add support for pre and post commit hooks

This allows for instance integration of etckeeper

[TT: Reorganized code a bit, and modified to use single
directory commit_hooks.d with argument for script of stage.]

src/apk_database.h

@@ -219,6 +219,7 @@ int apk_db_write_config(struct apk_database *db);
 int apk_db_permanent(struct apk_database *db);
 int apk_db_check_world(struct apk_database *db, struct apk_dependency_array *world);
 int apk_db_fire_triggers(struct apk_database *db);
+int apk_db_run_script(struct apk_database *db, char *fn, char **argv);
 void apk_db_update_directory_permissions(struct apk_database *db);
 
 struct apk_package *apk_db_pkg_add(struct apk_database *db, struct apk_package *pkg);

src/audit.c

@@ -179,11 +179,8 @@ static int audit_directory_tree_item(void *ctx, int dirfd, const char *name)
 	struct apk_file_info fi;
 	int reason = 0;
 
-	if (bdir.len + bent.len + 1 >= sizeof(atctx->path))
-		return -ENOMEM;
-
-	if (apk_fileinfo_get(dirfd, name, APK_FI_NOFOLLOW, &fi) < 0)
-		return -EPERM;
+	if (bdir.len + bent.len + 1 >= sizeof(atctx->path)) return 0;
+	if (apk_fileinfo_get(dirfd, name, APK_FI_NOFOLLOW, &fi) < 0) return 0;
 
 	memcpy(&atctx->path[atctx->pathlen], bent.ptr, bent.len);
 	atctx->pathlen += bent.len;
@@ -273,7 +270,7 @@ done:
 		apk_db_dir_unref(db, child, FALSE);
 
 	atctx->pathlen -= bent.len;
-	return reason < 0 ? reason : 0;
+	return 0;
 }
 
 static int audit_directory_tree(struct audit_tree_ctx *atctx, int dirfd)

src/commit.c

@@ -216,6 +216,40 @@ static void run_triggers(struct apk_database *db, struct apk_changeset *changese
 	}
 }
 
+#define PRE_COMMIT_HOOK		0
+#define POST_COMMIT_HOOK	1
+
+struct apk_commit_hook {
+	struct apk_database *db;
+	int type;
+};
+
+static int run_commit_hook(void *ctx, int dirfd, const char *file)
+{
+	static char *const commit_hook_str[] = { "pre-commit", "post-commit" };
+	struct apk_commit_hook *hook = (struct apk_commit_hook *) ctx;
+	struct apk_database *db = hook->db;
+	char fn[PATH_MAX], *argv[] = { fn, (char *) commit_hook_str[hook->type], NULL };
+
+	if ((apk_flags & (APK_NO_SCRIPTS | APK_SIMULATE)) != 0)
+		return 0;
+
+	snprintf(fn, sizeof(fn), "etc/apk/commit_hooks.d" "/%s", file);
+	if (apk_verbosity >= 2) apk_message("Executing: %s", fn);
+
+	if (apk_db_run_script(db, fn, argv) < 0 && hook->type == PRE_COMMIT_HOOK)
+		return -1;
+
+	return 0;
+}
+
+static int run_commit_hooks(struct apk_database *db, int type)
+{
+	struct apk_commit_hook hook = { .db = db, .type = type };
+	return apk_dir_foreach_file(openat(db->root_fd, "etc/apk/commit_hooks.d", O_RDONLY | O_CLOEXEC),
+				    run_commit_hook, &hook);
+}
+
 int apk_solver_commit_changeset(struct apk_database *db,
 				struct apk_changeset *changeset,
 				struct apk_dependency_array *world)
@@ -278,6 +312,9 @@ int apk_solver_commit_changeset(struct apk_database *db,
 		}
 	}
 
+	if (run_commit_hooks(db, PRE_COMMIT_HOOK) < 0)
+		return -1;
+
 	/* Go through changes */
 	foreach_array_item(change, changeset->changes) {
 		r = change->old_pkg &&
@@ -308,6 +345,7 @@ int apk_solver_commit_changeset(struct apk_database *db,
 all_done:
 	apk_dependency_array_copy(&db->world, world);
 	apk_db_write_config(db);
+	run_commit_hooks(db, POST_COMMIT_HOOK);
 
 	if (!db->performing_self_upgrade) {
 		if (errors)
@@ -328,7 +366,6 @@ all_done:
 				    db->installed.stats.packages);
 		}
 	}
-
 	return errors;
 }
 

src/database.c

@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <fcntl.h>
 #include <mntent.h>
+#include <libgen.h>
 #include <limits.h>
 #include <unistd.h>
 #include <malloc.h>
@@ -1877,6 +1878,34 @@ int apk_db_fire_triggers(struct apk_database *db)
 	return db->pending_triggers;
 }
 
+int apk_db_run_script(struct apk_database *db, char *fn, char **argv)
+{
+	int status;
+	pid_t pid;
+	static char * const environment[] = {
+		"PATH=/usr/sbin:/usr/bin:/sbin:/bin",
+		NULL
+	};
+
+	pid = fork();
+	if (pid == -1) {
+		apk_error("%s: fork: %s", basename(fn), strerror(errno));
+		return -2;
+	}
+	if (pid == 0) {
+		umask(0022);
+		if (fchdir(db->root_fd) == 0 && chroot(".") == 0)
+			execve(fn, argv, environment);
+		exit(127); /* should not get here */
+	}
+	waitpid(pid, &status, 0);
+	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+		apk_error("%s: script exited with error %d", basename(fn), WEXITSTATUS(status));
+		return -1;
+	}
+	return 0;
+}
+
 static int update_permissions(apk_hash_item item, void *ctx)
 {
 	struct apk_database *db = (struct apk_database *) ctx;

src/io.c

@@ -741,6 +741,7 @@ int apk_dir_foreach_file(int dirfd, apk_dir_file_cb cb, void *ctx)
 {
 	struct dirent *de;
 	DIR *dir;
+	int ret = 0;
 
 	if (dirfd < 0)
 		return -1;
@@ -759,11 +760,11 @@ int apk_dir_foreach_file(int dirfd, apk_dir_file_cb cb, void *ctx)
 			    (de->d_name[1] == '.' && de->d_name[2] == 0))
 				continue;
 		}
-		cb(ctx, dirfd, de->d_name);
+		ret = cb(ctx, dirfd, de->d_name);
+		if (ret) break;
 	}
 	closedir(dir);
-
-	return 0;
+	return ret;
 }
 
 struct apk_istream *apk_istream_from_file_gz(int atfd, const char *file)

src/package.c

@@ -979,14 +979,9 @@ void apk_ipkg_run_script(struct apk_installed_package *ipkg,
 			 struct apk_database *db,
 			 unsigned int type, char **argv)
 {
-	static char * const environment[] = {
-		"PATH=/usr/sbin:/usr/bin:/sbin:/bin",
-		NULL
-	};
 	struct apk_package *pkg = ipkg->pkg;
 	char fn[PATH_MAX];
-	int fd, status, root_fd = db->root_fd;
-	pid_t pid;
+	int fd, root_fd = db->root_fd;
 
 	if (type >= APK_SCRIPT_MAX || ipkg->script[type].ptr == NULL)
 		return;
@@ -1015,23 +1010,8 @@ void apk_ipkg_run_script(struct apk_installed_package *ipkg,
 	}
 	close(fd);
 
-	pid = fork();
-	if (pid == -1)
-		goto error;
-	if (pid == 0) {
-		umask(0022);
-		if (fchdir(root_fd) == 0 && chroot(".") == 0)
-			execve(fn, argv, environment);
-		exit(1);
-	}
-	waitpid(pid, &status, 0);
-	unlinkat(root_fd, fn, 0);
-	apk_id_cache_reset(&db->id_cache);
-
-	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
-		apk_error("%s: script exited with error %d", &fn[15], WEXITSTATUS(status));
+	if (apk_db_run_script(db, fn, argv) < 0)
 		ipkg->broken_script = 1;
-	}
 	return;
 error:
 	apk_error("%s: failed to execute: %s", &fn[15], apk_error_str(errno));