rpm: always replace existing repo-configuration

The installation script's main purpose is to perform a fresh install, because
it's not guaranteed to work correctly when updating an existing installation,
and we print a warning if we find docker is already installed. However, it's
known that the script is used to update existing installations.

The current script has some limitations for the update scenario;

- When using the script for installing from the staging domain, the existing
  repo configuration is not overwritten. When using `yum`, or older `dnf` versions
  this resulted in 2 separate repo files to be created (docker-ce.repo and
  docker-ce-staging.repo), which resulted in errors due to duplicate repo
  definitions with the same name.
- When using `dnf5`, we specified the filename to store the configuration,
  which resulted in an error;

        + sh -c 'dnf5 config-manager addrepo --save-filename=docker-ce.repo --from-repofile='\''https://download-stage.docker.com/linux/fedora/docker-ce-staging.repo'\'''
          File "/etc/yum.repos.d/docker-ce.repo" already exists and configures repositories with IDs "docker-ce-stable docker-ce-stable-debuginfo docker-ce-stable-source docker-ce-test docker-ce-test-debuginfo docker-ce-test-source docker-ce-nightly docker-ce-nightly-debuginfo docker-ce-nightly-source". Add "--overwrite" to overwrite.

  - On SLES, it would result in a similar error;

        + sh -c 'zypper addrepo https://download-stage.docker.com/linux/sles/docker-ce-staging.repo'
          Adding repository 'Docker CE Nightly - s390x' ......................................................................................[error]
          Repository named 'docker-ce-nightly' already exists. Please use another alias.
          Adding repository 'Docker CE Nightly - Debuginfo s390x' ............................................................................[error]
          Repository named 'docker-ce-nightly-debuginfo' already exists. Please use another alias.

This patch updates the script to overwrite / replace the existing repo config.
This brings the rpm-based installations in line with the Debian approach, which
unconditionally overwrites `/etc/apt/sources.list.d/docker.list`.

It's worth noting that this change will therefore overwrite any customisations
made to the repo-configurations, so a warning is added for that.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

install.sh

@@ -368,7 +368,9 @@ do_install() {
 			installation.
 
 			If you installed the current Docker package using this script and are using it
-			again to update Docker, you can safely ignore this message.
+			again to update Docker, you can ignore this message, but be aware that the
+			script resets any custom changes in the deb and rpm repo configuration
+			files to match the parameters passed to the script.
 
 			You may press Ctrl+C now to abort this script.
 		EOF
@@ -559,7 +561,7 @@ do_install() {
 				fi
 				if command_exists dnf5; then
 					$sh_c "dnf -y -q --setopt=install_weak_deps=False install dnf-plugins-core"
-					$sh_c "dnf5 config-manager addrepo --save-filename=docker-ce.repo --from-repofile='$repo_file_url'"
+					$sh_c "dnf5 config-manager addrepo --overwrite --save-filename=docker-ce.repo --from-repofile='$repo_file_url'"
 
 					if [ "$CHANNEL" != "stable" ]; then
 						$sh_c "dnf5 config-manager setopt \"docker-ce-*.enabled=0\""
@@ -568,6 +570,7 @@ do_install() {
 					$sh_c "dnf makecache"
 				elif command_exists dnf; then
 					$sh_c "dnf -y -q --setopt=install_weak_deps=False install dnf-plugins-core"
+					$sh_c "rm -f /etc/yum.repos.d/docker-ce.repo  /etc/yum.repos.d/docker-ce-staging.repo"
 					$sh_c "dnf config-manager --add-repo $repo_file_url"
 
 					if [ "$CHANNEL" != "stable" ]; then
@@ -577,6 +580,7 @@ do_install() {
 					$sh_c "dnf makecache"
 				else
 					$sh_c "yum -y -q install yum-utils"
+					$sh_c "rm -f /etc/yum.repos.d/docker-ce.repo  /etc/yum.repos.d/docker-ce-staging.repo"
 					$sh_c "yum-config-manager --add-repo $repo_file_url"
 
 					if [ "$CHANNEL" != "stable" ]; then
@@ -659,18 +663,23 @@ do_install() {
 					set -x
 				fi
 				$sh_c "zypper install -y $pre_reqs"
+				$sh_c "rm -f /etc/zypp/repos.d/docker-ce-*.repo"
 				$sh_c "zypper addrepo $repo_file_url"
-				if ! is_dry_run; then
-						cat >&2 <<-'EOF'
-						WARNING!!
-						openSUSE repository (https://download.opensuse.org/repositories/security:/SELinux) will be enabled now.
-						Do you wish to continue?
-						You may press Ctrl+C now to abort this script.
+
+				opensuse_factory_url="https://download.opensuse.org/repositories/security:/SELinux/openSUSE_Factory/"
+				if ! zypper lr -d | grep -q "${opensuse_factory_url}"; then
+					opensuse_repo="${opensuse_factory_url}security:SELinux.repo"
+					if ! is_dry_run; then
+						cat >&2 <<- EOF
+							WARNING!!
+							openSUSE repository ($opensuse_repo) will be enabled now.
+							Do you wish to continue?
+							You may press Ctrl+C now to abort this script.
 						EOF
-						( set -x; sleep 30 )
+						( set -x; sleep 20 )
+					fi
+					$sh_c "zypper addrepo $opensuse_repo"
 				fi
-				opensuse_repo="https://download.opensuse.org/repositories/security:/SELinux/openSUSE_Factory/security:SELinux.repo"
-				$sh_c "zypper addrepo $opensuse_repo"
 				$sh_c "zypper --gpg-auto-import-keys refresh"
 				$sh_c "zypper lr -d"
 			)