Impl ...

- launch.json: change debug cwd to the project root dir
- Add subcmd "mods"
- Docs
- Tidy up sample and debug config files
- Change core exec
  - 'dnf-list-instaled' -> 'rpm-list-installed' as dnf does not work
    on ro fs
  - Accept the exit code 1 from tar(allow live fs change)
- Add the generic sample config
- Fix 'run' subcmd not accepting empty task-id
- Change module loading: modules are not required to have
  the 'backup_backends' var
- Reduce required Python version by removing the use of match ... case
- Fix 'exec-append' not taking 'env' into account
- Remove use of exceptions from irrelevant packages
- Fix unimpl methods of NullBackupBackend
- Tidy up instantiation of raised exceptions
- Change "include" behaviour
  - Relative config paths are now resolved like #include C preprocessor
- Fix bug where "include" circular ref checked is not done with absolute
  paths of config files
- Add own exception hierachy
- aws-s3: change storage class only when "rot-storage-class" is
  different from "sink-storage-class"

7 files changed, 148 insertions, 189 deletions

diff --git a/src/conf/py-debug/aws.sample.jsonc b/src/conf/py-debug/aws.jsonc
index 46ad562..df9a63a 100644
--- a/src/conf/py-debug/aws.sample.jsonc
+++ b/src/conf/py-debug/aws.jsonc
@@ -1,6 +1,6 @@
 // PALHM Instance Config
 {
-	"include": [ "conf/py-debug/conf.d/core.jsonc" ],
+	"include": [ "conf.d/core.json" ],
 	"modules": [ "aws" ],
 	"nb-workers": 0, // assumed $(nproc) - default
 	// "nb-workers": 1, // to disable concurrent task despatch
@@ -48,7 +48,7 @@
 					"path": "pm-list.gz",
 					"group": "pre-start",
 					"pipeline": [
-						{ "type": "exec", "exec-id": "dnf-list-installed" },
+						{ "type": "exec", "exec-id": "rpm-list-installed" },
 						{ "type": "exec", "exec-id": "filter-gzip-plain" }
 					]
 				},
diff --git a/src/conf/py-debug/conf.d b/src/conf/py-debug/conf.d
new file mode 120000
index 0000000..a32163d
--- /dev/null
+++ b/src/conf/py-debug/conf.d
@@ -0,0 +1 @@
+../py-sample/conf.d
\ No newline at end of file
diff --git a/src/conf/py-debug/conf.d/core.jsonc b/src/conf/py-debug/conf.d/core.jsonc
deleted file mode 100644
index 4afe7f5..0000000
--- a/src/conf/py-debug/conf.d/core.jsonc
+++ /dev/null
@@ -1,44 +0,0 @@
-// PALHM Core Config
-{
-	"execs": [
-		// {
-		// 	"id": "Exec ID",
-		// 	"argv": [ "cmd", "--option1=opt1_val", "-o", "opt2_val" ],
-		// 	"env": { "NAME": "VAL" },
-		// 	"ec": "0", // this is assumed
-		// 	"ec": "0-127", // inclusive range (not terminated by a signal)
-		// 	"ec": "<1", // range (only 0)
-		// 	"ec": "<=1", // range (0 and 1)
-		// 	"ec": ">0", // range (always fail)
-		// 	"ec": ">=0", // range (only 0)
-		// 	"vl-stderr": 1 //  verbosity level of stderr produced by this process
-		//  verbosity level of stderr produced by this process. Ignored if used
-		//  as part of pipeline
-		// 	"vl-stdout": 2
-		// },
-		{
-			"id": "tar",
-			"argv": [ "/usr/bin/tar", "--xattrs", "--selinux" ]
-		},
-		{
-			"id": "filter-xz-parallel",
-			"argv": [ "/usr/bin/xz", "-T0" ]
-		},
-		{
-			"id": "filter-gzip-plain",
-			"argv": [ "/usr/bin/gzip" ]
-		},
-		{
-			"id": "filter-zstd-plain",
-			"argv": [ "/usr/bin/zstd" ]
-		},
-		{
-			"id": "dnf-list-installed",
-			"argv": [ "/usr/bin/dnf", "-yq", "list", "installed" ]
-		},
-		{
-			"id": "lsblk-all-json",
-			"argv": [ "/usr/bin/lsblk", "-JbOa" ]
-		}
-	]
-}
diff --git a/src/conf/py-debug/localfs.sample.jsonc b/src/conf/py-debug/localfs.jsonc
index ec12808..a33060d 100644
--- a/src/conf/py-debug/localfs.sample.jsonc
+++ b/src/conf/py-debug/localfs.jsonc
@@ -1,12 +1,12 @@
 // PALHM Instance Config
 {
-	"include": [ "conf/py-debug/conf.d/core.jsonc" ],
+	"include": [ "conf.d/core.json" ],
 	"nb-workers": 0, // assumed $(nproc) - default
 	// "nb-workers": 1, // to disable concurrent task despatch
 	// To unlimit the number of workers.
 	// Does not fail on resource alloc failure.
 	// "nb-workers": -1,
-	"vl": 4,
+	"vl": 3,
 	"tasks": [
 		{
 			"id": "backup",
@@ -45,7 +45,7 @@
 					"path": "pm-list.gz",
 					"group": "pre-start",
 					"pipeline": [
-						{ "type": "exec", "exec-id": "dnf-list-installed" },
+						{ "type": "exec", "exec-id": "rpm-list-installed" },
 						{ "type": "exec", "exec-id": "filter-gzip-plain" }
 					]
 				},
diff --git a/src/conf/py-debug/null.jsonc b/src/conf/py-debug/null.jsonc
new file mode 100644
index 0000000..b5ce9f8
--- /dev/null
+++ b/src/conf/py-debug/null.jsonc
@@ -0,0 +1,141 @@
+{
+	"include": [ "conf.d/core.json" ],
+	"nb-workers": 0, // assumed $(nproc)
+	// "nb-workers": 1, // to disable concurrent task despatch
+	// "nb-workers": -1, // to unlimit the number of workers.
+	"vl": 3,
+	"tasks": [
+		{
+			"id": "backup",
+			"type": "backup",
+			"backend": "null",
+			"object-groups": [
+				{ "id": "pre-start" },
+				{
+					"id": "data-dump",
+					"depends": [ "pre-start" ]
+				},
+				{
+					"id": "tar-0",
+					"depends": [ "data-dump" ]
+				},
+				{
+					"id": "tar-1",
+					"depends": [ "data-dump" ]
+				}
+			],
+			"objects": [
+				{
+					"path": "pm-list.zstd",
+					"group": "pre-start",
+					"pipeline": [
+						{ "type": "exec", "exec-id": "rpm-list-installed" },
+						{ "type": "exec", "exec-id": "filter-zstd-plain" }
+					]
+				},
+				{
+					"path": "lsblk.json.zstd",
+					"group": "pre-start",
+					"pipeline": [
+						{ "type": "exec", "exec-id": "lsblk-all-json" },
+						{ "type": "exec", "exec-id": "filter-zstd-plain" }
+					]
+				},
+				{
+					"path": "db.sql.zstd",
+					"group": "data-dump",
+					"pipeline": [
+						{
+							"type": "exec-inline",
+							"argv": [
+								"/bin/mysqldump",
+								"-uroot",
+								"--all-databases"
+							]
+						},
+						{ "type": "exec", "exec-id": "filter-zstd-parallel" }
+					]
+				},
+				{
+					"path": "root.tar.zstd",
+					"group": "tar-0",
+					"pipeline": [
+						{
+							"type": "exec-append",
+							"exec-id": "tar",
+							"argv": [
+								"-C",
+								"/",
+								"/etc",
+								"/home",
+								"/root",
+								"/var"
+							]
+						},
+						{ "type": "exec", "exec-id": "filter-zstd-parallel" }
+					]
+				},
+				{
+					"path": "srv.tar.zstd",
+					"group": "tar-1",
+					"pipeline": [
+						{
+							"type": "exec-append",
+							"exec-id": "tar",
+							"argv": [
+								"-C",
+								"/",
+								"/srv"
+							]
+						},
+						{ "type": "exec", "exec-id": "filter-zstd-parallel" }
+					]
+				}
+			]
+		},
+		{
+			"id": "update",
+			"type": "routine",
+			"routine": [
+				{
+					"type": "exec-inline",
+					"argv": [ "/bin/dnf", "--refresh", "-yq", "update" ]
+				},
+				{
+					"type": "exec-inline",
+					"argv": [ "/bin/sa-update" ]
+				}
+			]
+		},
+		{
+			"id": "reboot",
+			"type": "routine",
+			"routine": [
+				{
+/*
+ * Block SIGTERM from systemd/init.d so PALHM can exit gracefully after issuing
+ * reboot.
+ */
+					"type": "builtin",
+					"builtin-id": "sigmask",
+					"param": [
+						{ "action": "block", "sig": [ "TERM" ] }
+					]
+				},
+				{
+					"type": "exec-inline",
+					"argv": [ "/sbin/reboot" ]
+				}
+			]
+		},
+		{
+			"id": "default",
+			"type": "routine",
+			"routine": [
+				{ "type": "task", "task-id": "backup" },
+				{ "type": "task", "task-id": "update" },
+				{ "type": "task", "task-id": "reboot" }
+			]
+		}
+	]
+}
diff --git a/src/conf/py-debug/null.sample.jsonc b/src/conf/py-debug/null.sample.jsonc
deleted file mode 100644
index a83de95..0000000
--- a/src/conf/py-debug/null.sample.jsonc
+++ /dev/null
@@ -1,140 +0,0 @@
-// PALHM Instance Config
-{
-	"include": [ "conf/py-debug/conf.d/core.jsonc" ],
-	"nb-workers": 1,
-	"vl": 3,
-	"tasks": [
-		{
-			"id": "backup",
-			"type": "backup",
-			"backend": "null",
-			"object-groups": [
-				{ "id": "pre-start" },
-				{
-					"id": "data-dump",
-					"depends": [ "pre-start" ]
-				},
-				{
-					"id": "tar-media-0",
-					"depends": [ "data-dump" ]
-				},
-				{
-					"id": "tar-media-1",
-					"depends": [ "data-dump" ]
-				}
-			],
-			"objects": [
-				{
-					"path": "pm-list.gz",
-					"group": "pre-start",
-					"pipeline": [
-						{ "type": "exec", "exec-id": "dnf-list-installed" },
-						{ "type": "exec", "exec-id": "filter-gzip-plain" }
-					]
-				},
-				{
-					"path": "lsblk.json.gz",
-					"group": "pre-start",
-					"pipeline": [
-						{
-							"type": "exec-append",
-							"exec-id": "lsblk-all-json",
-							"argv": [ "-a" ]
-						},
-						{ "type": "exec", "exec-id": "filter-gzip-plain" }
-					]
-				},
-				{
-					"path": "random-dump.sql.xz",
-					"group": "data-dump",
-					"pipeline": [
-						{
-							"type": "exec-inline",
-							"argv": [
-								"/bin/dd",
-								"if=/dev/urandom",
-								"bs=4096",
-								"count=512",
-								"status=none"
-							]
-						},
-						{ "type": "exec", "exec-id": "filter-xz-parallel" }
-					]
-				},
-				{
-					"path": "random-dump.0.xz",
-					"group": "tar-media-0",
-					"pipeline": [
-						{
-							"type": "exec-inline",
-							"argv": [
-								"/bin/dd",
-								"if=/dev/zero",
-								"bs=4096",
-								"count=512",
-								"status=none"
-							]
-						},
-						{ "type": "exec", "exec-id": "filter-xz-parallel" }
-					]
-				},
-				{
-					"path": "random-dump.1.xz",
-					"group": "tar-media-1",
-					"pipeline": [
-						{
-							"type": "exec-inline",
-							"argv": [
-								"/bin/dd",
-								"if=/dev/zero",
-								"bs=4096",
-								"count=512",
-								"status=none"
-							]
-						},
-						{ "type": "exec", "exec-id": "filter-xz-parallel" }
-					]
-				}
-			]
-		},
-		{
-			"id": "update",
-			"type": "routine",
-			"routine": [
-				{
-					"type": "exec-inline",
-					"argv": [ "/bin/echo", "0" ]
-				},
-				{
-					"type": "exec-inline",
-					"argv": [ "/bin/sleep", "1" ]
-				},
-				{
-					"type": "exec-inline",
-					"argv": [ "/bin/echo", "1" ]
-				}
-			]
-		},
-		{
-			"id": "default",
-			"type": "routine",
-			"routine": [
-				{ "type": "task", "task-id": "backup" },
-				{ "type": "task", "task-id": "update" },
-				{
-					// Block SIGTERM from systemd/init.d so the program is not
-					// affected by the reboot command.
-					"type": "builtin",
-					"builtin-id": "sigmask",
-					"param": [
-						{ "action": "block", "sig": [ "TERM" ] }
-					]
-				},
-				{
-					"type": "exec-inline",
-					"argv": [ "/bin/true" ]
-				}
-			]
-		}
-	]
-}
diff --git a/src/conf/py-debug/palhm.jsonc b/src/conf/py-debug/palhm.jsonc
new file mode 120000
index 0000000..fb68baf
--- /dev/null
+++ b/src/conf/py-debug/palhm.jsonc
@@ -0,0 +1 @@
+aws.jsonc
\ No newline at end of file