Reinstate CI image generation mirrors

[philwebb]

With REGISTRY_MIRRORS configured we see:

#1 [internal] load build definition from Dockerfile
#1 sha256:d0812f6ccffdc9c6488480148afee979d748d217c44eee780ba5f7de5108b5f5
#1 transferring dockerfile: 161B done
#1 DONE 0.1s

#2 [internal] load .dockerignore
#2 sha256:150344f79d1eb08f4684437d1dca0a22d5236f06b88ed384014e8d3417d156c9
#2 transferring context: 2B done
#2 DONE 0.1s

#3 [internal] load metadata for docker.io/library/ubuntu:focal-20210119
#3 sha256:4c0241cf95fb80c85c021abb209ca339f9ccda596f98ae40afb89a526810fed0
#3 ERROR: encountered unknown type text/html; children may not be fetched
------
 > [internal] load metadata for docker.io/library/ubuntu:focal-20210119:
------

error: failed to solve: rpc error: code = Unknown desc = failed to solve with frontend dockerfile.v0: failed to create LLB definition: encountered unknown type text/html; children may not be fetched

FATA[0000] failed to build: build: exit status 1        
FATA[0000] failed to run task: exit status 1            

[philwebb]

Seems to be an issue with mirrors configured. Removing:

  REGISTRY_MIRRORS: ((docker-hub-mirror))

works.

[philwebb]

With more debug output from buildctl

fetching philwebb/oci-build-task@sha256:8fd200e2ed0032cbebe7077e7d9ec9909347d56d4a9642ab149ce3455a271bdc

188c0c94c7c5 [==========================================] 2.7MiB/2.7MiB

35c1ded50856 [==========================================] 8.5MiB/8.5MiB

3dacbed1adad [==========================================] 1.0KiB/1.0KiB

190f6af812c3 [========================================] 41.5MiB/41.5MiB

6bd7fec1d645 [==========================================] 4.1MiB/4.1MiB

5148cfe4605d [==========================================] 2.6MiB/2.6MiB

3e7da5038aee [==============================================] 623b/623b

selected worker: eda2e949-c0d6-4c64-a59b-59aa5f4487e9

INFO[0000] building image                               

DEBU[0000] running buildctl --debug build --progress plain --frontend dockerfile.v0 --local context=ci-images-git-repo/ci/images --local dockerfile=ci-images-git-repo/ci/images/ci-image --opt filename=Dockerfile --output type=docker,dest=/tmp/build/acc0072f/image/image.tar 

DEBU[0000] serving grpc connection                      

#2 [internal] load .dockerignore

#2 sha256:988321aa40db16157566df66b98a1b080faef314603abb6c8290c87bad9ed170

#2 transferring context:

#2 transferring context: 2B done

#2 DONE 0.1s


#1 [internal] load build definition from Dockerfile

#1 sha256:2c9df745001c9fec281c45fdaed9b9aa2bbcf5327484f8c1858becf23be74f62

#1 transferring dockerfile: 161B done

#1 DONE 0.1s


#3 [internal] load metadata for docker.io/library/ubuntu:focal-20210119

#3 sha256:4c0241cf95fb80c85c021abb209ca339f9ccda596f98ae40afb89a526810fed0

#3 ERROR: encountered unknown type text/html; children may not be fetched

DEBU[0000] stopping session                             

------

 > [internal] load metadata for docker.io/library/ubuntu:focal-20210119:

------

error: failed to solve: rpc error: code = Unknown desc = failed to solve with frontend dockerfile.v0: failed to create LLB definition: encountered unknown type text/html; children may not be fetched

133 v0.8.0 buildkitd --root /scratch/buildkitd --addr unix:///scratch/buildkitd/buildkitd.sock --config /scratch/buildkitd/builtkitd.toml --debug

github.com/moby/buildkit/util/imageutil.childrenConfigHandler.func1

	/src/util/imageutil/config.go:165

github.com/containerd/containerd/images.HandlerFunc.Handle

	/src/vendor/github.com/containerd/containerd/images/handlers.go:55

github.com/containerd/containerd/images.Handlers.func1

	/src/vendor/github.com/containerd/containerd/images/handlers.go:65

github.com/containerd/containerd/images.HandlerFunc.Handle

	/src/vendor/github.com/containerd/containerd/images/handlers.go:55

github.com/containerd/containerd/images.Dispatch.func1

	/src/vendor/github.com/containerd/containerd/images/handlers.go:134

golang.org/x/sync/errgroup.(*Group).Go.func1

	/src/vendor/golang.org/x/sync/errgroup/errgroup.go:57

runtime.goexit

	/usr/local/go/src/runtime/asm_amd64.s:1357


133 v0.8.0 buildkitd --root /scratch/buildkitd --addr unix:///scratch/buildkitd/buildkitd.sock --config /scratch/buildkitd/builtkitd.toml --debug

github.com/moby/buildkit/frontend/dockerfile/builder.Build.func3.1

	/src/frontend/dockerfile/builder/build.go:422

golang.org/x/sync/errgroup.(*Group).Go.func1

	/src/vendor/golang.org/x/sync/errgroup/errgroup.go:57

runtime.goexit

	/usr/local/go/src/runtime/asm_amd64.s:1357


133 v0.8.0 buildkitd --root /scratch/buildkitd --addr unix:///scratch/buildkitd/buildkitd.sock --config /scratch/buildkitd/builtkitd.toml --debug

github.com/moby/buildkit/solver/llbsolver.(*llbBridge).Solve

	/src/solver/llbsolver/bridge.go:138

github.com/moby/buildkit/solver/llbsolver.(*Solver).Solve

	/src/solver/llbsolver/solver.go:128

github.com/moby/buildkit/control.(*Controller).Solve

	/src/control/control.go:275

github.com/moby/buildkit/api/services/control._Control_Solve_Handler.func1

	/src/api/services/control/control.pb.go:1489

github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryServer.func1.1.1

	/src/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:25

github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc.OpenTracingServerInterceptor.func1

	/src/vendor/github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc/server.go:57

main.unaryInterceptor.func1

	/src/cmd/buildkitd/main.go:540

github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryServer.func1.1.1

	/src/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:25

github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryServer.func1

	/src/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:34

github.com/moby/buildkit/api/services/control._Control_Solve_Handler

	/src/api/services/control/control.pb.go:1491

google.golang.org/grpc.(*Server).processUnaryRPC

	/src/vendor/google.golang.org/grpc/server.go:1082

google.golang.org/grpc.(*Server).handleStream

	/src/vendor/google.golang.org/grpc/server.go:1405

google.golang.org/grpc.(*Server).serveStreams.func1.1

	/src/vendor/google.golang.org/grpc/server.go:746

runtime.goexit

	/usr/local/go/src/runtime/asm_amd64.s:1357


186 v0.8.0 buildctl --addr=unix:///scratch/buildkitd/buildkitd.sock --debug build --progress plain --frontend dockerfile.v0 --local context=ci-images-git-repo/ci/images --local dockerfile=ci-images-git-repo/ci/images/ci-image --opt filename=Dockerfile --output type=docker,dest=/tmp/build/acc0072f/image/image.tar

github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryClient.func1.1.1

	/src/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:72

github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc.OpenTracingClientInterceptor.func1

	/src/vendor/github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc/client.go:60

github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryClient.func1.1.1

	/src/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:72

github.com/grpc-ecosystem/go-grpc-middleware.ChainUnaryClient.func1

	/src/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go:81

google.golang.org/grpc.(*ClientConn).Invoke

	/src/vendor/google.golang.org/grpc/call.go:35

github.com/moby/buildkit/api/services/control.(*controlClient).Solve

	/src/api/services/control/control.pb.go:1321

github.com/moby/buildkit/client.(*Client).solve.func2

	/src/client/solve.go:201

golang.org/x/sync/errgroup.(*Group).Go.func1

	/src/vendor/golang.org/x/sync/errgroup/errgroup.go:57

runtime.goexit

	/usr/local/go/src/runtime/asm_amd64.s:1357


186 v0.8.0 buildctl --addr=unix:///scratch/buildkitd/buildkitd.sock --debug build --progress plain --frontend dockerfile.v0 --local context=ci-images-git-repo/ci/images --local dockerfile=ci-images-git-repo/ci/images/ci-image --opt filename=Dockerfile --output type=docker,dest=/tmp/build/acc0072f/image/image.tar

github.com/moby/buildkit/client.(*Client).solve.func2

	/src/client/solve.go:214

golang.org/x/sync/errgroup.(*Group).Go.func1

	/src/vendor/golang.org/x/sync/errgroup/errgroup.go:57

runtime.goexit

	/usr/local/go/src/runtime/asm_amd64.s:1357


FATA[0000] failed to build: build: exit status 1        

FATA[0000] failed to run task: exit status 1            

[philwebb]

https://github.com/moby/buildkit/blob/7641cbf96184bd14b127d2565869e62c1827a1c9/frontend/dockerfile/dockerfile2llb/convert.go#L250