gf-run.py (create qcow2 clones and upload data to them)

gf-run.py

#!/usr/bin/python3

import os
import shutil
import subprocess
import sys

index = int(sys.argv[1])
num_disks = int(sys.argv[2])
base = os.path.abspath("mybase.img")

os.environ["LIBGUESTFS_DEBUG"] = "1"
#os.environ["LIBGUESTFS_TRACE"] = "1"

tmp_dir = "/tmp/gf-run.%d" % os.getpid()

MAPPING = str.maketrans('0123456789','ABCDEFGHIJ')

if os.path.exists(tmp_dir):
    shutil.rmtree(tmp_dir)
os.makedirs(tmp_dir)

configs = []
for i in range(num_disks):
    name = "node%d" % i
    data1 = b"X" * 4000
    data1_f = os.path.join(tmp_dir, "%s.data1" % name)
    with open(data1_f, "wb") as f:
        f.write(data1)
    data2 = b"Y" * (256*1024)
    data2_f = os.path.join(tmp_dir, "%s.data2" % name)
    with open(data2_f, "wb") as f:
        f.write(data2)
    uploads = {
        "/data1": data1_f,
        "/data2": data2_f,
    }
    label = ("%d" % i).translate(MAPPING)  # can only contain a-zA-Z
    part = 1
    configs.append((name, uploads, label, part))

# Generate all qcow2 files
gfcmd = [
    "guestfish", "--",
]
for name, uploads, label, part in configs:
    qcowfile = os.path.join(tmp_dir, "%s.qcow2" % name)
    if not os.path.exists(base):
        raise RuntimeError("No such backing file: %s" % image)
    gfcmd.extend([
        "disk-create", qcowfile, "qcow2", "-1", "backingfile:%s" % base, "compat:1.1", ":",
        "add", qcowfile, "label:%s" % label, ":",
    ])
gfcmd.extend([
    "run", ":",
])
for name, uploads, label, part in configs:
    gfcmd.extend(["mount", "/dev/disk/guestfs/%s%d" % (label, part), "/", ":"])
    for dst, src in uploads.items():
        gfcmd.extend(["upload", src, dst, ":"])
    gfcmd.extend(["umount", "/", ":"])
res = subprocess.run(gfcmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
if res.returncode:
    err_f = os.path.join(tmp_dir, "err")
    with open(err_f, "wb") as f:
        f.write(res.stdout)
    raise RuntimeError("guestfish(%d) exited with code %d" % (index, res.returncode))

# No failure, tidy up
shutil.rmtree(tmp_dir)