- See also
This document describes additional open source command line tools that are provided by Semaphore and available in all VMs.
cache tool helps optimize CI/CD runtime by reusing files that your project depends on but are not part of version control. You should typically use caching to:
- Reuse your project's dependencies, so that Semaphore fetches and installs them only when the dependency list changes.
- Propagate a file from one block to the next.
Cache is created on a per project basis and available in every pipeline job. All cache keys are scoped per project. Total cache size is 9.6GB.
cache tool uses key-path pairs for managing cached archives. An archive can be a single file or a directory.
cache supports the following options:
cache store key path
cache store our-gems vendor/bundle cache store gems-$SEMAPHORE_GIT_BRANCH vendor/bundle cache store gems-$SEMAPHORE_GIT_BRANCH-revision-$(checksum Gemfile.lock) vendor/bundle
cache store command archives a file or directory specified by
path and associates it with a given
cache store uses
tar, it automatically removes any leading
/ from the given
path value. Any further changes of
path after the store command completes will not be automatically propagated to cache. The command always passes, i.e. exits with return code 0.
In case of insufficient disk space,
cache store frees disk space by deleting the oldest keys.
cache restore key[,second-key,...]
cache restore our-gems cache restore gems-$SEMAPHORE_GIT_BRANCH cache restore gems-$SEMAPHORE_GIT_BRANCH-revision-$(checksum Gemfile.lock),gems-master
Restores an archive which partially matches any given
key. In case of a cache hit, archive is retrieved and available at its original path in the job environment. Each archive is restored in the current path from where the function is called.
In case of cache miss, the comma-separated fallback takes over and command looks up the next key. If no archives are restored command exits with 0.
cache has_key key
cache has_key our-gems cache has_key gems-$SEMAPHORE_GIT_BRANCH cache has_key gems-$SEMAPHORE_GIT_BRANCH-revision-$(checksum Gemfile.lock)
Checks if an archive with provided key exists in cache. Command passes if key is found in the cache, otherwise is fails.
Lists all cache archives for the project.
cache delete key
cache delete our-gems cache delete gems-$SEMAPHORE_GIT_BRANCH cache delete gems-$SEMAPHORE_GIT_BRANCH-revision-$(checksum Gemfile.lock)
Removes an archive with given key if it is found in cache. The command always passes.
Removes all cached archives for the project. The command always passes.
Note that in all commands of
cache has_key command can fail (exit with non-zero status).
cache tool depends on the following environment variables which are automatically set in every job environment:
SEMAPHORE_CACHE_URL: stores the IP address and the port number of the cache server (
SEMAPHORE_CACHE_USERNAME: stores the username that will be used for connecting to the cache server (
SEMAPHORE_CACHE_PRIVATE_KEY_PATH: stores the path to the SSH key that will be used for connecting to the cache server (
tar to archive the specified directory or file.
The GitHub repository used in a Semaphore 2.0 project is not automatically cloned for reasons of efficiency.
libcheckout script includes the implementation of a single function named
checkout() that is used for making available the entire GitHub repository of the running Semaphore 2.0 project to the VM used for executing a job of the pipeline. The
checkout() function is called as
checkout from the command line.
checkout() function of the
libcheckout script depends on the following three Semaphore environment variables:
SEMAPHORE_GIT_URL: This environment variable holds the URL of the GitHub repository that is used in the Semaphore 2.0 project (
SEMAPHORE_GIT_DIR: This environment variable holds the UNIX path where the GitHub repository will be placed on the VM (
SEMAPHORE_GIT_SHA: This environment variable holds the SHA key for the HEAD reference that is used when executing
git reset -q --hard.
All these environment variables are automatically defined by Semaphore 2.0.
checkout command supports the
--use-cache flag. The purpose of that flag is to tell
checkout to get the contents of the GitHub repository from the Semaphore Cache server instead of the GitHub servers because it is faster.
If there is no cache entry for the active GitHub repository, the functionality of the
--use-cache flag will create it.
When using the
checkout supports the following environment variables:
SEMAPHORE_GIT_CACHE_AGE: This environment variable specifies how often the cache for that GitHub repository will get updated. Its value is always in seconds and by default it is
259200, which is 3 days. The value that you are going to choose depends on your project and how ofter it gets updated.
SEMAPHORE_GIT_CACHE_KEEP: Each time there is an update to the cache, the key in the Cache server is also being updated. Before updating the key, the previous key that is related to the current project is deleted. This environment variable tells Semaphore Cache server to keep a history. The default value of
Notice that the
checkout command automatically changes the current working directory in the Operating System of the VM to the directory defined in the
SEMAPHORE_GIT_DIR environment variable.
The following command will tell
checkout to use the Semaphore Cache server to get the contents of the GitHub repository instead of using GitHub server:
If you set
1 then it will keep two copies in the Semaphore Cache server: the active one and the previous one.
If you set
SEMAPHORE_GIT_CACHE_AGE=86400, then the cache for the GitHub repository will get updated after 1 day.
libchecksum scripts provides the
checksum is useful for tagging artifacts or generating cache keys. It takes a single argument, a file path, and outputs an
$ checksum package.json 3dc6f33834092c93d26b71f9a35e4bb3
retry script is used for retrying a command for a given amount of times at given time intervals – waiting for resources to become available or waiting for network connectivity issues to be resolved is the main reason for using the
Command Line Parameters
retry bash script supports two command line parameters:
--times: this is used for defining the number of retries before giving up. The default value is 3.
--sleep: this is used for defining the time interval between retries. The default value is 0.
retry bash script only depends on the
$ retry lsa -l /usr/bin/retry: line 46: lsa: command not found [1/3] Execution Failed with exit status 127. Retrying. /usr/bin/retry: line 46: lsa: command not found [2/3] Execution Failed with exit status 127. Retrying. /usr/bin/retry: line 46: lsa: command not found [3/3] Execution Failed with exit status 127. No more retries.
In the previous example the
retry command will never be successful because the
lsa command does not exist.
$ ./retry.sh -t 5 -s 10 lsa -l ./retry.sh: line 46: lsa: command not found [1/5] Execution Failed with exit status 127. Retrying. ./retry.sh: line 46: lsa: command not found [2/5] Execution Failed with exit status 127. Retrying. ./retry.sh: line 46: lsa: command not found [3/5] Execution Failed with exit status 127. Retrying. total 8 -rwxr-xr-x 1 mtsouk staff 1550 Aug 30 10:58 retry.sh
In the previous example, the
retry script succeeded after three failed tries.
sem-service script is a utility for starting, stopping and getting the status of background services. Started services will listen on 0.0.0.0 and their default port. The 0.0.0.0 IP address includes all available network interfaces. Essentially, you will be using services as if they were natively installed in the Operating System.
Command Line Parameters
The general form of a
sem-service command is as follows:
sem-service start [mysql | postgres | redis | memcached | mongodb | elasticsearch] [version]
sem-service command requires at least two parameters: the first one is the task you want to perform and the second parameter is the name of the service that will be used for the task. The third parameter is optional and is the version of the service that you want to start. If no
version value is given, a default value will be used according to the following list:
- mysql: The default value is
- postgres: The default value is
- redis: The default value is
- memcached: The default value is
- mongodb: The default value is
- elasticsearch: The default value is
sem-service pulls images from Docker Hub and supports all versions that are available in Docker Hub. You can find the list of available versions at the following URLs:
- ElasticSearch: https://hub.docker.com/_/elasticsearch/
- MySQL: https://hub.docker.com/_/mysql/
- PostgreSQL: https://hub.docker.com/_/postgres/
- Redis: https://hub.docker.com/_/redis/
- MongoDB: https://hub.docker.com/_/mongo/
- Memcached: https://hub.docker.com/_/memcached/
Please note that none of these databases is already installed on the Semaphore 2.0 VM. Only clients for MySQL and PostgreSQL are installed by default, which means that you will need to install clients for the other services on your own.
sem-service utility has no dependencies apart from the need for a working Docker Hub site. However, depending on the service you want to use, you might need to install additional software such as a client for connecting to the service.
The following are valid uses of
sem-service start redis sem-service stop redis sem-service start redis 5 sem-service status postgres sem-service start postgres 11 sem-service status mysql sem-service start memcached sem-service start elasticsearch sem-service start elasticsearch 6.5.2 sem-service start mongodb sem-service start mongodb 3.2
Example sem-service Project
version: v1.0 name: Testing sem-service agent: machine: type: e1-standard-2 os_image: ubuntu1804 blocks: - name: Databases task: env_vars: - name: DB_NAME value: "test" jobs: - name: MySQL commands: - sem-service start mysql - sudo apt-get install -y -qq mysql-client - mysql --host=0.0.0.0 -uroot -e "create database $DB_NAME" - mysql --host=0.0.0.0 -uroot -e "show databases" | grep $DB_NAME - sem-service status mysql - name: PostgreSQL commands: - sem-service start postgres - sudo apt-get install -y -qq postgresql-client - createdb -U postgres -h 0.0.0.0 $DB_NAME - psql -h 0.0.0.0 -U postgres -c "\l" | grep $DB_NAME - sem-service status postgres - name: Redis commands: - sem-service start redis - sem-service status redis - name: Memcached commands: - sem-service start memcached - sem-service status memcached
sem-version utility is used for changing the version of a programming language on the executed Virtual Machine (VM), which mainly happens for compatibility issues.
The supported programming languages are
Command Line Parameters
The general form of the
sem-version utility is as follows:
sem-version [PROGRAMMING LANGUAGE] [VERSION]
[PROGRAMMING LANGUAGE] is one of
node. The value of the
[VERSION] parameter depends on the programming language used because different programming languages have different versioning systems.
sem-version utility mainly depends on the programming languages and the versions of the programming languages that are installed on the Virtual Machine (VM) used for executing a job of a pipeline.
Changing the active Go version to 1.9 is as simple as executing the next command in a job of a pipeline:
sem-version go 1.9
Example sem-version project
The following is an example Semaphore 2.0 project that uses
version: v1.0 name: Testing sem-version agent: machine: type: e1-standard-2 os_image: ubuntu1804 blocks: - name: sem-version task: jobs: - name: Using sem-version commands: - go version - sem-version go 1.9 - go version