HodDB

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HodDB
​HodDB is a query processor and database for Brick models.
Configuration
BOSSWAVE Entity
HodD optionally exposes an API over BOSSWAVE, requiring an entity ($HODDB_ENTITY) with publich/subscribe capabilities on a namespace. Create the entity and place it in a known location that you don't mind being mounted into a docker container (such as /etc/hod).
The permissions MDAL needs are all permissions on some prefix ending in s.hod, e.g.
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bw2 mkdot -f $PRIVILEGED_ENTITY             \
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          -t $HODDB_ENTITY                  \
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          -u $NAMESPACE/services/s.hod/*   \
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          -x PC*                            \
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          -m 'HodDB operation'
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The URI argument here (minus s.hod, i.e. $NAMESPACE/services) should be included in the configuration for the HodDB service
Config File
HodDB configuration is documented on the HodDB site. it is replicated here
HodDB is configured with a YAML file. By default, this file is called hodconfig.yml and is loaded from the directory HodDB is executed from, though this can be changed with the --config/-c command line option when executing the hod binary. All paths below are relative to the location from which hod is executed.
Configuration defaults are as follows; there's usually no reason to change these aside from the list of buildings to load and the network and BOSSWAVE configuration. Default options are commented out
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######## HodDB Configuration
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####
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# Location and structure of database
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####
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# how we load data into the database.
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# The keys here are the names of the graphs and how they are referred to when
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# querying. The values are file paths to the source for each graph
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# CHANGE THIS!
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Buildings:
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    ciee: buildings/ciee.ttl
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    sdh: buildings/sdh.ttl
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    soda: buildings/soda.ttl
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# the location of the database files
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# DBPath: _hoddb
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# the path to the TTL file containing Brick relationships
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# BrickFrameTTL: "$GOPATH/src/github.com/gtfierro/hod/BrickFrame.ttl"
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# the path to the TTL file containing Brick classes
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#BrickClassTTL: "$GOPATH/src/github.com/gtfierro/hod/Brick.ttl"
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​
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####
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# Interface Enabling
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####
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# Enable HTTP server
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EnableHTTP: true
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# Enable BOSSWAVE server
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EnableBOSSWAVE: true
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​
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####
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# HTTP Server Configuration
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####
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# port to run the server on
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#ServerPort: 47808
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# Whether or not to serve on IPv6
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#UseIPv6: false
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# Whether or not to serve on localhost. If false, serves on a public interface
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#ListenAddress: 0.0.0.0
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# Path to the server directory of hod, which contains the necessary HTML files
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#StaticPath: $GOPATH/src/github.com/gtfierro/hod/server
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# If specified, serve the frontend over HTTPS using golang.org/x/crypto/acme/autocert
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# If left blank (default), just serve over HTTP
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#TLSHost: ""
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​
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####
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# BOSSWAVE Server Configuration
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####
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​
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# BOSSWAVE agent
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#BW2_AGENT: 172.17.0.1:28589
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# BOSSWAVE entity. CHANGE THIS!
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BW2_DEFAULT_ENTITY: path/to/entity/file
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# Base URI. CHANGE THIS!
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HodURI: scratch.ns/hod
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​
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####
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# configuration for verbosity during operation
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####
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# Show the namespace prefixes
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#ShowNamespaces: false
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# Show the built dependency graph of query terms
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#ShowDependencyGraph: false
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# Show the set of operations in the query plan
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#ShowQueryPlan: false
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# Show the latencies of creating the query plan
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#ShowQueryPlanLatencies: false
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# Show the latencies of each operation in the query plan
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#ShowOperationLatencies: false
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# Show the full latency of the query (and its larger components)
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#ShowQueryLatencies: false
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# Set log level. In order of increasing verbosity:
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# Debug, Info, Notice, Warning, Error, Critical
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#LogLevel: Error
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Example
Here is a brief example of how to set up the configuration.
The directory 'sample' has the hodconfig.yaml file above. We create a folder called buildings to store our 3 TTL files representing 3 Brick models. This is indicted to HodDB in the Buildings configuration option above.
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$ tree
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.
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├── buildings
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│   ├── ciee.ttl
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│   ├── sdh.ttl
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│   └── soda.ttl
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└── hodconfig.yaml
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We can then execute HodDB against this configuration with
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$ docker run -d --name hod -v `pwd`/sample:/etc/hod -p 47808:47808 gtfierro/hod:latest
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Installation
HodDB is shipped as a Docker container image gtfierro/hod:latest (most recent version is gtfierro/hod:0.5.6. You can build this container yourself by running make container in a cloned copy of the HodDB repository.
Run with Kubernetes
If you are running Kubernetes on your node/cluster, then you can easily install HodDB by using its Kubernetes file.
Keep in mind that HodDB currently requires a volume mount where the mdal.yaml configuration file is stored.
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# snippet of HodDB kubernetes file
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...
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  spec:
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      containers:
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          - name: hod
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            image:  gtfierro/hod:0.5.6
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            imagePullPolicy: Always
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            ports:
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              - containerPort: 47808
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            volumeMounts:
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              - name: hodconfig
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                mountPath: /etc/hod
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      volumes:
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          - name: hodconfig
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            hostPath:
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              path: << config directory >> # <-- create this host folder and place all HodDB config there
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                                           #     including the building models and hodconfig.yaml file
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To execute HodDB as a Kubernetes service, use the following:
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curl -O https://github.com/gtfierro/hod/blob/master/kubernetes/deployhod.yaml
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# edit deployhod.yaml and setup HodDB config directory as specified above
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kubectl create -f deployhod.yaml
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Run with Docker
If you are not running Kubernetes, you can invoke the MDAL container directly
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$ docker run -d --name hod -v /path/to/config/dir:/etc/hod -p 47808:47808 gtfierro/hod:latest
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Using
The HodDB site has several guides on how to use HodDB and Brick:
​Making Brick models​
​Brick query language​
HTTP Interface
HodDB has a convenient user interface for running, building and visualizing queries. By default this interface is available on port 47808.
Access Control
The HodDB commandline tool has a couple utilities for granting access to a HodDB database as well as granting access to a Brick model.
For access control to a HodDB instance, use the hod check and hod grant commands:
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NAME:
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   hod check - Check access to HodDB on behalf of some key
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​
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USAGE:
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   hod check [command options] [arguments...]
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​
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OPTIONS:
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   --agent value, -a value   Local BOSSWAVE Agent (default: "127.0.0.1:28589") [$BW2_AGENT]
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   --entity value, -e value  The entity to use [$BW2_DEFAULT_ENTITY]
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   --key value, -k value     The key or alias to check
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   --uri value, -u value     The base URI of HodDB
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NAME:
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   hod grant - Grant access to HodDB to some key
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​
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USAGE:
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   hod grant [command options] [arguments...]
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​
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OPTIONS:
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   --agent value, -a value     Local BOSSWAVE Agent (default: "127.0.0.1:28589") [$BW2_AGENT]
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   --entity value, -e value    The entity to use [$BW2_DEFAULT_ENTITY]
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   --bankroll value, -b value  The entity to use for bankrolling [$BW2_DEFAULT_BANKROLL]
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   --expiry value              Set the expiry on access to HodDB measured from now e.g. 3d7h20m
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   --key value, -k value       The key or alias to check
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   --uri value, -u value       The base URI of HodDB
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Note: There is currently no access control on the HTTP interface.
TODO: document capability URIs for Brick model access
Using
Configuration
Last modified 2yr ago
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