ARROW-14840: [R][CI] test-ubuntu-20.10-docs nightly build failing due…

… to R install issue

I'm not 100% sure why this fixes this fail, but downgrading the Ubuntu version to 20.04 seems to fix it, and here's my reasoning.

So, apt-key, which is used as part of the R bit of the docs build is now deprecated[1] and Ubuntu 20.10 (Groovy Gorilla) is no longer a supported release as of 22nd July 2021 [2] which can apparently cause issues subsequently trying to do stuff via apt[3].

Reading the R docs for Ubuntu packages[4], it says there that "Package for the current R 4.1. release* are available for most stable Desktop releases of Ubuntu until their official end of life date" which maybe explains why the URL for R packages works fine for focal[5] but results in a 404 error for groovy [6].

The way of getting the signing key for updating packages changed [4] to no longer use apt-key [7] - I have no idea if this had any effect either, but to be on the safe side I have updated that too.

[1] https://manpages.debian.org/testing/apt/apt-key.8.en.html
[2] https://wiki.ubuntu.com/Releases
[3] https://news.itsfoss.com/ubuntu-20-10-end-of-life/
[4] https://cran.r-project.org/bin/linux/ubuntu/
[5] https://cran.r-project.org/bin/linux/ubuntu/focal-cran40/
[6] https://cran.r-project.org/bin/linux/ubuntu/groovy-cran40/
[7] http://web.archive.org/web/20210618164400/https://cloud.r-project.org/bin/linux/ubuntu/

Closes apache#11815 from thisisnic/ARROW-14840

Authored-by: Nic Crane <thisisnic@gmail.com>
Signed-off-by: Jonathan Keane <jkeane@gmail.com>

ci/docker/linux-apt-docs.dockerfile

@@ -27,9 +27,8 @@ RUN apt-get update -y && \
         dirmngr \
         apt-transport-https \
         software-properties-common && \
-    apt-key adv \
-        --keyserver keyserver.ubuntu.com \
-        --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9 && \
+    wget -qO- https://cloud.r-project.org/bin/linux/ubuntu/marutter_pubkey.asc | \
+        tee -a /etc/apt/trusted.gpg.d/cran_ubuntu_key.asc && \
     add-apt-repository 'deb https://cloud.r-project.org/bin/linux/ubuntu '$(lsb_release -cs)'-cran40/' && \
     apt-get install -y --no-install-recommends \
         autoconf-archive \
@@ -81,8 +80,9 @@ RUN pip install \
         meson \
         breathe==4.29.0 \
         ipython \
+        pydata-sphinx-theme \
         sphinx \
-        pydata-sphinx-theme
+        sphinx-tabs
 
 COPY c_glib/Gemfile /arrow/c_glib/
 RUN gem install --no-document bundler && \

ci/docker/linux-apt-lint.dockerfile

@@ -41,9 +41,8 @@ RUN apt-get update && \
     && rm -rf /var/lib/apt/lists/*
 
 ARG r=4.1
-RUN apt-key adv \
-        --keyserver keyserver.ubuntu.com \
-        --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9 && \
+RUN wget -qO- https://cloud.r-project.org/bin/linux/ubuntu/marutter_pubkey.asc | \
+        tee -a /etc/apt/trusted.gpg.d/cran_ubuntu_key.asc && \
     # NOTE: R 3.5 and 3.6 are available in the repos with -cran35 suffix
     # for trusty, xenial, bionic, and eoan (as of May 2020)
     # -cran40 has 4.0 versions for bionic and focal

ci/docker/linux-apt-r.dockerfile

@@ -34,9 +34,8 @@ RUN apt-get update -y && \
         dirmngr \
         apt-transport-https \
         software-properties-common && \
-    apt-key adv \
-        --keyserver keyserver.ubuntu.com \
-        --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9 && \
+    wget -qO- https://cloud.r-project.org/bin/linux/ubuntu/marutter_pubkey.asc | \
+        tee -a /etc/apt/trusted.gpg.d/cran_ubuntu_key.asc && \
     # NOTE: R 3.5 and 3.6 are available in the repos with -cran35 suffix
     # for trusty, xenial, bionic, and eoan (as of May 2020)
     # -cran40 has 4.0 versions for bionic and focal

dev/release/post-09-docs.sh

@@ -43,7 +43,7 @@ popd
 pushd "${ARROW_DIR}"
 git checkout "${release_tag}"
 
-UBUNTU=20.10 archery docker run \
+archery docker run \
   -v "${ARROW_SITE_DIR}/docs:/build/docs" \
   -e ARROW_DOCS_VERSION="${version}" \
   ubuntu-docs

dev/tasks/tasks.yml

@@ -1256,14 +1256,6 @@ tasks:
         GO: 1.15
       run: debian-go
 
-  test-ubuntu-20.10-docs:
-    ci: azure
-    template: docker-tests/azure.linux.yml
-    params:
-      env:
-        UBUNTU: "20.10"
-      run: ubuntu-docs
-
   test-ubuntu-default-docs:
     ci: azure
     template: docker-tests/azure.linux.yml