feat: support for ostree systems

Feature: Allow running and testing the role with ostree managed nodes.

Reason: We have users who want to use the role to manage ostree
systems.

Result: Users can use the role to manage ostree managed nodes.
Signed-off-by: Rich Megginson <[email protected]>

.ansible-lint

@@ -22,3 +22,5 @@ exclude_paths:
   - examples/roles/
 mock_roles:
   - linux-system-roles.postfix
+mock_modules:
+  - ansible.utils.update_fact

.ostree/README.md

@@ -0,0 +1,3 @@
+*NOTE*: The `*.txt` files are used by `get_ostree_data.sh` to create the lists
+of packages, and to find other system roles used by this role.  DO NOT use them
+directly.

.ostree/get_ostree_data.sh

@@ -0,0 +1,123 @@
+#!/bin/bash
+
+set -euo pipefail
+
+role_collection_dir="${ROLE_COLLECTION_DIR:-fedora/linux_system_roles}"
+ostree_dir="${OSTREE_DIR:-"$(dirname "$(realpath "$0")")"}"
+
+if [ -z "${4:-}" ] || [ "${1:-}" = help ] || [ "${1:-}" = -h ]; then
+    cat <<EOF
+Usage: $0 packages [runtime|testing] DISTRO-MAJOR[.MINOR] [json|yaml|raw|toml]
+The script will use the packages and roles files in $ostree_dir to
+construct the list of packages needed to build the ostree image.  The script
+will output the list of packages in the given format
+- json is a JSON list like ["pkg1","pkg2",....,"pkgN"]
+- yaml is the YAML list format
+- raw is the list of packages, one per line
+- toml is a list of [[packages]] elements as in https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html-single/composing_installing_and_managing_rhel_for_edge_images/index#creating-an-image-builder-blueprint-for-a-rhel-for-edge-image-using-the-command-line-interface_composing-a-rhel-for-edge-image-using-image-builder-command-line
+The DISTRO-MAJOR.MINOR is the same format used by Ansible for distribution e.g. CentOS-8, RedHat-8.9, etc.
+EOF
+    exit 1
+fi
+category="$1"
+pkgtype="$2"
+distro_ver="$3"
+format="$4"
+pkgtypes=("$pkgtype")
+if [ "$pkgtype" = testing ]; then
+    pkgtypes+=(runtime)
+fi
+
+get_rolepath() {
+    local ostree_dir role rolesdir roles_parent_dir
+    ostree_dir="$1"
+    role="$2"
+    roles_parent_dir="$(dirname "$(dirname "$ostree_dir")")"
+    rolesdir="$roles_parent_dir/$role/.ostree"
+    # assumes collection format
+    if [ -d "$rolesdir" ]; then
+        echo "$rolesdir"
+        return 0
+    fi
+    # assumes legacy role format like linux-system-roles.$role/
+    for rolesdir in "$roles_parent_dir"/*-system-roles."$role"/.ostree; do
+        if [ -d "$rolesdir" ]; then
+          echo "$rolesdir"
+          return 0
+        fi
+    done
+    # look elsewhere
+    if [ -n "${ANSIBLE_COLLECTIONS_PATHS:-}" ]; then
+        for pth in ${ANSIBLE_COLLECTIONS_PATHS//:/ }; do
+            rolesdir="$pth/ansible_collections/$role_collection_dir/roles/$role/.ostree"
+            if [ -d "$rolesdir" ]; then
+                echo "$rolesdir"
+                return 0
+            fi
+        done
+    fi
+    return 1
+}
+
+get_packages() {
+    local ostree_dir pkgtype pkgfile rolefile
+    ostree_dir="$1"
+    for pkgtype in "${pkgtypes[@]}"; do
+        for suff in "" "-$distro" "-${distro}-${major_ver}" "-${distro}-${ver}"; do
+            pkgfile="$ostree_dir/packages-${pkgtype}${suff}.txt"
+            if [ -f "$pkgfile" ]; then
+                cat "$pkgfile"
+            fi
+        done
+        rolefile="$ostree_dir/roles-${pkgtype}.txt"
+        if [ -f "$rolefile" ]; then
+            local roles role rolepath
+            roles="$(cat "$rolefile")"
+            for role in $roles; do
+                rolepath="$(get_rolepath "$ostree_dir" "$role")"
+                get_packages "$rolepath"
+            done
+        fi
+    done | sort -u
+}
+
+format_packages_json() {
+    local comma pkgs pkg
+    comma=""
+    pkgs="["
+    while read -r pkg; do
+        pkgs="${pkgs}${comma}\"${pkg}\""
+        comma=,
+    done
+    pkgs="${pkgs}]"
+    echo "$pkgs"
+}
+
+format_packages_raw() {
+    cat
+}
+
+format_packages_yaml() {
+    while read -r pkg; do
+        echo "- $pkg"
+    done
+}
+
+format_packages_toml() {
+    while read -r pkg; do
+        echo "[[packages]]"
+        echo "name = \"$pkg\""
+        echo "version = \"*\""
+    done
+}
+
+distro="${distro_ver%%-*}"
+ver="${distro_ver##*-}"
+if [[ "$ver" =~ ^([0-9]*) ]]; then
+    major_ver="${BASH_REMATCH[1]}"
+else
+    echo ERROR: cannot parse major version number from version "$ver"
+    exit 1
+fi
+
+"get_$category" "$ostree_dir" | "format_${category}_$format"

.ostree/packages-runtime.txt

@@ -0,0 +1 @@
+postfix

.ostree/roles-runtime.txt

@@ -0,0 +1,2 @@
+firewall
+selinux

.sanity-ansible-ignore-2.12.txt

@@ -0,0 +1 @@
+roles/postfix/.ostree/get_ostree_data.sh shebang!skip

.sanity-ansible-ignore-2.13.txt

@@ -0,0 +1 @@
+roles/postfix/.ostree/get_ostree_data.sh shebang!skip

.sanity-ansible-ignore-2.14.txt

@@ -0,0 +1 @@
+roles/postfix/.ostree/get_ostree_data.sh shebang!skip

.sanity-ansible-ignore-2.15.txt

@@ -0,0 +1 @@
+roles/postfix/.ostree/get_ostree_data.sh shebang!skip

.sanity-ansible-ignore-2.9.txt

@@ -0,0 +1 @@
+roles/postfix/.ostree/get_ostree_data.sh shebang!skip

README-ostree.md

@@ -0,0 +1,66 @@
+# rpm-ostree
+
+The role supports running on [rpm-ostree](https://coreos.github.io/rpm-ostree/)
+systems. The primary issue is that the `/usr` filesystem is read-only, and the
+role cannot install packages. Instead, it will just verify that the necessary
+packages and any other `/usr` files are pre-installed. The role will change the
+package manager to one that is compatible with `rpm-ostree` systems.
+
+## Building
+
+To build an ostree image for a particular operating system distribution and
+version, use the script `.ostree/get_ostree_data.sh` to get the list of
+packages. If the role uses other system roles, then the script will include the
+packages for the other roles in the list it outputs.  The list of packages will
+be sorted in alphanumeric order.
+
+Usage:
+
+```bash
+.ostree/get_ostree_data.sh packages runtime DISTRO-VERSION FORMAT
+```
+
+`DISTRO-VERSION` is in the format that Ansible uses for `ansible_distribution`
+and `ansible_distribution_version` - for example, `Fedora-38`, `CentOS-8`,
+`RedHat-9.4`
+
+`FORMAT` is one of `toml`, `json`, `yaml`, `raw`
+
+* `toml` - each package in a TOML `[[packages]]` element
+
+```toml
+[[packages]]
+name = "package-a"
+version = "*"
+[[packages]]
+name = "package-b"
+version = "*"
+...
+```
+
+* `yaml` - a YAML list of packages
+
+```yaml
+- package-a
+- package-b
+...
+```
+
+* `json` - a JSON list of packages
+
+```json
+["package-a","package-b",...]
+```
+
+* `raw` - a plain text list of packages, one per line
+
+```bash
+package-a
+package-b
+...
+```
+
+What format you choose depends on which image builder you are using.  For
+example, if you are using something based on
+[osbuild-composer](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html-single/composing_installing_and_managing_rhel_for_edge_images/index#creating-an-image-builder-blueprint-for-a-rhel-for-edge-image-using-the-command-line-interface_composing-a-rhel-for-edge-image-using-image-builder-command-line),
+you will probably want to use the `toml` output format.

README.md

@@ -20,7 +20,9 @@ If the `postfix` is a role from the `fedora.linux_system_roles`
 collection or from the Fedora RPM package, the requirement is already
 satisfied.
 
-Otherwise, please run the following command line to install the collection.
+The role requires additional collections to manage `rpm-ostree` systems.
+If you need to manage `rpm-ostree` systems, run the below command to
+install the collections.
 
 ```bash
 ansible-galaxy collection install -r meta/collection-requirements.yml
@@ -48,6 +50,10 @@ package and replaces the existing `/etc/postfix/main.cf` and
 `/etc/postfix/master.cf` files. <!--- wokeignore:rule=master -->
 Ensure to back up those files to preserve your settings.
 
+**WARNING**: When managing `rpm-ostree` systems, the role cannot reinstall the
+postfix package, so it just replaces the modified config files with empty files.
+This is not idempotent.
+
 If you specify only `previous: replaced` under the `postfix_conf` dictionary,
 the role re-installs the `postfix` package and enables the `postfix` service
 without applying any configuration.
@@ -191,6 +197,10 @@ set to true `postfix_backup` is ignored):
     - linux-system-roles.postfix
 ```
 
+## rpm-ostree
+
+See README-ostree.md
+
 ## License
 
 Copyright (C) 2017 Jaroslav Škarvada <[email protected]>

meta/collection-requirements.yml

@@ -1,4 +1,6 @@
 # SPDX-License-Identifier: MIT
 ---
 collections:
+  - ansible.posix
+  - ansible.utils
   - fedora.linux_system_roles

tasks/main.yml

@@ -8,6 +8,7 @@
   when:
     - postfix_conf.previous is defined
     - postfix_conf.previous == "replaced"
+    - ansible_facts.pkg_mgr | d() != "ansible.posix.rhel_rpm_ostree"
   block:
     # It is assumed that the only package providing config files that might
     # be modified is postfix - if this is not so, then additional
@@ -29,6 +30,33 @@
         selectattr('stdout', 'search', ' /etc/postfix/.*[.]cf($|\n)') |
         list | length > 0
 
+- name: Remove configuration for replacement
+  when:
+    - postfix_conf.previous | d() == "replaced"
+    - ansible_facts.pkg_mgr | d() == "ansible.posix.rhel_rpm_ostree"
+  block:
+    # It is assumed that the only package providing config files that might
+    # be modified is postfix - if this is not so, then additional
+    # packages need to be added to this check
+    - name: Get status of config files
+      command: rpm -V --nomtime {{ item }}  # noqa command-instead-of-module
+      loop: "{{ __postfix_packages }}"
+      register: __postfix_packages_status
+      failed_when: false
+      changed_when: false
+
+    - name: Remove config files - make empty
+      copy:
+        dest: "{{ item }}"
+        content: "\n"  # to make postconf -e happy
+        mode: preserve
+      loop: "{{ mod_cf_files }}"
+      vars:
+        mod_cf_files: "{{ __postfix_packages_status.results |
+          map(attribute='stdout') | map('default', '') |
+          map('regex_findall', ' (/etc/postfix/.*[.]cf)(?:$|\n)') | select |
+          flatten | list }}"
+
 - name: Configure firewall
   include_tasks: firewall.yml
 

tasks/set_facts.yml

@@ -5,3 +5,21 @@
     gather_subset: "{{ __postfix_required_facts_subsets }}"
   when: __postfix_required_facts |
     difference(ansible_facts.keys() | list) | length > 0
+
+- name: Ensure correct package manager for ostree systems
+  vars:
+    ostree_pkg_mgr: ansible.posix.rhel_rpm_ostree
+    ostree_booted_file: /run/ostree-booted
+  when: ansible_facts.pkg_mgr | d("") != ostree_pkg_mgr
+  block:
+    - name: Check if system is ostree
+      stat:
+        path: "{{ ostree_booted_file }}"
+      register: __ostree_booted_stat
+
+    - name: Set package manager to use for ostree
+      ansible.utils.update_fact:
+        updates:
+          - path: ansible_facts.pkg_mgr
+            value: "{{ ostree_pkg_mgr }}"
+      when: __ostree_booted_stat.stat.exists