image build: use cmake

[pinheadmz]

Closes #672

Seems to be working for me so far locally, will test a few other options as well.

Should we add a test to CI for this? It might just take too long to run...

[willcl-ark]

We do need this, but it will break rebuilding <= v28.0 images...

I think we should simply add a new dockerfile with this in. When combined with #669 having multiple dockerfiles becomes easy to handle IMO. To build v28.0 you'd just run:

docker buildx bake bitcoin-28

and for >28.0 you'd do:

docker buildx bake bitcoin-29
# or perhaps we can get working...?
docker buildx bake <commit sha>

and let the bake magic handle which dockerfile is used for you.

[pinheadmz]

Ah brilliant mate. Will review baker first then rebase this. 👨‍🍳

[danvergara]

I did this PR to leverage bake and cmake together

willcl-ark#32

[deadmanoz]

Won't be able to build images <= v28.X if this change is made.

I tested building v28.1 using the new bake functional:

• pre this change - builds fine
• post this change - build fails

28.35 + ./configure 'LDFLAGS=-L/lib/' 'CPPFLAGS=-g0 -I/include/ --param ggc-min-expand=1 --param ggc-min-heapsize=32768' '--prefix=/opt/bitcoin' '-DWITH_ZMQ=ON'
28.48 configure: error: unrecognized option: '-DWITH_ZMQ=ON'

[deadmanoz]

@pinheadmz, @willcl-ark do you wish for users to be able to use warnet image build for arbitrary Bitcoin Core commits (pre the CMake switchover of bitcoin/bitcoin#30454)?

If so, we'll need to support the 2 different styles of build_args (and reference the different Dockerfiles) to do so.

https://gist.github.com/hebasto/2ef97d3a726bfce08ded9df07f7dab5e

[pinheadmz]

@deadmanoz yes but I think it's fair to assume that from now on, all pull requests will be cmake-based. However, I guess it's possible that someone may want to modify an old version of bitcoin and test that in warnet...

I wonder if there's an easy trick we can use to determine which build system to execute, maybe just like the presence of autogen.sh in the root directory ?