[RFC 0/4] Introduce experimental support for image generation from S3

[Yifan Zhao]

From: zhaoyifan <zhaoyifan28 at huawei.com>

This patch set allows mkfs.erofs to build images from a new data backend:
S3 (or other S3 API compatible object storage services).
Currently, the support is limited, including:
1. Only supports building index-only images.
2. Only object key and size is respected during building.
3. Only supports AWS Signature Version 2 authentication.

The current feature support meets our team's business needs. I hope to work
with the community in my spare time to polish this patch set, making the
support fully featured.

zhaoyifan (4):
  erofs-utils: mkfs: introduce source_mode enumeration
  erofs-utils: introduce build support for libcurl, openssl and libxml2
    library
  erofs-utils: mkfs: introduce `--s3=...` option
  erofs-utils: mkfs: support EROFS index-only image generation from S3

 configure.ac       |  41 +++
 include/erofs/s3.h |  42 ++++
 lib/Makefile.am    |   5 +
 lib/s3.c           | 612 +++++++++++++++++++++++++++++++++++++++++++++
 mkfs/Makefile.am   |   3 +-
 mkfs/main.c        | 296 +++++++++++++++++-----
 6 files changed, 937 insertions(+), 62 deletions(-)
 create mode 100644 include/erofs/s3.h
 create mode 100644 lib/s3.c

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2.46.0