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introduce gotd(8), a Git repository server reachable via ssh(1) This is an initial barebones implementation which provides the absolute minimum of functionality required to serve got(1) and git(1) clients. Basic fetch/send functionality has been tested and seems to work here, but this server is not yet expected to be stable. More testing is welcome. See the man pages for setup instructions. The current design uses one reader and one writer process per repository, which will have to be extended to N readers and N writers in the future. At startup, each process will chroot(2) into its assigned repository. This works because gotd(8) can only be started as root, and will then fork+exec, chroot, and privdrop. At present the parent process runs with the following pledge(2) promises: "stdio rpath wpath cpath proc getpw sendfd recvfd fattr flock unix unveil" The parent is the only process able to modify the repository in a way that becomes visible to Git clients. The parent uses unveil(2) to restrict its view of the filesystem to /tmp and the repositories listed in the configuration file gotd.conf(5). Per-repository chroot(2) processes use "stdio rpath sendfd recvfd". The writer defers to the parent for modifying references in the repository to point at newly uploaded commits. The reader is fine without such help, because Git repositories can be read without having to create any lock-files. gotd(8) requires a dedicated user ID, which should own repositories on the filesystem, and a separate secondary group, which should not have filesystem-level repository access, and must be allowed access to the gotd(8) socket. To obtain Git repository access, users must be members of this secondary group, and must have their login shell set to gotsh(1). gotsh(1) connects to the gotd(8) socket and speaks Git-protocol towards the client on the other end of the SSH connection. gotsh(1) is not an interactive command shell. At present, authenticated clients are granted read/write access to all repositories and all references (except for the "refs/got/" and the "refs/remotes/" namespaces, which are already being protected from modification). While complicated access control mechanism are not a design goal, making it possible to safely offer anonymous Git repository access over ssh(1) is on the road map.
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1 .\"

2 .\" Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>

3 .\"

4 .\" Permission to use, copy, modify, and distribute this software for any

5 .\" purpose with or without fee is hereby granted, provided that the above

6 .\" copyright notice and this permission notice appear in all copies.

7 .\"

8 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

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10 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

11 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

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13 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

14 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

15 .\"

16 .Dd $Mdocdate$

17 .Dt GOTD.CONF 5

18 .Os

19 .Sh NAME

20 .Nm gotd.conf

21 .Nd gotd configuration file

22 .Sh DESCRIPTION

23 .Nm

24 is the run-time configuration file for

25 .Xr gotd 8 .

26 .Pp

27 The file format is line-based, with one configuration directive per line.

28 Any lines beginning with a

29 .Sq #

30 are treated as comments and ignored.

31 .Sh GLOBAL CONFIGURATION

32 The available global configuration directives are as follows:

33 .Bl -tag -width Ds

34 .It Ic unix_socket Ar path

35 Set the path to the unix socket which

36 .Xr gotd 8

37 should listen on.

38 If not specified, the path

39 .Pa /var/run/gotd.sock

40 will be used.

41 .It Ic unix_group Ar group

42 Set the

43 .Ar group ,

44 defined in the

45 .Xr group 5

46 file, which is allowed to access

47 .Xr gotd 8

48 via

49 .Xr gotsh 1 .

50 The

51 .Xr gotd 8

52 user must be a secondary member of this group.

53 If not specified, the group _gotsh will be used.

54 .It Ic user Ar user

55 Set the

56 .Ar user

57 which will run

58 .Xr gotd 8 .

59 Initially,

60 .Xr gotd 8

61 requires root privileges in order to create its unix socket and start

62 child processes in a

63 .Xr chroot 2

64 environment.

65 Afterwards,

66 .Xr gotd 8

67 drops privileges to the specified

68 .Ar user .

69 If not specified, the user _gotd will be used.

70 .El

71 .Sh REPOSITORY CONFIGURATION

72 At least one repository context must exist for

73 .Xr gotd 8

74 to function.

75 .Pp

76 A repository context is declared with a unique

77 .Ar name ,

78 followed by repository-specific configuration directives inside curly braces:

79 .Pp

80 .Ic repository Ar name Brq ...

81 .Pp

82 .Xr got 1

83 and

84 .Xr git 1

85 clients can connect to a repository by including the repository's unique

86 .Ar name

87 in the request URL.

88 Clients appending the string

89 .Dq .git

90 to the

91 .Ar name

92 will also be accepted.

93 .Pp

94 If desired, the

95 .Ar name

96 may contain path-separators,

97 .Dq / ,

98 to expose repositories as part of a virtual client-visible directory hierarchy.

99 .Pp

100 The available repository configuration directives are as follows:

101 .Bl -tag -width Ds

102 .It Ic path Ar path

103 Set the path to the Git repository.

104 .EL

105 .Sh FILES

106 .Bl -tag -width Ds -compact

107 .It Pa /etc/gotd.conf

108 Location of the

109 .Nm

110 configuration file.

111 .El

112 .Sh EXAMPLES

113 .Bd -literal -offset indent

114 # Default unix_group and user values:

115 unix_group _gotsh

116 user _gotd

118 # This repository can be accessed via ssh://user@example.com/src

119 repository "src" {

120 	path "/var/git/src.git"

123 # This repository can be accessed via

124 # ssh://user@example.com/openbsd/ports

125 repository "openbsd/ports" {

126 	path "/var/git/ports.git"

128 .Ed

129 .Sh SEE ALSO

130 .Xr got 1 ,

131 .Xr gotsh 1 ,

132 .Xr group 5 ,

133 .Xr gotd 8