snapd supports being configured through a configuration file located at a default location of /etc/snap/snapd.conf on Linux systems or by passing a configuration file in through the --config command line flag when starting snapd. YAML and JSON are currently supported for configuration file types.
snapd runs without a configuration file provided and will use the default values defined inside the daemon (shown below). There is an order of precedence when it come to default values, configuration files, and flags when snapd starts. Any value defined in the default configuration file located at /etc/snap/snapd.conf will take precedence over default values. Any value defined in a configuration file passed via the --config flag will be used in place of any default configuration file on the system and override default values. Any flags passed in on the command line during the start up of snapd will override any values defined in configuration files and default values.
In order of precedence (from greatest to least):
- Command-line flags
- Configuration file passed in via the
--configflag - Default configuration file (if exists)
- Default values per configuration setting
The configuration file is comprised of different sections for each module that the snap daemon can run. Settings specifically for the snap daemon are defined on the top level, along with configuration sections for Control, Scheduler, REST API Server, and Tribe. Below, each section will be detailed in YAML format broken out for each section. A full example configuration file can be seen in YAML or JSON format in examples/configs in the project source.
When defining a configuration in YAML format, options or sections can be commented out if the value provided will not be different from the default value configured by the system.
This section comprises of configuration settings that are specific for the snap daemon.
---
# log_level for the snap daemon. Supported values are
# 1 - Debug, 2 - Info, 3 - Warning, 4 - Error, 5 - Fatal.
# Default value is 3.
log_level: 3
# log_path sets the path for logs for the snap daemon. By
# default snapd prints all logs to stdout. Any provided
# path will send snapd logs to a file called snapd.log in
# the provided directory.
log_path: /var/log/snap
# Gomaxprocs sets the number of cores to use on the system
# for snapd to use. Default for gomaxprocs is 1
gomaxprocs: 1The control section contains settings for configuring the Control module within the snap daemon. These configuration settings are specific for the running of plugins and the plugins section under control allows for passing of plugin specific configuration items to the plugins during a task run.
control:
# auto_discover_path sets a directory to auto load plugins on the start
# of the snap daemon
auto_discover_path: /opt/snap/plugins
# cache_expiration sets the time interval for the plugin cache to use before
# expiring collection results from collect plugins. Default value is 500ms
cache_expiration: 500ms
# max_running_plugins sets the size of the available plugin pool for each
# plugin loaded in the system. Default value is 3
max_running_plugins: 3
# keyring_paths sets the directory(s) to search for keyring files for signed
# plugins. This can be a comma separated list of directories
keyring_paths: /opt/snap/plugins/keyrings
# plugin_trust_level sets the plugin trust level for snapd. The default state
# for plugin trust level is enabled (1). When enabled, only signed plugins that can
# be verified will be loaded into snapd. Signatures are verifed from
# keyring files specided in keyring_path. Plugin trust can be disabled (0) which
# will allow loading of all plugins whether signed or not. The warning state allows
# for loading of signed and unsigned plugins. Warning messages will be displayed if
# an unsigned plugin is loaded. Any signed plugins that can not be verified will
# not be loaded. Valid values are 0 - Off, 1 - Enabled, 2 - Warning
plugin_trust_level: 1
# plugins section contains plugin config settings that will be applied for
# plugins across tasks.
plugins:
all:
password: p@ssw0rd
collector:
all:
user: jane
pcm:
all:
path: /usr/local/pcm/bin
versions:
1:
user: john
someint: 1234
somefloat: 3.14
somebool: true
psutil:
all:
path: /usr/local/bin/psutil
publisher:
influxdb:
all:
server: xyz.local
password: $password
processor:
movingaverage:
all:
user: jane
versions:
1:
user: tiffany
password: new passwordThe scheduler section of the configuration file configures settings for the Scheduler module inside the snap daemon.
scheduler:
# work_manager_queue_size sets the size of the worker queue inside snapd scheduler.
# Default value is 25.
work_manager_queue_size: 25
# work_manager_pool_size sets the size of the worker pool inside snapd scheduler.
# Default value is 4.
work_manager_pool_size: 4The restapi section of the configuration file configures settings for enabling and running the REST API as part of the snap daemon. The snapctl command line tool uses the REST API to manage snapd on a host.
restapi:
# enable controls enabling or disabling the REST API for snapd. Default value is enabled.
enable: true
# https enables HTTPS for the REST API. If no default certificate and key are provided, then
# the REST API will generate a private and public key to use for communication. Default
# value is false
https: false
# rest_auth enables authentication for the REST API. Default value is false
rest_auth: false
# rest_auth_password sets the password to use for the REST API. Currently user and password
# combinations are not supported.
rest_auth_password: changeme
# rest_certificate is the path to the certificate to use for REST API when HTTPS is also enabled.
rest_certificate: /etc/snap/certs/snap.pub
# rest_key is the path to the private key for the certificate in use by the REST API
# when HTTPs is enabled.
rest_key: /etc/snap/certs/snap.key
# port sets the port to start the REST API server on. Default is 8181
port: 8181The tribe section of the configuration file configures settings for enabling and running tribe as part of the snap daemon.
tribe:
# enable controls enabling tribe for the snapd instance. Default value is false.
enable: false
# bind_addr sets the IP address for tribe to bind.
bind_addr: 0.0.0.0
# bind_port sets the port for tribe to listen on. Default value is 6000
bind_port: 6000
# name sets the name to use for this snapd instance in the tribe
# membership. Default value defaults to local hostname of the system.
name: snaphost-01
# seed sets the snapd instance to use as the seed for tribe communications
seed: 192.168.1.2:6000The same configuration settings above can also be provided in a JSON formatted configuration file. Unlike YAML which allows for commenting out unused options or whole sections, those unused options and/or sections are just removed from the JSON file.
{
"log_level": 1,
"control": {
"cache_expiration": "1s",
"plugin_trust_level": 0
},
"restapi": {
"enable": true,
"https": true,
"port": 8282
}
}