base: introduced docker file for Ubuntu 20.04

[mtitov]

Issues to resolve:

• [x] ~python of version 3.6 (for Ubuntu 20.04, the default version is 3.8)~
  • edited on 09/17: keep this for future PR (see ticket #74)
• [x] use default python package
• [x] errors while building image for swift/t

  => ERROR [5/8] RUN ./install-deps.sh                                                                                                                                                                                                                              0.2s
  ------                                                                                                                                                                                                                                                                  
  > [5/8] RUN ./install-deps.sh:
  #9 0.225 ./install-deps.sh: 14: Syntax error: Bad fd number
  ------
  executor failed running [/bin/sh -c ./install-deps.sh]: exit code: 2

• [x] OpenMPI installation (script install-mpi.sh used for CentOS7/8 is commented out)

[j-woz]

I was able to reproduce this. It is due to the fact that sh != bash on Ubuntu. This fix works for me:

index f842563..42c6519 100755
--- a/docker/swift-t/install-deps.sh
+++ b/docker/swift-t/install-deps.sh
@@ -4,7 +4,7 @@ set -eux
 # INSTALL DEPENDENCIES
 # Currently just Tcl

-if which tclsh8.6 >& /dev/null
+if which tclsh8.6 > /dev/null 2>&1
 then
   # Tcl is installed, probably via package manager.
   # Note that this does not check for tcl-devel,
diff --git a/docker/swift-t/install-swift-t.sh b/docker/swift-t/install-swift-t.sh
index 2c6f2e8..6e02921 100755
--- a/docker/swift-t/install-swift-t.sh
+++ b/docker/swift-t/install-swift-t.sh
@@ -13,8 +13,7 @@ PATH=/opt/tcl-8.6.11/bin:$PATH
 git clone https://github.com/swift-lang/swift-t.git

 # Build it
-pushd swift-t/dev/build
+cd swift-t/dev/build
 cp -v swift-t-settings.sh.template swift-t-settings.sh
 sed -i "/SWIFT_T_PREFIX=/s@=.*@=$SWIFT_ROOT@" swift-t-settings.sh
 ./build-swift-t.sh
-popd

I think it makes sense to include this fix with this PR because this is part of Ubuntu compatibility.

[mtitov]

Thank you, @j-woz ! That got resolved

[mtitov]

@dongahn @andre-merzky @mturilli @j-woz adding python installation script brings another point for internal reorganization in base docker files, which should be in sync with #70 (and there is one more input parameter for future consideration - python version). (1) for pip - use python installation script and set virtualenv (..-m venv..), (2) for conda - use conda installation script (maybe current code for conda in #70 could be also moved into a separate script? @zekemorton) and create conda env (conda create -p...)

UPDATE (09/17)

1. Python management is set for the next PR (see ticket #74)
2. This PR will use default python package and will be merged before PR #70, thus to be covered by it

[dongahn]

@mtitov: is this ready to go in? As I remember the only things that were needed was 1) resolve Swif/T issues and 2) use the distro provided Python 3 RPM. Let me know.

[mtitov]

@dongahn sorry for the delay, it is ready now p.s. even we switched back to default python, I still keep the python script in (just FYI)

[dongahn]

Not a problem. If the python script isn't used, you can take it off and do a separate PR to be reviewed more quickly. But it's minor enough, I will trust your judgement. Thanks. Let's discuss tomorrow with a goal to land it soon.

[dongahn]

Thanks @andre-merzky for reviewing and merging!

BTW, you could also set the merge-when-passing label and mergefyio handles it. (Could be the case a manual merge was required for this case though...)

[andre-merzky]

BTW, you could also set the merge-when-passing label and mergefyio handles it. (Could be the case a manual merge was required for this case though...)

Ah, sorry, I forgot that this is policy here, will do next time! (manual merge was not necessary)

[dongahn]

A manual merge is perfectly fine and this is not a problem at all. It is just that mergefyIO would do a bit more check for us. Robot :-)!!