1 21dc3794 2022-01-28 op # gmid quickstart guide
  2 7c6bf71d 2021-10-11 op 
  3 0111ad5d 2021-10-09 op gmid can be run in two different “modes”:
  4 0111ad5d 2021-10-09 op 
  5 0111ad5d 2021-10-09 op * configless: a quick way to serve a directory tree from the shell, useful for testing a capsule before uploading it
  6 0111ad5d 2021-10-09 op * daemon mode: gmid reads the configuration file and runs in the background
  7 0111ad5d 2021-10-09 op 
  8 0111ad5d 2021-10-09 op To run gmid in the “configless” mode, just type:
  9 0111ad5d 2021-10-09 op 
 10 0111ad5d 2021-10-09 op ```serve a directory tree from the shell
 11 0111ad5d 2021-10-09 op $ gmid path/to/dir
 12 0111ad5d 2021-10-09 op ```
 13 0111ad5d 2021-10-09 op 
 14 540d05de 2021-10-09 op gmid will then generate a certificate inside ~/.local/share/gmid and serve the given directory locally.
 15 0111ad5d 2021-10-09 op 
 16 fc4b58d4 2021-10-11 op ## Setting up a capsule with gmid
 17 0111ad5d 2021-10-09 op 
 18 c57dc42b 2022-01-05 op To host a Gemini capsule you need to run gmid in “daemon” mode, and so a configuration file is needed.  The format of the configuration file is described in the manpage and is quite flexible, but something like the following should be enough to start:
 19 fc4b58d4 2021-10-11 op 
 20 0111ad5d 2021-10-09 op ```sample configuration file
 21 0111ad5d 2021-10-09 op # /etc/gmid.conf
 22 0111ad5d 2021-10-09 op 
 23 0111ad5d 2021-10-09 op server "example.com" {
 24 33c4c3a5 2021-10-13 op 	cert "/etc/ssl/example.com.pem"
 25 33c4c3a5 2021-10-13 op 	key  "/etc/ssl/private/example.com.key"
 26 33c4c3a5 2021-10-13 op 
 27 33c4c3a5 2021-10-13 op 	# path to the root directory of your capsule
 28 0111ad5d 2021-10-09 op 	root "/var/gemini/example.com"
 29 0111ad5d 2021-10-09 op }
 30 0111ad5d 2021-10-09 op ```
 31 0111ad5d 2021-10-09 op 
 32 33c4c3a5 2021-10-13 op A certificate is needed for the capsule.  Generate one for e.g. using contrib/gencert:
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 34 0111ad5d 2021-10-09 op => https://git.omarpolo.com/gmid/tree/contrib/gencert contrib/gencert
 35 0111ad5d 2021-10-09 op 
 36 0111ad5d 2021-10-09 op ```generate a certificate using contrib/gencert
 37 0111ad5d 2021-10-09 op $ ./contrib/gencert example.com
 38 0111ad5d 2021-10-09 op Generating a 4096 bit RSA private key
 39 0111ad5d 2021-10-09 op .................................................++++
 40 0111ad5d 2021-10-09 op ..........++++
 41 0111ad5d 2021-10-09 op writing new private key to './example.com.key'
 42 0111ad5d 2021-10-09 op -----
 43 0111ad5d 2021-10-09 op 
 44 0111ad5d 2021-10-09 op Generated files:
 45 0111ad5d 2021-10-09 op         ./example.com.pem : certificate
 46 0111ad5d 2021-10-09 op         ./example.com.key : private key
 47 0111ad5d 2021-10-09 op ```
 48 0111ad5d 2021-10-09 op 
 49 33c4c3a5 2021-10-13 op Move ‘example.com.pem’ and ‘example.com.key’ to a safe place and double check that the ‘cert’ and ‘key’ options in the configuration points to these files.
 50 0111ad5d 2021-10-09 op 
 51 33c4c3a5 2021-10-13 op For example, save them in ‘/etc/ssl/’ (as root)
 52 0111ad5d 2021-10-09 op 
 53 33c4c3a5 2021-10-13 op ```how to save the certificate and private key in /etc/ssl
 54 33c4c3a5 2021-10-13 op # mkdir -p /etc/ssl/private
 55 33c4c3a5 2021-10-13 op # chown 700 /etc/ssl/private
 56 33c4c3a5 2021-10-13 op # mv example.com.pem /etc/ssl/
 57 33c4c3a5 2021-10-13 op # mv example.com.key /etc/ssl/private/
 58 33c4c3a5 2021-10-13 op ```
 59 33c4c3a5 2021-10-13 op 
 60 0111ad5d 2021-10-09 op Then running gmid is as easy as
 61 0111ad5d 2021-10-09 op 
 62 0111ad5d 2021-10-09 op ```running gmid
 63 0111ad5d 2021-10-09 op $ gmid -c /etc/gmid.conf
 64 0111ad5d 2021-10-09 op ```
 65 0111ad5d 2021-10-09 op 
 66 fc4b58d4 2021-10-11 op Congratulations, your capsule is online!
 67 0111ad5d 2021-10-09 op 
 68 fc4b58d4 2021-10-11 op 
 69 0111ad5d 2021-10-09 op ## Securing your gmid installation
 70 0111ad5d 2021-10-09 op 
 71 0111ad5d 2021-10-09 op gmid employs various techniques to prevent the damage caused by bugs, but some steps needs to be done manually.
 72 0111ad5d 2021-10-09 op 
 73 33c4c3a5 2021-10-13 op If gmid was installed from your distribution package manager, chance are that it already does all of this and is also providing a service to run gmid automatically (e.g. a rc script, a systemd unit file, …)  Otherwise, it’s heavily suggested to create at least a dedicated user.
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 75 0111ad5d 2021-10-09 op 
 76 0111ad5d 2021-10-09 op ### A dedicated user
 77 0111ad5d 2021-10-09 op 
 78 fc4b58d4 2021-10-11 op Ideally, gmid should be started as root and drop privileges to a local user.  This way, the certificates can be readable only by root.  For example, on GNU/linux systems a ‘gmid’ user can be created with:
 79 0111ad5d 2021-10-09 op 
 80 0111ad5d 2021-10-09 op ```how to create the gmid user
 81 35340c9f 2021-10-09 op # useradd --system --no-create-home -s /bin/nologin -c "gmid Gemini server" gmid
 82 0111ad5d 2021-10-09 op ```
 83 0111ad5d 2021-10-09 op 
 84 3c04ffc0 2022-03-09 op If you use systemd-sysusers:
 85 3c04ffc0 2022-03-09 op 
 86 3c04ffc0 2022-03-09 op ```how to create the gmid user, using systemd-sysusers
 87 3c04ffc0 2022-03-09 op # systemd-sysusers contrib/gmid.sysusers
 88 3c04ffc0 2022-03-09 op ```
 89 3c04ffc0 2022-03-09 op 
 90 0111ad5d 2021-10-09 op Please consult your OS documentation for more information on the matter.
 91 0111ad5d 2021-10-09 op 
 92 0111ad5d 2021-10-09 op The configuration then needs to be adjusted to include the ‘user’ directive at the top:
 93 0111ad5d 2021-10-09 op 
 94 0111ad5d 2021-10-09 op ```how to use the ‘user’ option
 95 0111ad5d 2021-10-09 op # /etc/gmid.conf
 96 0111ad5d 2021-10-09 op user "gmid"
 97 0111ad5d 2021-10-09 op 
 98 0111ad5d 2021-10-09 op server "example.com" { … }
 99 0111ad5d 2021-10-09 op ```
100 0111ad5d 2021-10-09 op 
101 fc4b58d4 2021-10-11 op gmid then needs to be started with root privileges, but will then switch to the provided user automatically.  If by accident the ‘user’ option is omitted and gmid is running as root, it will complain loudly in the logs.
102 0111ad5d 2021-10-09 op 
103 0111ad5d 2021-10-09 op 
104 0111ad5d 2021-10-09 op ### chroot
105 0111ad5d 2021-10-09 op 
106 0111ad5d 2021-10-09 op It’s a common practice for system daemons to chroot themselves into a directory.  From here on I’ll assume /var/gemini, but it can be any directory.
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108 fc4b58d4 2021-10-11 op A chroot on UNIX-like OS is an operation that changes the “apparent” root directory (i.e. the “/”) from the current process and its child.  Think of it like imprisoning a process into a directory and never letting it escape until it terminates.
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110 fc4b58d4 2021-10-11 op Using a chroot may complicate the use of CGI scripts, because then all the dependencies of the scripts (sh, perl, libraries…) need to be installed inside the chroot too.  For this very reason gmid supports FastCGI.
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112 0111ad5d 2021-10-09 op The chroot feature requires a dedicate user, see the previous section.
113 0111ad5d 2021-10-09 op 
114 0111ad5d 2021-10-09 op To chroot gmid inside a directory, use the ‘chroot’ directive in the configuration file:
115 0111ad5d 2021-10-09 op 
116 0111ad5d 2021-10-09 op ```how to use the ‘chroot’ option
117 0111ad5d 2021-10-09 op # /etc/gmid.conf
118 0111ad5d 2021-10-09 op 
119 35340c9f 2021-10-09 op user "gmid"
120 35340c9f 2021-10-09 op 
121 0111ad5d 2021-10-09 op # the given directory, /var/gemini in this case, must exists.
122 0111ad5d 2021-10-09 op chroot "/var/gemini"
123 0111ad5d 2021-10-09 op ```
124 0111ad5d 2021-10-09 op 
125 0111ad5d 2021-10-09 op Note that once ‘chroot’ is in place, every ‘root’ directive is implicitly relative to the chroot, but ‘cert’ and ‘key’ aren’t!
126 0111ad5d 2021-10-09 op 
127 0111ad5d 2021-10-09 op For example, given the following configuration:
128 0111ad5d 2021-10-09 op 
129 0111ad5d 2021-10-09 op ```example configuration using chroot
130 0111ad5d 2021-10-09 op # /etc/gmid.conf
131 0111ad5d 2021-10-09 op 
132 0111ad5d 2021-10-09 op user "gmid"
133 0111ad5d 2021-10-09 op chroot "/var/gemini"
134 0111ad5d 2021-10-09 op 
135 0111ad5d 2021-10-09 op server "example.com" {
136 0111ad5d 2021-10-09 op 	cert "/etc/ssl/example.com.pem"
137 0111ad5d 2021-10-09 op 	key  "/etc/ssl/example.com.key"
138 0111ad5d 2021-10-09 op 	root "/example.com"
139 0111ad5d 2021-10-09 op }
140 0111ad5d 2021-10-09 op ```
141 0111ad5d 2021-10-09 op 
142 0111ad5d 2021-10-09 op The certificate and the key path are the specified ones, but the root directory of the virtual host is actually “/var/gemini/example.com/”.