Improve logging

hack/demo.py

@@ -11,29 +11,39 @@ from pathlib import Path
 import testgres
 
 
+def run_command(args):
+    print('> Cmd:', ' '.join(args))
+    p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True)
+    ret = p.wait()
+    output = p.stdout.read().strip()
+    if output:
+        print(textwrap.indent(output, '>> '))
+    if ret != 0:
+        raise subprocess.CalledProcessError(ret, args)
+
+
 def make_tarfile(output_filename, source_dir):
+    print("* Packing the backup into a tarball")
     cmd = ["tar", r"--transform=s/\.\///", "-C", str(source_dir), "-cf", str(output_filename), "."]
-    print("Command: ", " ".join(cmd))
-    r = subprocess.check_output(cmd).decode()
-    print(textwrap.indent(r, "> "))
+    run_command(cmd)
 
 
 def create_tenant(tenant_id):
-    cmd = f"neon_local tenant create --tenant-id {tenant_id}"
-    print("Run command:", cmd)
-    r = subprocess.check_output(cmd.split()).decode()
-    print(textwrap.indent(r, "> "))
+    print("* Creating a new tenant")
+    cmd = ["neon_local", "tenant", "create", f"--tenant-id={tenant_id}"]
+    run_command(cmd)
 
 
-def from_backup_at(args, backup_dir: Path):
+def import_backup(args, backup_dir: Path):
+    tar = Path('/tmp/base.tar')
+    make_tarfile(tar, backup_dir / 'data')
+
+    print("* Importing the timeline into the pageserver")
+
     manifest = json.loads((backup_dir / "data" / "backup_manifest").read_text())
     start_lsn = manifest["WAL-Ranges"][0]["Start-LSN"]
     end_lsn = manifest["WAL-Ranges"][0]["End-LSN"]
-    print("LSNs:", start_lsn, end_lsn)
-
-    print("Make tarball")
-    tar = Path("/tmp/base.tar")
-    make_tarfile(tar, backup_dir / "data")
+    print("> LSNs:", start_lsn, end_lsn)
 
     cmd = (
         "neon_local timeline import "
@@ -45,50 +55,45 @@ def from_backup_at(args, backup_dir: Path):
         f"--node-name {args.node}"
     )
 
-    print("Run neon_local")
-    r = subprocess.check_output(cmd.split()).decode()
-    print(textwrap.indent(r, "> "))
+    run_command(cmd.split())
 
 
 def debug_prints(node):
-    print("RELID:", node.execute("select 'foo'::regclass::oid")[0][0])
-    print("DBs:", node.execute("table pg_database"))
-    print("foo:", node.execute("table foo"))
+    tuples = node.execute("table foo")
+    oid = node.execute("select 'foo'::regclass::oid")[0][0]
+    print("> foo's tuples:", tuples, "&", "oid:", oid)
+    print("> DBs:", node.execute("select oid, datname from pg_database"))
 
 
 def main(args):
-    print("Create a node")
+    print("* Creating a node")
     node = testgres.get_new_node()
     node.init(unix_sockets=False, allow_streaming=True).start()
-    node.execute(
-        """
-        create table foo as select 1;
-    """
-    )
+    node.execute("create table foo as select 1")
     debug_prints(node)
     # node.pgbench_init(scale=1)
 
-    print("Create a backup")
+    print("* Creating a backup")
     backup = node.backup()
     backup_dir = Path(backup.base_dir)
+    print("> Backup dir:", backup_dir)
 
     # pr = backup.spawn_primary().start()
     # debug_prints(pr)
     # exit(1)
 
-    print("Import a backup")
     create_tenant(args.tenant_id)
-    from_backup_at(args, backup_dir)
+    import_backup(args, backup_dir)
 
-    print("Backup dir:", backup_dir)
-    print("Tenant:", args.tenant_id)
-    print("Timeline:", args.timeline_id)
-    print("Node:", args.node)
+    print("> Tenant:", args.tenant_id)
+    print("> Timeline:", args.timeline_id)
+    print("> Node:", args.node)
 
-    cmd = f"neon_local pg start --tenant-id={args.tenant_id} --timeline-id={args.timeline_id} {args.node}".split()
-    r = subprocess.check_output(cmd).decode()
-    print(textwrap.indent(r, "> "))
+    print("* Starting postgres")
+    cmd = ["neon_local", "pg", "start", f"--tenant-id={args.tenant_id}", f"--timeline-id={args.timeline_id}", args.node]
+    run_command(cmd)
 
+    print("* Opening psql session...")
     cmd = ["psql", "host=127.0.0.1 port=55433 user=cloud_admin dbname=postgres"]
     subprocess.call(cmd)