Hi all, sorry to butt in.
I am little curious about why do we have to do the overwritten via
environment variables after
loading the configuration from file. Could we support to do the
substitution while loading the
"flink-conf.yaml" file?
For example, I have the following config options in my flink-conf.yaml.
fs.oss.accessKeyId: $(FS_OSS_ACCESS_KEY_ID)
fs.oss.accessKeySecret: $(FS_OSS_ACCESS_KEY_SECRET)
I expect these environment variables could be substituted when loading the
configuration file. It is
very similar to use "*envsubst < /tmp/flink-conf.yaml >
/tmp/flink-conf-1.yaml*".
I know this is a rejected alternative. But I think some reasons could not
stand on.
* We could use $(FS_OSS_ACCESS_KEY_ID) instead of ${FS_OSS_ACCESS_KEY_ID}
for the environment definition
to avoid escape issues. I think the Kubernetes has the same behavior[1].
Maybe many users are already familiar with it.
* Users do not need to know the conversion between flink config option and
environment name. Because they could use
any name they want.
* It is true that we need to maintain a flink configuration file
which simply maps all keys to some environment variables. But
for Yarn and K8s deployment(both standalone on K8s and native), we already
have such a file, which is shipped from client
or mounted from a ConfigMap.
@Ingo This solution could perfectly work with Kubernetes deployment and is
easier to use. We could use a ConfigMap for
storing the flink-conf.yaml, and using secrets to exposed as environment
variables for the authentication informations.
[1].
https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/#using-environment-variables-inside-of-your-config
Best,
Yang
Chesnay Schepler <ches...@apache.org> 于2021年1月27日周三 上午8:03写道：
> In the end DYNAMIC_PROPERTIES behaves exactly like env.java.opts;
> meaning that the existing rules set by the JVM apply.
>
> Here's an example: export DYNAMIC_PROPERTIES='-Drest.port=1234
> -Dother.option="iContainAn=Sign"'
>
> This would then be appended as is to the /java/ command.
> (
> Conceptually at least; shells are annoying when it comes to
> quotes/whitespace; good old http://mywiki.wooledge.org/BashFAQ/050.
> Something like java ... $(eval echo ${DYNAMIC_PROPERTIES} handles
> quotes nicely, but no spaces in values.
>
> We should really move more logic from the scripts into the
> BashJavaUtils...
> )
>
> On 1/26/2021 11:17 PM, Khachatryan Roman wrote:
> >> Here's an example: My option key is custom.my_backend_option. With the
> >> current design, the corresponding env variable would be
> >> CUSTOM_MY_BACKEND_OPTION, which would be converted into
> >> custom.my.backend.option .
> > I think we don't have to translate CUSTOM_MY_BACKEND_OPTION back.
> Instead,
> > we should use the key from the ConfigOption.
> > I'm assuming that not every ENV VAR will end up in the Configuration -
> > only those for which a matching ConfigOptions is found.
> >
> > I'm also fine with a single ENV VAR (DYNAMIC_PROPERTIES). It's already a
> > big improvement.
> > In the future, we can consider adding smth like ConfigOption.withEnvVar
> for
> > some (most popular) options.
> >
> > However, escaping is still not clear to me: how would kv-pairs be
> > separated? What if such a separator is in the value itself? What if '='
> is
> > in the value?
> > Or am I missing something?
> >
> > Regards,
> > Roman
> >
> >
> > On Tue, Jan 26, 2021 at 6:41 PM Till Rohrmann <trohrm...@apache.org>
> wrote:
> >
> >> Thinking a bit more about the DYNAMIC_PROPERTIES, I have to admit that I
> >> like the fact that it works around the problem of encoding the key names
> >> and that it is more powerful wrt to bulk changes. Also the fact that one
> >> can copy past configuration snippets is quite useful. Given these
> aspects
> >> and that we wouldn't exclude any mentioned configuration scenarios, I
> would
> >> also be ok following this approach given that we support it for all
> Flink
> >> processes.
> >>
> >> Cheers,
> >> Till
> >>
> >> On Tue, Jan 26, 2021 at 5:10 PM Ingo Bürk <i...@ververica.com> wrote:
> >>
> >>> Hi everyone,
> >>>
> >>> thanks for the livid discussion, it's great to see so many opinions and
> >>> ideas!
> >>>
> >>> The point about underscores is a very valid point where the current
> FLIP,
> >>> if we were to stick with it, would have to be improved. I was going to
> say
> >>> that we should exclude that from the discussion about the merits of
> >>> different overall solutions, but I am afraid that this makes the "how
> to
> >>> name EVs" question even more convoluted, and that in turn directly
> impacts
> >>> the usefulness of the FLIP as a whole which is about a more convenient
> way
> >>> of configuring Flink; names which are too cryptic will not achieve
> that.
> >>> So
> >>> in this regard I am in agreement with Chesnay.
> >>>
> >>> After all these considerations, speaking from the Kubernetes context,
> it
> >>> seems to me that using the dynamic properties works best (I can use
> config
> >>> key names as-is) and requires no change, so I'm actually just leaning
> >>> towards that. However, the Kubernetes context is, I guess, not the only
> >>> one
> >>> to consider.
> >>>
> >>>
> >>> Best regards
> >>> Ingo
> >>>
> >>> On Tue, Jan 26, 2021 at 3:48 PM Chesnay Schepler <ches...@apache.org>
> >>> wrote:
> >>>
> >>>> Mind you that we could of course solve these character issues by first
> >>>> nailing down which characters we allow in keys (presumably:
> [a-z0-9-.]).
> >>>>
> >>>> On 1/26/2021 3:45 PM, Chesnay Schepler wrote:
> >>>>> Here's an example: My option key is custom.my_backend_option. With
> the
> >>>>> current design, the corresponding env variable would be
> >>>>> CUSTOM_MY_BACKEND_OPTION, which would be converted into
> >>>>> custom.my.backend.option .
> >>>>>
> >>>>> It is true that users could still parse the original system property
> >>>>> as a fall-back, but it seems to partially invalidate the goal and
> >>>>> introduce the potential for surprises and inconsistent behavior.
> >>>>>
> >>>>> What would happen if the option were already defined in the
> >>>>> flink-conf.yaml, but overwritten with the env variable? Users would
> >>>>> have to check every time they access a configuration whether the
> >>>>> system property was also set and resolve things manually. Naturally
> >>>>> things might also conflict with whatever prioritization we come up
> >>> with.
> >>>>> Now you might say that this is only necessary if the option contains
> >>>>> special characters, but then we're setting users up for a surprise
> >>>>> should they ever rename an existing option to contain an underscore.
> >>>>>
> >>>>> As for newlines, I wouldn't expect newline characters to appear
> within
> >>>>> DYNAMIC_VARIABLE, but I guess it would follow the same behavior as if
> >>>>> you would declare them on the command-line?
> >>>>>
> >>>>> One more downside I see is that from a users perspective I'd always
> >>>>> have to do this conversion manually. You can't just copy stuff from
> >>>>> the documentation (unless we duplicate every single mention), nor can
> >>>>> you easily switch between environment variables and dynamic
> >>>>> properties/flink-conf.yaml . For the use-cases that people seems to
> be
> >>>>> concerned about (where you have lots of variables) I would think that
> >>>>> this is a deal-breaker.
> >>>>>
> >>>>> On 1/26/2021 2:59 PM, Khachatryan Roman wrote:
> >>>>>> @Chesnay
> >>>>>> could you explain how underscores in user-defined properties would
> be
> >>>>>> affected with transformation like STATE_BACKEND -> state.backend?
> >>>>>> IIUC, this transformation happens in Flink and doesn't alter ENV
> >>>>>> vars, so
> >>>>>> the user app can still parse the original configuration.
> >>>>>> OTH, I'm a bit concerned whether the newline should be escaped by
> the
> >>>>>> user
> >>>>>> in DYNAMIC_VARIABLES.
> >>>>>>
> >>>>>> @Ingo Bürk <i...@ververica.com>
> >>>>>> I feel a bit lost in the discussion) Maybe we can put an
> intermediate
> >>>>>> summary of pros and cons of different approaches into the FLIP?
> >>>>>>
> >>>>>> And for completeness, we could combine DYNAMIC_VARIABLES approach
> >>> with
> >>>>>> passing individual variables.
> >>>>>>
> >>>>>>
> >>>>>> Regards,
> >>>>>> Roman
> >>>>>>
> >>>>>>
> >>>>>> On Tue, Jan 26, 2021 at 12:54 PM Chesnay Schepler <
> >>> ches...@apache.org>
> >>>>>> wrote:
> >>>>>>
> >>>>>>> I think we have to assume that some user has a custom config option
> >>>>>>> that
> >>>>>>> uses underscores.
> >>>>>>>
> >>>>>>> That said, we can probably assume that no one uses other special
> >>>>>>> characters like question marks and such, which are indeed allowed
> by
> >>>>>>> the
> >>>>>>> YAML spec.
> >>>>>>>
> >>>>>>> These kind of questions are precisely why I prefer the
> >>>>>>> DYNAMIC_VARIABLES
> >>>>>>> approach; you don't even have to worry about this stuff.
> >>>>>>> The only question we'd have to answer is whether manually defined
> >>>>>>> properties should take precedent or not.
> >>>>>>>
> >>>>>>> @Uce I can see how it could be cumbersome to modify, but at the
> same
> >>>>>>> time you can implement whatever other approach you want on top of
> >>> it:
> >>>>>>> // this is a /conceptual /example for an optional setting
> >>>>>>> DYNAMIC_VARIABLES="${REST_PORT_SETTING}"
> >>>>>>> if _someCondition_:
> >>>>>>> export REST_PORT_SETTING="-Drest.port=1234"
> >>>>>>>
> >>>>>>> // this is a /conceptual /example for a configurable setting
> >>>>>>> DYNAMIC_VARIABLES="-Drest.port=${MY_FANCY_VARIABLE:-8200}"
> >>>>>>> if _someCondition_:
> >>>>>>> export MY_FANCY_VARIABLE="1234"
> >>>>>>>
> >>>>>>> Additionally, this makes it quite easy to audit stuff, since we can
> >>>>>>> just
> >>>>>>> eagerly log what DYNAMIC_VARIABLES is set to.
> >>>>>>>
> >>>>>>> On 1/26/2021 12:48 PM, Xintong Song wrote:
> >>>>>>>> @Ufuk,
> >>>>>>>> I also don't find any existing options with underscores in their
> >>> keys.
> >>>>>>>> However, I do not find any explicit rules forbid using them
> either.
> >>>>>>>> I'm
> >>>>>>> not
> >>>>>>>> saying this should block the FLIP. Just it would be nice to beware
> >>> of
> >>>>>>> this
> >>>>>>>> issue, and maybe ensure the assumption with test cases if we
> >>> finally
> >>>>>>> decide
> >>>>>>>> to go with these mapping rules.
> >>>>>>>>
> >>>>>>>> Thank you~
> >>>>>>>>
> >>>>>>>> Xintong Song
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> On Tue, Jan 26, 2021 at 7:27 PM Ufuk Celebi <u...@apache.org>
> >>> wrote:
> >>>>>>>>> @Xingtong: The assumption for the mapping was that we only have
> >>>>>>>>> dots and
> >>>>>>>>> hyphens in the keys. Do you have an example for a key which
> >>> include
> >>>>>>>>> underscores? If underscores are common for keys (I couldn't find
> >>> any
> >>>>>>>>> existing options that use it), it would certainly be a blocker
> for
> >>>>>>>>> the
> >>>>>>>>> discussed approach.
> >>>>>>>>>
> >>>>>>>>> On Tue, Jan 26, 2021, at 11:46 AM, Xintong Song wrote:
> >>>>>>>>>> - The naming conversions proposed in the FLIP seems not
> >>>>>>>>>> bijective
> >>>>>>> to
> >>>>>>>>> me.
> >>>>>>>>>> There could be problems if the configuration key contains
> >>>>>>> underscores.
> >>>>>>>>>> - a_b -> FLINK_CONFIG_a_b
> >>>>>>>>>> - FLINK_CONFIG_a_b -> a.b
> >>>>>>>
> >>>>
>
>
