CODEWITHSUNDEEP
shellmakefilevagrantyamlvagrantfile
moluzhui
moluzhui

Reputation: 1093

How does the makefile write user-defined variables to the yaml file to support vagrantfile fetch parameters

I have a project which use makefile to control vagrant, I want to put the vagrant parameter into the makefile, such as cpu, memory, ip, hostname, forwarded_port and the like. I find a way that vagrantfile read yaml file to parameterize vagrantfile. So makefile needs a target to read all the user option variables and write them to config.yaml as key-value pairs.

The sample is as follows

# === BEGIN USER OPTIONS ===
BOX_OS ?= fedora
# Box setup
#BOX_IMAGE
# Disk setup
DISK_COUNT ?= 1
DISK_SIZE_GB ?= 25
# VM Resources
MASTER_CPUS ?= 2
MASTER_MEMORY_SIZE_GB ?= 2
NODE_CPUS ?= 2
NODE_MEMORY_SIZE_GB ?= 2

NODE_COUNT ?= 2
# Network
MASTER_IP ?= 192.168.26.10
NODE_IP_NW ?= 192.168.26.
POD_NW_CIDR ?= 10.244.0.0/16

...
...
# === END USER OPTIONS ===

The echo command does achieve it

# Makefile
envInit:
    @echo "POD_NW_CIDR : \"$(POD_NW_CIDR)\"" > ${FILECWD}/configs.yaml

But too many variables can be too complex.

Is there a way to bulk read variables and their values and write them to a yml file

I would very appreciate it if you guys can tell me how to achieve it that bulk read variables and their values and write them to a yml file.

Upvotes: 1

Views: 1309

Answers (3)

Vroomfondel
Vroomfondel

Reputation: 2898

You can write directly to a file with GNUmakes $(file) function:

define newline :=
$(strip)
$(strip)
endef
space := $(strip) $(strip)#
-never-matching := ¥# character 165, this is used as a list element that should never appear as a real element

option-names = $(subst $(-never-matching),,$(filter $(-never-matching)%,$(subst $(-never-matching)$(space),$(-never-matching),$(-never-matching)$(strip $(subst $(newline), $(-never-matching),$1)))))


# define your user options in as many separate parts as you like, spaces and empty lines included:
define USER_OPTIONS +=
a = spaces are no problem

b = "neither nearly all 'other' characters: 8&)("
endef

define USER_OPTIONS +=

c = baz baf
d = foobar
endef

# make all definition make variables verbatim 
$(eval $(USER_OPTIONS))

YAML_FORMAT := $(foreach name,$(call option-names,$(USER_OPTIONS)),$(newline)$(name) : $($(name)))

# write the file. Warning: this happens before any rule is run!
$(file >test.yaml,$(YAML_FORMAT))

$(info $(foreach name,$(call option-names,$(USER_OPTIONS)),<$(name) : $($(name))> ))

The trick lies in the clustering of all relevant user option variables in one multi-line make variable. The function option-names pulls all identifiers from that variable into a separate list.

I took the newline etc. character definitions from the GNUmake table toolkit which has many functions for "programmatic" make.

Upvotes: 0

moluzhui
moluzhui

Reputation: 1093

@flyx Thank you for you answer, your code does work great. But I seem to have found a more convenient way, and I've partially modified it.

printvars:
    @echo$(foreach V,$(sort $(.VARIABLES)), \
        $(if $(filter-out environment% default automatic,$(origin $V)),$(info $V: $($V))))

But there is still a gap between achieving the goal.

# the Makefile test file
FILECWD = $(shell pwd)

# === BEGIN USER OPTIONS ===
CLOUD_IP ?= 192.168.79.222
CLOUD_NAME ?= cloud
CLOUD_CPU ?= 6
CLOUD_MEMORY ?= 8


# === END USER OPTIONS ===

printvars:  
    @echo$(foreach V,$(sort $(.VARIABLES)), \
        $(if $(filter-out environment% default automatic,$(origin $V)),$(info $V: $($V))))

make printvars's output contains a number of other variables

$ make printvars 
.DEFAULT_GOAL: printvars
CLOUD_IP: 192.168.79.222
CLOUD_MEMORY: 8
CLOUD_NAME: cloud
CURDIR: /testmakecreateyml0930
FILECWD: /testmakecreateyml0930
GNUMAKEFLAGS: 
MAKEFILE_LIST:  Makefile
MAKEFLAGS: 
SHELL: /bin/sh

And it can only be printed and not exported to the yaml file.This is only one step away from success.

I would appreciate it if you could help me modify it to achieve my goal

Upvotes: 0

flyx
flyx

Reputation: 39688

Define all user options (along with the default values) as a list, so that they are iterable:

# list of user options with default values
userOptions = \
  BOX_OS=2 \
  DISK_COUNT=1 \
  MASTER_IP=192.168.26.10

# replace each default value with the env value, if any
userOptionValues = $(foreach i, $(userOptions), \
  $(word 1, $(subst =, ,$i))=$(or \
      $($(word 1, $(subst =, ,$i))), $($(word 1, $(subst =, ,$i))), $(word 2, $(subst =, ,$i))))

# write the yaml file
envInit:
# empty the file
    @printf "" > configs.yaml
# write a line for each option
    @for i in $(userOptionValues); do \
        printf "%s : %s\n" "$$(printf $$i | cut -d= -f1)" "$$(printf $$i | cut -d= -f2)" >> configs.yaml; \
    done

Upvotes: 1

Related Questions