, so this sort of implies that DoD has no interest in Docker as their container of choice. Edit: to clarify, I was thinking the HPC systems are RHEL, and account for a fairly large number of RHEL licenses. Certainly the "enterprise" is outlook, sharepoint, and a ton of Win7 terminals.
    - greyboy 11y ago
      Interesting. All the DoD systems we interface with run Windows. There may be a mixture, we just don't work with those systems.
      - niels_olson 11y ago
        Valid point. I guess I was thinking the HPC systems. Certainly every client-facing terminal is a Windows box. I don't know much about the network stack, but there's clearly a lot of Windows there too.
chomp 11y ago
OpenStack dropped support for CentOS 6 in its Kilo release, so this isn't too surprising. CentOS 6 was released in 2011, which is 4 years old. A lot of features Docker uses have been highly improved since the 2.6 days, so it makes sense to drop support for operating systems which don't support some things.
- harlowja 11y ago
  Correction, openstack dropped python 2.6 support in its kilo release, you can of course run python 2.7 on centos6.x/rhel6.x (and I know companies doing this, including godaddy and yahoo) via a variety of manners, and then openstack will work for you again (until u can shift to centos7.x or rhel7.x).
JupiterMoon 11y ago
I guess that Red Hat will have to keep supporting it with security updates then?
- nickstinemates 11y ago
  As per their support model for 6.x, but, in the description: RedHat themselves only support Docker on RHEL7 (as stated by https://access.redhat.com/solutions/1378023 https://access.redhat.com/solutions/1378023, and confirmed by several people)
  - visualphoenix 11y ago
    Right but this is odd considering they used to support it and only quietly updated their support document in May. If a fellow issue commenter on github hadn't linked to it I (and everyone else) would have missed it.
    - nickstinemates 11y ago
      I don't know what they've said when publicly, but the intention of 6.x on their end related to support for Docker has always been best efforts in terms of their support practices. Docker support by Red Hat in RHEL7 is actually a compelling differentiation they use in the field to get their existing customer base to upgrade. This conversation goes back to the moment we started talking about it before the announcement[1] in September 2013 1: http://www.redhat.com/en/about/press-releases/red-hat-and-dotcloud-collaborate-on-docker-to-bring-next-generation-linux-container-enhancements-to-openshift http://www.redhat.com/en/about/press-releases/red-hat-and-do...
- kokey 11y ago
  Docker isn't part of RHEL, it's only available on RHEL6 as part of EPEL. The EPEL package maintainers will, in theory, keep supporting the rather old version of Docker (1.5) in EPEL for another 5 years.
  - rdtsc 11y ago
sysk 11y ago
I have a very limited understanding of how distributions work so this is probably a stupid question but why don't RHEL/CentOS update the Linux kernel they ship with their 6.x OS? Isn't the kernel supposed to never break user space apps?
- dchest 11y ago
  They don't update whole kernel, but they backport features and bug fixes from newer kernels to the ones they ship.
- WestCoastJustin 11y ago
  RHEL focuses on stability over bleeding edge features. What this typically means is that you will have an older kernel / user land packages installed, then Redhat backports security patches into it's maintained ports. You can read about it here [1]. The end result is a fairly stable kernel and system OS. But, you have to live with an older feature set (think 2-3+ year old package with just security patches applied). I've maintained lots of RHEL boxes as a sysadmin -- here's my take. This type of release cycle works pretty well, in that you can almost always apply patches without hosing your system due to "new features". One example of something this protects you against, is a package changing the expected config file format, or maybe the expected command line arguments. Another good example, would be a change to a kernel driver for some storage array, or network interface, that could quickly break lots of systems! This type of release cycle also gives commercial software vendors a known target to develop against and sell support for. Say for example, that you are using an enterprise database like Oracle/Sybase/DB2, they will verify their product works against RHEL 5.x/6.x/7.x and give you commercial support, as they have a pretty good understanding of what you are running. But, if the kernel/packages are always moving targets, it would be near impossible to support your end platform, so this also adds to the backporting of security patches without adding features thought process. Although, it is also a pain, in that you are typically way behind on cool things happening out there on other distros. So, there are pros and cons to it. But, if you are running a large mission critical DB cluster, you typically want things to be extremely stable, so for the target market (the enterprise) this works pretty well. [1] https://access.redhat.com/security/updates/backporting https://access.redhat.com/security/updates/backporting
X-Istence 11y ago
I am not surprised. RHEL 6 is getting long in the tooth!
jareds 11y ago
I use cent OS 6.6 on a server because it is similar to the software our customers run. I also like using docker even though our customers do not. At this point I'm just going to install ubuntu server and use Vagrant so I can run what ever OS I need.
ams6110 11y ago
I don't know why they ever bothered. People running RHEL are among the most conservative Linux users there are. We have some of that where I work. We have big production systems still running RHEL 5 (which RedHat still supports, and for those systems the less you change the less of your time they demand). Anyone still using RHEL 6 is not really the sort of person who jumps onto the latest container or cloud frameworks the moment they are released. If they are into virtualization at all, they are probably using VMWare.
- nodesocket 11y ago
  I have to argue with your point a bit. I actually prefer RHEL (CentOS) and if given a choice, I still run CentOS. It is what I started with, and now am most familiar with, but agree the package versions are super old and outdated. I do like yum more than apt, but probably again because it is was I'm most familiar with.
  - uxp 11y ago
    I agree. I'm more DevOps, (really, just a dev that is super comfortable in an ops position) and my go-to distro has always been Debian, but nearly every position I've had has been supporting applications on Ubuntu. It wasn't until my last position when we were acquired and thrown into a CentOS ESXi datacenter that I really started to love CentOS's release cycle. You won't get all the somewhat recent or cool features without feeling like you're treading into the territory of hacks and warranty-voiding (try running Xen on Cent or RHEL), but you'll also not dread keeping your servers up to date, or keeping on top of the latest logoed vulnerability sweeping the net. I'd guess that 99% of the standard LAMP and at least 80% of the common Rails, SQL, K/V almost-crud apps could benefit from CentOS.
- devonkim 11y ago
  Most people running RHEL and RH-based distros tend to want to stay behind the curve as much as possible for many (typically legitimate) reasons. When a rash of OpenSSL vulnerabilities showed up, some older distributions were not affected because the packages they were on were so old they hadn't picked up some of the code that had been patched in for over a couple years that was flawed. But users and developers on these systems do want to have a chance to run some modern stuff like containers as well because there's a strong chance that they'll have to support their software for 10+ years potentially. On one system I worked on I saw that the architecture called for support for the same exact distribution for over 10 years - these are the kinds of places that will be paying Microsoft extra to support XP n years after it's gone EOL.

69 points by visualphoenix 11y ago

armab 11y ago

That's strange. CentOS 6.x is still very popular.

FooBarWidget 11y ago
And shipping with kernel 2.6 and being 4 years old.
- x5n1 11y ago
  yeah it makes sense the 2.6 kernel is too ancient. They have kept it patched up, but upward and onward!
visualphoenix 11y ago
Yeah it's huge in the enterprise. Not everyone has migrated to 7.x with systemd yet.
- swinglock 11y ago
  Far from it, I would be surprised if even most RHEL installations ran RHEL 7 yet.
dice 11y ago
Hell, CentOS 5 is still pretty widely deployed (and supported by RH until 2017).
- visualphoenix 11y ago
  And if you recall, RedHat touted Docker support in 6.5: http://www.redhat.com/en/about/press-releases/red-hat-launches-latest-version-of-red-hat-enterprise-linux-6 http://www.redhat.com/en/about/press-releases/red-hat-launch...
justincormack 11y ago
But it is very old, and does not support a lot of features that new software like docker needs. The enterprise release cycle is just too slow for software that is dependent on kernel features.
astockwell 11y ago
Compatibility with CentOS was a big driver to adopting Docker at my prior employer. It's benefits were made even more pronounced on semi-legacy systems like that.
- visualphoenix 11y ago
  Completely agreed. It has been a huge help in the migration of legacy systems to containers while underlying monitoring and config infrastructure is being updated to support systemd.
  - huslage 11y ago
    You can still use 6.x as a base layer inside the container, just not on the host OS.

mcescalante 11y ago

For anyone else curious, Docker 1.8's target release date is August 4th, so basically in a month all support will be dropped for RHEL/Centos 6.x. Definitely a bit concerning to me. I'm quite interested to see how the whole Open Container Project pans out, and I'm pleased by the prospect of it, just hoping they successfully iron out some of the "Docker wrinkles" that have shown over the course of it's lifecycle in the last few years. No 6.x support from the get go doesn't necessarily put a great taste in my mouth, so far.

visualphoenix 11y ago
Super worrying to me too. 1.8 marked the move to Open Container Project. I guess this means Open Container Project won't be supporting 6.x. It would have been nice to get more than 1 month of notice.
- deleted 11y ago
  [deleted]
- niels_olson 11y ago
  Interesting sidelight: DoD uses RHEL almost exclusively, so this sort of implies that DoD has no interest in Docker as their container of choice. Edit: to clarify, I was thinking the HPC systems are RHEL, and account for a fairly large number of RHEL licenses. Certainly the "enterprise" is outlook, sharepoint, and a ton of Win7 terminals.
  - greyboy 11y ago
    Interesting. All the DoD systems we interface with run Windows. There may be a mixture, we just don't work with those systems.
    - niels_olson 11y ago
      Valid point. I guess I was thinking the HPC systems. Certainly every client-facing terminal is a Windows box. I don't know much about the network stack, but there's clearly a lot of Windows there too.

chomp 11y ago

OpenStack dropped support for CentOS 6 in its Kilo release, so this isn't too surprising. CentOS 6 was released in 2011, which is 4 years old. A lot of features Docker uses have been highly improved since the 2.6 days, so it makes sense to drop support for operating systems which don't support some things.

harlowja 11y ago
Correction, openstack dropped python 2.6 support in its kilo release, you can of course run python 2.7 on centos6.x/rhel6.x (and I know companies doing this, including godaddy and yahoo) via a variety of manners, and then openstack will work for you again (until u can shift to centos7.x or rhel7.x).

JupiterMoon 11y ago

I guess that Red Hat will have to keep supporting it with security updates then?

nickstinemates 11y ago
As per their support model for 6.x, but, in the description: RedHat themselves only support Docker on RHEL7 (as stated by https://access.redhat.com/solutions/1378023 https://access.redhat.com/solutions/1378023, and confirmed by several people)
- visualphoenix 11y ago
  Right but this is odd considering they used to support it and only quietly updated their support document in May. If a fellow issue commenter on github hadn't linked to it I (and everyone else) would have missed it.
  - nickstinemates 11y ago
    I don't know what they've said when publicly, but the intention of 6.x on their end related to support for Docker has always been best efforts in terms of their support practices. Docker support by Red Hat in RHEL7 is actually a compelling differentiation they use in the field to get their existing customer base to upgrade. This conversation goes back to the moment we started talking about it before the announcement[1] in September 2013 1: http://www.redhat.com/en/about/press-releases/red-hat-and-dotcloud-collaborate-on-docker-to-bring-next-generation-linux-container-enhancements-to-openshift http://www.redhat.com/en/about/press-releases/red-hat-and-do...
kokey 11y ago
Docker isn't part of RHEL, it's only available on RHEL6 as part of EPEL. The EPEL package maintainers will, in theory, keep supporting the rather old version of Docker (1.5) in EPEL for another 5 years.
- rdtsc 11y ago

sysk 11y ago

I have a very limited understanding of how distributions work so this is probably a stupid question but why don't RHEL/CentOS update the Linux kernel they ship with their 6.x OS? Isn't the kernel supposed to never break user space apps?

dchest 11y ago
They don't update whole kernel, but they backport features and bug fixes from newer kernels to the ones they ship.
WestCoastJustin 11y ago
RHEL focuses on stability over bleeding edge features. What this typically means is that you will have an older kernel / user land packages installed, then Redhat backports security patches into it's maintained ports. You can read about it here [1]. The end result is a fairly stable kernel and system OS. But, you have to live with an older feature set (think 2-3+ year old package with just security patches applied). I've maintained lots of RHEL boxes as a sysadmin -- here's my take. This type of release cycle works pretty well, in that you can almost always apply patches without hosing your system due to "new features". One example of something this protects you against, is a package changing the expected config file format, or maybe the expected command line arguments. Another good example, would be a change to a kernel driver for some storage array, or network interface, that could quickly break lots of systems! This type of release cycle also gives commercial software vendors a known target to develop against and sell support for. Say for example, that you are using an enterprise database like Oracle/Sybase/DB2, they will verify their product works against RHEL 5.x/6.x/7.x and give you commercial support, as they have a pretty good understanding of what you are running. But, if the kernel/packages are always moving targets, it would be near impossible to support your end platform, so this also adds to the backporting of security patches without adding features thought process. Although, it is also a pain, in that you are typically way behind on cool things happening out there on other distros. So, there are pros and cons to it. But, if you are running a large mission critical DB cluster, you typically want things to be extremely stable, so for the target market (the enterprise) this works pretty well. [1] https://access.redhat.com/security/updates/backporting https://access.redhat.com/security/updates/backporting

X-Istence 11y ago

I am not surprised. RHEL 6 is getting long in the tooth!

jareds 11y ago

I use cent OS 6.6 on a server because it is similar to the software our customers run. I also like using docker even though our customers do not. At this point I'm just going to install ubuntu server and use Vagrant so I can run what ever OS I need.

ams6110 11y ago

I don't know why they ever bothered. People running RHEL are among the most conservative Linux users there are. We have some of that where I work. We have big production systems still running RHEL 5 (which RedHat still supports, and for those systems the less you change the less of your time they demand). Anyone still using RHEL 6 is not really the sort of person who jumps onto the latest container or cloud frameworks the moment they are released. If they are into virtualization at all, they are probably using VMWare.

nodesocket 11y ago
I have to argue with your point a bit. I actually prefer RHEL (CentOS) and if given a choice, I still run CentOS. It is what I started with, and now am most familiar with, but agree the package versions are super old and outdated. I do like yum more than apt, but probably again because it is was I'm most familiar with.
- uxp 11y ago
  I agree. I'm more DevOps, (really, just a dev that is super comfortable in an ops position) and my go-to distro has always been Debian, but nearly every position I've had has been supporting applications on Ubuntu. It wasn't until my last position when we were acquired and thrown into a CentOS ESXi datacenter that I really started to love CentOS's release cycle. You won't get all the somewhat recent or cool features without feeling like you're treading into the territory of hacks and warranty-voiding (try running Xen on Cent or RHEL), but you'll also not dread keeping your servers up to date, or keeping on top of the latest logoed vulnerability sweeping the net. I'd guess that 99% of the standard LAMP and at least 80% of the common Rails, SQL, K/V almost-crud apps could benefit from CentOS.
devonkim 11y ago
Most people running RHEL and RH-based distros tend to want to stay behind the curve as much as possible for many (typically legitimate) reasons. When a rash of OpenSSL vulnerabilities showed up, some older distributions were not affected because the packages they were on were so old they hadn't picked up some of the code that had been patched in for over a couple years that was flawed. But users and developers on these systems do want to have a chance to run some modern stuff like containers as well because there's a strong chance that they'll have to support their software for 10+ years potentially. On one system I worked on I saw that the architecture called for support for the same exact distribution for over 10 years - these are the kinds of places that will be paying Microsoft extra to support XP n years after it's gone EOL.