Allow script to run without init system (in containers)

README.md

@@ -0,0 +1,75 @@
+# postgresql-setup
+
+## Requires
+
+### BuildRequires
+- make
+- m4
+- docbook-utils
+- help2man
+- elinks (pretty README.rpm-dist)
+- postgresql-server (detect current version)
+
+### Requires
+- coreutils
+
+### Suggested BuildRequires
+- util-linux (mountpoint utility)
+
+### Maintainer's BuildRequires
+- autoconf
+- automake
+- autoconf-archive
+
+## Usage
+This script is used as a wrapper around PostgreSQL initialization and upgrade
+commands. It also parses init system service files and/or environment files to
+correctly find datadir based on current system.
+
+### Initialization
+To initialize new PostgreSQL data directory use `./postgresql-setup --initdb`.
+
+### Upgrade
+To upgrade existing PostgreSQL data directory to use newer PostgreSQL version
+use `./postgresql-setup --upgrade`.
+
+If your distribution doesn't include this
+script with PostgreSQL and you are using this on your own, please update
+`./etc/postgresql-setup/upgrade/postgresql.conf` to reflect your setup.
+
+### Running without systemd/init system
+Your setup might not include systemd as the init system or include any
+init system at all. This would be the case in most of the base container images
+for example. This script will try to compensate by parsing systemd
+service file in preconfigured path directly. By default the path is
+`/lib/systemd/system`.
+
+If there is no systemd service file, or for whatever reason the script is unable
+to find valid PostgreSQL data directory, you can still provide PostgreSQL data
+directory path manually by using `--datadir` argument. For example when
+initializing new data directory use `postgresql-setup --initdb --datadir=/my/path`.
+
+This feature is most beneficial when using this script inside container images,
+as it gives you the most control with least dependencies.
+
+## Maintainer notes
+Be careful about paths. You might need to tweak paths either in the configure
+  files, or in code based on your environment.
+- Line 49 of `./bin/postgresql-setup.in` in function `builddir_source ()` has to
+  be changed to location of your project otherwise you won't be able to run your
+  build without full installation into system paths
+    - For example line should be `. "/postgresql-setup/$file"` if your
+      working project is located at `/postgresql-setup`
+    - *Do NOT commit/merge this change*
+
+### Build instructions
+1. `autoreconf -vfi`
+2. `./configure --prefix=/usr`
+    - Prefix needed for fedora environment - one of the path tweaks that are needed
+3. `make`
+
+After aforementioned steps, you should be able to run freshly built
+postgresql-setup script directly from /bin folder in this repo.
+
+If no init system is present, PostgreSQL server can be run after initialization
+via `/usr/bin/pg_ctl -D /var/lib/pgsql/data -l /var/lib/pgsql/logfile start`

bin/postgresql-setup.in

@@ -85,16 +85,11 @@ Options:
                              string).  When no UNIT_NAME is explicitly passed,
                              the 'postgresql' string is used by default.
   --port=PORT                port where the initialized server will listen for
-                             connections"
-
-test 0 -eq @WANT_SYSVINIT@ && \
-USAGE_STRING+="
-  --new-systemd-unit         We dropped this option for security reasons.
-                             Nowadays, please use the root-only script
-                             @sbindir@/@NAME_BINARYBASE@-new-systemd-unit.
-  --datadir                  Dropped with --new-systemd-unit."
-
-USAGE_STRING+="
+                             connections
+  --datadir                  Override automatic detection of PostgreSQL data
+                             directory. If your system is using systemd as init
+                             system, it is advisable to change data directory
+                             path in service file instead.
   --upgrade-from-unit=UNIT   Select proper unit name to upgrade from.  This
                              has similar semantics as --unit option.
   --upgrade-ids              Print list of available IDs of upgrade scenarios to
@@ -401,6 +396,37 @@ handle_service_env()
     done
 }
 
+handle_service_file()
+{
+    local service_file="$1"
+    local line var_name var_value
+    debug "Parsing ${service_file}"
+    local systemd_env="$(cat "${service_file}")" \
+        || { return; }
+
+    while IFS= read -r line; do
+        # Only lines starting with Environment=
+        [[ "$line" =~ ^Environment= ]] || continue
+
+        # Remove 'Environment=' prefix
+        line="${line#Environment=}"
+
+        for env_val in $line; do
+            var_name="${env_val%%=*}"
+            var_value="${env_val#*=}"
+            debug "Found environment variable: $var_name=$var_value"
+
+            case "$var_name" in
+                PGDATA)
+                    unit_pgdata="$var_value"
+                    ;;
+                PGPORT)
+                    unit_pgport="$var_value"
+                    ;;
+            esac
+        done
+    done <<< "$systemd_env"
+}
 
 handle_envfile()
 {
@@ -418,6 +444,7 @@ handle_envfile()
     # Note that the env file parser in systemd does not perform exactly the
     # same job.
     unset PGPORT PGDATA
+    # Source the file, loading the variables in it
     . "$file"
     envfile_pgdata="$PGDATA"
     envfile_pgport="$PGPORT"
@@ -503,18 +530,35 @@ service_configuration()
             && set_var "$datavar" "@PGDATADIR@"
         handle_envfile "@initscriptsconfdir@/$service"
     else
-        # We ship two service files, @NAME_SERVICE@.service and
-        # @NAME_SERVICE@@.service.  The former has PGDATA set by default
-        # similarly to sysvinit case.
-        handle_service_env "$service"
-        handle_service_envfiles "$option_mode" "$service"
+        if grep -q systemd /proc/1/comm; then
+            # If booted with systemd as PID 1, we try to find the variables
+            # using systemctl show -p Environment= @NAME_SERVICE@.service
+            # We ship two service files, @NAME_SERVICE@.service and
+            # @NAME_SERVICE@@.service.  The former has PGDATA set by default
+            # similarly to sysvinit case.
+            debug "System booted with systemd as PID 1, using systemctl to find"\
+                  "service configuration for $service"
+            handle_service_env "$service"
+            handle_service_envfiles "$option_mode" "$service"
+        else
+            # If not booted with systemd, we try to find the service file in
+            # predefined path and parse it manually.
+            warn "System not booted with systemd as PID 1. Manually parsing service"\
+                 "file @INIT_SYSTEM_SERVICE_PATH@/$service.service"
+            handle_service_file "@INIT_SYSTEM_SERVICE_PATH@/$service.service"
+        fi
     fi
 
     # EnvironmentFile beats Environment configuration in systemd.  In sysvinit
     # there is no "unit_pgdata".  So make sure the envfile_gpdata is used later
     # than unit_pgdata.
     test -n "$unit_pgdata"      && set_var "$datavar" "$unit_pgdata"
     test -n "$envfile_pgdata"   && set_var "$datavar" "$envfile_pgdata"
+    # If the user specified --datadir, take priority over all
+    if [ -n "${option_datadir}" ]; then
+        info $"Using datadir from --datadir: $option_datadir"
+        set_var "$datavar" "$option_datadir"
+    fi
 
     # skip for the first run
     test initdb = "$mode" && return
@@ -571,6 +615,7 @@ option_service="@NAME_SERVICE@"
 option_port=
 option_debug=0
 option_upgradefrom_unit=
+option_datadir=
 
 # Content of EnvironmentFile= files fills those:
 envfile_pgdata=
@@ -626,10 +671,9 @@ while true; do
             shift 2
             ;;
 
-        --datadir|--new-systemd-unit)
-            error   $"Removed option --new-systemd-unit/--datadir, please use"
-            error_q $"@sbindir@/@NAME_BINARYBASE@-new-systemd-unit script"
-            exit 1
+        --datadir)
+            option_datadir="$2"
+            shift 2
             ;;
 
         --debug)
@@ -698,7 +742,7 @@ debug "service name: $option_service"
 service_configuration initdb pgdata UNUSED "$option_service"
 
 test "$pgdata" = default \
-    && die $"no db datadir (PGDATA) configured for '$option_service$srvsuff' unit"
+    && die $"no db datadir (PGDATA) found, try using --datadir option"
 
 [[ "$pgdata" =~ ^/.* ]] \
     || die $"the PostgreSQL datadir not absolute path: '$pgdata', try --debug"
@@ -775,7 +819,10 @@ fi
 
 ## LAST CHECK THE SETUP ##
 
-check_daemon_reload
+if grep -q systemd /proc/1/comm; then
+    # Check only if we are running under systemd.
+    check_daemon_reload
+fi
 
 # These variables are read by underlying utilites, rather export them.
 export PGDATA=$pgdata

configure.ac

@@ -20,9 +20,11 @@ _AX_TEXT_TPL_SUBST([TEST_GEN_FILES_LIST], [.generated_files])
 
 WANT_SYSVINIT=0
 INIT_SYSTEM=systemd
+INIT_SYSTEM_SERVICE_PATH=/lib/systemd/system
 test -d /usr/lib/systemd/system/ || {
     INIT_SYSTEM=sysvinit
     WANT_SYSVINIT=1
+    INIT_SYSTEM_SERVICE_PATH=
 }
 AM_CONDITIONAL([WANT_SYSVINIT], [test "$WANT_SYSVINIT" -eq 1])
 _AX_TEXT_TPL_SUBST([WANT_SYSVINIT])
@@ -221,6 +223,7 @@ _AX_TEXT_TPL_SUBST([NAME_BINARYBASE])
 _AX_TEXT_TPL_SUBST([NAME_PACKAGE])
 _AX_TEXT_TPL_SUBST([NAME_SERVICE])
 _AX_TEXT_TPL_SUBST([NAME_SERVICE_VARNAME])
+_AX_TEXT_TPL_SUBST([INIT_SYSTEM_SERVICE_PATH])
 
 AC_MSG_CHECKING([whether to install compat %pgtest_* macros])
 # This hack shouldn't be removed sooner than once the F27 postgresql is EOL,
@@ -235,10 +238,11 @@ AC_OUTPUT
 
 AC_MSG_NOTICE([Configured the folowing way:
 
-    PostgreSQL version: $PGVERSION
-    PGDATADIR:          $PGDATADIR
-    PostgreSQL service: $NAME_SERVICE
-    PostgreSQL package: $NAME_PACKAGE
-    PostgreSQL bin_pfx: $NAME_BINARYBASE
-    Init system:        $INIT_SYSTEM
+    PostgreSQL version:    $PGVERSION
+    PGDATADIR:             $PGDATADIR
+    PostgreSQL service:    $NAME_SERVICE
+    PostgreSQL package:    $NAME_PACKAGE
+    PostgreSQL bin_pfx:    $NAME_BINARYBASE
+    Init system:           $INIT_SYSTEM
+    Init system services:  $INIT_SYSTEM_SERVICE_PATH
 ])