Server How To

Setting Up a Koji Build System

The Koji components may live on separate resources as long as all resources are able to communicate. This document will cover how to setup each service individually, however, all services may live on the same resource.

Knowledge Prerequisites

  • Basic understanding of SSL and authentication via certificates and/or Kerberos credentials

  • Basic knowledge about creating a database in PostgreSQL and importing a schema

  • Working with psql

  • Basic knowledge about Apache configuration

  • Basic knowledge about dnf/yum/createrepo/mock - else you’ll not be able to debug problems!

  • Basic knowledge about using command line

  • Basic knowledge about RPM building

  • Simple usage of the Koji client

  • For an overview of yum, mock, Koji (and all its subcomponents), mash, and how they all work together, see the excellent slides put together by Steve Traylen at CERN.

Package Prerequisites

On the server (koji-hub/koji-web)

  • httpd

  • mod_ssl

  • postgresql-server

  • mod_wsgi

On the builder (koji-builder)

  • mock

  • setarch (for some archs you’ll require a patched version)

  • rpm-build

  • createrepo

A note on filesystem space

Koji will consume copious amounts of disk space under the primary KojiDir directory (as set in the kojihub.conf file - defaults to /mnt/koji). However, as koji makes use of mock on the backend to actually create build roots and perform the builds in those build roots, it might come to a surprise to users that a running koji server will consume large amounts of disk space under /var/lib/mock and /var/cache/mock as well. Users should either plan the disk and filesystem allocations for this, or plan to modify the default mock build directory in the kojid.conf file. If you change the location, ensure that the new directories are owned by the group “mock” and have 02755 permission.

Koji Authentication Selection

Koji primarily supports Kerberos and SSL Certificate authentication. For basic koji command line access, plain user/pass combinations are possible. However, kojiweb does not support plain user/pass authentication and once either Kerberos or SSL Certificate authentication is enabled for kojiweb, the plain user/pass method will stop working entirely. For this reason we encourage skipping the plain user/pass method altogether and properly configuring either Kerberos or SSL Certification authentication from the start.

The decision on how to authenticate users will affect all other actions you take in setting up koji. For this reason it is a decision best made up front.

For Kerberos authentication

a working Kerberos environment (the user is assumed to either already have this or know how to set it up themselves, instructions for it are not included here) and the Kerberos credentials of the initial admin user will be necessary to bootstrap the user database.

For SSL authentication

SSL certificates for the xmlrpc server, for the various koji components, and one for the admin user will need to be setup (the user need not know how to create certificate chains already, we include the instructions for this below).

Setting up SSL Certificates for authentication

Certificate generation

Create the /etc/pki/koji directory and copy-and-paste the ssl.cnf listed here, and save it in the new directory. This configuration file is used along with the openssl command to generate the SSL certificates for the various koji components.

ssl.cnf

HOME                    = .
RANDFILE                = .rand

[ca]
default_ca              = ca_default

[ca_default]
dir                     = .
certs                   = $dir/certs
crl_dir                 = $dir/crl
database                = $dir/index.txt
new_certs_dir           = $dir/newcerts
certificate             = $dir/%s_ca_cert.pem
private_key             = $dir/private/%s_ca_key.pem
serial                  = $dir/serial
crl                     = $dir/crl.pem
x509_extensions         = usr_cert
name_opt                = ca_default
cert_opt                = ca_default
default_days            = 3650
default_crl_days        = 30
default_md              = sha256
preserve                = no
policy                  = policy_match

[policy_match]
countryName             = match
stateOrProvinceName     = match
organizationName        = match
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[req]
default_bits            = 2048
default_keyfile         = privkey.pem
default_md              = sha256
distinguished_name      = req_distinguished_name
attributes              = req_attributes
x509_extensions         = v3_ca # The extensions to add to the self signed cert
string_mask             = MASK:0x2002

[req_distinguished_name]
countryName                     = Country Name (2 letter code)
countryName_default             = AT
countryName_min                 = 2
countryName_max                 = 2
stateOrProvinceName             = State or Province Name (full name)
stateOrProvinceName_default     = Vienna
localityName                    = Locality Name (eg, city)
localityName_default            = Vienna
0.organizationName              = Organization Name (eg, company)
0.organizationName_default      = My company
organizationalUnitName          = Organizational Unit Name (eg, section)
commonName                      = Common Name (eg, your name or your server\'s hostname)
commonName_max                  = 64
emailAddress                    = Email Address
emailAddress_max                = 64

[req_attributes]
challengePassword               = A challenge password
challengePassword_min           = 4
challengePassword_max           = 20
unstructuredName                = An optional company name

[usr_cert]
basicConstraints                = CA:FALSE
nsComment                       = "OpenSSL Generated Certificate"
subjectKeyIdentifier            = hash
authorityKeyIdentifier          = keyid,issuer:always

[v3_ca]
subjectKeyIdentifier            = hash
authorityKeyIdentifier          = keyid:always,issuer:always
basicConstraints                = CA:true

Although it is not required, it is recommended that you edit the default values in the [req_distinguished_name] section of the configuration to match the information for your own server. This will allow you to accept most of the default values when generating certificates later. The other sections can be left unedited.

Generate CA

The CA is the Certificate Authority. It’s the key/cert pair used to sign all the other certificate requests. When configuring the various koji components, both the client CA and the server CA will be a copy of the CA generated here. The CA certificate will be placed in the /etc/pki/koji directory and the certificates for the other components will be placed in the /etc/pki/koji/certs directory. The index.txt file which is created is a database of the certificates generated and can be used to view the information for any of the certificates simply by viewing the contents of index.txt.

cd /etc/pki/koji/
mkdir {certs,private,confs}
touch index.txt
echo 01 > serial
openssl genrsa -out private/koji_ca_cert.key 2048
openssl req -config ssl.cnf -new -x509 -days 3650 -key private/koji_ca_cert.key \
-out koji_ca_cert.crt -extensions v3_ca

The last command above will ask you to confirm a number of items about the certificate you are generating. Presumably you already edited the defaults for the country, state/province, locale, and organization in the ssl.cnf file and you only needed to hit enter. It’s the organizational unit and the common name that we will be changing in the various certs we create. For the CA itself, these fields don’t have a hard requirement. One suggestion for this certificate is to use the FQDN of the server.

If you are trying to automate this process via a configuration management tool, you can create the cert in one command with a line like this:

openssl req -config ssl.cnf -new -x509 \
-subj "/C=US/ST=Oregon/L=Portland/O=IT/CN=koji.example.com" \
-days 3650 -key private/koji_ca_cert.key -out koji_ca_cert.crt -extensions v3_ca

Generate the koji component certificates and the admin certificate

Each koji component needs its own certificate to identify it. Two of the certificates (kojihub and kojiweb) are used as server side certificates that authenticate the server to the client. For this reason, you want the common name on both of those certs to be the fully qualified domain name of the web server they are running on so that clients don’t complain about the common name and the server not being the same. You can set the OU for these two certificates to be kojihub and kojiweb for identification purposes.

For the other certificates (kojira, kojid, the initial admin account, and all user certificates), the cert is used to authenticate the client to the server. The common name for these certs should be set to the login name for that specific component. For example the common name for the kojira cert should be set to kojira so that it matches the username. The reason for this is that the common name of the cert will be matched to the corresponding user name in the koji database. If there is not a username in the database which matches the CN of the cert the client will not be authenticated and access will be denied.

When you later use koji add-host to add a build machine into the koji database, it creates a user account for that host even though the user account doesn’t appear in the user list. The user account created must match the common name of the certificate which that component uses to authenticate with the server. When creating the kojiweb certificate, you’ll want to remember exactly what values you enter for each field as you’ll have to regurgitate those into the /etc/koji-hub/hub.conf file as the ProxyDNs entry.

When you need to create multiple certificates it may be convenient to create a loop or a script like the on listed below and run the script to create the certificates. You can simply adjust the number of kojibuilders and the name of the admin account as you see fit. For much of this guide, the admin account is called kojiadmin.

#!/bin/bash
# if you change your certificate authority name to something else you will
# need to change the caname value to reflect the change.
caname=koji

# user is equal to parameter one or the first argument when you actually
# run the script
user=$1

openssl genrsa -out private/${user}.key 2048
cat ssl.cnf | sed 's/insert_hostname/'${user}'/'> ssl2.cnf
openssl req -config ssl2.cnf -new -nodes -out certs/${user}.csr -key private/${user}.key
openssl ca -config ssl2.cnf -keyfile private/${caname}_ca_cert.key -cert ${caname}_ca_cert.crt \
    -out certs/${user}.crt -outdir certs -infiles certs/${user}.csr
cat certs/${user}.crt private/${user}.key > ${user}.pem
mv ssl2.cnf confs/${user}-ssl.cnf

Generate a PKCS12 user certificate (for web browser)

This is only required for user certificates.

openssl pkcs12 -export -inkey private/${user}.key -in certs/${user}.crt \
    -CAfile ${caname}_ca_cert.crt -out certs/${user}_browser_cert.p12

When generating certs for a user, the user will need the ${user}.pem, the ${caname}_ca_cert.crt, and the ${user}_browser_cert.p12 files which were generated above. The ${user}.pem file would normally be installed as ~/.fedora.cert, the ${caname}_ca_cert.crt file would be installed as both ~/.fedora-upload-ca.cert and ~/.fedora-server-ca.cert, and the user would import the ${user}_brower_cert.p12 into their web browser as a personal certificate.

Copy certificates into ~/.koji for kojiadmin

You’re going to want to be able to send admin commands to the kojihub. In order to do so, you’ll need to use the newly created certificates to authenticate with the hub. Create the kojiadmin user then copy the certificates for the koji CA and the kojiadmin user to ~/.koji:

kojiadmin@localhost$ mkdir ~/.koji
kojiadmin@localhost$ cp /etc/pki/koji/kojiadmin.pem ~/.koji/client.crt   # NOTE: It is IMPORTANT you use the PEM and NOT the CRT
kojiadmin@localhost$ cp /etc/pki/koji/koji_ca_cert.crt ~/.koji/clientca.crt
kojiadmin@localhost$ cp /etc/pki/koji/koji_ca_cert.crt ~/.koji/serverca.crt

Note

See /etc/koji.conf for the current system wide koji client configuration. Copy /etc/koji.conf to ~/.koji/config if you wish to change the config on a per user basis.

Setting up Kerberos for authentication

The initial configuration of a kerberos service is outside the scope of this document, however there are a few specific things required by koji.

DNS

The koji builders (kojid) use DNS to find the kerberos servers for any given realm.

_kerberos._udp    IN SRV  10 100 88 kerberos.EXAMPLE.COM.

The trailing dot denotes DNS root and is needed if FQDN is used.

Principals and Keytabs

It should be noted that in general you will need to use the fully qualified domain name of the hosts when generating the keytabs for services.

You will need the following principals extracted to a keytab for a fully kerberized configuration, the requirement for a host key for the koji-hub is currently hard coded into the koji client.

host/kojihub@EXAMPLE.COM

Used by the koji-hub server when communicating with the koji client

HTTP/kojiweb@EXAMPLE.COM

Used by the koji-web server when performing a negotiated Kerberos authentication with a web browser. This is a service principal for Apache’s mod_auth_gssapi.

koji/kojiweb@EXAMPLE.COM

Used by the koji-web server during communications with the koji-hub. This is a user principal that will authenticate koji-web to Kerberos as “koji/kojiweb@EXAMPLE.COM”. Koji-web will proxy the mod_auth_gssapi user information to koji-hub (the ProxyPrincipals koji-hub config option).

koji/kojira@EXAMPLE.COM

Used by the kojira server during communications with the koji-hub

compile/builder1.example.com@EXAMPLE.COM

Used on builder1 to communicate with the koji-hub. This is a user principal that will authenticate koji-builder to Kerberos as “compile/builder1.example.com@EXAMPLE.COM”. Each builder host will have its own unique Kerberos user principal to authenticate to the hub.

PostgreSQL Server

Once the authentication scheme has been setup your will need to install and configure a PostgreSQL server and prime the database which will be used to hold the koji users.

Configuration Files

  • /var/lib/pgsql/data/pg_hba.conf

  • /var/lib/pgsql/data/postgresql.conf

Install PostgreSQL

Install the postgresql-server package:

# yum install postgresql-server

Initialize PostgreSQL DB:

Initialize PostgreSQL:

# On RHEL 7:
root@localhost$ postgresql-setup initdb

# Or RHEL 8 and Fedora:
root@localhost$ postgresql-setup --initdb --unit postgresql

And start the database service:

root@localhost$ systemctl enable postgresql --now

Setup User Accounts:

The following commands will setup the koji account and assign it a password

root@localhost$ useradd koji
root@localhost$ passwd koji

Setup PostgreSQL and populate schema:

The following commands will:

  • create the koji user within PostgreSQL

  • create the koji database within PostgreSQL

  • set a password for the koji user

  • create the koji schema using the provided /usr/share/doc/koji*/docs/schema.sql file from the koji package.

root@localhost$ su - postgres
postgres@localhost$ createuser --no-superuser --no-createrole --no-createdb koji
postgres@localhost$ createdb -O koji koji
postgres@localhost$ psql -c "alter user koji with encrypted password 'mypassword';"
postgres@localhost$ logout
root@localhost$ yum -y install koji
root@localhost$ su - koji
koji@localhost$ psql koji koji < /usr/share/doc/koji*/docs/schema.sql
koji@localhost$ exit

Note

When issuing the command to import the psql schema into the new database it is important to ensure that the directory path /usr/share/doc/koji*/docs/schema.sql remains intact and is not resolved to a specific version of koji. In test it was discovered that when the path is resolved to a specific version of koji then not all of the tables were created correctly.

Note

When issuing the command to import the psql schema into the new database it is important to ensure that you are logged in as the koji database owner. This will ensure all objects are owned by the koji database user. Upgrades may be difficult if this was not done correctly.

Authorize Koji-hub to PostgreSQL

Koji-hub is the only service that needs direct access to the database. Every other Koji service talks with the koji-hub via the API calls.

Example: Everything on localhost

In this example, the koji-hub Apache server is running on the same system as the PostgreSQL server, so we can use local-only connections over a Unix domain socket.

  1. Edit /var/lib/pgsql/data/pg_hba.conf to have the following contents:

    #TYPE   DATABASE    USER    CIDR-ADDRESS      METHOD
    local   koji        koji                       trust
    local   all         postgres                   peer
    

    Explanation:

    • The local connection type means the postgres connection uses a local Unix socket, so PostgreSQL is not exposed over TCP/IP at all.

    • The local koji user should only have access to the koji database. The local postgres user will have access to everything (in order to create the koji database and user.)

    • The CIDR-ADDRESS column is blank, because this example only uses local Unix sockets.

    • The trust method means that PosgreSQL will permit any connections from any local user for this username. We set this for the koji user because Apache httpd runs as the apache system user rather than the koji user when it connects to the Unix socket. trust is not secure on a multi-user system, but it is fine for a single-purpose Koji system.

      The peer method means that PostgreSQL will obtain the client’s operating system username and use that as the allowed username. This is safer than trust because only the local postgres system user will be able to access PostgreSQL with this level of access.

  2. Edit /var/lib/pgsql/data/postgresql.conf and set listen_addresses to prevent TCP/IP access entirely:

    listen_addresses = ''
    

Example: Separate PostgreSQL and Apache servers

In this example, the PostgreSQL server “db.example.com” is running on one host, and the koji-hub Apache server talks to this PostgreSQL server over the network. The koji-hub Apache server has an IP address of 192.0.2.1 (IPv4) and 2001:db8::1 (IPv6), so we authorize connections from both addresses for the koji user account.

  1. Edit /var/lib/pgsql/data/pg_hba.conf to have the following contents:

    #TYPE   DATABASE    USER    CIDR-ADDRESS      METHOD
    host    koji        koji    192.0.2.1/32       md5
    host    koji        koji    2001:db8::1/128    md5
    local   all         postgres                   peer
    

    The md5 authentication mechanism is available in PostgreSQL 9 (RHEL 7). On PostgreSQL 10 (RHEL 8+ and Fedora), use the stronger scram-sha-256 mechanism instead, and set password_encryption = scram-sha-256 in postgresql.conf.

  2. Edit /var/lib/pgsql/data/postgresql.conf and set listen_addresses so that PostgreSQL will listen on all network interfaces:

    listen_addresses = '*'
    

Activating changes

You must reload the PostgreSQL daemon to activate changes to postgresql.conf or pg_hba.conf:

root@localhost$ systemctl reload postgresql

Bootstrapping the initial koji admin user into the PostgreSQL database

You must add the initial admin user manually to the user database using sql commands. Once you have bootstrapped this initial admin user, you may add additional users and change privileges of those users via the koji command line tool.

However, if you decided to use the simple user/pass method of authentication, then any password setting/changing must be done manually via sql commands as there is no password manipulation support exposed through the koji tools.

The sql commands you need to use vary by authentication mechanism.

Maintaining database

For now, there is one table which needs periodical cleanup. As postgres doesn’t have any mechanism for this, we need to do it via some other mechanism. Default handling is done by cron, but can be substituted by anything else (Ansible tower, etc.)

Script is by default installed on hub as /usr/sbin/koji-sweep-db. It has also corresponding koji-sweep-db service and timer. Note, that timer is not enabled by default, so you need to run usual systemctl commands:

systemctl enable --now koji-sweep-db.timer

If you don’t want to use this script, be sure to run following SQL with appropriate age setting. Default value of one day should be ok for most deployments. As there will be tons of freed records, additional VACUUM can be handy.

DELETE FROM sessions WHERE update_time < NOW() - '1 day'::interval;
VACUUM ANALYZE sessions;

Optionally (if you’re using reservation API for content generators), you could want to run also reservation cleanup:

DELETE FROM build_reservations WHERE update_time < NOW() - '1 day'::interval;
VACUUM ANALYZE build_reservations;

Set User/Password Authentication

root@localhost$ su - koji
koji@localhost$ psql
koji=> insert into users (name, password, status, usertype) values ('admin-user-name', 'admin-password-in-plain-text', 0, 0);

Kerberos authentication

The process is very similar to user/pass except you would replace the first insert above with this:

root@localhost$ su - koji
koji@localhost$ psql <<EOF
with user_id as (
insert into users (name, status, usertype) values ('admin-user-name', 0, 0) returning id
)
insert into user_krb_principals (user_id, krb_principal) values (
(select id from user_id),
'admin@EXAMPLE');
EOF

SSL Certificate authentication

There is no need for either a password or a Kerberos principal, so this will suffice:

root@localhost$ su - koji
koji@localhost$ psql
koji=> insert into users (name, status, usertype) values ('admin-user-name', 0, 0);

Give yourself admin permissions

The following command will give the user admin permissions. In order to do this you will need to know the ID of the user.

koji=> insert into user_perms (user_id, perm_id, creator_id) values (<id of user inserted above>, 1, <id of user inserted above>);

Note

If you do not know the ID of the admin user, you can get the ID by running the query:

koji=> select * from users;

You can’t actually log in and perform any actions until kojihub is up and running in your web server. In order to get to that point you still need to complete the authentication setup and the kojihub configuration. If you wish to access koji via a web browser, you will also need to get kojiweb up and running.

Koji Hub

Koji-hub is the center of all Koji operations. It is an XML-RPC server running under mod_wsgi in the Apache httpd. koji-hub is passive in that it only receives XML-RPC calls and relies upon the build daemons and other components to initiate communication. Koji-hub is the only component that has direct access to the database and is one of the two components that have write access to the file system.

Configuration Files

  • /etc/koji-hub/hub.conf

  • /etc/koji-hub/hub.conf.d/*

  • /etc/httpd/conf/httpd.conf

  • /etc/httpd/conf.d/kojihub.conf

  • /etc/httpd/conf.d/ssl.conf (when using ssl auth)

Install koji-hub

Install the koji-hub package along with mod_ssl:

# yum install koji-hub mod_ssl

Required Configuration

We provide example configs for all services, so look for httpd.conf, hub.conf, kojiweb.conf and web.conf in source repo or related rpms.

/etc/httpd/conf/httpd.conf

The apache web server has two places that it sets maximum requests a server will handle before the server restarts. The xmlrpc interface in kojihub is a python application, and processes can sometimes grow outrageously large when it doesn’t reap memory often enough. As a result, it is strongly recommended that you set both instances of MaxConnectionsPerChild in httpd.conf to something reasonable in order to prevent the server from becoming overloaded and crashing (at 100 the httpd processes will grow to about 75MB resident set size before respawning).

<IfModule prefork.c>
...
MaxConnectionsPerChild  100
</IfModule>
<IfModule worker.c>
...
MaxConnectionsPerChild  100
</IfModule>
<IfModule event.c>
...
MaxRequestsPerChild  100
</IfModule>

/etc/httpd/conf.d/kojihub.conf

The koji-hub package provides this configuration file. You will need to modify it based on your authentication type. Instructions are contained within the file and should be simple to follow.

For example, if you are using SSL authentication, you will want to uncomment the section that looks like this:

# uncomment this to enable authentication via SSL client certificates
# <Location /kojihub/ssllogin>
#         SSLVerifyClient require
#         SSLVerifyDepth  10
#         SSLOptions +StdEnvVars
# </Location>

/etc/httpd/conf.d/ssl.conf

If you are configuring your server for httpd (and you really should), then your SSLCertificate* directives will generally live in the main ssl.conf file. This part is mostly independent of Koji. It’s something you would do for any httpd instance.

The part that matters to Koji is this – if you are using SSL authentication, then the CA certificate you configure in SSLCACertificateFile here should be the same one that you use to issue user certificates.

SSLCertificateFile /etc/pki/koji/certs/kojihub.crt
SSLCertificateKeyFile /etc/pki/koji/private/kojihub.key
SSLCertificateChainFile /etc/pki/koji/koji_ca_cert.crt
SSLCACertificateFile /etc/pki/koji/koji_ca_cert.crt

/etc/koji-hub/hub.conf

This file contains the configuration information for the hub. You will need to edit this configuration to point Koji Hub to the database you are using and to setup Koji Hub to utilize the authentication scheme you selected in the beginning.

DBName = koji
DBUser = koji

# If PostgreSQL is on another host, set that here:
#DBHost = db.example.com
#DBPass = mypassword

KojiDir = /mnt/koji
LoginCreatesUser = On
KojiWebURL = http://kojiweb.example.com/koji

If koji-hub is running on the same server as PostgreSQL and you are using Unix sockets to query the database, omit the DBHost, DBPort, and DBPass variables. Do not set DBHost to localhost, or else PostgreSQL will attempt to connect with TCP through 127.0.0.1 instead of using the Unix socket.

If koji-hub is running on a separate server from PostgreSQL, you must set the DBHost and DBPass options. You must also configure SELinux to allow Apache to connect to the remote PostgreSQL server:

root@localhost$ setsebool -P httpd_can_network_connect_db=1

Note, the database password (DBPass parameter) is a sensitive value. The hub.conf file should have 0640 root/apache file permissions to restrict access. If you’re not installing the hub from RPM, double-check these permissions.

Furthermore, you can install any config file in /etc/koji-hub/hub.conf.d directory. These files are read at first and main config is allowed to override all these values. So, you can use e.g. /etc/koji-hub/hub.conf.d/secret.conf for sensitive values. Typical usecase for separate config is policy configuration file.

Doc page about hub options in Hub conf.

Authentication Configuration

/etc/koji-hub/hub.conf

If using Kerberos, these settings need to be valid and inline with other services configurations.

ProxyPrincipals = koji/kojiweb@EXAMPLE.COM
HostPrincipalFormat = compile/%s@EXAMPLE.COM

If using SSL auth, these settings need to be valid and inline with other services configurations for kojiweb to allow logins.

ProxyDNs should be set to the DN of the kojiweb certificate. For example:

DNUsernameComponent = CN
ProxyDNs = CN=example.com,OU=kojiweb,O=Example Org,ST=Massachusetts,C=US

Koji filesystem skeleton

Above in the kojihub.conf file we set KojiDir to /mnt/koji. For certain reasons, if you change this, you should make a symlink from /mnt/koji to the new location (note: this is a bug and should be fixed eventually). However, before other parts of koji will operate properly, we need to create a skeleton filesystem structure for koji as well as make the file area owned by apache so that the xmlrpc interface can write to it as needed.

cd /mnt
mkdir koji
cd koji
mkdir {packages,repos,work,scratch,repos-dist}
chown apache.apache *

SELinux Configuration

Configure SELinux to allow Apache write access to /mnt/koji:

root@localhost$ setsebool -P allow_httpd_anon_write=1
root@localhost$ semanage fcontext -a -t public_content_rw_t "/mnt/koji(/.*)?"
root@localhost$ restorecon -r -v /mnt/koji

If you’ve placed /mnt/koji on an NFS share, enable a separate boolean to allow Apache access to NFS:

root@localhost$ setsebool -P httpd_use_nfs=1

Check Your Configuration

At this point, you can now restart apache and you should have at least minimal operation. The admin user should be able to connect via the command line client, add new users, etc. It’s possible at this time to undertake initial administrative steps such as adding users and hosts to the koji database.

So we will need a working client to test with.

Koji cli - The standard client

The koji cli is the standard client. It can perform most tasks and is essential to the successful use of any koji environment.

Ensure that your client is configured to work with your server. The system-wide koji client configuration file is /etc/koji.conf, and the user-specific one is in ~/.koji/config. You may also use the -c option when using the Koji client to specify an alternative configuration file.

If you are using SSL for authentication, you will need to edit the Koji client configuration to tell it which URLs to use for the various Koji components and where their SSL certificates can be found.

For a simple test, all we need is the server and authentication sections.

[koji]

;url of XMLRPC server
server = http://koji-hub.example.com/kojihub

;url of web interface
weburl = http://koji-web.example.com/koji

;url of package download site
topurl = http://koji-filesystem.example.com/kojifiles

;path to the koji top directory
topdir = /mnt/koji

; configuration for SSL athentication

;client certificate
cert = ~/.koji/client.crt

;certificate of the CA that issued the HTTP server certificate
serverca = ~/.koji/serverca.crt

The following command will test your login to the hub:

root@localhost$ koji moshimoshi

Koji Web - Interface for the Masses

Koji-web is a set of scripts that run in mod_wsgi and use the Cheetah templating engine to provide an web interface to Koji. koji-web exposes a lot of information and also provides a means for certain operations, such as cancelling builds.

Configuration Files

  • /etc/httpd/conf.d/kojiweb.conf

  • /etc/httpd/conf.d/ssl.conf

  • /etc/kojiweb/web.conf

  • /etc/kojiweb/web.conf.d/*

Install Koji-Web

Install the koji-web package along with mod_ssl:

# yum install koji-web mod_ssl

Required Configuration

/etc/httpd/conf.d/kojiweb.conf

The koji-web package provides this configuration file. You will need to modify it based on your authentication type. Instructions are contained within the file and should be simple to follow.

For example, if you are using SSL authentication, you would want to uncomment the section that looks like this:

# uncomment this to enable authentication via SSL client certificates
# <Location /koji/login>
#     SSLVerifyClient require
#     SSLVerifyDepth  10
#     SSLOptions +StdEnvVars
# </Location>

/etc/httpd/conf.d/ssl.conf

Similarly to the hub configuration, if you are using https (as you should), then you will need to configure your certificates. This is something you might do for any httpd instance and is mostly independent of Koji

If you are using SSL authentication, then the CA certificate you configure in SSLCACertificateFile here should be the same one that you use to issue user certificates.

SSLCertificateFile /etc/pki/koji/certs/kojihub.crt
SSLCertificateKeyFile /etc/pki/koji/private/kojihub.key
SSLCertificateChainFile /etc/pki/koji/koji_ca_cert.crt
SSLCACertificateFile /etc/pki/koji/koji_ca_cert.crt

/etc/kojiweb/web.conf

You will need to edit the kojiweb configuration file to tell kojiweb which URLs it should use to access the hub, the koji packages and its own web interface. You will also need to tell kojiweb where it can find the SSL certificates for each of these components. If you are using SSL authentication, the “WebCert” line below must contain both the public and private key. You will also want to change the last line in the example below to a unique password. Also check the file permissions (due to Secret value) if you’re not installing koji web from rpm (0640, root/apache by default).

Furthermore, you can install any config file in /etc/kojiweb/web.conf.d directory. These files are read at first and main config is allowed to override all these values. So, you can use e.g. /etc/kojiweb/web.conf.d/secret.conf for sensitive values.

[web]
SiteName = koji
# KojiTheme =

# Necessary urls
KojiHubURL = https://koji-hub.example.com/kojihub
KojiFilesURL = http://koji-filesystem.example.com/kojifiles

## Kerberos authentication options
; WebPrincipal = koji/web@EXAMPLE.COM
; WebKeytab = /etc/httpd.keytab
; WebCCache = /var/tmp/kojiweb.ccache

## SSL authentication options
; WebCert = /etc/pki/koji/koji-web.pem
; KojiHubCA = /etc/pki/koji/ca_cert.crt

LoginTimeout = 72

# This must be set before deployment
#Secret = CHANGE_ME

LibPath = /usr/share/koji-web/lib

Filesystem Configuration

You’ll need to make /mnt/koji/ web-accessible, either here, on the hub, or on another web server altogether.

This URL will go into various clients such as: * /etc/kojiweb/web.conf as KojiFilesURL * /etc/kojid/kojid.conf as topurl * /etc/koji.conf as topurl

Alias /kojifiles/ /mnt/koji/
<Directory "/mnt/koji/">
    Options Indexes
    AllowOverride None
    # Apache < 2.4
    #   Order allow,deny
    #   Allow from all
    # Apache >= 2.4
    Require all granted
</Directory>

Wherever you configure this, please go back and set it correctly in /etc/kojiweb/web.conf now.

Web interface now operational

At this point you should be able to point your web browser at the kojiweb URL and be presented with the koji interface. Many operations should work in read only mode at this point, and any configured users should be able to log in.

Koji Daemon - Builder

Kojid is the build daemon that runs on each of the build machines. Its primary responsibility is polling for incoming build requests and handling them accordingly. Koji also has support for tasks other than building such as creating livecd images or raw disk images, and kojid is responsible for handling these tasks as well. The kojid service uses mock for creating pristine build environments and creates a fresh one for every build, ensuring that artifacts of build processes cannot contaminate each other. All of kojid is written in Python and communicates with koji-hub via XML-RPC.

Configuration Files

  • /etc/kojid/kojid.conf - Koji Daemon Configuration

  • /etc/sysconfig/kojid - Koji Daemon Switches

  • /etc/mock/site-defaults.cfg - Mock’s base configuration file

All options for kojid.conf are described here.

Mock-tuning options are described here.

Install kojid

Install the koji-builder package:

# yum install koji-builder

Required Configuration

Add the host entry for the koji builder to the database

You will now need to add the koji builder to the database so that they can be utilized by koji hub. Make sure you do this before you start kojid for the first time, or you’ll need to manually remove entries from the sessions and users table before it can be run successfully.

kojiadmin@localhost$ koji add-host kojibuilder1.example.com i386 x86_64

The first argument used after the add-host command should the hostname of the builder. The second argument is used to specify the architecture which the builder uses.

/etc/kojid/kojid.conf

Edit each koji builder’s kojid.conf file to point at the Koji hub:

; The URL for the xmlrpc server
server=http://hub.example.com/kojihub

Set the “user” value to the FQDN of the builder host. For example, if you added the host with koji add-host kojibuilder1.example.com, set “user” to kojibuilder1.example.com:

user = kojibuilder1.example.com

The builder must reach the filesystem over HTTP. Set “topurl” to the same value that you’ve configured for Koji clients (above):

# The URL for the file access
topurl=http://koji-filesystem.example.com/kojifiles

If the “topurl” setting uses an HTTPS URL with a cert signed by a custom CA, the Koji builder must trust the CA system-wide.

You may change “workdir”, but it may not be the same as KojiDir on the kojihub.conf file. It can be something under KojiDir, just not the same as KojiDir.

; The directory root for temporary storage
workdir=/tmp/koji

The root of the koji build directory (i.e., /mnt/koji) must be mounted on the builder and configured as “topdir”. A Read-Only NFS mount is the easiest way to handle this.

# The directory root where work data can be found from the koji hub
topdir=/mnt/koji

Authentication Configuration (SSL certificates)

/etc/kojid/kojid.conf

If you are using SSL, edit these settings to point to the certificates you generated at the beginning of the setup process.

;client certificate
; This should reference the builder certificate we created on the kojihub CA, for kojibuilder1.example.com
; ALSO NOTE: This is the PEM file, NOT the crt
cert = /etc/kojid/kojid.pem

;certificate of the CA that issued the HTTP server certificate
serverca = /etc/kojid/koji_ca_cert.crt

Every unique builder host must have its own unique keypair (PEM file) in /etc/kojid/. If you generated the certificates on another host, move them to each builder.

Authentication Configuration (Kerberos)

/etc/kojid/kojid.conf

If using Kerberos, these settings need to be valid and inline with other services configurations.

; the username has to be the same as what you used with add-host
;user =

host_principal_format=compile/%s@EXAMPLE.COM

By default it will look for the Kerberos keytab in /etc/kojid/kojid.keytab

Note

Kojid will not attempt kerberos authentication to the koji-hub unless the username field is commented out

Source Control Configuration

/etc/kojid/kojid.conf

The allowed_scms setting controls which source control systems the builder will accept. It is a space-separated list of entries in one of the following forms:

hostname:path[:use_common[:source_cmd]]
!hostname:path

where

hostname is a glob pattern matched against SCM hosts.

path is a glob pattern matched against the SCM path.

use_common is boolean setting (yes/no, on/off, true/false) that indicates whether koji should also check out /common from the SCM host. The default is on.

source_cmd is a shell command to be run before building the srpm, with commas instead of spaces. It defaults to make,sources.

The second form (!hostname:path) is used to explicitly block a host:path pattern. In particular, it provides the option to block specific subtrees of a host, but allow from it otherwise

allowed_scms=
    !scm-server.example.com:/blocked/path/*
    scm-server.example.com:/repo/base/repos*/:no
    alt-server.example.com:/repo/dist/repos*/:no:fedpkg,sources

The explicit block syntax was added in version 1.13.0.

SCM checkout can contain multiple spec files (checkouted or created by source_cmd). In such case spec file named same as a checkout directory will be selected.

Note

We provide build_from_scm hub policy as an equivalent in version 1.26.0. It is a preffered way now as it a) allows centralized policy management without need to update all builders b) provides whole policy DSL and further information which can be used to determining the result.

For more details, please refer to Allowed SCMs and Defining Hub Policies.

Add the host to the createrepo channel

Channels are a way to control which builders process which tasks. By default hosts are added to the ‘’default’’ channel. At least some build hosts also needs to be added to the ‘’createrepo’’ channel so there will be someone to process repo creation tasks initiated by kojira.

kojiadmin@localhost$ koji add-host-to-channel kojibuilder1.example.com createrepo

A note on capacity

The default capacity of a host added to the host database is 2. This means that once the load average on that machine exceeds 2, kojid will not accept any additional tasks. This is separate from the maxjobs item in the configuration file. Before kojid will accept a job, it must pass both the test to ensure the load average is below capacity and that the current number of jobs it is already processing is less than maxjobs. However, in today’s modern age of quad core and higher CPUs, a load average of 2 is generally insufficient to fully utilize hardware.

koji edit-host --capacity=16 kojibuilder1.example.com

The koji-web interface also offers the ability to edit this value to admin accounts.

Start Kojid

Once the builder has been added to the database you must start kojid

root@localhost$ systemctl enable kojid --now

Check /var/log/kojid.log to verify that kojid has started successfully. If the log does not show any errors then the koji builder should be up and ready. You can check this by pointing your web browser to the web interface and clicking on the hosts tab. This will show you a list of builders in the database and the status of each builder.

Kojira - Dnf|Yum repository creation and maintenance

Configuration Files

  • /etc/kojira/kojira.conf - Kojira Daemon Configuration

Install kojira

Install the koji-utils package:

# yum install koji-utils

Required Configuration

Add the user entry for the kojira user

The kojira user requires the repo permission to function.

kojiadmin@localhost$ koji add-user kojira
kojiadmin@localhost$ koji grant-permission repo kojira
/etc/kojira/kojira.conf

This needs to point at your koji-hub.

; The URL for the xmlrpc server
server=http://koji-hub.example.com/kojihub

Additional Notes

  • Kojira needs read-write access to /mnt/koji.

  • There should only be one instance of kojira running at any given time.

  • It is not recommended that kojira run on the builders, as builders only should require read-only access to /mnt/koji.

Authentication Configuration

/etc/kojira/kojira.conf

If using SSL, these settings need to be valid.

;client certificate
; This should reference the kojira certificate we created above
cert = /etc/pki/koji/kojira.pem

;certificate of the CA that issued the HTTP server certificate
serverca = /etc/pki/koji/koji_ca_cert.crt

If using Kerberos, these settings need to be valid.

;configuration for Kerberos authentication

;the kerberos principal to use
;principal = kojira@EXAMPLE.COM

;location of the keytab
;keytab = /etc/kojira/kojira.keytab
/etc/sysconfig/kojira

The local user kojira runs as needs to be able to read and write to /mnt/koji/repos/. If the volume that directory resides on is root-squashed or otherwise unmodifiable by root, you can set RUNAS= to a user that has the required privileges.

Start Kojira

root@localhost$ service kojira start

Check /var/log/kojira/kojira.log to verify that kojira has started successfully.

Bootstrapping the Koji build environment

For instructions on importing packages and preparing Koji to run builds, see Server Bootstrap.

For instructions on using External Repos and preparing Koji to run builds, see External Repo Server Bootstrap.

Useful scripts and config files for setting up a Koji instance are available here.

Minutia and Miscellany

Please see KojiMisc for additional details and notes about operating a koji server.