The Capstanfile is a YAML config file for specifying Capstan images.
An minimal file looks as follows:
base: cloudius/osv-base
cmdline: /tools/hello.so
build: make
files:
/tools/hello.so: hello.so
base specifies the base image that is amended with files use capstan images (local images) for a list of available images.
cmdline is the startup command line passed to OSv.
build specifies an optional build command.
files is a map of files that are amended to the base image. The left side
specifies the full path of the file as it will appear in the image and the
right side specifies a relative path to current directory of the actual file
that is added to the image.
File mapping supports basename variable substitution with the "&" character. You can specify this:
files:
/usr/app/app.jar: build/&
which expands to the following during build:
files:
/usr/app/app.jar: build/app.jar
Here /usr/app/app.jar is the path in the built image and build/app.jar
is the file that is picked up from the local filesystem.
rootfs specifies a directory that is amended to the base image. The directory hierarchy
in the base image will be the same as in the rootfs directory. If rootfs is not specified
in Capstanfile, a default rootfs directory named ROOTFS will be used. If both files and rootfs
are specified, both will be used to amended the base image.
The easiest way to create Capstan base images is to use the OSv shell script build-capstan-base-image.
The aforementioned script accepts list of OSv apps, creates an image and optionally copies
it to the local Capstan repo like so:
./scripts/build-capstan-base-image cloudius/python3 python3x 'OSv base with Python 3'Capstan also supports installing RPMs with the rpm-base option:
rpm-base:
name: java-1.7.0-openjdk
version: 1.7.0.60
release: 2.4.5.0.fc19
arch: x86_64