awscicdPractitioner

Mastering Buildspec in AWS CodeBuild: What You Need to Know

5 min read AWS DocsApr 28, 2026Reviewed for accuracy

Practitioner — Hands-on experience recommended

Buildspec files exist to streamline your CI/CD process in AWS CodeBuild. They allow you to define a collection of build commands and settings in a structured YAML format. This is essential for automating builds, ensuring consistency, and reducing manual errors in your deployment pipeline.

A buildspec file, named buildspec.yml, typically resides in the root of your source directory. You can customize its location using AWS CLI commands if needed. The buildspec includes various parameters like version, run-as, and env, which dictate how your build runs. For instance, the run-as parameter specifies the Linux user that executes the commands, while env can represent custom environment variables crucial for your build. The phases section is where you define the steps of your build process, such as install, pre_build, build, and post_build, each capable of handling commands and error management.

In production, pay attention to the versioning of your buildspec. Although version 0.1 is still supported, it's best practice to use version 0.2 for new projects. Be cautious with sensitive information; AWS access key IDs are hidden in logs, but it's advisable not to store sensitive values in environment variables at all. This can prevent accidental exposure of critical data during builds. Also, remember that while the buildspec is powerful, it can become complex quickly, so keep your commands clear and concise to avoid confusion.

Key takeaways

→Define your build process clearly using a `buildspec.yml` file.
→Utilize the `run-as` parameter to specify the Linux user for command execution.
→Leverage the `phases` section to organize your build steps effectively.
→Always use version 0.2 of the buildspec for new projects.
→Avoid storing sensitive values in environment variables to enhance security.

Why it matters

Using buildspec files effectively can significantly reduce build errors and streamline your CI/CD pipeline, leading to faster deployments and more reliable software delivery.

Code examples

Bash

"export PACKAGE_NAME=$(cat package.json | grep name | head -1 | awk -F: '{print $2 }' | sed 's/[",]//g')"

YAML

1version: 0.2
2run-as: Linux-user-name
3env:
4shell: shell-tag
5variables:
6  key: "value"
7  key: "value"
8parameter-store:
9  key: "value"
10  key: "value"
11exported-variables:
12    - variable
13variablesecrets-manager:
14  key: secret-id:json-key:version-stage:version-id
15git-credential-helper: no | yes
16proxy:
17upload-artifacts: no | yes
18logs: no | yes
19batch:
20  fast-fail: false | true
21  #build-list:
22  #build-matrix:
23  #build-graph:
24  #build-fanout:
25phases:
26  install:
27    run-as: Linux-user-name
28    on-failure: ABORT | CONTINUE | RETRY | RETRY-count| RETRY-regex| RETRY-count-regex
29    commands:
30      - command
31    finally:
32      - command
33  pre_build:
34    run-as: Linux-user-name
35    on-failure: ABORT | CONTINUE | RETRY | RETRY-count| RETRY-regex| RETRY-count-regex
36    commands:
37      - command
38    finally:
39      - command
40  build:
41    run-as: Linux-user-name
42    on-failure: ABORT | CONTINUE | RETRY | RETRY-count| RETRY-regex| RETRY-count-regex
43    commands:
44      - command
45    finally:
46      - command
47  post_build:
48    run-as: Linux-user-name
49    on-failure: ABORT | CONTINUE | RETRY | RETRY-count| RETRY-regex| RETRY-count-regex
50    commands:
51      - command
52    finally:
53      - command
54reports:
55  report-group-name-or-arn:
56    files:
57      - location
58      - location
59base-directory: location
60discard-paths: no | yes
61file-format: report-format
62artifacts:
63  files:
64    - location
65  name: artifact-name
66discard-paths: no | yes
67base-directory: location
68exclude-paths: excluded-paths
69enable-symlinks: no | yes
70s3-prefix: prefix
71secondary-artifacts:
72  artifactIdentifier:
73    files:
74      - location
75  name: secondary-artifact-name
76discard-paths: no | yes
77base-directory: location
78artifactIdentifier:
79  files:
80    - location
81  discard-paths: no | yes
82base-directory: location
83cache:
84  key: key
85  fallback-keys:
86    - fallback-key
87  action: restore | save
88  paths:
89    - path