Обсуждение: [GENERAL] psql doesn't pass on exported shell environment functions
In hindsight I'm not surprised but couldn't find a ready explanation on the web and figured I'd inquire here. In short: "export VAR" and "export -f functionname" behave differently when psql is acting as a relay.
//main-script
#!/usr/bin/env bash
function testfunction() {
echo "Function Test"
}
export TEST_ENVVAR='Test'
export -f testfunction
psql "service=postgres" <<SQL
\! ./psql-call-bash
SQL
./psql-call-bash
//psql-call-bash script
#!/usr/bin/env bash
echo "Enter"
echo "EnvVar: $TEST_ENVVAR"
echo "Invoking Function..."
testfunction
exit
// command (after making both the above executable)
./main-script > output.txt 2>&1
//output.txt
Enter
EnvVar: Test
Invoking Function...
./psql-call-bash: line 7: testfunction: command not found
Enter
EnvVar: Test
Invoking Function...
Function Test
I was really hoping the first output block would match the second, specifically the "Function Test" line being present instead of "./psql-call-bash: line 7: testfunction: command not found"
Apparently exported variables go someplace different than exported functions :(
I don't suppose this is something that can be fixed in psql...
David J.
David G. Johnston wrote:
> In hindsight I'm not surprised but couldn't find a ready explanation on the web and
> figured I'd inquire here. In short: "export VAR" and "export -f functionname" behave
> differently when psql is acting as a relay.
It works for me on Linux with 9.6.3 psql:
laurenz:~> cat psql-call-bash
#!/usr/bin/env bash
echo "Enter"
echo "EnvVar: $TEST_ENVVAR"
echo "Invoking Function..."
testfunction
exit
laurenz:~> chmod 0700 psql-call-bash
laurenz:~> function testfunction() { echo "Function Test"; }
laurenz:~> export -f testfunction
laurenz:~> export TEST_ENVVAR='Test'
laurenz:~> psql
Border style is 2.
Line style is unicode.
psql (9.6.3)
Type "help" for help.
test=> \!
laurenz:~> ./psql-call-bash
Enter
EnvVar: Test
Invoking Function...
Function Test
Yours,
Laurenz Albe
Re: [GENERAL] psql doesn't pass on exported shell environment functions
От
"David G. Johnston"
Дата:
David G. Johnston wrote:
> In hindsight I'm not surprised but couldn't find a ready explanation on the web and
> figured I'd inquire here. In short: "export VAR" and "export -f functionname" behave
> differently when psql is acting as a relay.
It works for me on Linux with 9.6.3 psql:
Except you haven't recreated the scenario I presented.
You only are involving a single script and that script defines "testfunction" itself (which makes exporting pointless). In my example the script being executed within the psql script does not define testfunction itself.
-> == execute in subshell
main-script (def func) -> psql -> psql-call-bash (invoke func)
David J.
David G. Johnston wrote: >> It works for me on Linux with 9.6.3 psql: > > Except you haven't recreated the scenario I presented. > > You only are involving a single script and that script defines "testfunction" itself > (which makes exporting pointless). In my example the script being executed within the > psql script does not define testfunction itself. > > -> == execute in subshell > > main-script (def func) -> psql -> psql-call-bash (invoke func) I am confused; my shell script does *not* contain a function definition. I copied and pasted a shell session: First, show the script that contains a function invocation. Then, define and export the function. Then, call psql Then, escape to a subshell. Then, call the script that successfully calls the function. Am I missing something? Yours, Laurenz Albe
Albe Laurenz <laurenz.albe@wien.gv.at> writes:
> David G. Johnston wrote:
>> Except you haven't recreated the scenario I presented.
> Am I missing something?
I wonder what platform David is using. This looks suspiciously like
a feature that macOS' SIP would be designed to break.
It would be interesting to capture the output of "env" in the sub-shell
to see which environment variables and functions are getting through.
regards, tom lane
Re: [GENERAL] psql doesn't pass on exported shell environment functions
От
"David G. Johnston"
Дата:
David G. Johnston wrote:
>> It works for me on Linux with 9.6.3 psql:
>
> Except you haven't recreated the scenario I presented.
>
> You only are involving a single script and that script defines "testfunction" itself
> (which makes exporting pointless). In my example the script being executed within the
> psql script does not define testfunction itself.
>
> -> == execute in subshell
>
> main-script (def func) -> psql -> psql-call-bash (invoke func)
I am confused; my shell script does *not* contain a function definition.
Am I missing something?
Nope, it was a combination of ERRNOCAFFINE and not seeing a second script.
I'm using Ubuntu 16.04
I tried your way of not using a "main-script" and got the same result.
I can see the exported environment variable TEST_ENVVAR in the "env" output of the psql \! subshell. "declare -Fx" shows no results.
I replaced "/usr/bin/env bash" with "/bin/bash" to no effect.
David J.
Re: [GENERAL] psql doesn't pass on exported shell environment functions
От
"David G. Johnston"
Дата:
I'm using Ubuntu 16.04
Seems to be a regression since this works on my 14.04 setup.
David J.
Re: [GENERAL] psql doesn't pass on exported shell environment functions
От
"David G. Johnston"
Дата:
I'm using Ubuntu 16.04Seems to be a regression since this works on my 14.04 setup.
Sorry for the append but my 14.04 setup is using 9.5 while the 16.04 setup is using 9.6.
David J.
"David G. Johnston" <david.g.johnston@gmail.com> writes:
> I'm using Ubuntu 16.04
Hmph. Works for me on RHEL6. I'm betting that Ubuntu has put in some
weird security restriction, possibly an overreaction to the "shellshock"
bug which was in the exported-functions feature.
regards, tom lane
Re: [GENERAL] psql doesn't pass on exported shell environment functions
От
"David G. Johnston"
Дата:
"David G. Johnston" <david.g.johnston@gmail.com> writes:
> I'm using Ubuntu 16.04
Hmph. Works for me on RHEL6. I'm betting that Ubuntu has put in some
weird security restriction, possibly an overreaction to the "shellshock"
bug which was in the exported-functions feature.
Thank you both for looking at this. While my curiosity is still piqued I've solved the original problem without resorting to exporting a function through a psql invocation. Fortunately, exported functions are still seen by directly called bash scripts so a few other areas where I leverage that feature are still working.
I've haven't totally discounted local configuration interplay here - my bashrc is non-trivial and there a few differences between the setups besides versions - though a security enhancement in 16.04 seems plausible.
David J.