Look in more directories for Postgres binaries

This makes PostgresCluster compatible with images from other distros.

Issue: PGO-864

Author: cbandy

internal/patroni/config.go

@@ -484,8 +484,6 @@ func instanceYAML(
 	}
 
 	postgresql := map[string]any{
-		// TODO(cbandy): "bin_dir"
-
 		// Missing here is "connect_address" which cannot be known until the
 		// instance Pod is created. That value should be injected using the downward
 		// API and the PATRONI_POSTGRESQL_CONNECT_ADDRESS environment variable.

internal/patroni/reconcile.go

@@ -105,7 +105,14 @@ func InstancePod(ctx context.Context,
 		}
 	}
 
-	container.Command = []string{"patroni", configDirectory}
+	// Start Patroni in an environment that prioritizes executables of the specified Postgres version.
+	// NOTE: Patroni ignores PATH when "postgresql.bin_dir" is set.
+	//
+	// https://patroni.readthedocs.io/en/latest/yaml_configuration.html#postgresql
+	container.Command = []string{
+		"sh", "-c", "--", postgres.ShellPath(inCluster.Spec.PostgresVersion) + ` && exec "$@"`, "--",
+		"patroni", configDirectory,
+	}
 
 	container.Env = append(container.Env,
 		instanceEnvironment(inCluster, inClusterPodService, inPatroniLeaderService,

internal/patroni/reconcile_test.go

@@ -140,6 +140,12 @@ func TestInstancePod(t *testing.T) {
 	assert.Assert(t, cmp.MarshalMatches(template.Spec, `
 containers:
 - command:
+  - sh
+  - -c
+  - --
+  - PATH="/usr/lib/postgresql/11/bin:/usr/libexec/postgresql11:/usr/pgsql-11/bin${PATH+:${PATH}}"
+    && exec "$@"
+  - --
   - patroni
   - /etc/patroni
   env:

internal/postgres/config.go

@@ -405,7 +405,7 @@ func startupCommand(
 	instance *v1beta1.PostgresInstanceSetSpec,
 	parameters *ParameterSet,
 ) []string {
-	version := fmt.Sprint(cluster.Spec.PostgresVersion)
+	version := cluster.Spec.PostgresVersion
 	dataDir := DataDirectory(cluster)
 	logDir := parameters.Value("log_directory")
 	walDir := WALDirectory(cluster, instance)
@@ -463,7 +463,7 @@ chmod +x /tmp/pg_rewind_tde.sh
 `
 	}
 
-	args := []string{version, walDir}
+	args := []string{fmt.Sprint(version), walDir}
 	script := strings.Join([]string{
 		`declare -r expected_major_version="$1" pgwal_directory="$2"`,
 
@@ -485,6 +485,9 @@ chmod +x /tmp/pg_rewind_tde.sh
 		// Function to change a directory symlink while keeping the directory contents.
 		strings.TrimSpace(bashSafeLink),
 
+		// Prioritize executables for this major version of Postgres.
+		ShellPath(version),
+
 		// Log the effective user ID and all the group IDs.
 		`echo Initializing ...`,
 		`results 'uid' "$(id -u ||:)" 'gid' "$(id -G ||:)"`,

internal/postgres/reconcile_test.go

@@ -274,6 +274,7 @@ initContainers:
       set -x; mv --no-target-directory "${current}" "${desired}"
       ln --no-dereference --force --symbolic "${desired}" "${name}"
     )
+    PATH="/usr/lib/postgresql/11/bin:/usr/libexec/postgresql11:/usr/pgsql-11/bin${PATH+:${PATH}}"
     echo Initializing ...
     results 'uid' "$(id -u ||:)" 'gid' "$(id -G ||:)"
     if [[ "${pgwal_directory}" == *"pgwal/"* ]] && [[ ! -d "/pgwal/pgbackrest-spool" ]];then rm -rf "/pgdata/pgbackrest-spool" && mkdir -p "/pgwal/pgbackrest-spool" && ln --force --symbolic "/pgwal/pgbackrest-spool" "/pgdata/pgbackrest-spool";fi