Fix 'got a git repository' error when building Docker container

[leoromanovsky]

Problem

When building a Buffalo app in a docker container a strange error was thrown but the build would complete successfully:

remote: Digest: sha256:92867f528f630f5bf005d689d0b4ba2f2b836311a4780b55b2939e2f52a9d665
remote: Status: Downloaded newer image for gobuffalo/buffalo:v0.16.14
remote:  ---> a1dd7fd2e2df
remote: Step 2/26 : ENV GO111MODULE on
remote:  ---> Running in 89295b6ec0f4
remote: Removing intermediate container 89295b6ec0f4
remote:  ---> 4cd418d36fc1
remote: Step 3/26 : ENV GOPROXY http://proxy.golang.org
remote:  ---> Running in c69be3eff0ff
remote: Removing intermediate container c69be3eff0ff
remote:  ---> f4be33df0b5c
remote: Step 4/26 : RUN mkdir -p /src/github.com/REDACTED
remote:  ---> Running in b82307115821
remote: Removing intermediate container b82307115821
remote:  ---> cba902efa2c6
remote: Step 5/26 : WORKDIR /src/github.com/REDACTED
remote:  ---> Running in 83b58a59e29c
remote: Removing intermediate container 83b58a59e29c
remote:  ---> da642a1e3b65
remote: Step 6/26 : ADD package.json .
remote:  ---> 459d6c56c425
remote: Step 7/26 : ADD yarn.lock .
remote:  ---> fd73d444bca7
remote: Step 8/26 : RUN yarn install --no-progress
remote:  ---> Running in 05c78a296961
remote: yarn install v1.22.4
remote: [1/4] Resolving packages...
remote: [2/4] Fetching packages...
remote: info [email protected]: The platform "linux" is incompatible with this module.
remote: info "[email protected]" is an optional dependency and failed compatibility check. Excluding it from installation.
remote: info [email protected]: The platform "linux" is incompatible with this module.
remote: info "[email protected]" is an optional dependency and failed compatibility check. Excluding it from installation.
remote: [3/4] Linking dependencies...
remote: [4/4] Building fresh packages...
remote: Done in 19.67s.
remote: Removing intermediate container 05c78a296961
remote:  ---> 490da65f0ba6
remote: Step 9/26 : COPY go.mod go.mod
remote:  ---> 7df2a3a12e34
remote: Step 10/26 : COPY go.sum go.sum
remote:  ---> 30b716e2cedd
remote: Step 11/26 : RUN go mod download
remote:  ---> Running in 327d972716fd
remote: Removing intermediate container 327d972716fd
remote:  ---> 0c97e39c81ab
remote: Step 12/26 : ADD . .
remote:  ---> 6b78a534067d
remote: Step 13/26 : RUN cd /src/github.com/REDACTED
remote:  ---> Running in 5dd9ec5332de
remote: Removing intermediate container 5dd9ec5332de
remote:  ---> 6f7663dfbe4c
remote: Step 14/26 : RUN buffalo build --static -o /bin/app
remote:  ---> Running in 8ed99d5fced6
remote: fatal: not a git repository (or any of the parent directories): .git
remote: ERRO[2020-09-14T04:39:38Z] exit status 128
remote: Verifying deploy... done.
remote: Running release command...
remote:
remote: [POP] 2020/09/14 04:41:35 warn - ignoring file .git-keep because it does not match the migration file pattern
remote: [POP] 2020/09/14 04:41:35 warn - ignoring file .pop-tmp.md because it does not match the migration file pattern
remote: [POP] 2020/09/14 04:41:35 info - Migrations already up to date, nothing to apply
remote: [POP] 2020/09/14 04:41:35 info - 0.0431 seconds
remote: Waiting for release.... done.

I learned from (#2028) that buffalo creates a git repository if it is run in a directory without. That is the source of the ERRO message above (which might be more appropriate to title a warning).

I'm not attempting to modify that behavior, as the commentor in (#2028) asked.

Changes

I am avoiding Buffalo needing to complain about not being in a git repository and attempting to create one itself by running git init in the copied source directory. This is a light-weight operation and the directory itself is temporary - just being needed momentarily to build the binary.

The alternative approach would be to copy the user's .git directory into the Docker container. This is not idea because it could be a very large directory, thereby increasing the container. It is also unnecessary for the purposes of building a Buffalo binary.

Testing

Testing on a local application with the changes - it did not display the error message:

Done in 27.56s.
Removing intermediate container 34af82e82fa6
 ---> 2d2079091a84
Step 9/26 : COPY go.mod go.mod
 ---> ed7a79eba6a3
Step 10/26 : COPY go.sum go.sum
 ---> ef87dca08ff2
Step 11/26 : RUN go mod download
 ---> Running in 935d0504d598
Removing intermediate container 935d0504d598
 ---> b154340008b3
Step 12/26 : RUN git init
 ---> Running in 9c82f38cfa77
Initialized empty Git repository in /src/github.com/leoromanovsky/REDACTED/.git/
Removing intermediate container 9c82f38cfa77
 ---> 40f6576f4951
Step 13/26 : ADD . .
 ---> 3909c4509bbd
Step 14/26 : RUN buffalo build --static -o /bin/app
 ---> Running in 9c33b6d6f473
# github.com/leoromanovsky/REDACTED
/usr/bin/ld: /tmp/go-link-061009694/000007.o: in function `mygetgrouplist':
/workdir/go/src/os/user/getgrouplist_unix.go:16: warning: Using 'getgrouplist' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-061009694/000006.o: in function `mygetgrgid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:38: warning: Using 'getgrgid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-061009694/000006.o: in function `mygetgrnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:43: warning: Using 'getgrnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-061009694/000006.o: in function `mygetpwnam_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:33: warning: Using 'getpwnam_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-061009694/000006.o: in function `mygetpwuid_r':
/workdir/go/src/os/user/cgo_lookup_unix.go:28: warning: Using 'getpwuid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /tmp/go-link-061009694/000004.o: in function `_cgo_26061493d47f_C2func_getaddrinfo':
/tmp/go-build/cgo-gcc-prolog:58: warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
Removing intermediate container 9c33b6d6f473
 ---> c355980c1f66
Step 15/26 : FROM alpine
latest: Pulling from library/alpine
df20fa9351a1: Pull complete
Digest: sha256:185518070891758909c9f839cf4ca393ee977ac378609f700f60a771a2dfe321
Status: Downloaded newer image for alpine:latest
 ---> a24bb4013296
Step 16/26 : RUN apk add --no-cache curl
 ---> Running in 9c79b62dbd7e
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz
(1/4) Installing ca-certificates (20191127-r4)
(2/4) Installing nghttp2-libs (1.41.0-r0)
(3/4) Installing libcurl (7.69.1-r0)
(4/4) Installing curl (7.69.1-r0)
Executing busybox-1.31.1-r16.trigger
Executing ca-certificates-20191127-r4.trigger
OK: 7 MiB in 18 packages
Removing intermediate container 9c79b62dbd7e
 ---> d7875879240a
Step 17/26 : RUN apk add --no-cache bash
 ---> Running in 566974a6cc54
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz
(1/4) Installing ncurses-terminfo-base (6.2_p20200523-r0)
(2/4) Installing ncurses-libs (6.2_p20200523-r0)
(3/4) Installing readline (8.0.4-r0)
(4/4) Installing bash (5.0.17-r0)
Executing bash-5.0.17-r0.post-install
Executing busybox-1.31.1-r16.trigger
OK: 9 MiB in 22 packages
Removing intermediate container 566974a6cc54
 ---> 1887f52a3fa9
Step 18/26 : RUN apk add --no-cache ca-certificates
 ---> Running in 46d4b59df3af
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz
OK: 9 MiB in 22 packages
Removing intermediate container 46d4b59df3af
 ---> 705a3a215739
Step 19/26 : RUN cd /
 ---> Running in 6fe2ae53fca8
Removing intermediate container 6fe2ae53fca8
 ---> 5328e7e5579b
...REDACTED...
Removing intermediate container 1a05dd626c9c
 ---> 5fc6d4fd9fe2
Step 22/26 : WORKDIR /bin/
 ---> Running in 69761bc4832f
Removing intermediate container 69761bc4832f
 ---> 68b10035914d
Step 23/26 : COPY --from=builder /bin/app .
 ---> c95aca90d553
Step 24/26 : ENV ADDR=0.0.0.0
 ---> Running in 0c7e6c5d917b
Removing intermediate container 0c7e6c5d917b
 ---> 4b892d73f384
Step 25/26 : EXPOSE 3000
 ---> Running in 2bf30298fa21
Removing intermediate container 2bf30298fa21
 ---> a051440b2393
Step 26/26 : CMD exec /bin/app
 ---> Running in 0b425b8bd4d5
Removing intermediate container 0b425b8bd4d5
 ---> 96144062a260
Successfully built 96144062a260
Successfully tagged REDACTED:latest
111

Fixes: 
* https://github.com/gobuffalo/buffalo/issues/2048
* https://github.com/gobuffalo/buffalo/issues/2033

[paganotoni]

Hey @leoromanovsky, Thanks for adding this one. We fixed it on #v0.16.16, I'm closing this PR.