wireprotov2: change command response protocol to include a leading map
The error handling mechanism for the new wire protocol isn't very
well-defined. This commit takes us a step in the right direction
by introducing a leading CBOR map for command responses. This map
will contain an overall result of the command.
Currently, the map indicates whether the command was overall
successful or if an error occurred. And if an error occurred, that
error is present in the map.
There is still a dedicated error frame. My intent is to use that
for protocol-level errors and for errors that are encountered after
the initial response frame has been sent. This will be clarified in a
later commit.
Differential Revision: https://phab.mercurial-scm.org/D3385
$ . $TESTDIR/wireprotohelpers.sh
$ hg init server
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid -E error.log
$ cat hg.pid > $DAEMON_PIDS
A normal capabilities request is serviced for version 1
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: 458\r\n
s> \r\n
s> batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
A proper request without the API server enabled returns the legacy response
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: foo\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: 458\r\n
s> \r\n
s> batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
Restart with just API server enabled. This enables serving the new format.
$ killdaemons.py
$ cat error.log
$ cat >> server/.hg/hgrc << EOF
> [experimental]
> web.apiserver = true
> EOF
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid -E error.log
$ cat hg.pid > $DAEMON_PIDS
X-HgUpgrade-<N> without CBOR advertisement uses legacy response
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: 458\r\n
s> \r\n
s> batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
X-HgUpgrade-<N> without known serialization in X-HgProto-<N> uses legacy response
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> x-hgproto-1: some value
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: some value\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: 458\r\n
s> \r\n
s> batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
X-HgUpgrade-<N> + X-HgProto-<N> headers trigger new response format
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-cbor\r\n
s> Content-Length: 496\r\n
s> \r\n
s> \xa3Dapis\xa0GapibaseDapi/Nv1capabilitiesY\x01\xcabatch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
cbor> {b'apibase': b'api/', b'apis': {}, b'v1capabilities': b'batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash'}
Restart server to enable HTTPv2
$ killdaemons.py
$ enablehttpv2 server
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid -E error.log
Only requested API services are returned
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-cbor\r\n
s> Content-Length: 496\r\n
s> \r\n
s> \xa3Dapis\xa0GapibaseDapi/Nv1capabilitiesY\x01\xcabatch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
cbor> {b'apibase': b'api/', b'apis': {}, b'v1capabilities': b'batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash'}
Request for HTTPv2 service returns information about it
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: exp-http-v2-0001 foo bar
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: exp-http-v2-0001 foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-cbor\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> \xa3Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa7Eheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyCnewCnewColdColdInamespaceBnsKpermissions\x81DpushHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullIbranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullKcompression\x82\xa1DnameDzstd\xa1DnameDzlibNrawrepoformats\x82LgeneraldeltaHrevlogv1Qframingmediatypes\x81X&application/mercurial-exp-framing-0005GapibaseDapi/Nv1capabilitiesY\x01\xcabatch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
cbor> {b'apibase': b'api/', b'apis': {b'exp-http-v2-0001': {b'commands': {b'branchmap': {b'args': {}, b'permissions': [b'pull']}, b'capabilities': {b'args': {}, b'permissions': [b'pull']}, b'heads': {b'args': {b'publiconly': False}, b'permissions': [b'pull']}, b'known': {b'args': {b'nodes': [b'deadbeef']}, b'permissions': [b'pull']}, b'listkeys': {b'args': {b'namespace': b'ns'}, b'permissions': [b'pull']}, b'lookup': {b'args': {b'key': b'foo'}, b'permissions': [b'pull']}, b'pushkey': {b'args': {b'key': b'key', b'namespace': b'ns', b'new': b'new', b'old': b'old'}, b'permissions': [b'push']}}, b'compression': [{b'name': b'zstd'}, {b'name': b'zlib'}], b'framingmediatypes': [b'application/mercurial-exp-framing-0005'], b'rawrepoformats': [b'generaldelta', b'revlogv1']}}, b'v1capabilities': b'batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash'}
capabilities command returns expected info
$ sendhttpv2peerhandshake << EOF
> command capabilities
> EOF
creating http peer for wire protocol version 2
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> vary: X-HgProto-1,X-HgUpgrade-1\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: exp-http-v2-0001\r\n
s> accept: application/mercurial-0.1\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> user-agent: Mercurial debugwireproto\r\n
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-cbor\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> \xa3Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa7Eheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyCnewCnewColdColdInamespaceBnsKpermissions\x81DpushHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullIbranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullKcompression\x82\xa1DnameDzstd\xa1DnameDzlibNrawrepoformats\x82LgeneraldeltaHrevlogv1Qframingmediatypes\x81X&application/mercurial-exp-framing-0005GapibaseDapi/Nv1capabilitiesY\x01\xcabatch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
sending capabilities command
s> POST /api/exp-http-v2-0001/ro/capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> *\r\n (glob)
s> content-type: application/mercurial-exp-framing-0005\r\n
s> content-length: 27\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> user-agent: Mercurial debugwireproto\r\n
s> \r\n
s> \x13\x00\x00\x01\x00\x01\x01\x11\xa1DnameLcapabilities
s> makefile('rb', None)
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-exp-framing-0005\r\n
s> Transfer-Encoding: chunked\r\n
s> \r\n
s> 1e2\r\n
s> \xda\x01\x00\x01\x00\x02\x012
s> \xa1FstatusBok\xa4Hcommands\xa7Eheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyCnewCnewColdColdInamespaceBnsKpermissions\x81DpushHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullIbranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullKcompression\x82\xa1DnameDzstd\xa1DnameDzlibNrawrepoformats\x82LgeneraldeltaHrevlogv1Qframingmediatypes\x81X&application/mercurial-exp-framing-0005
s> \r\n
received frame(size=474; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=eos)
s> 0\r\n
s> \r\n
response: [{b'status': b'ok'}, {b'commands': {b'branchmap': {b'args': {}, b'permissions': [b'pull']}, b'capabilities': {b'args': {}, b'permissions': [b'pull']}, b'heads': {b'args': {b'publiconly': False}, b'permissions': [b'pull']}, b'known': {b'args': {b'nodes': [b'deadbeef']}, b'permissions': [b'pull']}, b'listkeys': {b'args': {b'namespace': b'ns'}, b'permissions': [b'pull']}, b'lookup': {b'args': {b'key': b'foo'}, b'permissions': [b'pull']}, b'pushkey': {b'args': {b'key': b'key', b'namespace': b'ns', b'new': b'new', b'old': b'old'}, b'permissions': [b'push']}}, b'compression': [{b'name': b'zstd'}, {b'name': b'zlib'}], b'framingmediatypes': [b'application/mercurial-exp-framing-0005'], b'rawrepoformats': [b'generaldelta', b'revlogv1']}]
$ cat error.log